The first observation is that blond hair is exhibited by a little less than 20% of the white population; smaller than the estimates mentioned above. Second, consistent with Razib's previous look at published data from Iceland and the Netherlands, blue eyes are more common in men than in women. Also like the European data, green eyes are more common in women, though the NLSY difference is not as extreme. Blond hair is also more common in females. The trend in all three groups is for females to report lighter hair pigmentation; 66% of white males report darker hair, compared with 55% of females, and both black and Hispanic females are much more likely than men to report 'brown' hair instead of 'black'. Unfortunately, since the data are self-reported it's difficult to know how much of this is subjective. Is this a further example of lighter pigmentation in women, or does sexual dimorphism in pigmentation lead men and/or women to view their own pigmentation as more "sex-typical"?

I was also curious about how these figures differ for various European-American ancestries:

English ancestry Americans and German Americans are very similar for eye and hair color. Hair color is somewhat darker with the French and Irish, and much darker for Italians. Eye color is not darker for the Irish, but is again somewhat darker for the French, and much darker for the Italians.

Finally, we've also discussed the link between personality, behavior, and light pigmentation before, so I took some quick, rough looks to see if there was any signal within the English/German sample. The answer is: not from what I could see. There were no meaningful differences between dark and light haired people in getting in trouble with the police, in getting into physical fights at school or work, or in pregnancy before marriage.

Labels: anthropometry, human biodiversity, NLSY, Pigmentation

There is actually a simple explanation that is well known to geneticists and statisticians, but not widely understood by the general public or, for that matter, by political leaders. Consider a quantitative trait that is distributed according to the normal, bell-shaped curve. IQ can serve as an example. About one person in 750 has an iq of 148 or higher. In a population with an average of about 108 rather than 100, hardly a noticeable difference, about 5 times as many will be in this high range. In a population averaging 8 points lower, there will be about 6 times fewer. A small difference of 8 points in the mean translates to severalfold differences in the extremes.

...

My conclusion, to repeat, is that whenever a society singles out individuals who are outstanding or unusual in any way, the statistical contrast between means and extremes comes to the fore. I think that recognizing this can eventually only help politicians and social policymakers.

The MAF [minor allele frequency] for the SLC24A5 g.13242G>A polymorphism [the ancestral allele] (0.114) in the Indian population is closer to that of Caucasian European populations (0.000-0.020) than to that of East Asians (0.979-0.989) and Africans (0.730-0.980)...This is surprising given that, as a whole, people of Indian origin have darker skin tone compared to Europeans. The East Asian and African populations share a similarly high frequency of the minor allele of the SLC24A5 g.13242G>A SNP, which in itself is surprising as East Asians are typically of much lighter skin than Africans. It is also interesting that the t-test suggested a greater similarity in MAF between Indians and those of populations in the Americas (Puerto Rican, Mexican, and Amerindian), who are of a similar skin tone....

To find out, a team led by John Gabrieli, a professor at the McGovern Institute for Brain Research at MIT, asked 10 East Asians recently arrived in the United States and 10 Americans to make quick perceptual judgments while in a functional magnetic resonance imaging (fMRI) scanner--a technology that maps blood flow changes in the brain that correspond to mental operations.

Subjects were shown a sequence of stimuli consisting of lines within squares and were asked to compare each stimulus with the previous one. In some trials, they judged whether the lines were the same length regardless of the surrounding squares (an absolute judgment of individual objects independent of context). In other trials, they decided whether the lines were in the same proportion to the squares, regardless of absolute size (a relative judgment of interdependent objects).

In previous behavioral studies of similar tasks, Americans were more accurate on absolute judgments, and East Asians on relative judgments. In the current study, the tasks were easy enough that there were no differences in performance between the two groups.

However, the two groups showed different patterns of brain activation when performing these tasks. Americans, when making relative judgments that are typically harder for them, activated brain regions involved in attention-demanding mental tasks. They showed much less activation of these regions when making the more culturally familiar absolute judgments. East Asians showed the opposite tendency, engaging the brain's attention system more for absolute judgments than for relative judgments.

...eyes of different colors are related to differents in perception and innate behavior, as psychologists have discovered.²³ Some of their tests have shown that dark-eyed persons are more aware of color and lighter-eyed ones of form; the former prefer bright hues and the latter lighter ones. Light eyes tend to envision panoramas, dark ones to concentrate on details

Behavioral variations are focused on the differences between "self-paced" and "reactive" responses to sudden stimuli. In the first subjects follow a well-known plan of animal behavior of pausing and deliberating before decision. In the second the subject flies into instant action (in animals), to attack or to flee. Of course, these behaviors are elaborated in man to govern many more-complex and subtler actions in speech and deed.

Light-eyed subjects are more likely to be self-paced, dark ones reactive. These differences are statistically significant and are patently genetic because they are equally represented in all age groups from kindergarten through professional life. When the iris color categories are extended from two to three, the subjects in the middle, with the mixed, green-to-hazel eyes, are found to share the benefits of the two extremes.

In one experiment ten of each of blue-eyed male, brown-eyed male, blue-eyed female, and brown-eyed female college students were wired to polygraphs and shown arousing pictures of sex and violence with appropriate sound effects. The brown-eyed subjects and the females responded more emotionally than the blue-eyed and male ones did.²⁴

In another test, the same investigator gave Rorschach tests to forty blue-eyed and forty brown-eyed males. The blue-eyed ones fared better with form than with color and vice versa.²⁵ In both tests only pure blue-eyed and pure brown-eyed persons were used.

Few people other than ophthalmologists seem to have looked at retinas, nor to have considered it remarkable that the fundus is of virtually the same color as the person's skin and for obvious reason that the underside of the retina is epidermis

The Negro and the mulatto get 1.75 fcp; the Hindu and the American Indian 1.16 fcp; the brunet European 0.66 fcp; and the Chinese, the blond and the albino get 0.22 fcp. The Negro's and the mulatto's retinas let through eight times as much light as did those of the Chinese, the blond, and the albino.

Once inside the cranial cavity, neural impulses produced by the visible light that has passed through the retinal screen follow one of two paths. One lot goes to the hypothalamus...This part of the brain is the primary control tower of the central nervous system for almost all of the self-starting and self-regulating activity of the body-the sleep cycle, body temperature, the digestive process, fighting and loving.

These activities are managed by the production inside the hypothalamus of regulatory hormones. In some cases directly, but more commonly indirectly, these hormones control the fabrication and release of other, more specialized hormones in the pituitary, or "master gland," seated in its bony saddle at the base of the braincase.

Two of these pituitary hormones become the raw material for making MSH (melanosome-stimulating hormone), so named because it darkens the pigment in amphibia and other cold-blooded animals. In man as in other mammals, it has yielded its pigment-darkening role to the built-in enzymes of the melanosomes themselves. Its only retention of its earlier function is to darken melanosomes.

Meanwhile, the rest of the neural impulses flow through a complicated channel into the brain's third ventricle. From there they continue through several different parts of the brain stem into the pineal gland.

...Among other hormones, the pineal makes melatonin, which flows onto the cortext...Melatonin is an inhibitor; MSH is a stimulator, and one of its results is the secretion of a substance that switches melatonin making in the pineal on and off in countermeasure with is own rate of flow. Thus, the more light the retina lets in, the more MSH will be secreted and the less melatonin.

MHS has two divisions...one affects the peripheral nervous system only, the other may reach the brain, while melatonin bathes only the latter...all else equal, the stronger the light that penetrates the retina the more automatic are the responses to it, and the weaker the light the more the same responses fall under the control of the learning and thinking part of the brain....

To show those who may doubt that MSH and melatonin really affect the behavior of mammals...the National institute of Child Health and Human Development of Bethesda, Maryland, removed the pineal glands from some black rats (hair color, not skin color), pretended to do so with others, and left a third lot unscathed. The victims of real surgery became hyperactive and nervous, but when she injected melatonin into them they calmed down; both the other lots behaved normally throughout.²⁹ Other researchers have given their animals shots of melatonin without operations. These injections reduced their avoidance responses,³⁰ making them pause in the face of danger, rather than fight or flee. These are the "self-paced" and "reactive" responses found among blue-eyed and black-eyed students.

But not all our melatonin is made in the pineal gland. In daylight the choroid, which encases the retina, makes more of this hormone than the pineal does, and in darkness the pineal secretes more than the eye does. This discovery was made by experiments on chicks and rats.³¹ If one seeks to apply it to man, it might be well to remember that the stroma, or outer part of the iris lying above the lens, is mesoderm and an extension of the vascular choroid, also mesoderm, in contrast to the retina, which is ectoderm, like the pigmented layer of the skin. An investigation along this line might possibly explain the differences found in reactions blue blue- and brown-eyed subjects by psychologists mentioend earlier, because blood from the choroid flows direclty into the main bloodstream, some of which feeds the brain.

... [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.

... 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.

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.

"However, the Science Museum feels that Nobel Prize winner James Watson's recent comments have gone beyond the point of acceptable debate and we are as a result cancelling his talk at the museum."

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.

Rick Kittles, an associate professor of genetic medicine at the University of Chicago, said Watson's remarks aren't backed by science.

Robert Sternberg, a prominent researcher on race and IQ at Tufts University, called Watson's statement "racist and most regrettable."

"It is unfortunate that some people with great expertise in one area sometimes lose their sense of perspective and come to view themselves as expert in areas about which they know nothing," Sternberg said Thursday in an e-mail response to questions. "They then proceed to embarrass themselves as well as society in general with their comments that express their own ideology rather than scientific findings."

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."

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.

... 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)

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.

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...)

[T]here is wide disagreement about what intelligence consists of and how - or even if - it can be measured in the abstract.

... 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.

... 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.

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.

In the same way, for many Africans who take Western IQ tests, "our problems aren't relevant to them," Sternberg said."

... [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.

... 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.

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)

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.

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.

... [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.

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.

To group the entire diverse populations of Africa together is a characteristically racist trick.

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.

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.

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.'

... [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.

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

... [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.

After a generation of reproduction the new mean time preference will be increased by (0.2 * .25) or 5% of a standard deviation. In 20 generations, 500 years, time preference should go up by a full standard deviation.

... 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

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.

Many of the reshaped genes are involved in taste, smell or digestion, suggesting that East Asians experienced some wrenching change in diet. Since the genetic changes occurred around the time that rice farming took hold, they may mark people's adaptation to a historical event, the beginning of the Neolithic revolution as societies switched from wild to cultivated foods.

Some of the genes are active in the brain and, although their role is not known, may have affected behavior. So perhaps the brain gene changes seen by Dr. Pritchard in East Asians have some connection with the psychological traits described by Dr. Nisbett.

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.

Let's look at rs:760761, rs:2619522 and rs:2619538, all of which are associated with increased or decreased intelligence in DTNBP1.

Regarding rs:760761, 18% of Europeans carry the T allele, which knocks about 8 points off the ol' IQ, compared to around 7% of East Asians and 37% of blacks.

Regarding rs:2619522, the numbers are similar. 18% of whites carry the G allele, which knocks about 7 points off the ol' IQ, versus around 8% of Asians and 35-36% of blacks...

Regarding rs:2619538, 61% of whites carry the T allele, which adds about 6.5 points to one's IQ, versus about 1% of Asians and 67% of blacks...

If 6% more blacks carry the T allele than whites (67% vs. 61%) on rs:2619538, and the T allele codes for 6.5 FSIQ (full scale IQ) points, then this gives blacks an advantage of .4 IQ points over whites from this SNP.

Also, if 60% more whites carry the T allele than Asians, and the T allele codes for 6.5 FSIQ points, than this gives whites an advantage of 3.9 IQ points over Asians from this SNP.

So the cumulative effect thus far would be:
minus 3.6 points for blacks relative to whites;
and minus 0.2 points for East Asians relative to whites.

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.

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.

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."

Schnupp said undernourished and undereducated people often perform worse on intelligence tests than the well off.

"Race has nothing to do with it, and there is no fundamental obstacle to black people becoming exceptionally bright," Schnupp said."

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.

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."

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.

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...

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...

When you analyze IQ gains over time, you often find that they do not constitute enhancement of these latent traits -- they do not seem to be general intelligence gains, or quantitative factor gains, or verbal factor gains (Wicherts et al, in press). In the language of factor analysis, this means that IQ gains over time tend to display 'measurement artifacts or cultural bias'. For a second time, we are driven to the conclusion that massive IQ gains are not intelligence gains or, indeed, any kind of significant cognitive gains. (pp 27-28)

Watson has apologized and retracted the outburst... He acknowledged that there is no evidence for what he claimed about racial differences in intelligence.

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 on that much at least, he's right. For one thing, science has no agreed-upon definition of "race": however you slice up the population, the categories look pretty arbitrary. For another, science has no agreed-upon definition of "intelligence" either

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."

"All our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really," the newspaper quoted him as saying.

"I cannot understand how I could have said what I am quoted as having said," Dr. Watson said in a statement given to The Associated Press. "There is no scientific basis for such a belief."

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".

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...

The overwhelming desire of society today is to assume that equal powers of reason are a universal heritage of humanity....

To question this is not to give in to racism. This is not a discussion about superiority or inferiority, it is about seeking to understand differences, about why some of us are great musicians and others great engineers.

Crass comments by Nobel laureates undermine our very ability to debate such issues, and thus damage science itself.

"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.

"He's done tremendous damage to science, to himself and to social equality," Coyne said. "It makes us all look bad."

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."

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.

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.

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....

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.

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.

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.

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].

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.
...
But even the people one might think should be his biggest allies aren't supporting that, including Tony Clayton, the special prosecutor who tried one of the Baton Rouge murder cases. Clayton, who is black, admits that he initially dismissed Frudakis as some white guy trying to substantiate his racist views. He no longer believes that and says "had it not been for Frudakis, we would still be looking for the white guy in the white pick-up truck." But then he adds, "We've been taught that we're all the same, that we bleed the same blood. If you subscribe to the (Frudakis) theory, you're saying we are inherently unequal."

Our findings demonstrate that to a large extent, SNPs identified as structure informative in one geographic region are not portable for the analysis of populations in a different geographic region, suggesting that the forces that shaped population structure in each geographic region have influenced different parts of the genome. However, analyzing jointly nine populations from around the world and 9,160 SNPs, we showed that using 50 PCA-correlated SNPs we can assign the studied individuals with 100% accuracy to their population of origin....

...As we have shown here, analyzing two independent Puerto Rican datasets, PCA-correlated SNPs can be successfully used to reproduce the structure of admixed populations and predict the ancestry proportions of the studied individuals. Interestingly, we found that interindividual variation across the Native American axis in the Puerto Rican samples that we studied was very low, perhaps depicting the fact that admixture with Native Americans occurred very long ago, and was random over several generations.