Wednesday, October 31, 2007
James Watson Tells the Inconvenient Truth: Faces the Consequences
posted by
Jason Malloy @ 10/31/2007 11:22:00 AM
![]() ![]() ... [M]ight it be fair also to say that the champions of 'no difference' in race or sex, or intelligence ... are the guardians of a greater 'untruth' that allows people to live together in mutual harmony, implying that these critics really deserve to be praised as our protectors even when they are factually wrong? ... it is roughly how the self-appointed guardians choose to present themselves - leaving aside, usually, the step of frankly admitting that they are promoting factual untruths when they know that they are.W.D. Hamilton - ("... one of the greatest evolutionary theorists of the 20th century"). Narrow Roads of Gene Land. Vol. II: The Evolution of Sex, p 332. The public intellectual forum is being manipulated with intimidation and coercion and you are being lied to. The media is not doing its job, and the scientific community is not playing its proper public role as a beacon of dispassionate truth seeking, as a conduit of knowledge to the public, or in fostering an open and fair intellectual climate. Both are abusing their power and authority to do the opposite of their honor bound social and intellectual roles; facts are being distorted in service of values. This post is a very long and detailed examination of what James Watson said, what the data reveal about James Watson's claims (i.e. are they, or are they not factually accurate), and what the media and scientists told the public about what the data reveal about James Watson's claims. ****************** It's difficult to name many more important living figures in 20th century biology than James Watson. He ushered in the current age of molecular biology with his achievements in 1953, he built up one of the world's greatest biological research facilities from damn near scratch, and he is a former head of the Human Genome Project. Given such an august curriculum vitae, you would think that this man perhaps understands just a few things about genetics. But given only the condescending media coverage, you'd think this eminent geneticist was somehow "out of his depth" on this one. In his interview with the Times on Oct. 14th, we learned that: ... [Watson] is "inherently gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really", and I know that this "hot potato" is going to be difficult to address. These thoughts were a continuation of an important theme in his new book Avoid Boring People: ... there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so. Although Watson's book had already been out for a month with these more euphemistic, but still obvious, comments on race and intelligence, no one expressed any outrage. In fact the reviews were reverential and universally positive. The explicit reference to intelligence and people of African heritage in his interview was clearly a violation of a much more formidable taboo. Still I am not aware of there being much noise about it until Oct. 17th when the Independent caused an immediate stir by calling attention to the remarks: Africans are less intelligent than Westerners says DNA pioneer. There's no point in rehashing the rapid sequence of events in detail: several of Watson's sold-out speaking engagements were cancelled, many critical articles appeared in the British press, trailed by the American press a few days later, hundreds of blogs were fuming with negative commentary, including ones by the editors of Scientific American and Wired Magazine, a number of associations issued statements condemning his words, and soon he was suspended from his chancellorship at Cold Spring Harbor. Watson cancelled his already ruined book tour and flew home to tend to the destruction. It was too late; the eminent biologist retired in disgrace on Oct. 26th. One thing, though, was conspicuously missing from this whole irritating denouement: any semblance of factual refutation. There is good reason for this: everything Watson got in trouble for saying was entirely correct! ****************** The "scientific community" is a broad and inappropriately encompassing term, but to the extent such a thing exists as a social or public entity (I'm not talking about the research literature), it is fair to say it has pronounced Watson's claims not only false, but also outside the bounds of "legitimate" scientific discourse. Since only a small fraction of scientific disciplines have any relevance to Watson's claims, it is clear almost all of these scientists are just evaluating the claims with the same ignorant, moralized mental framework people in the general public use to look at (and editorialize upon) scientific claims about evolution. Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? The Science Museum in London responded by canceling Watson's speaking engagement by deeming this claim, not only scientifically false, but outside the realm of "legitimate" scientific inquiry (Whatever that is!) altogether: In a statement, [The Science Museum in London] said: "We know that eminent scientists can sometimes say things that cause controversy and the Science Museum does not shy away from debating controversial topics. Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Francis Collins, Watson's successor over the Human Genome Project, told the media this is not true: Dr. Francis Collins, director of the National Human Genome Research Institute, said that "I am deeply saddened by the events of the last week, and understand and agree with Dr. Watson's undoubtedly painful decision to retire in the aftermath of a racist statement he made that was both profoundly offensive and utterly unsupported by scientific evidence. Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Rick Kittles told the media this is not true: Rick Kittles, an associate professor of genetic medicine at the University of Chicago, said Watson's remarks aren't backed by science. Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Robert Sternberg told the media that the 'scientific findings' show otherwise: Robert Sternberg, a prominent researcher on race and IQ at Tufts University, called Watson's statement "racist and most regrettable." Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Steven Rose told the media that the scientific literature shows otherwise: Steven Rose, a professor of biological sciences at the Open University and a founder member of the Society for Social Responsibility in Science, said: "... If [Watson] knew the literature in the subject he would know he was out of his depth scientifically, quite apart from socially and politically." Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? The Federation of American Scientists issued a statement condemning Watson, claiming that there is no scientific literature showing this: The Federation of American Scientists condemns the comments of Dr. James Watson that appeared in the Sunday Times Magazine on October 14th... The scientific enterprise is based on the promotion and proof of new ideas through evidence, however controversial, but Dr. Watson chose to use his unique stature to promote personal prejudices that are racist, vicious and unsupported by science. Unfortunately our esteemed band of sputtering media scientists forgot to provide, in all of these instances, any of their allegedly voluminous citations to the contrary. Allow me, then, to take a different position, with the added benefit of evidence: James Watson is one of the most important living figures in American science. The claim in his new book Avoid Boring People, that basic evolutionary logic predicts we should expect intelligence differences between racial groups is, if anything, an uncomplicated truth. Watson's claim in his recent interview with Charlotte Hunt-Grubbe that intelligence testing shows lower scores in Africa than Europe is likewise, entirely supported by the scientific literature. As is Dr. Watson's statement that there are many talented people of African descent, which clarifies he is speaking of different average scores, not that said populations are homogenous. Below I am adding 65 psychometric intelligence study citations for sub-Saharan Africa, collected in IQ & Global Inequality, Race Differences in Intelligence, and IQ & the Wealth of Nations. The citations cover 47% of SS African countries or 78% of the people by national population numbers. The studies vary in quality, sample size, and representativeness, but broadly agree in their findings. Representative studies of the school age population with large sample sizes do not exhibit higher scores, much less scores that approach anything like European norms. ****************** Sub-Saharan Africa Countries: 43 W/ data: 20 (47% coun/78% pop) Studies: 65 IQ: 68 West Africa Countries: 20 W/ Data: 6 (30% coun/65% pop) Studies: 15 IQ: 67 Central Africa Countries: 5 W/ Data: 3 (60% coun/80% pop) Studies: 9 IQ: 64 East Africa Countries: 8 W/ Data: 5 (63% coun/93% pop) Studies: 16 IQ: 72 Southern Africa Countries: 10 W/ Data: 6 (60% coun/76% pop) Studies: 25 IQ: 69 ****************** The recent August issue of the European Journal of Personality features a paper titled The g-factor of international cognitive ability comparisons: the homogeneity of results in PISA, TIMSS, PIRLS and IQ-tests across nations by German psychologist Heiner Rindermann. This paper includes an open peer commentary by 31 international scholars, as well as a response by Rindermann. The target paper provides valuable new IQ data from sub-Saharan African, or rather let's us know we have an overlooked source of intelligence data. I am adding these papers to the gnxpforum files section for you to access. Starting in the 1960s and picking up pace in the early 1990s various well-implemented student assessment tests have been conducted for the purposes of international educational comparisons, including the Trends in International Mathematics and Science Study (TIMSS), the International Educational Achievement (IEA) measures, and the OECD's Programme for International Student Assessment (PISA). The cross-cultural test construction, sampling techniques, and quality control for these tests are exemplary. These international tests have also included half a dozen sub-Saharan African countries, and the test construction and sampling techniques are likewise very good. For example Ghana, Botswana, and South Africa were included in TIMSS 2003. For each tested grade level, at least 5000 random students from 150 schools were tested in these countries. Gene Expression bloggers recognized the strong correlation between these types of tests and IQ as far back as 2004, but recently this has reached the academic literature. Last year Richard Lynn and Jaan Mikk reported correlations of .92-1.00 between IQ and TIMSS 2003 for math and science. In his paper, Heiner Rindermann takes this sort of analysis to the next level by collecting data from all 20 total international student assessment tests encompassing some 78 countries and comparing them with measured IQ data from 128 countries. Rindermann finds, first of all that the combined national student results correlate perfectly with the combined national IQ data (.98), demonstrating the assessment scores and the IQ scores are the same measured construct. With all these diverse kinds of tests for each nation, Rindermann examines the data together through factor analysis and finds that the g factor of intelligence explains some 95% of the variance in the test results: "Thus, cognitive ability differences across nations are by and large unidimensional". (p 681) The stable differences between nations in all cognitive type tests are explained by the g factor. Furthermore Rindermann emphasizes that, consistent with previous IQ testing, the g loaded international assessment tests reveal sub-Saharan African IQ scores that characteristically range from 1.5-2.5+ standard deviations below European and East Asian norms: ... I do not believe that the [sub-Saharan testing] scores at the general level are largely incorrect: The low values correspond to too many other variables and aspects standing for low cognitive abilities like results of student assessment and Piaget studies (e.g. Botswana in IEA-Reading 14 year-old pupils 1991 330, as IQ 75; South-Africa in TIMSS 8th graders 1999 259, as IQ 64; Ghana in TIMSS 8th graders 2003 266, as IQ 65; South-Africa in TIMSS 8th graders 2003 254, as IQ 63; plausibility considerations lead to lower results for the youth of Africa because of low school attendance rates and unrepresentative participation of countries), poor quality school systems, high skipping rates, low rates of high school degrees, low patent application rates, no famous universities, and many reports of everyday behaviour from officials, traders, journalists, ethnologists and other scientists in 19th century to this day... (p 770) Thus typical African IQ scores of 70 and below can still be taken as a reliable finding. It is not simply the manufactured data of racialist researchers, or a byproduct of inadequate testing procedures. And, more importantly from the standpoint of the Watson controversy, certainly no reliable body of evidence has shown anything like parity with typical European scores. I'd like to reiterate, then, that IQs below 70 do not by themselves signify mental retardation, as it is commonly understood as a pathological state. There are two types of retardation: familial and organic. The former is caused by normal population variation in intelligence while the latter is caused by diverse individual problems such as genetic defects or head injuries. Related to this, the IQ scores of people with familial retardation correlate normally with their parent and sibling's IQ scores (.50), while the IQ scores of people with organic retardation are not much associated with the IQs in their family. Retardation is measured by a combination of IQ and adaptive scales. Sometimes an IQ of 70 is used as the threshold of retardation. People with familial retardation and organic retardation of matched IQ perform the same in academic and training contexts, but organically retarded individuals do worse on the adaptive scales which measure things such as self-care, motor skills, and social functioning, signifying a broader range of mental dysfunction and some sort of developmental damage. In the US, consistent with the normal bell curve, there are proportionately about five times as many blacks (16%) with an IQ of 70 or below than there are whites (3%). But basically the same proportional number of whites and blacks are organically retarded (whites 1.5%, blacks 2.0%). (The g Factor, p 369) The African scores indicate that there are proportionately about seventeen times as many sub-Saharan Africans with IQs below 70 (50%) than American whites (3%), and possibly even more. While organic retardation is probably somewhat higher among Africans, due to overall more challenging health conditions, this should in no way be regarded as characteristic of their normal intelligence variation. There is nothing particularly meaningful or necessary about an IQ of 70 as a threshold for 'retardation'. La Griffe Du Lion writes: In 1959, [the American Association on Mental Deficiency] set the IQ threshold for mental retardation at 85. The civil rights movement of the next decade forced psychologists to rethink this boundary, because half the African American population fell below it. In 1973, responding to this concern, AAMD (by then AAMR) changed the threshold for retardation from IQ 85 to IQ 70. The boundary moved south by one standard deviation! The proportion of blacks below the threshold instantly dropped from about 50 percent to 12 percent. In other words 50% of modern Africans are no more 'mentally retarded' than 50% of African-Americans were 'mentally retarded' in the 1960s. These are labels of convenience designed for normal within-population variation. But the real world academic and economic consequences of IQs of 70-85 and below are the same no matter what you label them. ****************** INTELLIGENCE DOES NOT EXIST Groups of people may differ genetically in their average talents and temperaments ... proponents of ethnic and racial differences in the past have been targets of censorship, violence, and comparisons to Nazis. Large swaths of the intellectual landscape have been reengineered to try to rule these hypotheses out a priori (race does not exist, intelligence does not exist, the mind is a blank slate...)Steven Pinker - The Edge Annual Question - 2006. "What is your dangerous idea?" Of course pointing to the testing data alone is hardly sufficient to quell these latter-day inquisitors. There is, sadly, an infinite regress of obscurantist objections designed to intellectually moot these issues entirely. These objections are not scientific, and are at odds with the data, logic, and, more often, both. Systematic media misrepresentations of psychometric science have been occurring for going on 40 years. In 1988 Stanley Rothman and Mark Snyderman published The IQ Controversy, the Media and Public Policy. Along with data from their 1987 study of over 1000 scholars in fields familiar with IQ testing, such as psychology, sociology, and behavioral genetics, Rothman and Snyderman took a quantitative look at media coverage of IQ and demonstrated how this media coverage habitually diverged with mainstream scholarly opinion. This is particularly egregious during times of IQ controversy. Media reports and editorials were quick to attack Watson on the premise that any statement about intelligence measures is scientifically indefensible, because science cannot study something so immeasurable and indefinable as intelligence. Cornelia Dean reporting for the New York Times did just this: [T]here is wide disagreement about what intelligence consists of and how - or even if - it can be measured in the abstract. Laura Blue in Time Magazine asserted: ... science has no agreed-upon definition of "intelligence" either - let alone an agreed-upon method to test it. All kinds of cultural biases have been identified in IQ tests, for example. If there is something fundamental in our brains that regulates our capacity to learn, we have yet to separate its effects from the effects of everything that we experience after we're born. Similarly, Steven Rose in the New Statesmen: ... the question of what constitutes 'intelligence' is itself problematic - the word has much broader and diverse meanings than what can be encompassed in IQ tests. Robert Sternberg in the Chicago Tribune: Sternberg, a critic of traditional intelligence testing, believes intelligence can mean something different for different cultures. In parts of Africa, a good gauge of intelligence might be how well someone avoids infection with malaria -- a test of cleverness that most Americans likely would flunk. First of all, an intelligence test cannot and is not designed to tell you the reasons people score differently. So the fact that the test by itself has nothing to say about genetics is not a failure of the test. Second, the assertion of widespread chaos within science over intelligence is false. The statement that there are a number of theoretical differences about the concept of intelligence is only trivially true. In the practical context of research, provisional understanding, and 'normal science' this is rhetorically equivalent to underlining evolution as "only a theory" in media reports. Intelligence as a working scientific research concept and tool is both widespread (as a search for terms such as 'IQ', 'Intelligence' or 'cognitive ability' on PubMed, Google Scholar, or similar publication databases will show), and broadly consistent in approaches and shared theory, methods, premises, and data. The American Psychological Association's 11 member 'taskforce', assembled for a consensus statement on intelligence research, reported: ... [M]uch of our discussion is devoted to the dominant psychometric approach, which has not only inspired the most research and attracted the most attention (up to this time) but is by far the most widely used in practical settings. Third, "All kinds of cultural biases" certainly have not been reported in IQ tests. The tests are not "biased" in the sense that psychometricians use this term. Again the APA taskforce showed consensus on this issue: ... the relevant question is whether the tests have a "predictive bias" against Blacks, Such a bias would exist if African-American performance on the criterion variables (school achievement, college GPA, etc.) were systematically higher than the same subjects' test scores would predict. This is not the case. The actual regression lines (which show the mean criterion performance for individuals who got various scores on the predictor) for Blacks do not lie above those for Whites; there is even a slight tendency in the other direction (Jensen, 1980; Reynolds &:Brown, 1984). Considered as predictors of future performance, the tests do not seem to be biased against African Americans. Similarly Robert Sternberg argues that the tests are biased because they allegedly don't measure the sorts of abilities that are necessary for Africans to succeed in their unique environmental niche. This statement is not only a patronizing and idyllic caricature of African needs, but is also empirically false. This idea was addressed by psychologist Earl Hunt in his peer commentary on Rindermann: There are two reasons that national-level differences in intelligence have been disregarded. One is that it can be argued that intelligence, as evaluated by these tests, is a Western concept, and that the abilities evaluated by the tests may not be the ones valued by non-western societies. This is a spurious argument for two reasons. First, the economic indicators we are trying to relate to intelligence are also Western concepts. As the commentator Thomas Friedman has said, the world is flat. We are not asking whether or not various national populations have the ability to compete in their own societies, we are asking about their ability to compete in the Western-defined international marketplace. The tests are appropriately designed to address this question. (p 727) In fact, economists Eric A. Hanushek and Ludger Woessmann report that the association between economic outcomes and measured intelligence appear to be even higher within developing African countries than within Western countries. (pp 13-15) Similarly, at the national level, psychologists Earl Hunt and Werner Wittmann found that the relationship between GDP and national average IQ was stronger for the mostly African developing countries than it was among the developed industrial countries. (0.70 vs 0.58) In their literature review, Kendall, Verster, and Von Mollendorf found that correlations between employee performance and educational outcomes and cognitive ability did not differ for blacks and whites in Southern Africa. In other words, at school or on the job, an African white with an IQ score of 70 will perform no different than an African black with the same score. Similarly an African black with an IQ of 115 performs the same as an African white with the same score. So "our problems" certainly are relevant to Africans, and certainly are "their" problems. Unless issues such as child mortality, health, sanitation, rule of law, political stability, material comfort, global influence, and life expectancy are somehow not relevant to Africans. Appearances to the contrary, the mendacious Robert Sternberg is, in fact, implicitly agreeing with Watson, while nevertheless shouting him down in the media. Sternberg does not deny that psychometric general intelligence is as low as reported in Africa, nor does he deny that this psychometric intelligence has the academic and economic consequences that the "racist... know-nothing" Watson implied it did. In fact, Sternberg himself has conducted intelligence studies in East Africa, and found the same characteristically 70ish IQ scores, as well as correlations between IQ and academic achievement in this region similar to the correlations reported in developed countries. Thus Sternberg's reply to Watson in The New Scientist: The tests as they stand show some differences between various groups of children. The size of the differences and what groups do best in the tests depend on what is tested. For example, with various collaborators I have found that analytical tests of the kind traditionally used to measure so-called general abilities tend to favour Americans of European and Asian origin, while tests of creative and practical thinking show quite different patterns. On a test of oral storytelling, for example, Native Americans outperform other groups. Ok, so Sternberg agrees that people of European and Asian descent do better on the analytical and general ability tests that reflect the skills vital for functioning in a first-world globalized economy, and therefore must be claiming that Watson is a racist ignoramus only for privileging these general abstract reasoning abilities with the designation of 'intelligence' over the 'oral storytelling intelligence' of Native-Americans, or the 'mosquito dodging intelligence' of sub-Saharan Africans! But if oral storytelling or mosquito dodging are not useful "intelligences" for lifting an individual or a nation out of 1 dollar a day poverty, then Watson can hardly be faulted for expressing concern about the kinds of intelligence not abundant in Africa. Sternberg is perhaps the most blameworthy scientist to publicly condemn Watson, because he is familiar enough with the data to know Watson is right. His condescending statement that dodging mosquitoes is what characterizes the extent of African needs, is itself seemingly more "racist" than, if not completely identical in substance to, what Watson said. At least Watson appeared to show some sort of concern for what Africans countries require to industrialize, while Sternberg appears to be relativistically dismissing there are problems at all: "Africans are perfectly intelligent... for living like Africans!" Actually, I believe Sternberg is taking the stage to condemn the factually correct Watson for his own petty academic reasons: Sternberg believes his own unpopular 'practical intelligence' (PDF) model could become more popular if the dominant psychometric model becomes increasingly professionally and personally dangerous to touch. Like Howard Gardner's empirically unimpressive 'Multiple Intelligences', there is an intellectual market for politically correct ideas like Sternberg's model, and fanning the flames of controversy around psychometrics is one way these ideas can cheat to become more popular. Media red herrings about the supposed ineffability of intelligence or lies about the scientific worthlessness of intelligence testing are designed to moot honesty and openness on this issue, and simply side step the uncomfortable facts. But avoiding facts does not change reality or help shape it to our liking. Intelligence measures predict the kind of social and personal outcomes that people the world over agree are important and desirable. For this reason we need to start engaging this data instead of shooting the messengers. Especially when the messengers we are so casually discarding are important figures like James Watson. ****************** RACE DOES NOT EXIST Population genetics now provides a set of reasonably powerful statistical tools that allow us to determine whether... genes that play a role in the brain evolve much faster in certain human races than in others... The answers to such questions could clearly be awkward, if not incendiary... [O]ne of the most obvious questions about population genetic studies of human beings, especially human races [is s]hould they be performed?... The interesting point - and it's not widely appreciated - is that this question is rapidly becoming moot. Vast quantities of information about the human genome now pour into publicly available databases on a daily basis. These data are collected with the noblest of intentions (often medical) and are also made public for perfectly good reasons: citizens should have ready access to the fruits of publicly funded science. Indeed it's almost impossible to imagine how one could stop the sorts of studies I described above. In previous times, granting agencies, such as the NIH or NSF, could block funding for undesirable experiments or scientific journals could refuse to publish them. But with genomic data, minimal money is required (an Internet connection is enough) and any bright graduate student working in his parents' garage could ask and answer any awkward question he likes. And the Internet thoroughly dashes any chance of preventing the publication of unpleasant results.H. Allen Orr - 'Talking Genes', The New York Review of Books. Ubiquitous and prepackaged media tropes about race, perhaps more than intelligence, serve not as rational arguments but as apotropaic charms to ward off inconvenient ideas. Laura Blue in Time Magazine asserted: ... [T]here is no scientific basis for [Watson's comments] ... For one thing, science has no agreed-upon definition of "race": however you slice up the population, the categories look pretty arbitrary. Steven Rose in the New Statesman wrote: Second, the idea that there is a genetically meaningful African 'race' is nonsense. There is wide cultural and genetic diversity amongst African populations from south to north, from Ethiopians to Nigerians. There are, for example probably genetic as well as environmental reasons why Ethiopians make good marathon runners whereas Nigerians on the whole do not. The Guardian reported: Other scientists point out that our species is so young - Homo sapiens emerged from its African homeland only 100,000 years ago - that it simply has not had time to evolve any significant differences in intellectual capacity as its various groups of people have spread round the globe and settled in different regions. Only the most superficial differences - notably skin colour - separate the world's different population groupings. Underneath that skin, people are remarkably alike. The Chicago Tribue reported: Damaging statements such as Watson's -- and the potential for misuse of research on race -- has led many scientists to avoid the topic altogether. In a 1998 "Statement on 'Race,'" the American Anthropological Association concluded that ordinary notions of race have little value for biological research in part because of the relatively minor genetic differences among racial groups. Craig Venter offered this rebuttal to Watson: As Craig Venter, who pioneered much of America's work in decoding the human genome, put it: 'There is no basis in scientific fact or in the human gene code for the notion that skin colour will be predictive of intelligence.' And our friend Robert Sternberg similarly added: ... [T]here is nothing special about skin colour that serves as a basis for differentiating humans into so-called races... Curiously, we do not apply the concept of "race" to colours of dogs or cats... [These] problems with our understanding of ... race show that the criticism being levelled at Watson is based on science rather than political correctness... race is a socially constructed concept, not a biological one. Well, it's good to see that Venter and Sternberg are basing their criticisms on SCIENCE instead of political correctness! Of course the purposefully obscurantist conflation between 'skin color' and ancestry is something I've dealt with before. ![]() These individuals would not be classified by geneticists, sociologists, psychologists, physical anthropologists, or any sort of scientist as members of the European race. They would not self-identify as white Americans, nor would they be considered as such. They would be eligible for affirmative action. Human races, like dog 'breeds', are defined in the biological context by shared ancestry, not by single appearance traits. With ancestry you can predict many genes and many traits, but with single genes or single traits, you can not predict many other genes or traits. Which is why you can still easily identify the ancestry of the depigmented individuals in the above picture. Population ancestry predicts the sum patterns of one's genotype and phenotypical traits (e.g. general racial appearance) while any single variable - in this case, skin color - does not. Denial of this fact was dubbed Lewontin's Fallacy (PDF) by British geneticist A.W.F. Edwards. 'Skin color' is a false and intentionally misleading straw-definition of race, that dishonorable public scientists such as Sternberg and Venter use to manufacture consent for their ideological viewpoints about human equality. Steven Rose argues that the racial grouping 'sub-Saharan Africans' racistly lumps "diverse populations", but in the next breath uses such equally problematic and diversity encompassing racial categories as 'Nigerians' and 'Ethiopians'. And that is the problem with 'race' criticism, any population concept is diverse and fuzzy - German, Northwest European, New Yorker, Ashkenazi Jew, Asian - and yet the population concept is an essential cog in evolutionary science. The Neo-Darwinian Synthesis that grounded evolutionary theory in genetics, was the vital fusion of Darwin and population genetics. A population is a race is a population. To deny the population is literally a denial of evolution. Race critics don't and could never explain satisfactorily why groupings like 'sub-Saharan Africans', 'Mediterranean', or 'Dutch' have no place in science, and more importantly the way scientists do use such groupings in practice belies the alleged uselessness (that is, like intelligence, the population concept clearly allows them to perform 'normal science'). And, yes, Dr. Rose, 'African' is a genetically meaningful entity: In one of the most extensive of these studies to date, considering 1,056 individuals from 52 human populations, with each individual genotyped for 377 autosomal microsatellite markers, we found that individuals could be partitioned into six main genetic clusters, five of which corresponded to Africa, Europe and the part of Asia south and west of the Himalayas, East Asia, Oceania, and the Americas You'll note, also, that this coauthor of the extreme anti-hereditarian tract Not In Our Genes also suggests marathon running ability in Ethiopia has a genetic component. This belief has become socially acceptable, but the evidence for genetic differences in population intelligence is hardly less spectacular than the evidence for this difference. I don't recall the large transracial adoption study that tested for marathon running. Each of these inferences can be based on the cross-cultural consistency and physiological correlates (PDF) of performance. It is ideology, not data, which keeps Rose from drawing the same inferences about the intelligence difference. It is also ideology that allows Rose to keep his job for this comment, while Watson lost his job for his substantively identical, yet socially taboo comment. The claim that there has not been enough time for evolution to act on non-superficial traits is not scientific. First because nonsuperficial traits take no more time to evolve than superficial traits. More importantly, reasonable selection parameters allow for significant differences to arise between populations in 100 years, much less 100,000. Richard Lynn argues that genetics account for 1.3 SD in intelligence between sub-Saharan Africans and Europeans. Genetic anthropologist Henry Harpending illustrates how a 1 SD difference in a hypothetical trait, with a lower additive heritability than intelligence, could evolve in 500 years: ... [A]ssume time preference has an additive heritability of 25%. Assume that everyone with time preference more than 1 sd above the mean of the distribution has double the fitness of everyone else. About 16% of the population then has twice the number of offspring as everyone else on average. This is similar to Cochran and Harpending's model (PDF) for the evolution of Ashkenazi intelligence. Also allowing for .5-1 SD higher intelligence in mere centuries. Biologist Gerhard Meisenberg put it this way (PDF): ... the argument that the 100,000 years or so since the dispersal out of Africa were insufficient for the evolution of genetic differences is invalid. To create an IQ difference of, say, 15 points between two populations in 100,000 years, natural selection would have to drive their IQs apart by only 0.004 points every generation - about 1% of the selective pressure in late 20th-century America Furthermore, is it true that races only differ in a few appearance related genes? Nope. We already have this data and it's not true by a long shot. Nick Wade reported early last year in the New York Times: In a study of East Asians, Europeans and Africans, Dr. Pritchard and his colleagues found 700 regions of the genome where genes appear to have been reshaped by natural selection in recent times. In East Asians, the average date of these selection events is 6,600 years ago. In fact, far from being identical, virtually all genes that are related to individual differences in human health and behavior differ to some degree in their frequency between racial populations. This is something you can and should test for yourself. Gene Expression blogger p-ter recently wrote a very nice post titled So You Want to be a Population Geneticist. This is a How-2 for several genetic databases that can be used by anyone with an Internet connection to search for allele frequencies or signatures of selection. You can use these to look at the gene frequencies of the four population groups from the International HapMap Project: Utah whites, Nigerian Yoruba, Han Chinese, and Tokyo Japanese. You'll note then that the International HapMap Project is designed to illuminate the genetic differences between these four "sliced-up", "arbitrary", "diverse", "genetically meaningless" racial populations, that are "defined by skin color". Didn't the HapMap people get the memo from SCIENCE that these categories are a racist biological fiction??? Go into Google News, and look under search terms like 'gene' and 'genes', and pick any random recent news items reporting an association between some gene/s and some sort of individual differences. This would not include studies that e.g. talk about genes that differentiate humans or chimpanzees, or that claim no individual differences. Take the genes you find in the news and plug them into the HapMap Genome Browser , using p-ter's tips, and look how the frequencies differ. We even have an open thread for you to test your own hypotheses and report your findings from these databases. Unlike Watson's righteous regulators, we don't believe your hypotheses are immoral or "beyond the point of acceptable debate". Posters on the Half Sigma blog recently used p-ter's post to see how CHRM2, a gene described as the first "yielding consistent evidence of association with IQ across multiple studies conducted by independent research groups", was distributed across the HapMap populations: T is *way* more present than A in rs324650 among East Asians (91%) relative to Europeans (47%) and blacks (27%). Since T is associated with an increase in 4-5 points of performance IQ (what is that, anyway? Is that different from G?) that is significant. The poster 'Marc' continued by examining how alleles differed for DTNBP1: Let's look at rs:760761, rs:2619522 and rs:2619538, all of which are associated with increased or decreased intelligence in DTNBP1. A difference in one or two "intelligence genes" does not by itself suggest that one population is smarter than another, because evolutionary environments select for phenotypes not genotypes. So when populations have many genetic differences, the genes may interact in different ways, and some of the genes that make individuals more intelligent in one population may not have the same effect in another. (In other words if we'd prefer to not take the above results at face value, we have to accept that races are even more genetically different, not less) However, several pieces of evidence make it doubtful that most intelligence genes are like this. For one, mixed race people generally have IQ scores about midway between their parent populations. (save one study of Eurasian mixes) So I would say the gradual accumulation of similar results for other "intelligence genes" would certainly serve as evidence for the genetic viewpoint. These differences do illustrate, in yet another way, the falseness of popular arguments that races are genetically identical, or that genetic differences can somehow only exist for "appearance genes". But virtually any gene showing individual differences that you plug in those databases will also be distributed differently among racial groups and demonstrate the same points. ****************** THE MIND IS A BLANK SLATE James Watson implied a belief that the uniquely low intelligence of both continental Africans and African-Americans are probably related to familiar genetic causes. This belief is deemed unacceptable to express in public, even in most academic contexts, or hold in private. This is despite the fact that the research evidence in support of this position is stronger than the research evidence that contradicts it. Thus even top scientists like Watson are punished for holding beliefs that are more scientific and logical, while scientists that hold to less scientific beliefs and illogical arguments are rewarded. This is a rot on the soul of science. Many statements in the press asserted or implied that various environmental theories account for intelligence differences between ethnic groups. These statements do not, in fact, agree with the evidence. The Chicago Tribune asserted: The study of racial differences in IQ is among the most deeply contentious fields in all of science. Most researchers agree that tests have revealed some differences among racial groups -- but even larger differences between people of different income levels. Steven Rose asserted: Even where there are such average differences in IQ score, as for instance between Black and White populations in the US, there are no scientifically valid methods to enable one to untangle the many interacting factors of the validity of IQ tests themselves, as measures of anything other than school performance, educational and social deprivation, the history of slave-owners versus slaves and continuing racism, which may account for them. The Associated Press reported: Jan Schnupp, a lecturer in neurophysiology at Oxford University, said Watson's remarks "make it very clear that he is an expert on genetics, not on intelligence." Contrary to the above claims, differences in intelligence between income groups are not larger than intelligence differences between racial groups in the US, nor do differences in income or wealth account for the racial differences. Whites from households in the lowest income bracket have higher IQ scores than blacks from households in the highest income bracket: One of the most disturbing, I think perhaps the most disturbing fact in our whole book is that black students coming from families earning over 70,000 are doing worse on their SATS, on average--it's always on average--than white students from families in the lowest income group. You want to cry hearing that figure. I mean, it's so terrible. One of the largest modern sociology studies of American students found that ethnicity was the single most important predictor of academic achievement: Chin quotes with approval a book, "Beyond the Classroom," by Laurence Steinberg, B. Bradford Brown and Sanford M. Dornbusch, which says "of all the demographic factors we studied in relation to school performance, ethnicity was the most important. . . . In terms of school achievement, it is more advantageous to be Asian than to be wealthy, to have non-divorced parents, or to have a mother who is able to stay at home full time." Contra Rose, a number of experiments are able to test all of these environmental theories. For one transracial adoption experiments control for all the shared aspects of the environment that differ between whites and blacks (parenting, income, nutrition, neighborhood), while structural equation models test for possible uncommon factors between whites and blacks that could be acting on IQ (which would include things like racism). These experiments do not lend support to any existing or plausible environmental theories for the remaining lower intelligence scores of people of African descent in Western societies. The Minnesota Transracial Adoption Study found that, by adulthood, the difference in IQ scores between adopted black and adopted white children raised side by side in the same high income households in mostly homogeneous Northern US upper class neighborhoods was 18 IQ points (p 185): IQ at Age 7 IQ at Age 17 W-W 111.5 W-W 101.5 W-B 105.4 W-B 93.2 B-B 91.4 B-B 83.7 W-W = Adopted children with two white biological parents. W-B = Adopted children with one black and one white biological parent. B-B = Adopted children with two black biological parents. The W-W/W-B difference is 8.3 IQ points. The B-W/B-B difference is 9.5 IQ points. And the W-W/B-B difference is 17.8 IQ points. The difference in IQ scores between 2 black biological parent adoptees and 1 black biological parent adoptees is nearly 10 IQ points despite the fact that both share the exact same social identity. Similarly a dozen mixed race children that were raised under some mistaken information that they had two black biological parents nevertheless developed IQ scores like the other mixed race children. There are no simple or plausible environmental theories to explain these kinds of findings. An additional popular argument is that the Flynn Effect, the observed rise in IQ scores over time, is evidence that African-Americans or African countries will eventually reach parity with white norms. This typically includes the premise that white intelligence in the recent past was even lower than modern black intelligence. A typical example: US Blacks, with an average IQ today of 85, have the same IQ as US Whites with an IQ of 100 in 1957. If 1957 US Whites were not stupid, then neither are US Blacks today. It's time to shut up about the "low Black IQ", since by any reasonable standard, it is not really low at all. These arguments are wrong for the simple fact that the Flynn Effect is not a gain in real g factor intelligence, while the differences between nations and ethnic groups are differences in g factor intelligence. These findings led a 2004 team to state: It appears therefore that the nature of the Flynn effect is qualitatively different from the nature of B-W [Black-White] differences in the United States... [so] implications of the Flynn effect for B-W differences appear small... James Flynn, namesake of the secular increase, reiterates (DOC) these points: Factor analysis is a way of measuring this tendency of some people to do better or worse than average across the board; and it yields something called g (a sort of super-correlation coefficient), which psychologists call the general intelligence factor... Flynn believes the secular increase represents important changes in specific narrow aspects of developed cognitive style, but not a rise in g intelligence. It is therefore incorrect that 1945 US whites were less intelligent than 2007 US blacks. The Flynn Effect has little apparent bearing on racial intelligence gaps. This also applies to developing countries. The Flynn Effect reveals that IQ scores in the developed world were some 1.5-2 standard deviations lower in the beginning of the 20th century. (See this GNXP post for the data) These scores are similar to ones in modern African. Some studies also reveal even faster Flynn gains in developing countries than what we observe in developed countries, and it is argued these countries are simply experiencing, in slight delay, what happened in developed countries during the 20th century. But this interpretation is not tenable if there were no actual rises in g factor intelligence in developed countries. It is incorrect that developed countries had lower g intelligence in the first half of the 20th century corresponding to IQs of 70. Meanwhile, as the Rindermann paper reveals, the scores across modern nations do correspond to real intelligence differences. Likewise, extremely low IQ scores in modern Africa, unlike scores in developed countries prior to the mid-20th century, correspond to genuine deficits in g intelligence. With improvements in nutrition it is likely that scores in Africa will rise over time. But these increases will probably be genuine and of a different nature than what we observed in developed countries. It is unlikely that scores in Africa will meet or rise above those of African-Americans in the next century. All of this underlines the fact that IQ can't always be taken at face value. Gains or differences in IQ exceeding 1 SD can sometimes be 'hollow', or unreflective of real general intelligence, being manifested only at the lower order strata of intelligence. (See this paper examining how these false gains can arise through practice effects) Fortunately we have good methods for evaluating the construct validity of the tests and the integrity of the IQ scores. ****************** WATSON RECANTS? Many intellectuals refuse to interpret psychometric claims or ideas about human diversity rationally. Despite 100 years of data showing that ethnic groups differ in their general intelligence, these claims are still rejected on moral grounds. Many of those who deny these claims either implicitly believe that 'intelligence' is a reflection of human worth, or believe any claim of such a difference must be a cryptic assertion of racial worth. Either way it prevents the claims from being interpreted fairly, in the factual, rather than normative, manner intended by the people who attempt to discuss this science in an open forum. Watson's original statements about the lower general intelligence of Africans were interpreted as statements about the lower human worth of Africans. When Watson then publicly apologized that his words were being misinterpreted in this way and clarified that claims about racial intelligence differences are not claims about human worth, the confused media reported that Watson had recanted his claims about intelligence differences!! The science journal Nature ran an editorial claiming: Watson has apologized and retracted the outburst... He acknowledged that there is no evidence for what he claimed about racial differences in intelligence. Time magazine also suggested he retracted his intelligence claims: Watson said in a statement he issued at the Royal Society Thursday. "That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief." And Cornelia Dean at the New York Times asserted, not once, but in two separate reports that Watson retracted his intelligence claims. Even doctoring Watson's apology by cut-and-pasting together two entirely separate Watson quotes: In an interview published Sunday in The Times of London, Dr. Watson is quoted as saying that while "there are many people of color who are very talented," he is "inherently gloomy about the prospect of Africa." And again in another article: Dr. Watson... was quoted in The Times of London last week as suggesting that, overall, people of African descent are not as intelligent as people of European descent. In the ensuing uproar, he issued a statement apologizing "unreservedly" for the comments, adding "there is no scientific basis for such a belief". False. False. False. Dear media, Please read the actual text of James Watson's apology printed in the Independent, instead of mangling it and interpolating it with your own claims: To those who have drawn the inference from my words that Africa, as a continent, is somehow genetically inferior, I can only apologise unreservedly. That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief... Watson would only be retracting his intelligence claims if he considered those claims tantamount to claims of 'superiority' or 'inferiority', which he clearly emphasizes he doesn't. Watson is saying that questioning that all races are equal in intelligence is not racism, it is trying to figure out why the world looks the way it does, with the greatest engineers and the greatest musicians disproportionately coming, in a systematic way, from different racial backgrounds. In other words culturally separated people of African descent have been musical innovators across a diverse range of cultures (in the Middle East, Africa, Europe, North and South America, and the Caribbean), while culturally separated people of East Asian descent have excelled at math and science across a diverse range of cultures (in Asia, Europe, North and South America, and the Caribbean). This is not a claim of racial 'superiority' or 'inferiority', either in terms of legal worth or even in terms of overall talent - since groups all have different strengths and weaknesses. It is simply the recognition that people of different genetic heritage, on average, reveal different talents wherever they are found in the world, and there is one explanation that best accounts for these observations: evolution. In other words, Watson was thinking like a scientist. Which is exactly why he was punished. The moral laws of our society dictate that we are not allowed to think scientifically about some issues. Especially not in public. ****************** IN CLOSING: WHO DAMAGED SCIENCE? According to the media and members of the scientific community, James Watson hurt science itself. An editorial in the top science journal Nature asserted: Crass comments by Nobel laureates undermine our very ability to debate such issues, and thus damage science itself. Similarly the Chicago Tribune featured this: "The damage to Watson's legacy from his statements may be difficult to mend," said Jerry Coyne, a professor of evolutionary genetics at the University of Chicago. Along with E.O. Wilson, James Watson is perhaps the most distinguished living figure in American biology, and yet even he was not immune to immediate expulsion from the very lab he created and built up over 40 years of his life, and excommunication from the scientific establishment that celebrated him. All this for one crime: voicing scientific facts and hypotheses that made this community uncomfortable. The same personal and professional fate befell former Harvard president Larry Summers in 2005 for a purely academic discussion of females in science during an economics conference intended for discussing this very subject! What effect will this continuing intellectual mob violence have on future and current scientists and researchers who want to freely study human genetics, cross-cultural psychology, sociology, or any discipline that may reveal similar facts that have the potential to cause their professional or personal destruction by an intellectual community that resembles the medieval church? Those who punish, those who lie, those who silence, those who condemn, those who intimidate... they have corrupted science. They have injured the intellectual openness, freedom, and fairness of our society and our institutions, with untold costs to our collective human well-being. Not James D. Watson. ****************** APPENDIX I WEST AFRICA Cameroon IQ: 64 Age: Adults N: 80 Test: CPM Ref: Berlioz, L. (1955). Etude des progressive matrices faite sur les Africains de Douala. Bulletin du Centre Etude Recherce Psychotechnique, 4, 33-44. Equatorial Guinea IQ: 59 Age: 10-14 N: 48 Test: WISC-R Ref: Fernandez-Bellesteros, R., Juan-Espinoza, M., Colom, R., and Calero, M. D. (1997). Contextual and personal sources of individual differences in intelligence. In J. S. Carlson (Ed.), Advances in Cognition and Educational Practice. Greenwich, Cnn.: JAI Press. Ghana IQ: 67 Studies: 4 IQ: 80 Age: Adults N: 225 Test: CF Ref: Buj, V. (1981). Average IQ values in various European countries. Personality and Individual Differences, 2, 168-169. IQ: 62 Age: 15 N: 1,693 Test: CPM Ref: Glewwe, P. and Jaccoby, H. (1992). Estimating the determinants of Cognitive Achievement in Low Income Countries. Washington, D.C.: World Bank. IQ: 65 (266) Age: 16 N: 5,100 Test: TIMSS 2003 Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College. IQ: 67 TIMSS 2003: 266 (65) TIMSS sum: 301 TIMSS+PIRLS sum: 304 Sum: 300 Guinea IQ: 67 Studies: 2 IQ: 63 Age: 5-14 N: 50 Test: AAB Ref: Nissen, H. W., Machover, S. and Kinder, E. F. (1935). A study of performance tests given to a group of native African Negro children. British Journal of Psychology, 25, 308-355. IQ: 70 Age: Adults N: 1,144 Test: SPM Ref: Faverge, J. M. and Falmagne, J. C. (1962). On the interpretation of data in intercultural psychology. Psychologia Africana, 9, 22-96. Nigeria IQ: 69 Studies: 5 IQ: 70 Age: Children N: 480 Test: Leone Ref: Farron, O. (1966). The test performance of coloured children. Educational Research, 8, 42-57. IQ: 64 Age: Adults N: 86 Test: SPM Ref: Wober, M. (1969). The meaning and stability of Raven's matrices test among Africans. International Journal of Psychology, 4, 220-235. IQ: 69 Age: 6-13 N: 375 Test: CPM Ref: Fahrmeier, E. D. (1975). The effect of school attendance on intellectual development in Northern Nigeria. Child Development, 46, 281-285. IQ: 79 (401) Age: 15 N: 2,368 Test: IEA-R 1991 Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA. IQ: 69 ISARS: 34 (69) Sierra Leone IQ: 64 Studies: 2 IQ: 64 Age: Adults N: 122 Test: CPM Ref: Berry, J. W. (1966). Temne and Eskimo perceptual skills. International Journal of Psychology, 1, 207-229. IQ: 64 Age: Adults N: 33 Test: CPM Ref: Binnie-Dawson, J. L. (1984). Biosocial and endocrine bases of spatial ability. Psychologia, 27, 129-151. Benin Burkina Faso Chad Cote d'Ivoire Gabon The Gambia Guinea-Bissau Liberia Mali Mauritania Niger Sao Tome and Principe Senegal Togo CENTRAL AFRICA Democratic Republic of Congo IQ: 65 Studies: 5 IQ: 64 Age: Adults N: 67 Test: SPM Ref: Verhagen, P. (1956). Utilite actuelle des tests pour l'etude psychologique des autochones Congolese. Revue de Psychologie Appliquee, 6, 139-151. IQ: 68 Age: 10-15 N: 222 Test: SPM Ref: Laroche, J. L. (1959). Effets de repetition du Matrix 38 sur les resultats d'enfants Katangais. Bulletin du Centre d’etudes et Reserches Psychotechniques, 1, 85-99. IQ: 62 Age: 8 N: 47 Test: KABC Ref: Boivin, M. J. and Giordani, B. (1993). Improvements in cognitive performance for schoolchildren in Zaire following an iron supplement and treatment for intestinal parasites. Journal of Pediatric Psychology, 18, 249-264. IQ: 68 Age: 7-12 N: 95 Test: LABC Ref: Boivin, M. J., Giordani, B., and Bornfeld, B. (1995). Use of the tactual performance test for cognitive ability testing with African children. Neuropsychology, 9, 409-417. IQ: 65 Age: 7-9 N: 130 Test: KABC Ref: Giordani, B., Boivin, M. J., Opel, B., Nseyila, D. N., and Lauer, R. E. (1996). Use of the K-ABC with children in Zaire. International Journal of Disability, Development, and Education, 43, 5-24. Republic of Congo IQ: 64 Studies: 3 IQ: 64 Age: Adults N: 1,596 Test: SPM Ref: Latouche, G. L. and Dormeau, G. (1956). La foration professionelle rapide en Afrique Equatoriale Francaise. Brazzaville: Centre d'Etude des Problems du Travail. IQ: 64 Age: 17-29 N: 320 Test: SPM Ref: Ombredane, A., Robaye, F., and Robaye, E. (1952). Analyse des resultats d'une application experimentale du matrix 38 a 485 noirs Baluba. Bulletin Centre d'etudes et Reserches Psychotechniques, 7, 235-255. IQ: 73 Age: 8 N: 73 Test: SPM Ref: Nkaye, H. N., Huteau, M., and Bonnet, J. P. (1994). Retest effect on cognitive performance on the Raven Matrices in France and in the Congo. Perceptual and Motor Skills, 78, 503-510. Central African Republic IQ: 64 Age: Adults N: 1,149 Test: SPM Ref: Latouche, G. L. and Dormeau, G. (1956). La foration professionelle rapide en Afrique Equatoriale Francaise. Brazzaville: Centre d'Etude des Problems du Travail. Rwanda Burundi EAST AFRICA Sudan IQ: 71 Studies: 4 IQ: 69 Age: 7-16 N: 291 Test: Various Ref: Fahmy, M. (1964). Initial exploring of the intelligence of Shilluk children. Vita Humana, 7, 164-177. IQ: 64 Age: 6 N: 80 Test: DAM Ref: Badri, M. B. (1965a). The use of finger drawing in measuring the Goodenough quotient of culturally deprived Sudanese children. Journal of Psychology, 59, 333-334. IQ: 74 Age: 9 N: 292 Test: DAM Ref: Badri, M. B. (1965b). Influence of modernization on Goodenough quotients of Sudanese children. Perceptual and Motor Skills, 20, 931-932. IQ: 72 Age: 8-12 N: 148 Test: SPM Ref: Ahmed, R. A. (1989). The development of number, space, quantity, and reasoning concepts in Sudanese schoolchildren. In L. L. Adler (Ed.), Cross Cultural Research in Human Development. Westport, Conn.: Praeger. Kenya IQ: 72 Studies: 6 IQ: 69 Age: Adults N: 205 Test: CPM Ref: Boissiere, M., Knight, J. B., and Sabot, R. H. (1985). Earnings, schooling, ability, and cognitive skills. American Economic Review, 75,1016-1030. IQ: 75 Age: 6-10 N: 1,222 Test: CPM Ref: Costenbader, V. and Ngari, S. M. (2000). A Kenya standardisation of the Coloured Progressive Matrices. School Psychology International, 22, 258-268. IQ: 69 Age: 12-15 N: 85 Test: CPM-MH Ref: Sternberg, R. J., Nokes, C., Geissler, P. W., Prince, R., Okatcha, F., Bundy, D. A., and Grigorenko, E. L. (2002). The relationship between academic and practical intelligence: A case study in Kenya. Intelligence, 29, 401-418. IQ: 76 Age: 7 N: 118 Test: CPM Ref: Daley, Y. C., Whaley, S. E., Sigman, M. D., Espinosa, M. P., and Neuman, C. (2003). IQ on the rise: the Flynn effect in rural Kenyan children. Psychological Science, 14, 215-219. IQ: 89 Age: 7 N: 537 Test: CPM Ref: Daley, Y. C., Whaley, S. E., Sigman, M. D., Espinosa, M. P., and Neuman, C. (2003). IQ on the rise: the Flynn effect in rural Kenyan children. Psychological Science, 14, 215-219. IQ: 63 Age: 6 N: 184 Test: KABC Ref: Holding, P. A., Taylor, H. G., Kazungu, S. D., and Mkala, T. (2004). Assessing cognitive outcomes in a rural African population: development of a neuropsychological battery in Kilifi district. Journal of the International Neuropsychological Society, 10, 246-260. Tanzania IQ: 72 Studies: 3 IQ: 78 Age: 13-17 N: 2,959 Test: SPM Ref: Klingelhofer, E. L. (1967). Performance of Tanzanian secondary school pupils on the Raven Standard Progressive Matrices test. Journal of Social Psychology, 72, 205-215. IQ: 65 Age: Adults N: 179 Test: CPM Ref: Boissiere, M., Knight, J. B., and Sabot, R. H. (1985). Earnings, schooling, ability,and cognitive skills. American Economic Review, 75,1016-1030. IQ: 72 Age: 11-13 N: 458 Test: WCST Ref: Sternberg, R. J., Grigorenko, E. L., Ngorosho, D., Tantufuye, E., Mbise, A., Nokes, C., Jukes, M., and Bundy, D. A. (2002). Assessing intellectual potential in rural Tanzanian school children. Intelligence, 30, 141-162. Uganda IQ: 73 Age: 11 N: 2,019 Test: RPM Ref: Heyneman, S. P. and Jamison, D. T. (1980). Student learning in Uganda. Comparative Education Review, 24, 207-220. Ethiopia IQ: 64 Studies: 2 IQ: 65 Age: 15 N: 250 Test: SPM Ref: Lynn, R. (1994). The intelligence of Ethiopian immigrant and Israeli adolescents. International Journal of Psychology, 29, 55-56. IQ: 63 Age: 14-16 N: - Test: SPM Ref: Kazulin, A. (1998). Profiles of immigrant students' cognitive performance on Raven's Progressive Matrices. Perceptual and Motor Skills, 87, 1311-1314. Djibouti Eritrea Somalia SOUTHERN AFRICA Botswana IQ: 76 Studies: 2 IQ: 77 (366) Age: 15 N: 5,150 Test: TIMSS 2003 Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College. IQ: 75 (330) Age: 15 N: 4,768 Test: IEA-R 1991 Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA. TIMSS sum: 396 TIMSS+PIRLS sum: 398 Sum: 391 Mozambique IQ: 62 Studies: 2 IQ: 64 Age: 20 N: 149 Test: CPM Ref: Kendall, I. M. (1976). The predictive validity of a possible alternative to the Classification Test Battery. Psychologia Africana, 16, 131-146. IQ: 60 ISAMS: 24 (60) South Africa (blacks) IQ: 67 Studies: 13 IQ: 63 Age: 9 N: 350 Test: SPM Ref: Lynn, R. and Holmshaw, M. (1990). Black-white differences in reaction times and intelligence. Social Behavior and Personality, 18, 299-308. IQ: 67 Age: 8-10 N: 806 Test: CPM Ref: Jinabhai, C. C., Taylor, M., Rangongo, N. J., Mkhize, S., Anderson, S., Pillay, B. J., and Sullivan, K. R. (2004). Investigating the mental abilities of rural primary school children in South Africa. Ethnicity and Health, 9, 17-36. IQ: 67 Age: 14-17 N: 152 Test: WISC-R Ref: Skuy, M., Schutte, E., Fridjhon, P., and O'Carroll, S. (2001). Suitability of published neuropsychological test norms for urban African secondary school students in South Africa. Personality and Individual Differences, 30, 1413-1425. IQ: 65 Age: 10-12 N: 293 Test: AAB Ref: Fick, M. L. (1929). Intelligence test results of poor white, native (Zulu), colored, and Indian school children and the social and educational implications. South Africa Journal of Science, 26, 904-920. IQ: 75 Age: 8-16 N: 1,008 Test: SPM Ref: Notcutt, B. (1950). The measurement of Zulu intelligence. Journal of Social Research, 1, 195-206. IQ: 69 Age: Adults N: 153 Test: WAIS-R Ref: Nell, V. (2000). Cross-Cultural Neuropsychological Assessment. Mahwah, NJ: Lawrence Erlbaum. IQ: 64 Age: Adults N: 703 Test: SPM Ref: Notcutt, B. (1950). The measurement of Zulu intelligence. Journal of Social Research, 1, 195-206. IQ: 71 Age: Adults N: 140 Test: WISC-R Ref: Avenant, T. J. (1988). The Establishment of an Individual Intelligence Scale for Adult South Africans. Report No. P-91. Pretoria: Human Sciences Research Council. IQ: 68 Age: 15-16 N: 1,093 Test: JAT Ref: Lynn, R., and Owen, K. (1994). Spearman's hypothesis and test score differences between whites, Indians and blacks in South Africa. Journal of General Psychology, 121, 27-36. IQ: 63 Age: 16 N: 1,096 Test: SPM Ref: Owen, K. (1992). The suitability of Raven's Progressive Matrices for various groups in South Africa. Personality and Individual Differences, 13, 149-159. IQ: 64 (259) Age: 16 N: 8,146 Test: TIMSS 1999 Ref: Martin, M. O., Gregory, K. D., & Stemler, S. E. (Eds.) (2000). TIMSS Technical Report: IEA's Third International Mathematics and Science Study at the Eighth Grade (Boston, Intrenational study Center, Boston College). IQ: 63 (254) Age: 15 N: 8,952 Test: TIMSS 2003 Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College. IQ: 69 TIMSS 1995: 270 TIMSS 1999: 259 (64) TIMSS 2003: 254 (63) TIMSS sum: 304 TIMSS+PIRLS sum: 328 Sum: 324 Swaziland IQ: 64 ISAMS: 32 (64) Zambia IQ: 71 Studies: 2 IQ: 77 Age: 13 N: 759 Test: SPM Ref: MacArthur, R. S., Irvine, S. H., and Brimble, A. R. (1964). The Northern Rhodesia Mental Ability Survey. Lusaka: Rhodes Livingstone Institute. IQ: 64 Age: Adults N: 152 Test: SPM Ref: Pons, A. L. (1974). Administration of tests outside the cultures of their origin. 26th Congress of the South African Psychological Association. Zimbabwe IQ: 70 Studies: 3 IQ: 61 Age: 12-14 N: 204 Test: WISC-R Ref: Zindi, F. (1994). Differences in psychometric performance. The Psychologist, 7, 549-552. IQ: 70 Age: 12-14 N: 204 Test: SPM Ref: Zindi, F. (1994). Differences in psychometric performance. The Psychologist, 7, 549-552. IQ: 76 (372) Age: 16 N: 2,749 Test: IEA-R 1991 Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA. Angola Lesotho Malawi Namibia Labels: general intelligence, human biodiversity, national IQ, race, Watson
Monday, October 29, 2007
Genetic Elucidation of Human Hyperosmia to Isovaleric Acid (Open Access):
Humans can accurately discern thousands of odors, yet there is considerable inter-individual variation in the ability to detect different odors, with individuals exhibiting low sensitivity (hyposmia), high sensitivity (hyperosmia), or even "blindness" (anosmia) to particular odors. Such differences are thought to stem from genetic differences in olfactory receptor (OR) genes...which have both functional and inactive alleles in the population...Here, we provide evidence that a particular segregating OR gene is related to sensitivity to a sweaty odorant, isovaleric acid. We show that hypersensitivity towards this odorant is seen predominantly in individuals who carry at least one copy of the intact allele. Furthermore, we demonstrate that this hyperosmia is a complex trait, being driven by additional factors affecting general olfactory acuity. Our results highlight a functional role of segregating pseudogenes in human olfactory variability, and constitute a step towards deciphering the genetic basis of human olfactory variability. PLoS also has a nice write up for the lay audience, with a more frank title. Related: A universal olfactory aesthetic?, A world of sensory difference, PTC taste, balancing selection?, PTC, part II, Taste & behavior genetics, Genetics of taste and Slow & diverse food. Labels: Genetics
Sunday, October 28, 2007
Read Overcoming Bias. There is a non-trivial intersection of audiences between here & there.
![]() With that in mind, it was interesting to see this (properly done) study showing an association between type O blood type and reduced severity of malaria: Malaria has been a major selective force on the human population, and several erythrocyte polymorphisms have evolved that confer resistance to severe malaria. Plasmodium falciparum rosetting, a parasite virulence phenotype associated with severe malaria, is reduced in blood group O erythrocytes compared with groups A, B, and AB, but the contribution of the ABO blood group system to protection against severe malaria has received little attention. We hypothesized that blood group O may confer resistance to severe falciparum malaria through the mechanism of reduced rosetting. In a matched case-control study of 567 Malian children, we found that group O was present in only 21% of severe malaria cases compared with 44-45% of uncomplicated malaria controls and healthy controls...This work provides insights into malaria pathogenesis and suggests that the selective pressure imposed by malaria may contribute to the variable global distribution of ABO blood groups in the human population. Labels: Genetics
The Mission: Mitt Romney's strategies for success:
"There are answers in numbers-gold in numbers," he [Romney] wrote in "Turnaround: Crisis, Leadership, and the Olympic Games," his 2004 memoir. "Pile the budgets on my desk and let me wallow." His campaign manager, Beth Myers, told me recently that Romney regularly checks Mittromney.com, and sends off e-mails to aides, asking them to add more detailed information to the site. I still think Mitt Romney's religion will lose him too many votes on the margins of his target audience to make him viable. But if that isn't a problem, the data-jock attitude is a serious issue. There's no bar on being president and several standard deviations or more above the norm in intelligence. Thomas Jefferson was president of The American Philosophical Society; but suffrage was limited to the "higher orders" when he was head of the American state. Jimmy Carter might have had a physics degree, but he was a down home southern boy! I don't know if Romney is smart enough to know that he has to start actin' a bit dumb now and then. P.S. Of course, we could use a head of state with a head for numerical details. But that's low on the priority list for American presidential candidates judging by the current crop which is considered viable. Rhetorical skills seem more important judging by the notable surplus of lawyers.
Reading The Pursuit of Glory: Europe 1648-1815, and something reminded me of my post The Persistence of Bad Habits:
...To put the statistic another way, the net calorific value of the potato is 3.6 times that of grain.... The author notes that potatoes were brought back from the New World in the 16th century, but there was still strong resistance across most of Europe with the exception of the British Isles (especially Ireland) to their cultivation as late as the 18th century! In part this seems due to the structural biases in the way the peasants of Europe made their agriculture decisions and controlled their land. Communal consensus was critical and traditionalists could in practice veto innovation. In places like Russia the peasants were invariably on the margins already and so were especially suspicious of change, and they distrusted their overlords for whom they tilled the land only grudgingly. If there was such resistance to change in early modern Europe, one can not be surprised that agriculture took 4,000 years to spread across the continent! Nevertheless in the long view peasant resistance to change was probably not totally irrational. As I noted above there was a particularly strong fixation upon custom and tradition in the marginal lands of Russia where communities were extremely risk averse. And Ireland is to some extent an illustration of the "Malthusian Trap" that Greg Clark pointed to in A Farewell to Alms, their acceptance of a productive new crop resulted a population increase which subsequently was subject to a famine of more massive scope in the 19th century when the potato crop did fail. Clark's point that innovation for most of human history did not result in anything more than transitory gains in quality of life; more production was invariably consumed by natural increase in population after several generations. This explains how farming became the dominant lifestyle of human beings when the preponderance of evidence suggests that it is, for the typical human, inferior in quality of life measures (leisure, nutritional balance, etc.) to that of the hunter-gatherer. For farming communities on the expanding frontier life was invariably one of health & wealth, perhaps exemplified in our recent past by the fecundity and robustness of the typical American. The United States is such a young country that just as our frontier closed and the Malthusian Trap should have sprung an economic revolution in human history had already swept that inevitability aside; productivity kept increasing and fertility started dropping. But the psychology of the 18th century is in some ways still operative today. We are a species subject to fad and fashion, but when it comes to food old habits are often the last to die. And so they should be, what we put in our bodies is one of the most important set of decisions we make over our lifetimes. The aversion to GMOed foodstuffs and a preference to "authentic" and "organic" crops have many causes, but one of them is simply a romantic attachment to the ways of our ancestors (or at least what we perceive those ways to be!). Of course the consumer society is different from a peasant society, and so some elasticity in preference exists which might not have been found in the past simply because the craving for the exotic and novel loom much larger in the minds of humans who don't live on the margins of famine. A bigger question is to what extent societies are functionally adapted to their local ecologies as opposed to a flux of partly arbitrary norms which serve as the primary environment for individual fitness. Consider the idea that consumption of beef, and meat in general, in South Asia was an adaptation to local ecological conditions. Cattle were critical as producers of milk and draft animals. Meat is subject to spoilage in tropical conditions. So the ban on beef and vegetarianism are local adaptations. The problem with this idea is that it seems that both these practices were concentrated in the elite reaches of Indian culture until relatively recently, with adoption of non-consumption of beef being a hallmark of tribal assimilation into Hindu society and vegetarianism as indicative of Sanskritization on the part of lower castes attempting to move up the ladder of status & purity. In other words, if particular customs were adaptations to local ecological constraints, it is surprising that the groups which were least subject to these constraints propagated the practices. Wealthy families after all could afford wastefulness and conspicuous consumption to signal their attainment of material security. Rather, some have suggested that in fact the socially marginal consumed beef because their options were so few, while only the wealthy should afford a relatively well rounded vegetarian diet which substituted for the density of meat and did not result in nutritional deficiency.1 This is not to say that all functional arguments are irrelevant. Spiciness of cuisine correlates strongly with local climatic conditions after all. But many more local idiosyncrasies may simply be particular norms & values which serve as totems for elites, and which spread downward via emulation. The fact that baby names tend to drift like neutral genes illustrates that important and socially significant culture products can be relatively unconstrained by anything except for fashion. Of course one must add a layer of historical context to these models; the correlation between Old Testament names and Puritan religious beliefs in 17th century England and America is no coincidence. But in this case it illustrates that different social groups may have different norms, and to optimize individual fitness and increase social acceptability within the group one selects or is born into one must adhere to the norms of the group. Ecology is secondary to sociology. In evolutionary biology processes such as runaway sexual selection are subject to constraint due to the decrement in fitness that they imply at the boundaries. The most extreme case is a population which simply goes extinct due to the extremity of their preferences. Consider a sequence of generations subject to runaway sexual selection concurrent with years of ecological productivity. Subject to weak fitness constraints one can imagine a population shifting in phenotypic value so as to be extremely maladapted when the environment regime becomes less favorable. Nature corrects. And so does human culture; sects which are celibate, such as the Shakers, often have short histories. During times of religious ferment they may draw upon a large base of recruits, but when society wide fervor declines they may find that their cultural strategy is just unsustainable. But the sample space of strategies which humans can engage in is enormous even if you remove the ones which are relatively sensitive fluctuations in the environment. One can still leave room for functional constraint upon cultural forms and still adhere to the hypothesis that most cultural variation serves the role of horizontal group demarcation Addendum: The Pursuit of Glory is a very good book by the way. It is a good balance of social and narrative history, with a bias toward the former. 1 - Note that being a non-vegetarian does not imply meat consumption every day in the pre-modern peasant societies of Asia. Rather, it means that on occasion one may consume meat, but it is a rare luxury. Labels: History
Saturday, October 27, 2007
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Wouldn't it be nice (scientifically speaking) if you could deliberately separate twins at birth and then secretly follow up their development? But of course, you couldn't possibly do that...or could you?
Update: You can listen to them being interviewed on Talk of the Nation.
Friday, October 26, 2007
Matt finds some unexpected data regarding MHC polymorphism & mating systems. That's the great thing about science: confusing or unexpected results can be a good thing! Science is in part about 3 1/2 yard runs which push the ball forward and extend the drive. But sometimes science is also about leaving the stadium and starting a new game. I have a friend who just stumbled onto results which might decide a central debate within his field, against the "side" he was on! But he's happy about it, it might make his career, and he was probably wrong so it is all for the good.
Labels: Evolution
I know that The New Republic was purchased by CanWest, but it is funny to see "canada.com" in the title before redirecting to TNR's site (it's there for half a second). Seems pretty sloppy....
Couldn't find a thread on this yet: Actor/Politico/Author Ben Stein has apparently become a "You can't handle the truth"er. He appears in a documentary on the persecution of the intelligent design movement *yawn* but here's his key claim:
...[Stein] said in a telephone interview that he accepted the producers' invitation to participate in the film not because he disavows the theory of evolution - he said there was a "very high likelihood" that Darwin was on to something - but because he does not accept that evolution alone can explain life on earth. So it's not that he doesn't believe in evolution, it's (partially) that he doesn't trust the masses with the knowledge. There, he could be onto something..... Related: I'm in the middle of reading Watson's very entertaining Avoid Boring [Other] People, and he notes that at his 1946 U Chicago commencement, the university president said the only hope of avoiding disasters like WWII was to believe in the "brotherhood of man," a belief that was supposedly impossible without a parallel belief in the "fatherhood of God." Watson has a lot of great things to say about religion so far--no surprises, but still fun. He also has a lot of good academic career advice in handy numbered lists at the end of each chapter (e.g., "Have friends close to those who rule," "Channel rage through intermediaries," "Extend yourself intellectually through courses that initially frighten you," etc.,). Labels: Bueller, Evolution, Intelligent Design, Watson
OK, so the readers of this blog really helped the last time I had a tech issue, it was the Shift key sticking (actually, the problem is the left Shift key, hitting the right Shift key gets me out of the problem every time!). So now I have another issue...my AC adapter for my notebook had problems (the wires were torn up and it was sporadic in generating a current to power up the laptop). I ordered a new one, and it works great. But one problem: now the battery won't charge. When I plugged in the old adapter the battery did charge (I can get that adapter to work by tweaking with it A LOT), and then the new adapter charged the battery after I swapped it in. But that was a one off. Any thoughts? I doubt there's a problem with my battery since it happened only today when I got the new adapter. I don't see anything weird in the Power Options in the Control Panel. Specs below the fold if you are curious for my computer and adapter....
My laptop is a Compaq Presario v5000. Adapter: 75W AC Adapter Hi Capacity Power Product Model: EA10722 AC Input: 100-240V - 2.0A DC Output: 15-24V - 4.3 A I bought this from an online vendor and this was specifically marketed as compatible with the v5000 Presario.
Thursday, October 25, 2007
Former Miss Universe contestent weighs in on the Watson Affair
posted by
TangoMan @ 10/25/2007 12:40:00 PM
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The former Miss Singapore, Cheryl Marie Cordeiro, now domiciled in Sweden, takes a crack at analyzing the Watson Affair. She's clearly not a reactionary in that she tries to understand what Watson was saying and she goes to some effort to look at background information but along the way she falls into many of the expected traps that await those who rely on inaccurate information, to wit:
So, why do we need to assume that Watson is wrong if he says that "all testing shows that Blacks or Africans indicate that they are less intelligent"? Aren't we missing the small detail of how and by whom these tests were made? IQ tests, though widely accepted as a standard indicator of how "intelligent" an individual is, still comes with a white / western / male bias, because that is from where the tests originated. I don't think we need to doubt that white, western male scientists whose socio-cultural, historical and political backgrounds are different from those of the Africans or Black Americans. So, while these IQ tests cannot be "universal", they are often referred to as if they were. PS: - If you have time to kill and wish to see the amazing Ms. Cordeiro model her outfit of the day, then spend some time exploring her blog and marvel at the limitless wardrobe she's accumulated. Labels: Watson
Actually I don't know, but there's some evidence that extinct Neandertals were red heads!
Labels: Evolution
Back when this blog was young and its was age measured in months, not years, "godless capitalist" (gc) would debate Paul Orwin and Charles Murtaugh, especially on the issue of QTLs which affect normal variation in IQ. When gc made the case for possible genetic engineering of one's offspring to have higher IQs Murtaugh was aghast. His basic logic seemed to be that the QTLs which contribute to normal variation in IQ are of small effect, so there are many, and who knows what sorts of problems might be caused by "switching" dozens of genes from state A to B? Genes are often of course pleiotropic, and Murtaugh's assumption seemed to be that changing the genetic architecture in such a profound way might not be a good thing in the genetic background of the typical human. We're a species with a very high rate of spontaneous abortion, perhaps as much as 3/4 of fertilizations do not come to term. Much of this is likely due to chromosomal abnormalities, but there are likely other factors as well, so let's take Murtaugh's objection seriously for a minute.
What sort of superior child do most parents which frank eugenic inclinations want? Wouldn't you want your son to be both tall and extremely intelligent? For example, a male who is 1 standard deviation taller than the norm and 2 standard deviations more intelligent would be at a relatively advantage in life. But the chances of having a tall Mensa level IQ son is not high for most humans, and even if you assume some dependence of the deviation of one trait conditioned upon other, that dependence is likely still relatively weak. Finally, both of these are quantitative traits where the average effect from a given gene seems small in their contribution to normal human variation. The right flavor of HMGA2 gives you 1 extra centimeter, but that really isn't that much, and this is likely a QTL of very large effect for this trait (height). For intelligence the prospects may even be weaker. To engineer a very tall and intelligent son if you are of normal intelligence & height (the typical future consumers) would require alterations on many loci, and this is where Murtaugh might pipe up with cautionary tales. But then I thought of something: there are other traits where most of the variation seems associated with a few loci of large effect. Europeans' light skin is in large part due to SLC24A5, SLC45A2, TYR and OCA2. 4-6 loci probably account for around 90% of the variation. What about eye color? OCA2 is responsible for 3/4 of the variation, with TYR rounding out much of the balance. Skin color, eye color, even hair color; these are gross outward phenotypes controlled by a few loci of large effect! The loci are of such large effect I think that South Asian couples of middle complexion who want lighter skinned offspring can now feasibly engage in selective abortions to "load the die" so that their offspring are the "optimal" combination of their genes. We have the information and the technology. Then I began thinking, do people really care about total genome content in relation to their offspring? We've floated the possibility of switching a few hundred loci to shift the expected phenotypic value in the offspring, but the Murtaugh objection looms in the background. But we already have genetic backgrounds which have been "field tested" for viability and health in highly intelligent people. Why not just use them and fiddle around with the loci which control superficial physical appearance! What I'm saying here is that instead of taking the genetic material from one's own biological offspring and fiddling with hundreds of loci to shift the quantitative value of traits of interest such as height and IQ, why not create a clone of a tall and very intelligent person, and switch a few dozen loci so as to sculpt that individual so that it can pass as your natural offspring? Imagine that a Japanese couple hosts a tall Swedish exchange student who is both a stellar scholar and athlete, and is moderately tall to boot. Additionally, this individual has a very agreeable personality. The son they always wanted! Perhaps they can get that son. They could clone the student, and then make changes to complexion, hair form, eye color, nasal form and include in Asian traits such as the epicanthic fold. Eye color, hair color and skin color are known to some degree now, perhaps a dozen genes could do most of the trick. But what about nasal form? I don't honestly know. Epicanthic fold? Again, I don't know. I suspect that some of these traits are subject to QTLs of larger effect than height or intelligence. One would have to do the cost vs. benefit. Now, some of you might ask, "but why would people want to have offspring who are predominantly not descended from them?" Perhaps that is an issue for many or most people. Honestly though, I think if you could make a child resemble the midpoint of both parental phenotypes in terms of complexion and facial features the intellectual (conscious) knowledge would quickly be overruled by the reflexive (proximate) cognitive processes which would identify the physical resemblance and induce the normal emotional response (the main objection is that I do think that personality ticks are highly heritable, so perhaps some parents would start to treat their offspring as incongruous impostures who exhibit the right look, but with strange mannerisms). This goes to human psychology, it is a complicated area and there is some evidence that humans exhibit essentialisms which may transcend morphology. That being said, in this case I believe not all loci are created equal. If the "important" loci (those which contribute to visual parent-child resemblance) are identical by descent & state from the putative parents I think that many would enter into the tradeoff of alien genome content for the sake of building a "better baby." Anyway, just a thought I had on the way to the Post Office (I'm not shitting you!). Note: Even if the Murtaugh objection does not hold, it might be cheaper to do what I'm talking about. I don't really take the objection that much to heart, humans mix & match genes across genetic backgrounds all the time when we mate. The key would be to get the exogenous material in early during development so any problems would lead to a spontaneous abortion. Obviously playing with the genetic architecture after the child had been delivered might be more problematic. Also, though purchasing the rights to someone's genome for your offspring might be expense, I don't see how it would be that much more expensive than eggs purchased for fertility clinics are today. Of course, the types of parents I'm talking about are probably going to be in line for androids too. Let your imagination fly. Labels: Population genetics
Wednesday, October 24, 2007
Nature has weighed in on the Watson imbroglio with a ponderously written editorial, accusing him of "lending succor and comfort to racists around the globe". It concludes:
Many human geneticists are engaged in the sensitive task of unravelling differences between the world's population groups, all the while acknowledging that 'race' is an emotive and unscientific word. Others are investigating the equally sensitive genetics of 'desirable' traits, such as cognitive ability.Now, it's well-known that Watson is an asshole, and frankly I can't say I really care about the "punishments" he's getting (if he really said, as he is quoted, that his conclusions should be obvious to anyone that has worked with black employees, then, well, I can see how an organization with black employees might not want him around so much). I'm not too worried about the guy's prospects; he's no martyr. That said, he's brought to the attention of a larger crowd the "uncomfortable facts" that human geneticists are starting to face--populations differ genetically, and those genetic differences actually matter phenotypically. In the internets, Larry Moran is asking about the genetic component of intelligence, and the commenters over at Half Sigma have been having a field day looking through publicly available resources at the population distributions of alleles thought to be involved in IQ. I don't know how much any of this trickles up to the world at large, but if it does at all, and it accelerates the coming of the day when people can quit feeling awkward about the implications of genetic research and start saying forcefully that political equality is not dependent on biological identity, then ultimately this could be a good thing. So has James Watson damaged science itself? Hopefully, quite the contrary! Labels: Watson
I've mentioned the emergence of the dog as a model organism in genetics-- the resources available now have made all sorts of questions easy (well, not easy, but comparatively easy) to answer. One such question: what makes certain breeds of dog black? The answer is now available online at Science: a small deletion in a gene called CDB103.
The gene is interesting because it encodes a novel ligand for MC1R, mutations in which cause red hair in humans (and lighter fur in mammoths). The melanocortin pathway seems to be polymorphic in all mammals studied, perhaps due to similar selective pressures on coat/hair color. The authors have a neat picture of mice they turned black by inserting copies of the variant allele, which raises the question: can any dog breed be turned black? And if so, how much will people pay for it? Labels: Genetics, Pigmentation
I recently came across the term 'genophilia', meaning something like 'instinctive attachment to family and tribe'. It appears to be quite a buzz-word among the usual suspects.
I was interested to see that the origin of the term was ascribed to Francis Galton. I am reasonably familiar with Galton's works, but I did not recall him using this term. I therefore set out to find if he really invented it. To cut a long story short, he didn't. For the long story, see below the fold. On searching the internet for 'genophilia' I came across a Wiktionary entry for that term, which states (as of 24 October 2007), that the term was 'apparently coined by Sir Francis Galton', and contains the following alleged quotation: 1883: We would include among our standards of eugenic value sound physical health and good physique, intelligence, and moral qualities which make for social cohesion. The latter would comprise courage (but not aggressiveness), serenity or contentment, and cooperativeness. We would also here include the quality described above as genophilia (love of children). - Sir Francis Galton, Inquiries into Human Faculty and Development (Macmillan 1883) I have been unable to find this passage in Galton's 'Inquiries into Human Faculty and its [sic] Development' or any other of Galton's works. The substance and style of the passage are vaguely Galtonian, but there are three points of difficulty: - it is unlikely that Galton would use the word 'serenity' in this way - Galton usually referred to 'ability' rather than 'intelligence' - Galton usually put much emphasis on 'energy' as a desirable quality, but energy is not mentioned in this passage. Galton's own best-known listing of desirable eugenic qualities is 'health, energy, ability, manliness and courteous disposition' (Essays on Eugenics, 1909, p.37). Having failed to find the passage in Galton's works I searched the internet again, and was rewarded by finding a reference here to a use of the term 'genophilia' by C. P. Blacker, a mid-20th century British eugenic writer, in his book 'Eugenics: Galton and After' (Gerald Duckworth & Co., London, 1952). To confirm this I tracked down a library copy. The book's Index has references to 'genophilia' on pages 284 and 289. I find that the passage quoted in the Wiktionary entry is on page 289 of Blacker's book. It is clearly expressing Blacker's own views, and is not a quotation from Galton. I can only speculate that someone along the line has seen the quotation in conjunction with Blacker's title, which includes Galton's name, and jumped to the wrong conclusion. It did cross my mind to wonder whether the misattribution was a deliberate attempt to give the term a longer and more distinguished pedigree, but it is more likely to be a careless misreading of some secondary source. Blacker himself does not claim to have invented the term 'genophilia'. On page 284 he refers to 'genophilic instincts' and in a footnote says: 'The word "genophilia" is used by Dr. A. Spencer Patterson to denote the sentiments conveyed by the term philoprogenitiveness plus something more concrete in the shape of fondness of and delight in children'. I do not know anything about Dr. A. Spencer Patterson and do not intend to pursue the origin of the term any further. I could not find Patterson's name in the online British Library Catalogue. It should be noted that the original meaning of the term, as used by Blacker and apparently also Patterson, has little to do with 'instinctive attachment to family and tribe'. I have asked the Wiktionary administrators to amend the entry. It will be interesting to see how long it takes. I will also be interested to see whether the false attribution continues to be used elsewhere. I'm not holding my breath.
Tuesday, October 23, 2007
There are few issues in Farewell to Alms that I'm still chewing on. One of them is Greg Clark's dismissal of institutional and cultural barriers to development. In particular, Clark shows how practices such as usury, initially banned by the Church, were mainstreamed through work-arounds. I find this line of thought pretty persuasive, for example, look at what Israelis do during their fallow year. Proximately cultural practices are fixed parameters, but over time they generally evolve and shift. But there was something in Clark's argument which bothered me, he argues that the consistently worse hygiene of the English can explain their higher mortality rates vis-a-vis the Japanese, and therefore their elevated standard of living (more to go around for the fewer people left alive). Clark contrasts the efficient recycling of "night soil" and its distribution from urban areas out to farms where it could be used as fertilizer with the English practice of simply storing it within one's house until it could be thrown away like garbage.
But why do people persist in bad hygiene for centuries when it results in greater mortality? Shouldn't individuals who, for whatever reason, practice better hygiene slowly increase in numbers in relation to those who do not practice good hygiene? Are these habits simply not heritable? And I'm not simply wondering about hygiene here, what about practices like the Muslim ban on alcohol? From what I recall alcoholic beverages are not only good dense calorie sources, they also are less likely to carry high densities of pathogens then plain water. Muslims prided themselves on their customs of bathing and cleaning in relation to Europeans (in some areas of course bathing became dangerous because people might assume you had Muslim sympathies!), but it seems that their aversion to alcohol should have resulted in higher mortality from water born illness as well as poorer nutrition (exacerbated by Ramadan). I'm sure some of this is explained by dynamics such as the Handicap Principle. Humans show off and do all sorts of irrational things to illustrate that "they're the man." Circumcision as a rite of passage for teenagers anyone? That being said, I am also curious as to the cognitive biases and social pressures which make usury inevitable (obviously a financial system spurs wealth creation) but hygiene seem less critical. Is it because usury is a concern of a small minority who are highly motivated and a simple fiat change of the law can result in a switch? In contrast, hygiene is embedded in a whole suite of mores, practices and traditions, and requires self-control and conscious forethought. Even today it is relatively difficult to get many to wash their hands after they use a restroom! Labels: History
Well, not really. But here's a feature about a small town in northeastern Argentina which has had several centuries of self-imposed endogamy, resulting in a sharp increase in the incidence of albinism. This sort of thing isn't always a function of conscious custom or tradition, in Consanguinity, Inbreeding, and Genetic Drift in Italy L.L. Cavalli-Sforza documents the rapid drop in inbreeding with the penetration of modern transport into the mountains of Italy. Cavalli-Sforza notes that throughout much of 19th century Europe there were two opposing dynamics; on the one hand the decline in the power of the Catholic Church resulted in an increased frequency of consanguineous marriages (this happened in Protestant countries after the Reformation), but simultaneously more efficient transport increased gene flow across demes and many more people left their villages.
Labels: Genetics
The UK Office for National Statistics has just released its population projections for the next 25 years. The central projections are for UK population to rise to 65 million by 2016, and to 71 million by 2031. The ONS is careful to say that these are not forecasts, since the outcome will depend in part on policy decisions and other events which cannot be foreseen. So that's all right then.
The ONS's summary statement is here. Follow the first 'Related Link' to get access to the supporting documents.
Paul asked for recent comments. Look to the right. Just one note: that's a Haloscan widget, I can't fiddle around with the parameters or anything. Also, there are apparently Greasemonkey extensions which can give you a lot more control over Haloscan if you want. Just google it.
Labels: Blog
I just read The Great Upheaval: America and the Birth of the Modern World, 1788-1800, and the main thought I came away with was that the more intelligence and status are decoupled in a society, the greater the likelihood of revolution. I assume here that the wealthy bourgeois who were marginalized in the ancien regime attained their gains via sly cunning; surely a simplifying assumption. In any case, demagogues such as Jean-Paul Marat and Maximilian Robespierre acted and organized on behalf of the working man, but unsurprisingly they were personally marginalized intellectuals. The populace may be roused into vicious action against the elites of the age, but the snake always needs a wily head, invariably from aspirant elites.
Secondarily, I am struck by the quicksilver changes in the Spirit of the Age. In 1783 the American republic was a peculiar experiment, an aberration in the age of monarchy (there were small republics). Yet by 1800 the French Revolution had swept such expectations away, at least for a time. These 17 years arguably witnessed changes in the order of societies on a scale far greater than the 1960s across the West, or throughout the Easter Bloc during the 1990s. Labels: History
Monday, October 22, 2007
Are Some Men Predisposed To Pedophilia?:
A difference in average height is a trait found in other illnesses with biological links. The average difference in height was two centimeters, which is similar to the shorter height associated with schizophrenia or Alzheimer's disease. I'm really not that interested in the biological origins of pedophilia, instead my attention was drawn to the fact that such a height difference is known for a range of disorders. In The Mating Mind Geoffrey Miller hypothesized that variance in mutational load across individuals tracked beauty. This is basically a "good genes" model for why organisms exhibit sexual preferences. Miller was assuming a polygynous social system, but this makes me wonder as to the importance of "good health" due to provisioning in a monogamous species. Though height is about 80% heritable in modern environments that still leaves an unaccounted for 20%; where does that come from? Possibly infection or developmental instability early on for whatever exogenous reason. In pre-modern contexts one assumes that heritability would be a bit lower because of the random stresses during pregnancy and during early childhood growth. In any case, adult height in males would surely be a good proxy for how healthy he is, and how productive a provider he might be. Additionally, good genes is still operative in a scenario where ability to resist and fight off infection is a proxy for fitness.
I'm trying to raise money for Donors Choose again this year. The yield has been a little lower this year than last, so if you are inclined check out the projects below the fold or click icon:
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Saturday, October 20, 2007
Carl Zimmer interviews Craig Venter (video). They're talking most genomics and creating life from "scratch." Also, Esther Dyson talks about the personal genome.
Labels: Genetics
Greg Mankiw on why he closed comments. What do people think of /.'s moderation system? I don't comment there much, but I remember people would complain that unpopular views would be moded down too much. Of course, a forced registration would probably filter out the drive-by-tards who can't be bothered....
Labels: Blog
Friday, October 19, 2007
![]() The first is titled, conveniently enough, "Which evolutionary processes influence natural genetic variation for phenotypic traits?". The authors, of course, can't really answer the question, but they point to a number of studies examining specific traits and how natural selection has influenced their evolution. The picture is from a striking example of adaptive variation in coat color in mice. Another example that particularly caught my eye was that of variation in flower color in Linanthus. Those of you familiar with classic population genetics will recall that Linanthus was one of Sewall Wright's preferred examples of neutral phenotypic variation driven by isolation [pdf]. He was, as it turns out, probably wrong. Molecular data has the power to answer a lot of these questions, or at least allow them to be posed in a more testable manner. The second review focuses on the species that is becoming/has become the modern "model organism" for studies of selection-- humans. It's a very thorough summary of the recent scans for selection in the human genome, and anyone looking to get up to speed on the topic should read it. Selection in pervasive in the genome, and perhaps the only way to understand how it acts is through statistical analysis of genome sequence. The authors make this explicit, with an interesting nod to the oft-cited Lewontin and Gould spandrels paper. There are those who argue that functional evidence is essential for defining a region of the genome as being under selection, however, the deductive logic between selection and phenotype only goes in one direction-- that is, a region identified as being under selection using statistical methods is necessarily functional (with a certain false positive rate), but, as a modern fan of the spandrels paper might write, evidence of function does not necessarily imply selection. Human evolution has become something of a trendy topic, but as is often the case, it's trendy for a reason-- there is extensive data on genotype, phenotype, and environment coming available on our species, and this will allow us to tackle some of the longest standing debates in evolutionary biology. They are, after all, empirical questions. Labels: Evolution, Genetics, Population genetics
A great deal of confused and unreliable reporting is flying around concerning James Watson's comments on race and intelligence.
In the interests of public information, here is an article from today's London Independent which is signed by Watson and therefore, unless he disavows it, may be taken as accurately reflecting his current views. Added: And here is the article in the Sunday Times that started all the fuss. Since the relevant passage consists of short quotations taken from a long and informal conversation (some of it apparently conducted in a coffee shop or while driving a car), there is no guarantee that it is either accurate or fair in context, though there is nothing to suggest that the interviewer (a former student of Watson) had any hostile intent. Added on Sunday 21 October: The author of the Sunday Times article, the improbably named Charlotte Hunt-Grubbe, has a follow-up here in today's issue. An interesting extract: After a long day of conversation the topic of racial inequality was broached. It seemed an important extension to words he had written in his book. I would never have written something that I thought he would not be prepared to defend. I am not trying to destroy a brilliant scientist and I am genuinely horrified by the response. We need to squeeze every last drop of brilliance from this man if we are to continue hoping to unravel the genetic causes of disease. He strives to help young people in their careers. My biggest concern is that, by helping me, he has damaged himself. I could not hope more, that I am wrong. Labels: Watson
Wednesday, October 17, 2007
Evolgen is publishing original research on blogs. Definitely more than a 15 minute rant, really worth checking out and appreciationg. He's got 6 posts up so far.
Labels: Genetics
TC Boyle, perhaps my favorite modern short story writer, has a decent little piece in this week's New Yorker. The subject: a child who can't feel pain, performs tortuous tricks for money, and end up killing himself by jumping off a building. It was kind of fun to recognize that this wasn't just something he came up with off the top of his head--it's actually someone's life story. Some of you may remember this Nature paper from a while back, but if not, I'll refresh your memory:
The index case for the present study was a ten-year-old child, well known to the medical service after regularly performing 'street theatre'. He placed knives through his arms and walked on burning coals, but experienced no pain. He died before being seen on his fourteenth birthday, after jumping off a house roof.The story describes exactly that. Another of Boyle's memorable stories involves a primatologist who ends up sleeping with one of her subjects; one can only hope the inspiration for that one is not equally based in fact.
The Center for Strategic and International Studies has a report out (available here) entitled, "Synthetic Genomics: Options for Governance." I haven't read the whole thing, but it looks to be a consideration of the options for minimizing risks associated with widespread use of this technology. They are concerned first and foremost with malicious uses followed by lab safety and environmental safety. Take a look if policy is your bag. No recommendations, just laying options on the table.
Labels: dna synthesis, policy
In Genome-wide detection and characterization of positive selection in human populations there's an interesting part which intrigues me:
The EDAR polymorphism is notable because it is highly differentiated between the Asian and other continental populations...and also within Asian populations (in the top 1% of SNPs differentiated between the Japanese and Chinese HapMap samples). Genotyping of the EDAR polymorphism in the CEPH...global diversity panel...shows that it is at high but varying frequency throughout Asia and the Americas (for example, 100% in Pima Indians and in parts of China, and 73% in Japan)...Studying populations like the Japanese, in which the allele is still segregating, may provide clues to its biological significance. ![]() (note that this doesn't mean that I think there was selection for thick very straight hair. I assume it is likely a byproduct effect) Labels: Population genetics
The Samaritans: it's endogamy, not cousin-marriage (per se)
posted by
Razib @ 10/17/2007 01:14:00 PM
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There's an article up about Samaritans. The community is small, down to 350, and traditionally endogamous. That's a problem:
To explain his decision, he points to his own family. When he was a young man, High Priest Elazar's father decreed that he should marry his cousin. It was a mistake, he says now. Two of his three sons were born deaf and mute. Two others died. Mr. Cohen is his only healthy child. But note, this isn't just because the Samaritans are marrying first cousins. Rather, generations of endogamy has cranked up the coefficient of relationship so that deleterious alleles are now extant at an extremely high frequency. In the United States first cousins who marry are generally related because two of the parents are siblings. The other two parents are unrelated. When considering the possibility of the appearance of a rare deleterious recessive disease you only need to focus on one side of your family tree, you're safe not putting too much effort into the unrelated portion because you assume that they carry different rare alleles. This isn't true for the Samaritans, they're closely related every which direction. In any case, inbreeding reduces the effective population size and so cranks up the ability of random genetic drift to fix deleterious alleles. Consanguinity among obligately endogamous societies is a different order of inbreeding than what you might know from in the West. Though cousin marriage is not unknown (e.g., Charles Darwin), but isn't scaffolded by amplifying social customs (i.e., inbreeding vs. inbreedinggeneration n). Also, note that one generation of outbreeding can mask the deleterious alleles immediately. Nevertheless, many subsequent generations will of course still be subject to the recessive diseases of the Samaritans (though at a lower frequency) because one assumes that people of substantial Samaritan ancestry will still assortatively mate. And so they will bring together the deleterious alleles again. H/T Ikram. Labels: Population genetics
Nice little article in Nature. Here's the conclusion:
"This is a very delicate time, and a dangerous time, as people start to come up with things that the general public, or the media, or various groups might misinterpret," Sabeti says. "I like the fact that, so far, the evidence we find for natural selection in humans is only skin deep." Here's an interview with Pardis Sabeti (she is also the first speaker at this 2006 "Inspiration Festival" sponsored by Seed). She is lead author on Genome-wide detection and characterization of positive selection in human populations in the current issue of Nature (step away from the computer Assman....). Labels: human biodiversity
Tuesday, October 16, 2007
Africans are less intelligent than Westerners, says DNA pioneer:
The 79-year-old geneticist reopened the explosive debate about race and science in a newspaper interview in which he said Western policies towards African countries were wrongly based on an assumption that black people were as clever as their white counterparts when "testing" suggested the contrary. He claimed genes responsible for creating differences in human intelligence could be found within a decade. Well, 1) This isn't surprising coming from Watson. He has a long track record (one story from someone who has done research at Cold Harbor is just that, but many is a trend). 2) I'll be interested in seeing what he says in the book. I hope it is a bit more nuanced, seeing as not everyone in the First World is the same race. There are some black and brown people who are citizens of Western nations after all! Does his "our" include us? Who exactly is we Dr. Watson? 3) There are sensitive topics that are best spoken of clinically, bandying about anecdotes about black employees really won't cut it. That's low hanging fruit for Steve Rose. Seriously. 4) That being said, Watson is not a racialist, just as W.D. Hamilton was not racialist. He's just really blunt (or stupid or off his meds depending on how you look at it) and he is offering his opinion on what he believes to be the most parsimonious explanation for the variation he sees in the world out there. Is he wrong? Is he too much of a geneticist so that there is always nail ready for his hammer? Perhaps. I've said as much about W.D. Hamilton. Nevertheless, Watson's views aren't that exceptional. There are many other biologists who would view Watson's evaluation of the issues in regards to intergroup differences as reasonable, whether they agree with him or not. Not because they have a particular racialist impulses, but because evolutionary biology implies the plausibility of human variation on a host of traits. Including behavioral and cognitive traits. 5) A snip from the article: Steven Rose, a professor of biological sciences at the Open University and a founder member of the Society for Social Responsibility in Science, said: "This is Watson at his most scandalous. He has said similar things about women before but I have never heard him get into this racist terrain. If he knew the literature in the subject he would know he was out of his depth scientifically, quite apart from socially and politically." Ah, alas, the time for show trials is over comrade Rose. Now, here is something to repeat five times before breakfast: legal equality is not contingent upon biological equality, is does not necessarily imply ought and natural does not necessarily imply good. These are old lessons, centuries old, but it maybe that we have to learn these simple lessons again in the interests of a liberal order. What we hold to be good, true and right is not good, true and right because the world is as it is, but because it is what we wish it to be. And for us to most efficiently attain what we wish we must wrestle what what is. Live not for the fashions of the day, honor the timeless truths of nature. Addendum: Watson's new book is titled Avoid Boring People. Well, at least he's trying to contribute to the trend he's promoting. Labels: human biodiversity, Watson
Jonathan Eisen points to a Newsweek article interviewing 10 high-profile scientists about the future of biology. I think it's fair to presume that the title (the Einsteins of the 21st century) is a bit hyperbolic, but if you're a genomics neophyte, you might glean something from it.
I really only mention it because of Dr. Eisen's post. If you're going to click through, read the interview first, then his response. And prepare to be puzzled. The comments on the post are good for a bit of a laugh, if you're in the right mood. I kind of imagine a professor walking down the hall, this article in hand, shaking his fist at the sky: "Damn you, Newsweek! You've done it again, you devious bastards!"
Chris has a post, Women in Math, Science, and Engineering: Is It About the Numbers (And Not the Ones You Might Think)?, which addresses issues relating to women in science. Like the debate about IQ I'm not too interested in this...basically one's priors strongly effect their perception of the weight of the evidence and I don't see much value add in getting into arguments. That being said, a few quick points which I discussed with Chris:
1) During the Larry Summers affair I noted that though the proportion of women in mathematical fields differs cross-culturally, the rank order of fields is basically the same in terms of male & female ratio. In other words, the relative underrepresentation of women in mathematical fields seems culturally universal (e.g., in Mongolia where males are discouraged from pursuing higher education only in the mathematical sciences is there a sex ratio parity). 2) In female dominated fields males tend to increase in frequency as one ascends the ladder of achievement and prestige. Some of this might be due to age (e.g., established professors are from a time when women were extremely underrepresented in academia); but Chris points out that even across the undergrad to grad student chasm within his own field, cognitive psychology, it still plays out. 3) Speaking of which, the principle seems to operate on a very fine grained level. Within psychology it is cognitive psychology and psychometrics where women are least dominant. These are also fields where knowing some linear algebra is handy. Within the social sciences women are relatively thin on the ground in economics, which is the most formalized and mathematical discipline. 4) From a biological perspective it seems to me that some of this is likely going to be due to gene/gene expression/environment correlation. That is, small initial differences in biologically rooted propensities can lead to a "virtuous feedback" cycle. 5) Peer groups matter. To be succinct about it, I think female peer groups are nerd-killers. 6) The last two points are important. I think most reasonable people will agree these sorts of outcomes which manifest in young adulthood have many upstream variables (even if some are of relatively larger effect). This is why prior values matter so much in how plausible you find alternative explanations. That being said, I do think that the complexity of the issue here poses a problem for social engineers: a one-size-fits-all solution often presupposes one clean predictor of the difference (e.g., in this case a form of stereotype threat), which I don't think is really tenable. These solutions are unlikely to shock the social dynamic to a new equilibrium, so to maintain outcome you'll have to continue applying the "solution." The other alternative is to engage in radical social engineering and flip a host of parameters. I am skeptical that most people have the stomach for that, so what you're going to continue to see are "solutions" which will never address the underlying causes but apply a band-aid upon the "problem." 7) In the most general and big picture sense James F. Crow's observation that when you extract a set of individuals highly deviated from means across a wide range of traits the likelihood that intergroup differences will emerge are going to be very high. In other words, to be a world class sprinter or mathematician requires a joint set of traits where the mean for the candidate population is highly deviated from the central tendency. Even if the distribution of said traits differs only minimally across groups it is extremely likely that different groups will yield very different numbers of individuals who match the appropriate criteria. Finally, if you are going to comment on Chris' blog, be civil. He's had my back before, so I am not intending to send hecklers his way. Labels: Psychology
A comparison of resting-state brain activity in humans and chimpanzees:
In humans, the wakeful resting condition is characterized by a default mode of brain function involving high levels of activity within a functionally connected network of brain regions...We find that, like humans, chimpanzees show high levels of activity within default mode areas, including medial prefrontal and medial parietal cortex. Chimpanzees differ from our human sample in showing higher levels of activity in ventromedial prefrontal cortex and lower levels of activity in left-sided cortical areas involved in language and conceptual processing in humans. Our results raise the possibility that the resting state of chimpanzees involves emotionally laden episodic memory retrieval and some level of mental self-projection, albeit in the absence of language and conceptual processing. Any cognitive neuroscience people want to chip in? Addendum: Readers might be interested in this post by Chris Chatham on primate evolution & handedness & neuroscience. Labels: Neuroscience
Over at The Guardian. I don't need to summarize it, if you know Watson you know what you're in for....
Labels: Watson
Monday, October 15, 2007
Friday, October 12, 2007
The London Times on 10 October had an interesting profile/interview with the philosopher John Harris, whose latest book Enhancing Evolution was published recently. As the title suggests, Harris advocates a form of eugenics, among other controversial ideas. I haven't read the book yet, but it is definitely on my list.
![]() ![]() I'm intrigued by #27 on Bougainville, the Aita. From the text: An interesting hair phenotype that is sometimes seen in Island Melanesia (as well as among Australian Aborigines) is "blondism," in which individuals exhibit the characteristic darkly pigmented skin of the region while also having blond hair. This trait was most commonly observed in children whose hair generally darkened around puberty (Robins, 1991). However, in some cases, blondism persists into adulthood, although the hair appears somewhat darker than what is seen in children. The strikingly light hair of the Aita...is partially due to the high incidence of blondism among this group. So who are the Aita? They're an isolated "Papuan" group. In the context of Melanesia the appellation Papuan is simply a catchall for the host of ancient peoples who were extant in the region before the expansion of Austronesians within the last 5,000 years. Could the blondism be due to European admixture? From the text: The Aita live in an isolated mountainous region of northern Bougainville, and although the Ane'm had recently moved down to the coast they were originally an inland rather than shore-based group. It may be that the resistance of coastal groups to intermarriage with supposedly "darker" populations such as the Aita or Ane'm is really reflective of resistance to intermarriage with inland populations that are generally considered less sophisticated. Whatever the reason, this resistance may help strengthen the genetic differences observed between coastal and inland groups. The median skin color on Bougainville is amongst the darkest in the world, and the Aita are reputed to be among the darker residents of Bougainville. Additionally there is no report of blue eyes amongst these Melanesian peoples, which in Europeans is more common than blonde hair. Two papers, Melanesian mtDNA Complexity and Unexpected NRY Chromosome Variation in Northern Island Melanesia, shed some light on the genetic relationship of the Aita to the other groups in the region. They are it seems an ancient and rather isolated people who are geneticallyhomogeneous in a region characterized by a great deal of between group genetic variation. I am willing to hazard that presence of blondism in Melanesia is a function of the diversity of the region and its relative insulation from demographic sweeps which characterized much of the rest of the world. The Austronesians brought a more advanced culture and acculturated the coastal groups, but the ecology of Melanesia allowed the indigenous peoples, those termed Papuans, to maintain their existence inland. The high frequencies of an anomolous trait such as blondism among the Aita may simply be due to genetic drift through a population bottleneck. But a more curious question is the genetic architecture of blondism among these groups. The peoples of Bougainville are known to be functionally constrained in regards the genes which are implicated in controlling skin color variation. From Signatures of positive selection in genes associated with human skin pigmentation as revealed from analyses of single nucleotide polymorphisms: Our results showed that African populations tended to carry the ancestral alleles of the studied SNPs...and that human populations with dark skin colour tended to cluster together in the MDS and STRUCTURE analyses. The clustering of the Bougainville Islander population reflects the fact that this relationship is not (or at least not solely) caused by geography but also by the underlying pigmentation genes. Bougainville Islanders from Papua New Guinea are known to be one of the most highly pigmented people in the world...In our results they appeared to be closer to Sub-Saharan Africans populations - with whom they share the dark skin colour phenotype - than to the second Papuan New Guinea sample in the dataset, with whom they share their recent population history, as observed in several datasets based on neutral genetic variation from autosomal, Y-chromosomal and mtDNA analyses.... So how are they blonde? The genes which seem to control variation in human skin color seem to have some effect on hair color. Blondism in Europeans is simply due to low levels of eumelanin (brown) and pheomelanin (reddish), and the darkening of skin naturally has a tendency to upregulate the production of melanin globally so as to darken hair. How can the peoples of Bougainville retain dark skin while selectively downregulating the production to their hair? Well, we know that the region around OCA2 is implicated in a quasi-Mendelian disproportionate reduction in the pigment level in the iris. One assumes that something similar is theoretically feasible for hair.... Labels: human biodiversity, Pigmentation
Thursday, October 11, 2007
TopTen the Hottest Smart Girls In Hollywood (NSFW if you page down). Any thoughts? These are supposed to be intelligent women, so I note that there is a 20% representation of Ashkenazi Jews (1 full, 2 half). Three women on the list are black-white biracial, while one is 1/8 Burmese.
Related: Most intelligent actresses. Labels: Ladies
I'm wondering if anyone has the following problem with their computer: sometimes, without warning, my caps lock function flips. Basically if I have it on it goes lower case while if I have it off it goes upper case. Additionally, the period key (".") is always stuck as ">", and switching case doesn't help. Links on my browsers always open new windows, and using space to scroll down a page doesn't work. Finally, I can't just shut down and restart, I have to switch user in XP and then restart. Does this sound familiar to anyone? It happens at least half a dozen times during the day and it's starting to drive me crazy to the point that I might get a new laptop (I have a Compaq Presario that I run Windows XP on).
Why Middle Eastern cults matter, East Asian ones, not so much....
posted by
Razib @ 10/11/2007 12:01:00 PM
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Steve Sailer has an amusing post related to the one below about Middle Eastern religious diversity. It really isn't that easy to keep track of. I've emphasized quasi-Muslim groups, but what about the faction within Eastern Christianity? For example, start here and see if you can follow the links and make sense of it all. I also noted that most Muslims probably don't know about the large number of heterodox believers in Turkey to emphasize that even hypothetical "cultural insiders" really aren't, or at least they aren't knowledgeable to the level of granularity which is necessary for an accurate model. Why does this matter in the first place? First, locally it affects lives. Consider the Yezidi woman stoned for falling in love with a Sunni boy. The choices of hundreds of millions are scaffolded tightly by Bronze Age early Iron Age belief systems. Second, globally it is critical in generating a model of local power structures & relations. Look up Syria in CIA Factbook and you note that it is 3/4 Sunni. Syria then is a Sunni country? Well yes, except for the fact that the ruling clique is predominantly Alawite, a religious faction which is aligned with the Ithna Ashari Shia, who are dominant in Iran. Syria is often aligned with Shia groups in Lebanon and has had an alliance with Iran of long standing (during Iran-Iraq war Arab Baathist Syria was aligned against Arab Baathist Iraq and with Iran). But it isn't like the Middle East is the only region in the world with religious diversity, consider South Korea, which is about 1/4 Christian, 1/4 Buddhist and 1/2 non-affiliated (and many minor religions as well). Despite this diversity this is generally only of academic interest (though involvement of Korean Christians in missionary activities does have some geopolitical import). Why is the Middle East different?
I think it is fair to observe that religion is a central part of one's life in the Middle East in a manner that it is not in East Asia, but that is a trivial observation. Why does it matter so much? To understand that I think you need to go back late antiquity and the early medieval period. With the conversion of the Eastern Roman Empire to Christianity and the resurgence of Zoroastrianism in Sassanid Persia you started to see the fusion of a particular exclusive institutional religion with imperialism. Within the Sassanid state the situation of non-Zoroastrians varied dependent upon their relations with Rome. The progenitors of what became termed the Nestorian Church were Christian, but anti-Roman for theological reasons. It was tolerated, even encouraged among non-Iranian peoples. In contrast those Christian groups who had closer relations with Roman movements across the border were perceived as fifth columnists. Within the Roman Empire, what became Byzantium, theological faction was a major excuse for social and political convulsions and machinations (the famous Green and Blue factions behind the Nika Riots in Constantinople even favored different theological positions!). As the 5th and 6th centuries proceeded pagans were expelled from public life and forcibly converted. The long history of the persecution of Jews also began in earnest. In Persia the Shahs attempted to induce Armenian nobles to give up their Christianity and accept Zoroastrianism so that they could be totally assimilated into the warrior caste of the Sassanids. The rise of Islam extended this concept further, as non-Muslims were given formalized but secondary positions within society. Over the centuries Muslims took over all major secular roles (remember that St. John of Damascus held a leading position at the Umayyad court, as did his father, so it was not always so) and the non-Arab groups relegated their old languages (e.g., Aramaic, Coptic, Greek) to their liturgy. This meant that the main distinction within society was religious, and religious leaders became the representatives of their communities (though this might have been prefigured a bit during the Byzantine and Sassanid periods) in relation to the dominant Muslim ruling caste. During the Ottoman period Middle Eastern & Balkan society was organized into Millets, and the substitution of ethnic for religious identity continued (ethnic identity as such is a tricky concept and in many ways is rather modern for most peoples in any case). Though European style nationalism emerged in the form of pan-Turkism and pan-Arabism in the 19th and 20th century, these movements have not eliminated the tendency to default back to a religious identity, a phenomenon which has deep cultural roots because of the aforementioned histoy. East Asia is a study in contrast. Though religious movements and sentiments are often powerful, consider the Yellow Turbans or the Taipings, society has never been organized on confessional lines and religious institutions have repeatedly been subordinated and marginalized in relation to the state. Buddhism is a common religious bond across East Asia, but for most of history it has not had the relationship with the ruling clique that Christianity or Islam cultivated in Western Eurasia. When the Buddhist establishment became too powerful after a few centuries of ascendancy the Chinese state defrocked hundreds of thousands of monks and repossessed their lands. In Korea the Choson dynasty expelled the Buddhist religion from the centers of power and forced the monasteries to the mountains. In Japan religion was sharply controlled and an instrument of central power. The Tokugawa forced every family in Japan to register with a Buddhist temple not because of their piety, but to root out Christianity, which they perceived as a foreign religion and a tool of Western imperialism (Tokugawa Ieyasu's predecessors, Oda Nobunaga and Toyotomi Hideyoshi forged some ties with Christianity in part to marginalize the power of the Buddhist establishment). The Jesuit switch from dressing like Buddhist monks to Confucian Mandarins in China was a calculated maneuver once they realized that the elite held clerics in contempt. All this is not to imply that East Asia was a hot-bed of anti-clericalism which anticipated 19th century European nationalism. Buddhism was a major vector for the spread of Chinese civilization in early Japan, and Confucianism was patronized in both Choson Korea and to a lesser extent Tokugawa Japan. In China many Emperors were personal believers in Buddhism and Daoism and a variety of other religions. The key is that the relationship of religion to individuals and the community was (and is) often open, fluid and contextual. One might be a devotee to a form of Mahayana Buddhism on the one hand, but curtail the power of the clerisy in the interests of national strength. The founder of the Ming dynasty was educated at a Buddhist monastery but later championed Confucianism in the interests of securing the approval of the bureaucracy in his rebellion against the Mongols. The state might offer funds to various religions which provided services to the populace, both spiritual and material, as well as serving as glues for civil society, without elevating one to prominence. Such an opportunistic and non-dogmatic attitude persists today in East Asia. Shinto priests conduct ceremonies of life and the Buddhists those of death in Japan. In Korea a substantial number of Christians were once Buddhists and Buddhists were once Christians, and a subset of individuals promiscuously attend services in different religions concurrently. Small "New Religious Movements" always bubble in the cultural background. In China the trinity of Confucianism, Daoism and Buddhism had attained nearly official status as three coequal customary religious dispensations, along with local cults beneath them as well as the impersonal worship of Heaven above them. Christians have had leading positions in the 20th century across East Asia without resulting in total conversion of the society. Sun Ya-sen, Chiang Kai-shek and Lee Teng-hui were Christians (though the sincerity of the Christianity of the second has long been questioned, while the last also experimented with Buddhism seriously). The past two presidents of South Korea have come from the small but influential Catholic minority (while some of the previous presidents and dictators have been Protestant and Buddhist). Some of you might wonder how this dovetails with the known persecution of Christians in China. I think that one must be careful about exaggerating the extent of the persecution (there are no Christians being thrown to the tigers!), and, one can look to the past to comprehend the root of the hostility. In the 9th century concomitant with the persecution of Buddhism foreign religions such as Zoroastrianism, Manichaeanism, Christianity and Islam were suppressed. Buddhism itself was criticized by Confucian Mandarins as inimical to Chinese culture, a foreign import which undermined filial piety. In Japan Catholic Christianity's relationships with foreign powers was an important consideration the turn of the state against it. In South Korea Christianity was looked upon positively in the 20th century first because adherents of that religion resisted the Japanese colonialists, and second, it was the faith of the American protectors of their state. So long as religion or faith is not perceived as disrupting the order and harmony of the society it may find tolerance, but once it is perceived as destabilizing to social order it is often proscribed (see the Chinese rites controversy). In the Middle East religion is society, in East Asia it is a part of society. The Japanese state encouraged the Diaspora community to convert to the local religion of their new homelands, and that has generally been the tendency of East Asians abroad (the main exception here is in Muslim countries where food taboos tend to impose a break, but, a substantial number of Chinese in Southeast Asia seem to have converted nevertheless but simply lost their ethnicity and become Malayized, so to speak). This attitude is likely relatively familiar and comprehensible to many Westerners, for whom religion has become both private and a function of personal choice. Substantial numbers of Americans do not wear their faith on their sleeves and will change affiliations for relatively trivial reasons (e.g., Howard Dean become a Congregationalist because the Episcopal Church opposed a bike path in Burlington and is raising his children as Jews). On the other hand some Westerners have a different attitude, and their religion is an essential part of their identity, and changing their religion is a major event in their life (I do not want to minimize the religious identity of East Asian Protestant converts, nevertheless they are not as numerous within their society). One can point to many groups of evangelical Christians as manifesting some of these tendencies, but also consider Jews, who conceive of themselves as a faith and a nation. The hostility that some liberal Jews exhibit toward attempts by evangelicals to convert them, leading toward the accusations of cultural genocide, show that the mentality that one is born into a religion and that changing one's identity is an event of grave consequence is not alien to the Western mindset (e.g., "cultural Catholicism" and so on). In the Middle East one remains what one is born, Edward Said remained identified as an Arab Christian by others to his dying day despite his avowed atheism. One of the founders of pan-Arabism was Michel Aflaq, a Christian, was claimed to have converted to Islam upon his death by the ostensibly secular government of Iraq. Why? Religion mattered in Arab nationalism so much that one of its leading lights could not remain a Christian, he had to be fully assimilated into the Islamic identity. Said himself asserted that though he was not a Muslim by birth or profession his civilization was Islam. Would it make sense to say that Japanese civilization is Buddhist? Certainly Buddhism has had a major impact upon Japanese civilization, but Buddhism is not Japanese civilization. Some Arabs might make the argument that Islam is Arab civilization! (this is obviously less true of Persians) Middle Eastern society is carved up at the joints of religion. Centuries of persecution by Muslims has resulted in the non-orthodox engaging in habitual dissimulation and obfuscation. Religion is both highly salient and obscured. Consider crytpo-Jews in Spain, their Jewishness was secret and important at the same time. The most important variable in Middle Eastern life is one fraught with deception and double-speak, the skeleton of the society is garbed in superficiality. Fundamentalist Protestants have attacked Buddhist temples in South Korea and there are often complaints from Buddhists that their Christian acquaintances and superiors attempt to coerce them into converting, but the magnitude of the social distance and tension seems to be far less than in the Middle East. Individuals and families span the religious divides and theoretically choice is the primary factor in determining one's religion. The centrality of Islam in Middle Eastern culture is such that a non-Muslim head of state is not conceivable (this served as a check upon Boutros Boutros-Ghali's ambition in Egyptian politics). In contrast, East Asian societies have repeatedly been lead by people from a minority religious tradition. In Thailand Therevada Buddhism is the official religion (though in a much looser sense than say Shia Islam in Iran), but the general who leads the military junta is a Muslim. The Middle Eastern fixation on a head of state who is of the dominant religion is not unique, Carlos Menem of Argentina converted from Islam to Catholicism because the Argentine constitution of the time required that for the head of state. The pillarization of Middle Eastern society means that one must understand the pillars and their relationships to each other to model the culture properly. Religion is not a private matter, but a public parameter which operates in shaping the dynamics which characterize the sociey. The choices available in one's life, the opinions and alliances one makes, are strongly contingent upon one's notional confession. Obviously other segments of the hierarchy matter, clan and tribe and such, but for the smaller groups the tribe is coterminous with the confession. In any culture the psychological complexities and interests which a set of religious beliefs accrue to an individual are important in understanding their actions, but in the Middle East the principle ascends up the ladder of complexity that so that sociological complexities and interests accrue for religious identities of groups. So why does belief in obscure and esoteric religious systems matter so much in the Middle East? First, because it matters to individuals in how they relate to the world around them. Second, these beliefs demarcate the boundaries of important organs within the body politic which are critical in and of themselves as units of action within the society. Addendum: Any discussion of religion is under-girded by assumptions. For example, how important is belief & practice in determining behavior as opposed to material considerations? I don't think it is a black & white issue, people vary and circumstances vary, though I think over the long term material considerations tend to loom larger than esoterica of belief or constrains of ritual. Nevertheless, belief & ritual are critical in demarcating boundaries between groups, and no matter their putative substantive rationale the chasms between groups are relevant to our lives. The general thrust of my argument above is that in establishing ingroup vs. outgroup boundaries religion is a much better guide in the Middle East than in East Asia, or even the United States. Such generalizations are subject to variance of course, but I think the ratio of within to between group variance is much lower in the Middle East in terms of affiliation and identity when it comes to the trait of religion. Labels: Religion
Wednesday, October 10, 2007
Long time readers know I am interested in the existence in the Middle East of obscure, esoteric and cryptic religious groups. The knowledge of these groups is sketchy and often only surfaces due to geopolitical considerations or current events. Otherwise, why would some Americans know of the Yazidi Kurds of Iraq? These obscure groups can sometimes be quite numerous, the quasi-Shia Alevis of Turkey form about 20% of that nation's population (something most Muslims who do not live in Turkey are totally unaware of from what I can tell). I use terms like "quasi-Shia" because many of these groups are secretive about their beliefs and consultation of 10 different sources will produce 10 different answers as to their theologies, customs and provenance. The secrecy seems to have a natural origin: persecution. Islam in the Middle East is a religion which has often proscribed heterodox cults. Toleration toward religious minorities was fixed rather early on to putative "Peoples of the Book," other groups were officially not tolerated. This resulted common "work arounds." For example, the pagans of Haran were tolerated as Sabians, a group referred to in early Islamic literature (I say pagans because the people of Haran seemed to believe in a religion which originally emerged from late classical paganism as opposed to one of the "world religions"). Another common way to finesse the issue of toleration has been the slotting in of various assorted groups into the catchall category of Shia. The Alawites of Syria for example have followed this path. Most Sunni Muslims accept that Shia are Muslim, even if substandard ones, so it is a good way to ensure safety. But even "Shia" groups like the Alawites and Alevis keep a low profile, culturally conditioned from centuries pf persecution at the hands of the Ottoman Sunni orthodoxy.
Today I "stumbled" upon another weird sect, this one very numerous in a nation of interest called Iran. The group goes by various names, Yarsan/Yaresan, Kakeyi, Ahl-e Haqq or Ahl-i Haqq. The Nizari Ismaili community published a description of the group in the 1940s, in part because people were confusing them with the Nizaris. I'm not going to summarize their beliefs except to say that it has some core overlaps with Shia ideas, but "extends" them rather far and introduces ideas like reincarnation which don't seem conventional in Islam. Looking on google books & scholar I can say this: 1) adherents are disproportionately Kurdish, but it is multi-ethnic and accepts converts 2) it is grudgingly accepted as Shia within Iran but this seems to be a pragmatic consideration because 3) estimates of its numbers range from tens of thousands to 5 million, but somewhere around the magnitude of 1 million seems about right. Most of these within Iran, so the group is probably a few percent of the nation's population. Labels: Religion
Natural Variation in a Testosterone-Mediated Trade-Off between Mating Effort and Parental Effort:
Male birds frequently face a trade-off between acquiring mates and caring for offspring. Hormone manipulation studies indicate that testosterone often mediates this trade-off, increasing mating effort while decreasing parental effort. Little is known, however, about individual covariation between testosterone and relevant behavior on which selection might act. Using wild, male dark-eyed juncos,,,we measured individual variation in testosterone levels before and after standardized injections of gonadotropin-releasing hormone (GnRH)...We correlated these testosterone increases with behavioral measures of mating and parental effort...Males that showed higher postchallenge testosterone displayed more territorial behavior, and males that produced higher testosterone increases above initial levels displayed reduced parental behavior. Initial testosterone levels were positively but nonsignificantly correlated with aggression but did not predict parental behavior. These relationships suggest that natural variation in testosterone, specifically the production of short-term increases, may underlie individual variation in the mating effort/parental effort trade-off. We discuss the implications of these results for the evolution of hormonally mediated trade-offs. The results of this paper are not surprising, though not as clear as one would hope for. That being said, man is not a bird. So this paper, Testosterone and Marriage among Ariaal Men of Northern Kenya is of more interest: Recent studies suggest that differential human male investment in mating (male-male competition and mate-seeking behavior) and parenting effort may be associated with variation in testosterone levels. The Ariaal present an interesting test case because marital relations tend to be aloof and direct paternal care minimal by cross-cultural standards. Polygyny is prevalent and increases with age, and the age-set system highly structures the transition to marriage. A test of the effect of marital status on testosterone levels among the Ariaal involved 205 men aged 20 and older from a settled agropastoral community and nomadic populations. Each participant provided morning and afternoon saliva samples in which testosterone levels were measured, provided demographic background during interviews, and had anthropometrics taken. As predicted, during the dynamic ages (20–39) of transition from life as a bachelor and warrior to monogamous marriage, men with one wife had significantly lower testosterone levels than unmarried men. Contrary to prediction, however, polygynously married men did not have higher testosterone levels than their monogamously married counterparts. While variation in testosterone may be associated with mating effort in young Ariaal men, political networks and wealth may be better predictors of marital status in older men. ScienceDaily has more detail on this study. Man is obviously not a bird, but all men are not the Ariaal of Kenya, so one has to be cautious about the generalizing from one case study. That being said, the peculiarity of the results here point to the problem that human societies are so complicated in terms of countervailing parameters that epiphenomenally they can throw biosocial expectations for a loop. Virpi Lummaa's finding that the presence of grandfather's may reduce a child's fitness for example is a curious result which may simply be a sociological epiphenomenon which may take biology a while to catch up to...by which point social systems may have changed radically so as to make the issue moot. In the big-picture philosophical context the flexibility of social systems which characterizes our species, and is likely one of our adaptive traits, may be seen as a net wash. But in terms of proximate examination and understanding of human societies it obviously matters quite a bit. In the press there are often stories about men with powerful jaws being more attractive. Later there are follow ups which suggest that softer faced men are preferred except when women are fertile. From these data researchers often draw very general conclusions, but the polymoprhic tendency of human behavior and physique might suggest to us that the temporally protean nature of our societies and the wide scope for a host of stable niches across their enormous spatial spans may mean that these general explanations are ultimately irrelevant. Human variation could very well be a function of the constant balancing effects of changing social circumstances to which biological evolution can never be optimized. It isn't that our species is post-evolutionary, rather, the gene-culture co-evolutionary arms race is a more much complex and turbid dynamic than current models can conceptualize with clarity. Addendum: Some dynamics are simple enough; it seems clear that genes did catch up with cattle culture across most of Eurasia. Labels: Evolutionary Psychology
Tuesday, October 09, 2007
Ecological consequences of early Late Pleistocene megadroughts in tropical Africa:
Extremely arid conditions in tropical Africa occurred in several discrete episodes between 135 and 90 ka...Fossil and sedimentological data show that Lake Malawi itself, currently 706 m deep, was reduced to an ~125 m deep saline, alkaline, well mixed lake. This episode of aridity was far more extreme than any experienced in the Afrotropics during the Last Glacial Maximum (~35-15 ka). Aridity diminished after 95 ka, lake levels rose erratically, and salinity/alkalinity declined, reaching near-modern conditions after 60 ka. This record of lake levels and changing limnological conditions provides a framework for interpreting the evolution of the Lake Malawi fish and invertebrate species flocks. Moreover, this record, coupled with other regional records of early Late Pleistocene aridity, places new constraints on models of Afrotropical biogeographic refugia and early modern human population expansion into and out of tropical Africa. Labels: Evolution
[Added 10 October: The comments facility on this post has been temporarily suspended due to obscene or offensive comments. Anyone with serious comments can email them to DavidBGNXPtemp@hotmail.co.uk , and I will try to reply to and/or post the comments in due course.]
[Added 14 October: No-one has taken me up on this offer, but my attention has been drawn to a comment elsewhere. See the Note at the end of the post, below the fold.] In 2005 I commented on Frank Salter's theory of Ethnic Genetic Interests, as set out in his book On Genetic Interests: Family, Ethny and Humanity in an Age of Mass Migration (Frankfurt, Peter Lang, 2003). My post on 'Ethnic Genetic Interests: Part 1' (EPG1) summarised the theory, and stated some basic objections to it. 'Ethnic Genetic Interests: Part 2' (EPG2) covered more technical issues. A post on 'Interracial Marriage: Salter's Fallacy' (IMSF) dealt with a specific topic. Razib has informed me that Salter's book is available in a new edition (2006) from Transaction Publishers. The main text does not appear to have revised, but the word 'ethny' in the title has been changed to 'ethnicity'. The new edition also has a short Introduction commenting on reactions to the original edition. These include my own posts. For the small number of people who may be interested in such matters, I have transcribed the relevant passage from the Introduction below the fold, and added a few counter-comments of my own. In general, I think my posts can still speak for themselves, and I see no reason to make any fundamental change. I will however take the opportunity (below the fold) to correct an oversimplification. I should also say that although I disagree with Salter's conclusions, I recognise the ingenuity and thoroughness with which he has pursued his ideas. I also take the opportunity now to emphasise something I should have done previously: that differences in gene frequencies between human populations are in general fluid and transitory. Since Salter's aim is to preserve existing differences, this is fatal to his doctrines. Let us consider how such differences arise. First, they may be due to natural selection still in progress. If an allele is generally advantageous, it will sweep through the world population in a relatively short time. But the process does take some time (of the order of a few hundred generations), depending on the strength of the selective advantage, rates of migration and intermarriage, and so on. Some of the differences between populations are therefore likely to be due to the different stages that selection has reached in different places. Differences of this kind are essentially transitory, and will be eliminated by ongoing selection. The process is unstoppable, unless selective conditions change. All that is needed is a very small amount of gene transfer (introgression) between different populations, and selection will do the rest. Second, differences in gene frequencies may be due to genetic drift or founder effects in populations isolated from each other. In large populations (e.g. continental races) genetic drift is ineffective unless the alleles concerned are selectively neutral, and very slow even when they are. It is generally assumed (by Salter among others) that many of the genetic differences between human geographical races are of this kind, having arisen when populations were much smaller and more isolated than they are now. If so, then even moderate amounts of migration and intermarriage will narrow and eventually eliminate the existing differences. No feasible amount of 'Salterism' can halt the process, though it may slow it down. Finally, differences may be due to variation in selective conditions, such as climate, diet, and exposure to infectious diseases. Genetic differences in skin colour, metabolism, blood groups, and the immune system are probably of this kind. Such differences are often clinal and cut across conventional racial groupings, though in some cases (e.g. resistance to malaria) different genes may be responsible in different areas. It is a matter for legitimate concern that increased migration and intermarriage may weaken the adaptedness of populations to their distinctive selective regimes. However, compared to the huge changes that are taking place in selective regimes for other reasons, this seems a very minor concern. Moreover, since differences in selective conditions cut across racial or ethnic boundaries, the resulting differences in gene frequencies are only weakly correlated with Salter's coefficients of 'ethnic kinship'. I conclude that even if Salter's doctrine of ethnic genetic interests were sound in principle (which it isn't), in practice it would be either unnecessary or futile. A correction In EPG1 I commented that: Salter's doctrine is profoundly anti-eugenic. For Salter, it is in the interest of an individual to preserve and promote the gene frequencies of his own ethnic group, whether the existing gene frequency is good, bad or indifferent, as judged by qualitative criteria. So, for example, it is in the interest of American blacks to promote their own gene frequencies against those of American whites, even if in some respects it would be better for blacks themselves to change those gene frequencies. The doctrine of genetic interests is inherently backward-looking and conservative. In EPG2 I said: For Salter, it is by definition adaptive for an individual to maximise the number of copies of his own genetic material, regardless of its selective value. So, for example, it is adaptive for an individual with Huntingdon's [sic: should be 'Huntington's'] Disease to maximise the number of other Huntingdon's sufferers. and: Salter's theory implies, for example, that African populations who have migrated to temperate countries should seek to preserve their 'distinctive' African genes - even those, like the genes responsible for sickle-cell anemia, which are actively harmful in their new environment. In defence of Salter it has been pointed out (though not by Salter himself) that in a few passages he does explicitly allow for the promotion of 'eugenic' genetic change, for example (p.89 of both editions): Phenotypes can lose inclusive fitness through individual alleles in their genomes becoming maladaptive, due to mutation or to changes in the environment. Those dysfunctional alleles no longer serve the interests of the majority of the genes comprising the genome and thus the individual's genetic interests would be preserved or increased by substitution of maladaptive alleles.[i.e. their replacement by more adaptive alleles]. There are a few other such concessions. My posts therefore oversimplified Salter's doctrine, and I apologise for the oversight. In mitigation, I would plead that the relevant passages do not occur until nearly 100 pages into the book, they are not given much emphasis, and they are hedged around with qualifications. This is perhaps not surprising. They go against the general tendency of Salter's doctrine, and are difficult to reconcile with his emphasis on the overriding importance of genetic continuity as such. If we accept - as Salter does accept in these few passages - that the maladaptiveness of genes can override the 'ultimate' interest of genetic continuity, where does it end? Pursued to a logical conclusion, the implication of Salter's concessions is that the ultimate test of whether the frequency of a gene should be increased or decreased is its effect on fitness, not its current frequency within the 'ethny'. We would therefore be left with the absurd result that the only genes to which Salter's original doctrine of genetic interests applies are those that are selectively neutral! I now transcribe the passage from Salter's new Introduction which responds to my original posts: From the Introduction to the 2006 edition I [Salter] now turn to two technical points. One commentator has identified a terminological error that needs to be corrected (David B. 2005c [EPG2], point 1). Throughout On Genetic Interests I define an individual's genetic interests as consisting in his or her distinctive genes, some of which are found in kin and fellow ethnics. Such genes exist, but kinship generally consists of shared frequencies of genes, even when the genes concerned are not unique to any one individual. 'Distinctive genes' should be read as 'distinctive gene frequencies' or 'distinctive allele frequencies'. The same commentator thinks that making such a change weakens the emotive force of genetic interests (evidence that even some critics are impressed by it). 'Why anyone should consider this a "vital", "fundamental", or "ultimate" interest is beyond me. Why so much fuss about shifting a gene frequency from, say, 50 percent to 60 percent?' But kinship found within ethnies is homologous with that found within families. Are we to believe that parents do not have a vital, fundamental, or ultimate interest in their children? The point is that Hamilton's theory of inclusive fitness still applies whether genetic interests consist of unique genes or gene frequencies. If any branch of genetics is likely to have emotive force it is surely that which explains the evolutionary and social significance of kinship, whether in family or tribe. The same author [David B.] makes many other criticisms, including some thoughtful philosophical comments, but none are as decisive as that concerning distinctive genes. An example is his criticism of the argument I make in Chapter 8 (section 8.1) that exogamy, marrying outside the ethny, can reduce fitness (David B., 2005a [IMSF]. This is an interesting argument, but one made previously by Grafen, which I discuss on pp.262-5. Comments on Salter's Comments "The same commentator thinks that making such a change weakens the emotive force of genetic interests (evidence that even some critics are impressed by it)." In the cited post I didn't refer to 'the emotive force of genetic interests', so the 'evidence' is purely in Salter's imagination. My objection was to the absurdity of Salter's own emotive rhetoric, when we consider what the pursuit of his 'genetic interests' really involves, namely a minor tweaking of population frequencies for alleles which often have no adaptive significance in any case. "kinship found within ethnies is homologous with that found within families." I'm not sure what exactly Salter means by 'homologous', but in fact there are many important differences between the 'kinship' of randomly selected co-ethnics and the ordinary kinship of close relatives. I pointed out some of the differences here. I should however correct or clarify Note 2 to that post. I would now stress that 'relatedness' must always be measured relative to the gene frequencies of a specified population. (This is clearer in Sewall Wright's original correlational concept of relatedness than in the more recent and widely used concept of 'identity by descent'.) The average relatedness between randomly selected members of a population, relative to the gene frequencies of that population, is always zero (apart from sampling error). We therefore should not expect altruistic behaviour to evolve between random members of a population, so far as interactions within that population are concerned. "Are we to believe that parents do not have a vital, fundamental, or ultimate interest in their children?" It depends what is meant by 'interest'. Salter's own concept of 'genetic interest' seems to me to be mystical twaddle, so I do not believe that parents have an interest in their children in Salter's sense. Of course, it is undeniable that human individuals do literally care for their offspring. Humans have been selected for an unusual degree of parental care. If they do not have children of their own, they may by default care for their nieces or nephews, or even adopt unrelated children or pets. What I deny is that this specific evolved tendency for parental care derives from, or can be extended to, some general concern for 'genetic interests'. There is nothing to suggest that people usually have any concern for the genetic prospects of their more remote relatives, let alone of random 'coethnics'. "Hamilton's theory of inclusive fitness still applies whether genetic interests consist of unique genes or gene frequencies." Salter's frequent references to Hamilton seem to me to be little more than name-dropping. There is no real connection between Hamilton's theory and that of Salter. Hamilton's theory of inclusive fitness applies to the effects of particular genes (alleles). If an allele increases the inclusive fitness of its bearers, then we expect it to increase in frequency in the population until it is fixed. It does not (metaphorically) say to itself, 'Hey, we're up to 60 percent, we can stop now.' In Hamilton's theory an allele has no 'interest' of any kind in maintaining the existing frequency of that allele in the population (unless it is already fixed). Moreover, many of the alleles which differ in frequency between populations are selectively neutral, in which case they do not affect inclusive fitness, and are not covered by Hamilton's theory. Under Salter's theory, in contrast, individuals are exhorted to defend the existing allele frequencies of their own ethnic group, regardless of the selective value of those alleles (apart from the occasional concessions mentioned earlier). "This is an interesting argument, but one made previously by Grafen." No, it wasn't. I would be delighted to find myself in agreement with Alan Grafen, who is one of the most brilliant evolutionary theorists currently working, but on consulting the cited work of Grafen I do not find my own argument. The purpose of Grafen's paper [Grafen 1990] is to consider whether organisms have evolved mechanisms for recognizing kin. As a part of this project, he considers the claim (known as Genetic Similarity Theory) that individuals can detect the degree of general genetic similarity of other individuals to themselves. He further considers whether assortative mating is due to such detection of similarity, and whether mating with relatives would be advantageous from the point of view of inclusive fitness. On this last point, he discusses some pros and cons, and sagely concludes: 'Assortative mating in humans therefore seems unlikely to be explained by genetic similarity theory because it probably does not succeed in creating substantial relatedness between mates, it would be an unnecessarily costly way of mating with a relative, and it is dubious whether it is advantageous to mate with a relative anyway'. In reaching this conclusion he appears to accept that mating with relatives would, other things being equal, bring an increase in inclusive fitness, but thinks that this needs to be balanced against other considerations, such as inbreeding depression. In contrast, my own position is that mating with relatives (in this case, co-ethnics) in itself brings no increase in an individual's inclusive fitness at all, and that it is a fallacy to suppose otherwise. The key point to grasp is that, on neutral assumptions, each inbred mating replaces two outbred matings (one for each partner). I claim no great originality for this point, because (as I mentioned in my post) it is essentially the same as Dawkins's '10th Misunderstanding of Kin Selection', which I discussed here, with a correction here, which is the idea that 'Individuals should tend to inbreed, simply because this brings extra close relatives into the world'. Perhaps Grafen himself has fallen into this fallacy, but it would be more charitable to suppose that his discussion of the issue was simplified for the sake of brevity, as it was peripheral to his main concerns. As Dawkins recognises, there could be special cases in which inbreeding does increase inclusive fitness. In his discussion of interracial marriage, Salter puts some emphasis on parental care, arguing that this has a greater fitness benefit if offspring are more closely related to their parents, as they would be through inbreeding or breeding within the 'ethny'. This is an intricate point, but my tentative view is that Salter's position is largely but not entirely misconceived. In all species, there is a trade-off between the number of offspring produced and the amount of resources (including parental care) devoted to each offspring. The general evolutionary principle (usually attributed to David Lack, though he had several precursors) is that for each species there will be an optimum level of parental investment, at which the number of offspring who survive to maturity is maximised (subject to refinements over the timing of reproduction, as expressed in Fisher's 'Malthusian Parameter'). The optimum level is determined primarily by the ecological circumstances and habits of the species. As far as I can see, in general it does not make any difference to the optimum whether the breeding system favours inbreeding or outbreeding (except perhaps through side-effects such as the amount of competition between siblings). The optimum level, as determined by ecology, etc, maximises the reproduction of all the genes of the organism equally, including any genes that promote inbreeding or outbreeding. Such genes are therefore neutral with respect to the optimum level. It may however still be said that a gene for parental care would 'prefer' parental investment to be directed towards inbred offspring, who will on average contain more copies of that gene. I think this is true to the extent that if a parent has both inbred and outbred offspring, its genes for parental care would have an 'interest' in discriminating in favour of the inbred offspring, other things being equal. Of course, this interest would be offset by any reduction in the viability of inbred offspring due to inbreeding depression. In any case, I do not think that this limited preference for inbred offspring, where both inbred and outbred offspring already exist, should be confused with a general tendency to mate with relatives, and thereby to produce inbred offspring. This is an instance of the fallacy pointed out by Dawkins. I should also stress that even if there is some validity in Salter's comments on parental care, this would not affect my main criticism of his arguments against interracial marriage, which is that interracial marriage does not in general reduce the net 'genetic interests' of the participants, as fallaciously assumed by Salter. Ref: Grafen 1990: Alan Grafen, 'Do animals really recognize kin?', Animal Behaviour, 1990, 39, 42-54. Note added on 14 October: My attention has been drawn to a critique of the above post by J. W. Holliday. I won't give a link, as the critique is personally abusive, but those who are interested will be able to find it easily enough. I recommend it to connoisseurs of paranoid fantasy. I won't respond in detail. As a famous philosopher once said, comments on comments on comments (etc) are subject to the law of diminishing fleas. I will however pick up a few points. I emphasised in my post above that differences between populations due to genetic drift will be eroded and eliminated even by modest amounts of migration. Holliday appears to doubt this, but it is a well-established result of population genetics. The strength of genetic drift is inversely related to the size of the population. In a very large population, such as a continental race with a population of hundreds of millions, genetic drift in the population as a whole is extremely slow. Even low rates of migration - say, one in a thousand per generation - would be orders of magnitude more effective in changing gene frequencies. Indeed, subject to certain qualifications, even an exchange of one migrant per generation is sufficient to stop two populations drifting apart. Anything more than this, and the gene frequencies in the populations will tend to converge. Differences in gene frequencies due to differing selective conditions are another matter. Migration will tend to reduce them, but if selection is strong enough some differences may be maintained. I have never disputed this. Holliday assumes that I (or rather gnxp, which in his fantasies has a policy on such matters) advocate 'mass migration/miscegenation'. In fact, as I said in EGI1, 'there are sound arguments against large-scale, uncontrolled immigration '. I just don't think Salter's doctrines are 'sound arguments', and I believe it would be positively harmful to the case for immigration control if it became tainted with Salterism. As for 'miscegenation', I gave my considered views on the effects of interracial marriage here. In my 'Salter' post on the subject (IMSF) I was simply concerned to show that Salter's main argument against interracial marriage is a fallacy. Holliday concedes that it is a fallacy, but imagines that he can get Salter off the hook by pointing out that my assumption of 'neutrality' is unlikely to be strictly true in practice. Well, of course. It is an idealisation which simplifies the arithmetic for purposes of presentation. But Salter's own approach remains fallacious even if we relax the assumption. Holliday rejects my conclusion that "the implication of Salter's concessions is that the ultimate test of whether the frequency of a gene should be increased or decreased is its effect on fitness, not its current frequency within the 'ethny'." But Holliday's counter-argument is vague and unquantified. In Salter's system, an individual's EGIs are measured by multiplying the number of his 'co-ethnics' (other than close kin) by the relevant degree of ethnic 'kinship'. Any gene substitution which increases the fitness of the co-ethnics will therefore increase the individual's EGIs unless by making the substitution the degree of 'kinship' is reduced by a larger factor. This is extremely unlikely to be the case, since ethnic kinship is averaged over a large number of different genes (probably thousands). The effect of any single gene substitution on the degree of kinship would therefore be very small, and would be outweighed by even a modest fitness advantage (of the order of one in a thousand). It should also be noted that if we replace 'distinctive' genes, i.e. those with different gene frequencies between two populations, by genes that have equal frequencies in the two populations, then the negative kinship between the populations will also be reduced. I have pointed out previously that for consistency we should always count negative as well as positive EGIs, in which case the net effect of a gene substitution on EGIs is zero (assuming equal population sizes), and any fitness benefit of the substitution is pure gain. But as EGIs are nonsense anyway, I think this is like arguing about whether chimaeras bombinate in the void. Finally, Holliday stresses that Salter recognises the inevitability of genetic change and evolution even if his policy recommendations (essentially, preventing migration and intermarriage) were implemented. I agree that it is possible to find passages of this kind in his book. The fact remains that the overwhelming emphasis of his doctrine is on defending existing genes and gene frequencies as they are, and he does not (in my opinion) explain why some changes are to be cheerfully accepted while others are to be fought tooth and nail. If an author were to write a book making a passionate plea for freedom of speech as an 'ultimate' and 'overriding' value, but inserting sporadic unexplained concessions such as 'except for libel', 'except for obscenity', 'except for religious abuse', and so on, we would not form a high opinion of his or her consistency and intellectual rigour. Labels: human biodiversity
The genetic architecture of normal variation in human pigmentation: an evolutionary perspective and model:
It has long been noted that the vast majority of the genetic diversity found in the human species is distributed within geographic populations...Only 5-15% is observed between groups, reflecting our recent origin less than 200,000 years ago. In contrast and intriguingly, an estimated 88% of the total variation in skin color is found among geographic groups...The discordance is probably the consequence of intense selective pressure in the past on important attributes of the skin, the organ that most immediately and extensively interfaces with our environments. In terms of heuristics which allow us to filter and bias our perception of new data we look to the distribution of facts and processes which we know of prior. For example if I see that a trait is normally distributed and highly heritable I'm assuming that it hasn't been subject to a long period of strong direction selection, because that tends to eliminate the standing genetic variation necessary for these sorts of phenotypes. So you see two large geographic populations which are fixed for alternative alleles. Selection? Bottlenecks? Hitchhiking? Labels: Evolution
Monday, October 08, 2007
Steve has a review of Farewell to Alms up (part I). Interesting stuff, but I think he misreads one section:
And despite their poverty, Malthusian-era English workers at least lived better than their counterparts in much more crowded China and Japan. That's in part because they practiced population control through self-discipline, postponing marriage until they could afford it. Women didn't marry on average until age 24 to 26, and a minority never married. (Illegitimate births only made up 3-4 percent of the total.) As Jane Austen's novels show, marriage was a serious business revolving around love and money. On page 77 Greg Clark states: These patterns imply that, despite early and nearly universal marriage, the average woman in China or Japan around 1800 gave birth to fewer than 5 children, less than the half the biological possibility, resulting in a birth rate similar to that for eighteenth-century Europe. The English women who married had more children than the Chinese or Japanese women who married because they stayed in the game far longer. So the average worked out to be about the same, which is why Clark focuses on mortality rates to explain the population density differences. Search for the keywords "china number of children" on Amazon and check page 77 to see what I'm saying (page forward and backward to get full context). I remember this clearly because the similar birthrates surprised me. Labels: Economics
Kambiz of Anthropology.net is up for a blogging scholarship. Vote for him if you are so inclined here.
So here's Britney Spears escorted by paparazzi while going to get some sushi with her sister. The interesting point is how the paparazzi are out to protect the Spears. Why? Obviously Britney is their bread & butter. If, for example, one of them injured Britney so that she couldn't venture out...I wonder if the others would tear him to pieces?
Coevolution of languages and genes on the island of Sumba, eastern Indonesia:
...We examine linguistic and genetic variation in a contact zone on the eastern Indonesian island of Sumba, where Neolithic Austronesian farming communities settled and began interacting with aboriginal foraging societies ~3,500 years ago. Phylogenetic reconstruction based on a 200-word Swadesh list sampled from 29 localities supports the hypothesis that Sumbanese languages derive from a single ancestral Austronesian language. However, the proportion of cognates (words with a common origin) traceable to Proto-Austronesian (PAn) varies among language subgroups distributed across the island. Interestingly, a positive correlation was found between the percentage of Y chromosome lineages that derive from Austronesian (as opposed to aboriginal) ancestors and the retention of PAn cognates. We also find a striking correlation between the percentage of PAn cognates and geographic distance from the site where many Sumbanese believe their ancestors arrived on the island. These language-gene-geography correlations, unprecedented at such a fine scale, imply that historical patterns of social interaction between expanding farmers and resident hunter-gatherers largely explain community-level language evolution on Sumba.... Labels: History ![]() (note, to explore further please see the website for Abraham's Children. Also, Jon has a guest post over at Eye on DNA) 1) The past 10 years have been rather fertile in human genomics; and certainly the study of Jewish genetic history has been big news. You obviously had a lot to work with in your most recent book, Abraham's Children: Race, Identity, and the DNA of the Chosen People. But how much penetration has this knowledge had in your estimation in the broader Jewish American population? For example, is the likelihood that many Jewish foremothers were of gentile European ethnic background common knowledge? There is certainly a growing awareness of what might be called "Jewish genetics," focused mostly on disease research, such as the identification of breast cancer and neurological mutations found commonly in Jews. Jewish DNA research centers have sprung up around the world and efforts are underway to export into other ethnic communities the screening model developed by the Jewish community in New York, which had been devastated by a high incidence of Tay-Sachs, one of the many brain disorders that disproportionately target Jews. Although many secular Jews did not even know there was such a thing as a Jewish priesthood, there is now widespread awareness of the existence of the Cohan Modal Haplotype, the marker that traces about to the time of the first High Priest of the Jews, Aaron, Moses's brother. Whether this mutation originated with the biblical Aaron-there is no extra-biblical evidence that he or Moses even lived–or just to a person who lived 3000 or so years ago, and is the progenitor of one of the Cohanim lines, will likely never be known, however. As for the more nuanced narratives that have emerged from the study of Jewish genetics-such as the fact that most Ashkenazi Jews are descended on their maternal line from Christians or pagans who more than likely never went through a formal conversion (which would make most Ashkenazim non-Jews under Israeli law)—no, that's barely known. It could provoke some intriguing soul searching among Jews, especially Orthodox Jews, about what determines Jewishness. I'm looking forward to my talks to Jewish groups to see how this prickly issues plays out. 2) It seems that simple visual inspection yields the inference that Ashkenazi Jews are a population which arose out of hybridization between a Middle Eastern people and European stock. That is, though some Polish Jews could pass as Polish and some could pass as Lebanese, the majority seem to span the spectrum between. And yet we have had wild swings in perception over the last century in regards to whether Jews were a wholly foreign element or the descendants of converts. Can you elucidate the reasons why people have denied the witness of their eyes so thoroughly? As we all recognize, ethnicity and identity is closely bound with politics. The issue of "Jewish distinctiveness," for lack of a better phrase, long has been part of Jewish history. There were a number of periods during which Jews watered down their signature identity, self-selected or imposed, as a "chosen people." The Samaritans were a blend of Jews and non-Jews. Jews adopted many Hellenistic cultural practices during the Second Temple period, and intermarriage, particulalry among the educated elite, was not uncommon. There was also a fair amount of intermingling between Sephardic Jews and non-Jews during the Golden Age of Jewish, Muslim, Christian relations and in the century leading up to the Inquisition, which undoubtedly left a complicated imprint on the Jewish gene pool. Another more powerful wave of assimilation was touched off by the Jewish Enlightenment, which encouraged some Jews to drop their identity as "Jews first" and blend in culturally and through intermarriage with non-Jews, particularly in Greater Germany, in the 19th and early 20th enturies. In each of those cases, Jews assimilated along the edges but the Jewish community Maintained its central ethic of Jewish distinctiveness rooted in the belief that Judaism was a tribal religion tied by threads of ancestry, culture and belief. Each of those experiments in assimilation arguably ended badly for many Jews, with the Holocaust the most tragic and recent example. So, when a movement arose in the 1950s, most popularly propaganized by Arthur Koestler in The Thirteenth Tribe, that Ashkenazi Jews were mostly converts, its political and social attractiveness-Jews didn't have to suffer the consequences of their chosenness-many liberal Jews fervently embraced the idea. Beginning in the 1950s and 60s, it became fashionable for Jews to to reframe Judaism as a religion and not a "race," which fit with the anti-race ideology of post World War II Europe and America. Now, of course, DNA research has shown us that the story is a lot more complicated. Many Jews ARE descendants of converts, at least on the maternal side; but they have also maintained a relative blood purity on the male side that is extraordinary. The historical intermarriage rate of Jews (those who maintained their Jewish identity) remained at less than one half of one percent from biblical times until the mid twentieth century. And even after Askenazi males took on non-Jewish wives during the founding years of the medieval European Jewish community, Jewish fidelity took hold with a vengeance. 3) Some researchers have objected to the inferences made from the presence of the "Cohen Modal Haplotype" in disparate groups (e.g., some Hispano populations in the southwest). What is your sense about the current balance of opinion in the field of human genetics right now about its utility in ascertaining the signatures of past Jewish population movements and their subsequent acculturation? DNA analysis in its present state remains a relatively crude tool. It's fairly easy to track our paternal and maternal lines but those are only tiny threads of our genetic history, although the stories they tell carry a lot of romantic cachet. The rest of the human genome, however, remains pretty mysterious. Jews, because of their historical cultural and genetical isolation, are easier than most populations to track along the Y and mitochondrial DNA lines, but beyond that, the trails are heavily overgrown by the brush of paternal accidents and intermarriage, no matter how infrequent. Even supposedly clear cut findings-the three breast cancer mutations originated in Askhenazi Jews in the early medieval period---have been thrown asunder by the appearance of these mutations in pocket communities of Hispanos of the American Southwest, who trace their ancestry back to Spain, as Sephardic Jews before the Inquisition. At this point, genetic genealogy and anthropology is a great innovation for shedding light on all kinds of things, including disease origins, but its real value is as a complement to the other tools available to genealogists, anthropologists, archaeologists, and historians. 4) I am stuck by the high proportion of the CMH among the Bene Israel of Bombay. The Cohens were obviously just one lineage among many, and as you note after the destruction of the Second Temple the privileges and status of the priests were more symbolic and nominal as Rabbinical Judaism became the dominant dispensation. Was there some peculiarity among the Bene Israel in regards to the status of Cohens which might explain the disproportionate representation of this lineage? First let's address some myths about the CMH. About 50 percent of Jewish males with an oral tradition of being members of the Jewish priesthood, which by Jewish tradition originated with Aaron, carry a distinctive mutation known as the CMH. Yet it does not stand as genetic witness to the biblical tale of Moses and his brother Aaron. The original CMH studies suggested the mutation appeared at about the time Moses was believed to have led the Jews out of Egypt (if in fact Moses and Aaron even existed). More recent studies have identified at least two CMH markers, suggesting that the originating haplotype might date somewhat earlier, making the CMH more likely a marker of Semitic rather than Jewish ancestry. It is its found in fairly high frequency in Arab populations, in Oman and Iraq for example, and among Palestinaans, as well as in other nearby populations. The CMH is also found in populations believed to have Jewish ancestry, such as the Lemba of South Africa and the Bene Israel of India. The CMH is not common across all their members, however. As with the case of the broader Jewish population, the marker is concentrated in a priestly sub-group. Considering the history of cultural and genetic isolation expeerienced by the Bene Israel and the Lemba, and even more so by the priestly sub-clans, it's understandable that the CMH marker could have been preserved in such high frequencies. 5) Your book is obviously predicated on the revolution in scientific genealogy, nevertheless, you do offer some caution in terms of people reading too much into uni-parental results. My own general advice when friends ask me about purchase of these kits is that most of the time they won't find out anything they didn't know, though in particular circumstances (e.g., African Americans who want to fix on a particular tribal provenance for one lineage) I think it is worthwhile. What is your advice for the typical person in regards to scientific geneaology? Caveat emptor. Those determined to focus on the two narrow lines of human ancestry—on the Y chromosome and in mitochondrial DNA-will miss the complex web of connections––genetic and cultural––that shape identity. It's safe to say the narratives that emerge from the genes that we can now identify will be simplistic and often misleading. Consider the story of Harvard University's Henry Louis Gates, Jr., an African American, who was both shocked and bemused to learn that his DNA on his mother's side did not track back to the Yoruba people as he had long thought. The Yoruba have a rich mythology and are believed to have been among the most culturally sophisticated of the African cultures before the arrival of Europeans. "A number of exact matches turned up," Gates wrote, "leading straight back to that African Kingdom called Northern Europe, to the genes of (among others) a female Ashkenazi Jew. Maybe it was time to start listening to ‘My Yiddishe Mama," he quipped. DNA genealogy kits are great fun in helping us understand the general wanderings (minus the interesting migratory detours, some of which could have lasted thousands of years) of our male and female ancestors, but that's a limited story. Humans like to move around and fool around. As Gates' discovery underscores, there is a no way, using today's DNA technology, that he or any of us can retrace the movements of the many other genetic lines that contribute to our DNA. 6) In Taboo: Why Black Athletes Dominate Sports and Why We're Afraid to Talk About It I recall that you seemed to favor a "multi-regional" model for the origin of various populations and their distinctive characteristics. Have your conceptions of human evolutionary origins changed in the last 7 years at all? I note that you mention the Neandertal introgression work, which is predicated on predominant African origins overlain with a few salient "archaic" genetic elements. The scientific consensus, which I am comfortable with, suggests a common African origin for the various populations of the world. That said, elements of the mult-regional model are still in play. We now have evidence, for example, that the Aboriginal population of Australia was relatively distinct for nearly 50,000 years. The core population that remained in Africa also faced definining geographic isolation. Migratory populations that settled in northern Asia also were somewhat isolated for thousands of years, until after the last ice age. In each case, evolutionary forces played a role in shaping distinctive characteristics-physically and mentally. It's even possible-though highly speculative at this point-that the Neandertal genes or the genes of other remnant populations still to be identified could be present in one or another modern population, and have a unique impact. We truly are a diverse species, and in some characteristics, this diversity patterns itself by population; it's not just superficial. When the ranks of the top 100 meter runners, all of whom are of West African origin, is suddenly dominated by whites from Des Monies or Berlin, we might rethink that thesis, but as of now, it's pretty clear that human "races"-that word used for lack of a better popular term-do exist. 7) Since you wrote Taboo there has been some discussion about the decline black Americans in baseball and the influx of European players in basketball. Did you anticipate these shifts and the pubic comment they would engender? I'm amused when I read headlines, such as one that appeared last March on ESPN that "only 8.4 percent of major league players were black last season". You don't have to adjust your TV sets; the headline was indeed dead wrong. As Richard Lapchick writes in the most recent "Racial and Gender Report Card," issued last March, almost 30 percent of today's baseball players are Latino-and many of them have a high percentage of African genes. Journalists and ideologically inclined sociologists and anthropologists, often confuse the racial folk category of "black" with the geographical or linguistic category of "Latin American" or "Hispanic." Skin color is a mark of ancestry not country of residency. Categorizing black Latinos as "not black" is like saying that the emergence of Meb Keflezighi, the Eritrean (East African) born runner who became a naturalized US citizen in 1998, as an international superstar proves that American blacks, almost all of whom are of West African ancestry, are suddenly genetically able to compete as international marathoners. It's meaningless. How can anyone classify, say, David Ortiz, born in the Dominican Republic, as anything but black? Although the number of American blacks is declining in baseball-it was 20 percent a decade ago--the percentage of black baseball players from North and Latin America combined has not declined at all. If "black" is taken as a (somewhat superficial) marker of primarily West African ancestry, than the percentage of black baseball players is mor than 35 percent––at an all time high. Moreover, the top awards in baseball continue to be disproportionately won by players with West African ancestry. The influx of European white players in the NBA is an understandable byproduct of the globalization of the game and the booming economies of Eastern Europe. Culture plays a huge role in sports selection, creating a feedback loop between genetics and opportunity. Still, the white resurgence is greatly exaggerated. According to the Racial and Gender Report Card, whites made up about 25 percent of the players ten years ago. Today, despite all the publicity of a white revival, it's down to 23 percent. Moreover, most of the NBA's big-name superstars are blacks of West African ancestry. It's not an issue of black and white; it's an issue of body types; the sub-population of blacks from West Africa, including African Americans, have a slight biogenetic advantage over whites. 8) Has the genetic data changed your personal perspective at all as a Jewish American in any significant way? Jews are a funny lot when it comes to discussing the implications of genetic research, and I'm no different. We were brought up to believe that we were unique-if not chosen by God, which never sat well with athiests like myself, than at least culturally distinct. We were a modern day tribe with all the rituals, silent forms of communication, and initiation rites that puzzles and irritates many non-Jews. Yet Jews are also imbued with the belief that we should never, at all costs, publicly acknowledge this cultural distinctiveness for fear of stirring a backlash-stories of the Holocaust were drilled into us from childhood, so why court danger? Now research appears that suggests that our cultural exceptionalism may be rooted in genetics. This is both empowering and disquieting to Jews. It was no surprise to me that the sharpest, most vitriolic ideological attacks on Taboo, and surely to come on aspects of Abraham's Children, will come from self-proclaimed "liberal" Jews who will deny, in defiance of the evidence, that there are population based differences in behavior or physiology. That fact—it's not just an idea, after all—makes Jews nervous, even Jewish scientists who privately acknowledge these genetic based differences. When I wrote Taboo, I fcoused much attention on the theme highlighted in the subtitle: "….Why We are Afraid to Talk About It"-that is, why we are afraid to openly discuss human genetic differences. That was also a central theme of Abraham's Children. We talk a lot about diversity in the United States, as long as we wink and smile that this diversity is not real, just superificial, a cultural patina. But in some aspects of our humanity, it is very real, and such differences can have huge consequences in everything from sports performance to success in the classroom. The DNA data has solidified my conviction to follow my "Jewish instincts," nurtured by culture and pehaps by genetics over many centuries: challenge the conventional wisdom and spur constructive dialogue. 9) What was the information which most surprised you while you were doing the research for "Abraham's Children?" Time and again, I was shocked by the power and romance of DNA, the hold it has on som many people. I saw men and women literally upend their lives, literally, based on the tiniest sliver of genetic material. Why would a fervent Christian abandon her religious beliefs after discovering a distant connection to those of Jewish ancestry? Heck, we are all related if you go back far enough in time, to apes and even bacteria. Why the atraction to an ancient tribal religion? Having been brought up Jewish, it's difficult to appreciate the metaphysical power of Jewish religious and ancestral archetypes on so many non-Jews. Is it religious? Cultural? Genetic? It's baffling and fascinating. 10) Now that "Abraham's Children" is complete, what next? It's time to move from description to prescription. I'm planning, in my next book, to look at the public policy implications of the DNA revolution, particularly in education. Yes, it will be like walking through a minefield, but I'm used to that. Labels: 10 questions
Sunday, October 07, 2007
RPM points to a Language Log post which discusses and highlights the human ignorance of, and disinterest in, statistical thinking. Assman put up an interesting comment. I will say this:
1) There are some basic tools which many intelligent people are just plain ignorant of. On this weblog one reader, a medical doctor, was surprised by Bayes' rule, but immediately understood its relevance. This happens to all of us, there are amazing tools out there which we haven't encountered for a variety of reasons. And most of us are happy to pick up the tools if we see clear utility. 2) But, there's another problem, and that is the fact that statistical and probabilistic thinking is a real damper on "intellectual" conversation. By this, I mean that there are many individuals who wish to make inferences about the world based on data which they observe, or offer up general typologies to frame a subsequent analysis. These individuals tend to be intelligent and have college degrees. Their discussion ranges over topics such as politics, culture and philosophy. But, introduction of questions about the moments about the distribution, or skepticism as to the representativeness of their sample, and so on, tends to have a chilling affect on the regular flow of discussion. While the average human being engages mostly in gossip and interpersonal conversation of some sort, the self-consciously intellectual interject a bit of data and abstraction (usually in the form of jargon or pithy quotations) into the mix. But the raison d'etre of the intellectual discussion is basically signaling and cuing; in other words, social display. No one really cares about the details and attempting to generate a rigorous model is really beside the point. Trying to push the N much beyond 2 or 3 (what you would see in a college essay format) will only elicit eye-rolling and irritation. Note: And as Assman noted, the above isn't really relevant for most people who are probably too light on the g. Labels: Philosophy of science
Saturday, October 06, 2007
So I'm reading Robert Fagles' translation of The Iliad. Just curious, for those of you who know Greek and can read it, is there a major difference between the original and the translations? And more generally, for those of you fluent and literate in multiple languages do you see major issues with translating fiction and poetry?
Labels: Literature
Friday, October 05, 2007
Wired has an article up titled The Inconvenient Science of Racial DNA Profiling. The core of the story is Tony Frudakis, who has written papers such as Eye colour: portals into pigmentation genes and ancestry. The science is pretty easy to understand. You don't need that many genes to fix in on someone's likely racial identity. Take two genes, SLC24A5 and DARC. There are genetic variants in African Americans on these loci which are basically non-existent in those of European descent. Because African Americans are genetically admixed with about 20% of their ancestry being European they have a less unequivocal profile on these loci; but all you need to do is increase the number of genes to increase your confidence that you've made a positive identification.
The science is banal. The politics, less so. For example: Besides the expense, many people who might benefit from DNAWitness either don't know it exists or are extremely skeptical that it works. William C. Thompson, Chair of the Department of Criminology, Law & Society at UC Irvine is a prominent expert on the use of DNA in criminal trials but was only marginally familiar with this technology. When I tried to describe how it works, he literally screamed at me, calling Frudakis a hack and a charlatan who obviously did not understand statistics. William C. Thompson has written about forensic DNA evidence in his research, so his anger must not have been driven by ignorance. And as for the idea that because two populations have different genetic profiles that means that they are "inherently unequal," that's depends on what metric you're using as a measure. A lawyer should know that all Americans have the same rights and equal worth before the law whether they are good at digesting lactose or tall, both by the grace of genes. But think about what Frudakis is doing, he's taking genes and mapping them onto phenotypes. For example, if someone has a particular allele of OCA2 there is a strong conditional probability that they will, or won't, have blue eyes. Amazing! It changes everything! Who knew that blue eyes were genetic! Now we're all unequal...or are we? The fact is that everyone knows that skin color, hair form, eye color and a host of other traits are due to your inheritance, your genes. It just goes to show how magical most people view science in that they are terrified that now we know the genes which are responsible for the variation which we intuitively would assume was due to inheritance of different genetic variants in the first place. This goes to some extent to confirm A.W.F. Edwards' criticism of Lewontin's Fallacy, if we derive our normative prescriptions from science's understanding of nature our basis is fundamentally shaky because science does not deal in ultimate truths. Lewontin's obscurantism convinced everyone that genetic differences were trivial, even though they all noted the distinctive physical types which obviously derive from genetic differences. Now that genetics, or specifically genomics, is advanced enough to fill in the gaps and elucidate the genetic architecture underpinning distinctive physical types people are terrified because they rested in their presuppositions on Lewontin's Fallacy. Finally, there is the issue of the practical use of these tests. As noted in the article genomic profiles aren't necessarily cheap, and they aren't necessarily value added in some cases when cost is taken into account. But, if we are likely going to see the era of the $1,000 genome within the next 15 years, how expensive do you think a kit which checks a few dozen markers will be? For most people science is magical, but when the wizardry becomes a banal part of the consumer life through technology people accept it as a having real truth value. All the expositions of genetic correlation structure are going to do far less in debunking Lewontin's Fallacy than the coming ubiquity of personal genomics. Labels: human biodiversity
Here is an "interesting" paper, Changes in Sperm Quality and Numbers in Response to Experimental Manipulation of Male Social Status and Female Attractiveness:
Here we show in the fowl Gallus gallus, where social status determines copulation success, that dominant males produce more sperm than subordinates but that the quality of dominant males' sperm decreases over successive copulations, whereas that of subordinates remains constant. Experimentally manipulating male social status confirmed that ejaculate quality (the number and quality of sperm produced) was a response to the social environment rather than the result of intrinsic differences between dominant and subordinate males. We further show that dominant males responded to variation in female sexual ornamentation, which signals reproductive quality, by adjusting the number and quality of sperm they transferred, whereas subordinate males did not: they transferred ejaculates of similar quality to females with different ornament sizes. These results indicate that trade-offs between traits influencing reproductive success before and after copulation, combined with variation in social dynamics and female quality, may favor the evolution of phenotypically plastic alternative reproductive strategies. Related: Sperm competition. Labels: Evolution
Apropos of my post about patrilocality and genetics, here's an article (Open Access), Female-biased dispersal and patrilocal kin groups in a mammal with resource-defence polygyny:
Female-biased dispersal (FBD) is rare among mammals (e.g. African wild dogs Lycaon pictus...Chimpanzees Pan troglodytes...and its occurrence frequently correlates with resource-defence polygyny...However, a resource-defence strategy does not necessarily lead to FBD...and there are examples of mammals with FBD that do not follow a resource-defence mating strategy...In a considerable number of polygynous mammalian species, females may disperse to avoid inbreeding with their fathers when male tenure exceeds female age at first conception...In the greater sac-winged bat (Saccopteryx bilineata), females have been reported to disperse from their natal colony, whereas at least some of the male progeny remain in their natal colony...The mating system of this bat is best described as resource-defence polygyny...this would mean that females are assumed to disperse owing to the inbreeding risk arising from male philopatry. However, there are currently no studies investigating the causes for female dispersal in this species and if there is a risk of inbreeding arising from female breeding philopatry and male natal philopatry. Well, humans aren't bats. That being said, I wonder if philopatry is critical in inducing males to be "good dads." While females have perfect certainty as to who their offspring are, male paternity confidence is less assured. Matrilineal and matrifocal societies seem to be optimal scenarios for males not investing in their offspring because of lack of certainty and social supports for males (this is why maternal uncles loom large in many cultures). In contrast, patrilineal and patrifocal societies may serve as watchdogs which guarantee paternity certainty so that males can maximize their fitness by investing in their own offspring. If a man moves to live with his wife's family it seems likely that if she engaged in infidelity the chances would be far higher than not that her relatives would cover up for her; after all the coefficient of relatedness likely increases rather than decreases since the lover is likely to be a local. Labels: Evolutionary Psychology
Thursday, October 04, 2007
In Science there's a new report, Chimpanzees Are Rational Maximizers in an Ultimatum Game; the title says it all. On the other hand, The Evolutionary Origins of Human Patience: Temporal Preferences in Chimpanzees, Bonobos, and Human Adults doesn't clue you in in the title that chimpanzees have lower time preference when it come food (they're more patient and will take a bigger later payoff than humans). The most recent issue of The Economist covers these results as well as the finding of heritability in response to the ultimatum game.
Labels: Evolutionary Psychology
Wednesday, October 03, 2007
![]() Introducing a new model organism to the genetics community is (or perhaps, was) one of those things that happens once a generation or so-- the originals, back at the turn of the century, were the mouse and the fly, pioneered by Morgan and Castle. The organisms were abundant, relatively cheap to maintain, and had generally simple (for what was known at the time) genetics. It's easy to forget that it didn't have to be that way-- if some dude had really liked snakes, maybe the model organism of choice today would be the rattler. But over time, as resources, a community, and a base of knowledge build up, an organism gets entrenched in the system (let's say you're interested in the genetics of wing development-- do you really want to go out butterfly catching when there's a big room full of flies down the hall? And even if you do, what the hell are you going to feed them?). New organisms have been introduced, of course-- Brenner legendarily elevated the nemotode C. elegans to genetic superstardom, the zebrafish is increasingly popular, and there have always been "niche" organisms like the sea urchin or the subject of this post- the dog. But until recently, doing dog genetics must have been a real pain. All your friends are knocking out genes, doing fancy mutagenesis screens, and searching genomes for homologous sequence, while you're stuck mapping phenotypes to...oh, somewhere on chromosome 5 (there might be genes in the region, but you don't know, since the genome's not sequenced). Think human genetics circa 1985 (or ok, maybe 1995). But in the course of a couple years, all that's changed. Utilizing the highly-inbred nature of dog breeds and the recent genome sequence, people were able to develop a SNP chip for genome-wide association using <30,000 SNPs. And with that chip, they found the gene controlling a pigmentation trait in boxers using only 10 (10!) dogs. Estimating the cost of the chips at ~$400 (they're probably less), an interested breeder with a bunch of dogs on his hands could do a decent study the Mendelian phenotype of his choice for less than $20K. Early mouse geneticists took advantage of the existing infrastructure of mouse fanciers to advance their work; is the dog the new mouse? Besides humans, the dog is possibly the most interesting organism for taking advantage of new genomic technologies-- the huge variability in phenotype, the massive recent selection to create that variability, and the knowledge of ecology and history all combine to create a gold mine of insight waiting to be tapped. Labels: Genetics
Be Good Now, Or Else:
Neuroscientists have taken a step closer to a physiological explanation of why some people work and play well with others. Two areas in the brain appear to have key roles in how people conform with social norms. These parts of the brain mature slowly, which may help explain why adolescents are less easily cowed by the threat of punishment than are adults. Chris likes to joke that cognitive neuroscience basically tells us that "stuff happens in the brain." There's some truth in that, but I still think that methods like fMRI are going to be an important piece of the bigger jigsaw puzzle that is human nature. For example, variation in fMRI combined with behavior genetic expectation that said variation should have a biological (genetic) underpinning seems a lot more compelling than either datum alone. Also, ever notice how some people who were assholes when they were kids turn out normal? The conventional assumption is that people grow up and learn, but perhaps they couldn't learn for neurological reasons until they grew up! Labels: Neuroscience
Tuesday, October 02, 2007
When genetics is used as a supplement to history or anthropology it should ideally offer more precision and reduce the field of possibilities. Unfortunately that is not always the case. For example, when asking big questions such as "Are humans 'naturally' patrilocal?" genetics has generally come up with conflicting results. The fact is that about 70% of "traditional" societies are patrilocal; wives move to live with husbands and their family. Some genetic evidence seems to support this (e.g., greater mtDNA [female] variation than Y [male] lineage variation), but there is also variation within populations and some skepticism as to whether such simple comparisons between different uniparental loci really can give a definitive answer.
This paper in PLOS ONE tackles the question using comparisons with chimpazees to help calibrate our expectations, The Genetic Signature of Sex-Biased Migration in Patrilocal Chimpanzees and Humans: ...Here we review some methodological reasons for these inconsistencies, and take them into account to provide an unbiased characterization of mtDNA and NRY variation in chimpanzees, one of the few mammalian taxa where males routinely remain in and females typically disperse from their natal groups. We show that patterns of mtDNA and NRY variation are more strongly contrasting in patrilocal chimpanzees compared with patrilocal human societies. The chimpanzee data we present here thus provide a valuable comparative benchmark of the patterns of mtDNA and NRY variation to be expected in a society with extremely female-biased dispersal. Homo Sapiens, are a complex species. We're capable of a lot and our level ofsocial complexity isn't truly cognitively tractable for the mental toolkit that evolution has given us. So we make recourse to generalizations and first-order approximations. The problem with this is that sometimes the deviation away from the central tendency is as interesting and evolutionarily salient as the mode on the frequency distribution of the trait. When we say that 70% of human societies are patrilocal, that means that 30% are not. That also doesn't mean that 70% of human societies have always been patrilocal. It also doesn't quantify how much deviation there is from social expectation, e.g., perahps in the 70% of societies which are patrilocal a substantial minority of males move to the locality of the female, or, males and females from the same locality marry each other so that the whole dichotomy is rendered irrelevant (though even if you live within a village whether you reside in the relatives of the female or relatives of the male in an extended family circumstance is also an important point). Generalizing about the modal behavior of our species may leave the concept more analytically tractable, but it may also render our model inaccurate toward the point of uselessness. On the other hand, chimpanzees aren't that complex...at least compared to humans. Yes, I know that chimps are the geniuses of the animal kingdom, but the chimp is the Peter Keating of the animal world and we are the Howard Roarks. Unlike humans with their facultative complexity chimpanzee societies are pretty uniform. While there are exceptions to the rule (as in the famous Gombe troop), female chimps tend to leave their natal group while males tend to remain in their natal group. In shot, chimps seem to be much more obligate in their patrilocality than humans. The workers above note that both chimp lineages, the bonobo and common chimp, are patrilocal, so this is likely an ancestral characteristic of the clade dating back at least 1 million years. It seems that chimpanzees exhibit a much more unambiguous genetic signature of patrilocality than humans, the ratio of Y to mtDNA variance is significantly lower than in humans. There are some technical reasons why the human results could exhibit problems. For example, mtDNA might simply be more diverse than Y lineages for endogenous reasons (higher mutational rates?). Or there might be lower effective population size of one sex, which would skew the variation of the uniparental lineages independent of deme-to-deme gene flow. There are also issues of coarseness of analysis, the authors point out that in some human communities Fst analyses were preformed by spanning tribal groups where intermarriage was rather uncommon, while ignoring the pervasiveness of between deme gene flow on the intra-tribe level. Finally, there is the issue that human societies change. The Japanese were once matrilocal, but now the are patrilocal. Within historic times many matrilineal societies have shifted toward patrilocal practices (though sometimes there are ghosts of matrilineal practice, in ancient Egypt marriage to a woman of the royal line was often essential to solidify the claims of the male claimant). There variations over time can obscure or erase genetic patterns and replace them with new ones, and periodic oscillations would presumably result in a meta-stable level of diversity which balances out both mtDNA and Y. Chimps can get around some of these issues. Chimpanzee societies are more homogeneous in their behavior patterns, have been studied for nearly two centuries, and have been characterized to a very fine level of demic structure in terms of their social dynamics (even to the point of familial histories). In short, chimpanzees are empirically tractable because of their small numbers and limited set of behaviors. The similarity across the two clades and their relative homogeneity should reassure one that temporal variation is minimized. Because of their charismatic nature chimpanzees have also been tracked in a way which makes assessments of male vs. female migration patterns on the level of specific demes tenable (i.e., you couldn't get funding to do such detailed research on most species, so people have to engage in a lot more guesswork in terms of how they behave when no one is looking, which can explain why ethologists were long fooled by "monogamous" birds before DNA fingerprinting cleared up some issues). It seems only the most extremely patrilocal and polygynous human societies in the sample approached the chimp norm. To me this suggests that we'll have to be a bit more careful and qualified when talking about human patrilocality. Though we're not totally malleable and subject to great constraints, our behavioral flexibility is orders of magnitude more developed than the faculties of our chimp cousins. It shouldn't surprise if we tend to explore a far greater sample space of social systems, not only because we can, but also because we inhabit so many environmental and cultural ecosystems. Polyandry which consists of brothers marrying one woman in Tibet did not arise because it was natural; rather, it seems to be the best opportunity for reproduction that a low status male could attain in that society where resources were at a premium. It was a functional response to a specific set of circumstances. This work focuses on the dimension of male and female migration across adjacent demes, classical models of gene flow. And this likely works well for chimpanzees, and perhaps hunter-gatherers. But it seems excessively oversimplified when it comes to the mass societies which arose after the rise of agriculture. 4,000 years ago a man who was born in Switzerland was buried at Stonehenge. In their day the Mongol hordes swept from the Pacific to the plains of Pannonia, from Baikal to Baghdad. This was certainly a scattering of Y lineages of immense scale. These sorts of movements don't really work well with chimpanzee analogs...because, well, chimps have never produced transcontinental hordes! Atop the simmering activity of deme-to-deme wife and husband exchanges there will periodically flash a fire of migratory activity. Sometimes this will be a total folk movement, but I suspect that more often what you would see was a migration of males. There is much more variation in human social networks than among chimpanzees, so we should focus less on the mean outcome as opposed to the structure and pattern of the variation and its distribution. Note: You can discuss this paper over at PLOS ONE if you so choose! Langergraber KE, Siedel H, Mitani JC, Wrangham RW, Reynolds V, et al. (2007) The Genetic Signature of Sex-Biased Migration in Patrilocal Chimpanzees and Humans. PLoS ONE 2(10): e973. doi:10.1371/journal.pone.0000973 Related: Sperm competition. Labels: anthropology
Finally, behavioral economics & human variation! Heritability of ultimatum game responder behavior:
Experimental evidence suggests that many people are willing to deviate from materially maximizing strategies to punish unfair behavior. Even though little is known about the origins of such fairness preferences, it has been suggested that they have deep evolutionary roots and that they are crucial for maintaining and understanding cooperation among non-kin. Here we report the results of an ultimatum game, played for real monetary stakes, using twins recruited from the population-based Swedish Twin Registry as our subject pool. Employing standard structural equation modeling techniques, we estimate that > 40% of the variation in subjects' rejection behavior is explained by additive genetic effects. Our estimates also suggest a very modest role for common environment as a source of phenotypic variation. Based on these findings, we argue that any attempt to explain observed ultimatum bargaining game behavior that ignores this genetic influence is incomplete. That means that 40% of the variation in response to the Ultimatum Game is due to variation in genes. Yes, I know the Ultimatum Game is pretty bizarre. And I know there might be all sorts of complexities. But it's a start! (and it's Open Access) Labels: Behavior Genetics
Monday, October 01, 2007
![]() Labels: History
Below is a graph of the derived allele frequency spectrum in the three HapMap populations (from here). Many papers have been written about this spectrum, statistics have been derived around it, arguments have gone on about its interpretation, and now...we can simply look at it. Data is a wonderful thing.
![]() ADDENDUM: I should probably give a little explanation of the graph. Razib has added the names to the population labels, and the dotted line gives the expected allele frequency spectrum (given their two-chromosome ascertainment strategy, in case you're wondering why it's a straight line and not theta/i) under the assumption of a constant population size. The shift towards rare alleles in the Yoruba indicates a population expansion in recent history, and the shift towards common variants indicates a population bottleneck (or a longer-term small population size) in the European and Asian populations. Labels: Population genetics (if that video is taken off, here is the SNL link) What are the influences here? My guess below the fold.... I think it's LFO. Check out the two videos below Labels: gay media
Beyond A 'Speed Limit' On Mutations, Species Risk Extinction:
Harvard University scientists have identified a virtual "speed limit" on the rate of molecular evolution in organisms, and the magic number appears to be 6 mutations per genome per generation -- a level beyond which species run the strong risk of extinction as their genomes lose stability. This sort of biophysical process seems plausible to me. Natural selection needs some lack of fidelity during replication to have variation to work with, but evolutionary process seems like a moot point if noise overwhelms the informational signal. Here is an interesting "big picture" implication: The Shakhnovich speed limit also offers an explanation for observed differences in genome sizes between organisms with genome error correction -- such as bacteria, mammals, birds, and reptiles -- and those without, such as RNA viruses: In more complex organisms, cells have evolved correction systems to detect and fix errors in DNA replication. These systems drastically reduce the number of mutations per replication, increasing the mutational stability of the genome and allowing more intricate and delicate biological systems to develop without the risk of interruptive mutations. The paper will be out on PNAS this week. Related: Haldane's Dilemma: should we worry?. Labels: Genetics |