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December 11, 2004



Something a Little Fishy about the Parathyroid Glands...

The parathyroid glands, four little nodules located in your neck, play a huge role in regulating extracellular calcium homeostasis. By releasing something called calcium-sensing receptor, they detect the calcium level in your blood and if need be, send out parathyroid hormone to open up internal calicum stores and equalize levels.

According to a new study by Okabe & Grahm in PNAS, detailed similarity in the expression of numerous genes suggests "the parathyroid gland of tetrapods and the gills of fish most likely share a common evolutionary origin."

A BBC report on all this can be found here, and interested parties can, as always, email me for a PDF of the paper itself.

Posted by God Fearing Atheist at 06:49 PM | | TrackBack


Anthony Flew Gets Religion

You probably need to be a philosophy geek to fully appreciate this one, but renowned British philosopher Anthony Flew has gone from atheist to Deist in the space of a year. His theism will be immortalized in a new edition of God and Philosophy.

The journal Philosophia Christi has an interview with Flew available on-line and also as a PDF. Flew's reason for his change of heart is science's alleged difficulty in explaining "the origin of life and the complexity of nature."

I wonder why, if he was the sort to go for Intelligent Design, he's become convinced only now. The interview doesn't go into enough detail on that point, but Flew does outline his beliefs on divine revelation (possible but unlikely), the problem of evil (still unsolved), the possibility of an afterlife (he hopes not), the evidence for Jesus' resurrection (insufficient, but better than your average miracle), and Islam ("the uniting and justifying ideology of Arab imperialism"). He's considering

[...] the possibility of what my philosophical contemporaries in the heyday of Gilbert Ryle would have described as a knock-down falsification of Islam: something which is most certainly not possible in the case of Christianity. If I do eventually produce such a paper it will obviously have to be published anonymously.
Posted by jemima at 04:43 PM | | TrackBack


Monkey nonmusic

Are consonant intervals music to their ears? Spontaneous acoustic preferences in a nonhuman primate. The short of it:


In Experiment 3, however, subjects showed no preference for consonant over dissonant intervals. Finally, tamarins showed no preference in Experiment 4 for a screeching sound (comparable to fingernails on a blackboard) over amplitude-matched white noise. In contrast, humans showed clear preferences for the consonant intervals of Experiment 3 and the white noise of Experiment 4 using the same stimuli and a similar method. We conclude that tamarins' preferences differ qualitatively from those of humans. The preferences that support our capacity for music may, therefore, be unique among the primates, and could be music-specific adaptations.

I had to bold the part about about how tamarin preferences "differ qualitatively from those of humans." Sounds hilarious huh? I mean, they are tamarins!:

But in any case, so this particular monkey can't keep a tune (or whatever). Though I claim to be tone deaf, I am as terrified as the next guy by screeching on a blackboard, so I'm not inhuman. This evidence from tamarins tells us musicality might be a feature of the past 30 million years of the evolution of our lineage. Songbirds seem to be tweaked on FOXP2 as well, so musicality might be associated with the rise of language (going out on a limb!).

Related: Music is for the babies (in terms of evolution).

Posted by razib at 04:34 AM | | TrackBack


Get the premium content!

I let my subscription to The Economist lapse 4 months ago because I just stopped reading current events enough to justify it (I was reading about 2-3 articles a week out of any given issue), but I noticed today that you can get all their content by watching an add. Anyway, I'm sure most of you know already, but I figured I would spread the word....

Posted by razib at 01:02 AM | | TrackBack

December 10, 2004



Two More Correlates of g

Two more in-press papers from Intelligence.

The first, Prokosch et al., finds a .39 correlation between their most g-loaded tests (Raven's Advanced Progressive) and body symmetry. Their explanation is that

A parsimonious explanation for our findings is that both neurodevelopmental stability (as manifest in general intelligence) and morphodevelopmental stability (as manifest in body symmetry) tap into an underlying general “fitness factor” (Miller, 2000a and Miller, 2000b). In factor-analytic terms, general fitness is superordinate to these two forms of developmental stability. The existence of this superordinate fitness factor may explain why general intelligence positively correlates with so many fitness-related biological traits such as health, longevity, and physical attractiveness (Jensen & Sinha, 1993; Whalley & Deary, 2001; Zebrowitz et al., 2002).

Continue reading on Ultradarwinian

Posted by God Fearing Atheist at 02:49 PM | | TrackBack


The unAdapted mind?

While I'm on a mind kick, check out this 1998 ritique from Jerry Fodor of "psychological Darwinism" (in particular, two books, one by Steven Pinker and another by Henry Plotkin). I think you will be able to the infer the influence of a particular paleontologist on Fodor's thinking....

Posted by razib at 02:26 PM | | TrackBack


Bad theories & incongruities

A few weeks ago Will Wilkinson posted the following:


Similarly, I think the mind is pretty modular, if not massively so. Thus, I don't think there is anything like a general reasoning capacity...Yet I'm rather impressed by the data on G, and how it predicts quite a number of things. So what is G tracking if there is no general reasoning capacity?

Now, I've wondered about this as well, because I too tend to subscribe to modularity and a belief that g has great predictive power. What's going on? In Prehistory of the Mind Steven Mithen (another Steve & evolution!) suggests that "general intelligence" is a basic facility that is a rough tool that we share with other homonoids. In fact, Mithen believes that chimpanzees "learn" language with their general intelligence, thus, their lack of fluency in terms of syntax. In contrast, humans have a "language instinct," which allows us to naturally grasp the nuances of grammar as well as sponge up vocabularly. There is something to this general sketch, but here is my conception of what's going on. I'm going to start out with two facts:

  • We know that g is normally distributed (roughly).
  • We know that g correlates with many other cognitive capacities, for instance, mathematical aptitude.

For a trait influenced by a large number of genes the result is often a normal distribution in terms of the phenotypic expression. Since g is normally distributed it is plausible that it is a phenotype with a large constellation of genes upstream. And sure enough the work I've seen by behavorial geneticists like Robert Plomin tend to offer very small values for the additive contribution of any one locus (on the order of 1%).

In contrast, capacity for language (though not eloquence), is an on-off feature, that is, we all have the "language instinct," and some would argue that FOXP2 might be the "master" regulatory gene which is central to its function. Language is the archetypical module when we think of higher cognitive abilities.1 People can tell that a sentence sounds "wrong" without being able to elaborate why. Contrast this with mathematics, with its system of proofs. Theoretically mathematics is conceived as reflective rationality incarnate. But if you read books like The Number Sense you will note that mathematics itself seems to emerge from a synthesis of basic analog numerosity as well as linguistic and visuospatial capacities. In cases of individuals with brain injuries there are those who can lose the capacity for geometrical reasoning but may still be able to perform algebraic manipulations, and some individuals who "can not count" who can still make assertions about geometric questions by inspection. The evidence seems to be that mathematics is an emergent property of various cognitive domains. Papers that note the importance of "hemispheric integration" in mathematical aptitude also suggest it is a complex trait with many variables contributing to the full expression of the "phenotype."

And so with g. In Prehistory of the Mind Mithen argues that the interaction between the various modules facilitated by analogical thinking was crucial to the "Great Leap Forward" in human cognition, so he's basically saying the same thing. All the various subroutines, some of which, like language, have very focused primary tasks, nevertheless intersect and contribute to the formation of a "general intelligence" which transcends the limitations of any given module. I know Steven Pinker believes that religion is a byproduct of the interactions of various modules (in concert with environmental cues), so even massive modularity does not imply a hermetic seal between various cognitive processes in the minds of those who espouse that hypothesis. In both The Mating Mind by Geoffrey Miller and The Blank Slate by Pinker you have two books which seem to assume a modular mind and say some positive things about psychometry and the attempt to ferret out g. So the "Thus" part of Will's thought does not seem founded.

Anyway, my thoughts aren't fully fleshed out on this topic, but I simply wanted to elaborate on what I posted on Will's blog.

Addendum: Please note that the site about FOXP2 asserts that mutations to the gene also seem to have a major impact on "general intelligence" (verbal and non-verbal) something that the popular press reports tend to omit. Since language is likely one of the crucial building blocks of general reasoning capacity it stands to reasoning that the removal of this variable would cause havoc downstream.

1 - Steven Pinker has argued that the language module is more naturally decomposed into grammatical & lexical modules. See his work on irregular verbs.

Posted by razib at 01:02 PM | | TrackBack


Teachers - They Simply Can't Win

Chris Correa does a good job of summarizing a paper by Deborah Stipek, the Dean of the School of Education at Stanford, in which she notes that teachers tend to instruct African American and Hispanic children differently than they do Caucasion children. I won't be repeating Chris's analysis so give it a read to get a better understanding of this paper.


Stipek goes into great detail in explaining her methodological constructs for this study which primarily distinguish between didactic and constructivist pedagogies. Here is another source which more succinctly summarizes these two differing approaches to education:

In the didactic approach, learning is passive, with students receiving an incremental, ostensibly authoritative, predetermined linear sequence of facts from a teacher acting in the role of sage. Passive learning often involves memorisation, rote, or delivery of material via lecture, slideshow, handouts, etc. Active learning, on the other hand, is learning by doing.

The notion of teacher as a guide does not imply the teacher has no control or is not in an active role. Actually, the teacher must be able to exercise great finesse in creating and controlling the learning environment. In the constructivist approach, the teacher often acts in the role of facilitator, as opposed to an ultimate authoritative dispenser of knowledge. The didactic and constructivist approach can be summed up in this respect by the analogy "the sage on the stage versus the guide on the side."


A comparison of two teaching methodologies
DidacticConstructivist
PassiveActive
LinearNon-linear
Teacher as sageTeacher as guide
Little or no student choiceSignificant student choice
Part-to-wholeWhole-to-part
Skills taught in isolationSkills taught in a relevant context


Now, many of will recognize the didactic approach as the one we had in school, and quite a bit of it in university too, for that matter. Also, the many parents who clamor for Back to Basics schools are voicing their support for the didactic method:

Calgary, Alberta: Imagine a classroom where a teacher snaps her fingers and students repeat what she just said all together. That's one of the teaching strategies of the Foundations for the Future Charter School. Charter schools are publicly funded, but put special emphasis on one style of education. For Foundations, discipline and structure, repetition and concentration are the keys.

For students, uniforms are mandatory. They learn as a class, and lessons don't begin until they are sitting in the ready position--feet on the floor, hands together on the desk.

Teachers are encouraged to stick to a strict formula on how to give information to students. Creativity is not encouraged. Some prefer the style. One says it allows him to be a teacher, not a social worker or a psychologist. One visiting teacher who helps kids learn in-line skating says his more loose, free approach to teaching confuses some students. He says while they work well in groups, some have trouble working independently.

The Foundations method shows results. The students consistently rank higher on provincial achievement tests. Eight hundred students have signed up in the last 5 years, 4400 are on the waiting list.


Clearly, the constructivist-didactic dichotomy is not a black and white one for didactic can produce startling results and is in great demand by parents seeking escape from constructivist instruction. (Full Disclosure - I'm in favor of the socratic method and the related Harkness Table which are closer to the contructivist pedagogy but which absolutely require having a teacher who is whipsmart, has a mastery of the content knowledge and is able to outthink the students.)

Stipek makes clear her position that the didactic method inhibits the progress of the students and further that teachers differentiate by ethnicity in how they teach.

Both a high proportion of low-income children and a high proportion of African–American children predicted didactic teaching. The effect of the proportion of low-income children disappeared when ethnicity was added to the equation, suggesting that ethnicity, not family income, was the more powerful predictor of didactic teaching.


After noting that the teachers who participated in this study do indeed teach African-American and Hispanic children differently than Caucasions she begins her quest for the why of this situation. First she looks to whether the teacher's goals have predictive value:

As predicted, teachers’ goals were highly predictive of their teaching practices, with teachers who stressed higher-order thinking engaging in more constructivist and less didactic teaching, and teachers who stressed basic skills engaging in more didactic and less constructivist teaching. Teachers’ perceptions of barriers to parent involvement predicted didactic but not constructivist teaching. Relatively high proportions of African–American and, to a modest degree, high proportions of Latino students predicted low levels of constructivist and high levels of didactic teaching, even after variance associated with teachers’ goals and perceptions of family challenges was eliminated.


Stipek notes that there is still a tendency towards didactic process even after accounting for teacher goals. She neglects though to construct her model to account for the teacher's goals being influenced by the students themselves, though she does note this in her discussion of the findings. It's quite plausible to posit goal forming via an iterative process where the teacher's goals are tempered by experience. Of course others could see this process as the solidification of racist prejudices. I however, find it more plausible that with the teaching profession, until recently, giving more credence to the "love to teach" segment over the "mastery of content" faction, would skew towards the idealists in the profession who would have finely tuned racist radar and bend over backwards to be impartial. However, as the teacher's experience grows year after year they may start to discover that particular approaches may work better for some groups. There need not be nefarious motives ascribed.

Next, Stipek looks at the student's level of preparedness for the curriculm:

The proportion of children below grade level was the strongest predictor of the amount of constructivist teaching, more so than the proportion of low-income children or the ethnic composition of the school. Teachers may have avoided constructivist approaches in schools in which children were substantially behind academically because they believed that constructivist approaches, which usually involve a fair amount of child choice and initiative, would be inefficient. The proportion of children who were below grade level did not predict the amount of didactic teaching observed, however, after the proportion of low-income and African–American children were eliminated, suggesting that different student characteristics may influence the degree to which teachers use constructivist and didactic instructional approaches.

A finding regarding the target children in the larger study may also be relevant to the present findings related to didactic teaching (Miles&Stipek, submitted for publication). Teachers rated African–American children, especially African–American boys, as significantly more aggressive than both Caucasian and Latino children. Perhaps teachers felt a need to impose stricter control and to implement more structured, teacher-dominated instruction to maintain order in classrooms in which they perceived children to be hard to manage.


Now in this study Stipek focused on the challenges unique to pre-dominantly low income schools and the performance of African American and Hispanic children and in the end points to teacher goals as being the dominant predictor of pedagogy employed. Chris notes in his conclusion, and I think he's simultaneously being too charitable to this study and also stating the obvious:

But it’s important to remember there are significant differences in teaching practice - even in early elementary classrooms - that can help explain differences in young children’s motivation, social development, and academic achievement.


Yes Chris, teaching practice can help explain different outcomes, but this study does nothing of the sort. Stipek ends up pointing at teacher goals without modeling the goal forming process and without testing her findings across a wider socio-economic spectrum. The academic gap persists when controlled for SES, even for the top African-American and Hispanic students. Look to this report from the New York Times:

Yet whites and blacks taking similar level courses report that they spend the same time on homework. It is just that the results are different: 38 percent of whites who spend two hours on homework nightly get all their work done; only 20 percent of blacks spending two hours finish their homework — the Gap.

It would be politically convenient for Professor Ferguson, a black man raising his two children plus a nephew in a Boston suburb, if the Gap could be explained away by economics.

It cannot. When he controls for income, half the Gap persists. Among the richest families, blacks average B+, whites A-. How to explain it?


How to explain it indeed? Perhaps the education researchers should start looking outside their field at the research being published in genetics:

The g factor has a normal distribution in the general population, suggesting g is probably a product of several genes that interact with the environment. Moreover, although g correlates with the parental value, it has a tendency to be closer to the population mean, suggesting a regression to the mean. These observations suggest that some genetic variants that influence g will vary between populations rather than within populations. For instance, certain Asian populations have a frequency of 0.60 in COMT Met158 allele, which predicts lower COMT-enzyme activity and thereby better cognitive performance, while Caucasians have a frequency of 0.42 for the same allele.


These research results, in conjunction with a large body of psychological research on regression to the mean can in part, and in conjunction with environmental influences, explain the performance gap we see even amongst the highest SES participants. The children of the talented and well-off regress:

The BW- IQ gap increases with socio-economic status (SES). Because IQ correlates with SES, parents of higher SES have a higher average IQ-score. This means, that the offspring in the higher SES categories will show more pronounced regression towards the population mean. But because the population mean for blacks is lower, regression towards the mean will produce a more pronounced IQ lowering in the offspring of black parents, thereby widening the IQ gap between white and black offspring in these SES-segments. This is exactly what we observe (Jensen p.469 and 358).

Siblings of bright black children have lower IQ-scores as compared to siblings of equally bright white children (p.470-471). Regression to the mean helds true for both black and white sibling pairs over the full range of IQs (approximately from IQ 50 to IQ 150). "These regression findings can be regarded, not as proof of the default hypothesis, but as wholly consistent with it. No purely environmental hypothesis would have predicted such results" (p.471).


While I frequently enjoy poking fun at the idiocy of the teaching profession and the fads they fall for, like the switch to purple markers because red is more stressful and demoralizes students, while purple, the preferred color, has a more calming effect, I think that Stipek, in this case, gives teachers a bum rap by concluding that teacher's goals are formed independently of their experience in dealing with different populations of students.

While a teacher's influence is indeed important they can't work miracles and lawsuits, the NCLB, and court decisions notwithstanding, the most important participant in the educational process is the student and it is a disservice to them to ignore research into differential approaches which prove more beneficial for different groups.

In the end I'm not sold on a causative relationship between ethnicity, teachers' pedagogical choice and student performance. When the educational establishment begins to incorporate the research coming from genetics labs then exciting new fields of research will open up and this will quite possibly improve the school experiences for millions of children. Such research would be a welcome supplement to the strictly environmental models we see being published in journals, and which form the basis of our public policy.

Posted by TangoMan at 02:54 AM | | TrackBack


Still friends....

As many of you know Frank Miele, senior editor of Skeptic Magazine, is a Galtonian who interviewed Arthur Jensen for Intelligence, Race and Genetics and co-authored Race: The Reality of Human Differences with Vincent Sarich (a book in which Miele thanks Michael Shermer for his support). Michael Shermer is the publisher of Skeptic and the face of the "Skeptics Society," the man who hired Miele as senior editor. He is also a defender of the legacy of Stephen Jay Gould (who wrote the foreward for Shermer's book Why People Believe Weird Things) and evolutionary psychology. Things that make you go hhhmmm....

Posted by razib at 01:53 AM | | TrackBack

December 09, 2004



Interesting HapMap Graph

I stumbled upon this graph a week ago while looking at the supplementary information for the 2002 Gabriel et al. paper on the hapmap. Supplementary info isn't printed with the paper and you have to go to the website to look at it.

The layman's summary: you don't really need to know what F_st is to appreciate the significance of these plots. These graphics show whether allele frequencies between populations are positively correlated or not.

For example, consider base pair 100 on chromosome 1. Suppose that 30% of self-identified Yorubans have a G there and 70% have a C. With high probability, self-identified African Americans will have close to a 30/70 split, while essentially *no conclusion is possible* about what the G/C split will be in self-identified Europeans at that locus.

You can see this from the graph, as the Yoruban and African-American sample frequencies are very tightly correlated (fourth panel). However, the African-American and European sample frequencies are all over the map. Furthermore, the frequency differences between African and non-African populations are moderately correlated (fifth panel).

Posted by TangoMan at 08:23 PM | | TrackBack


Births, voting and Wogs

We now all now about Steve Sailer's story in the American conservative comparing State's White Fertility rates and the likelyhood of that state going for Bush in the last election. As a followup to this story, Dave Kopel guest-blogging at Glennreynolds.com points out Kos, of the Arch-leftist blog DailyKos, trying to spin this as the inherent immorality of the red states.

When Red States get their social problems under control, and things such as teen pregnancy down to nationwide lows, then they can try and foist their solutions on the rest of the country.

But as things currently stand, on this issue (as well as others like divorce), the Red States have no ground to stand on. Those crazy New Englad [sic] liberals are running circles around them in this tangible measure of their residents’ “values”.

I think this needs to be commented on since it is an example of the rampant political bigotry arising on the left, it is also important to show the creation of the new wog for the left, red-staters.

The etymology of the term "wog" shows it to come from England during their time of exploration and colonization. It is a term meaning "other" and implying to those it is used upon that they are; less than human, unintelligent, and immoral. If you take the recent "IQ by state vs. candidate preference" hoax, combine with Kos' own words showing he thinks red-staters are immoral "When Red States get their social problems under control" and less-than-human (i.e. not worthy of contributing to a national debate in a democracy) "then they can try and foist their solutions on the rest of the country.", one can see that he (and the left as a whole) considers the Bush voters as Wogs.

This is simple bigotry and, for a healthy democracy, it must stop.

Posted by scottm at 07:17 PM | | TrackBack


Maladapted to our Habitat

For millions of years we lived in tribal units, stretching back in time far beyond the origins of our species, and continuing almost up to the present. A mere 10,000 years ago, all our ancestors lived as hunter-gatherers. Probably, most of our ancestors were still hunter-gatherers only 5,000 years ago. But even after that date, we lived in small villages - from a social point of view not too different from a hunter-gathering tribe. Modern life, intimately bound to the social milieu of the city, became the native habitat of the majority only about a hundred years ago, and then only in the most technologically advanced countries of the world. It is a profound change for mankind that after millions of years of evolution for tribal life, we find ourselves in an habitat that doesn't support it.

It is my opinion that many of the psychopathologies of the modern world result from the breakdown of the tribal unit. We are highly adapted to tribal life, and only by understanding this fact, and what it implies, can we understand human nature. The bottom line is this: we are profoundly maladapted to our habitat. Symptoms of our maladaption include feelings of ennui, isolation and depression, so common in our society. From an evolutionary perspective, these are clearly disadvantageous. Who is more likely to survive and reproduce – a depressed, listless individual, or a happy, energetic individual? Clearly, these problems are severely selected against, and indeed in tribal societies living close to our original habitat these problems are rare. It could be argued that these feelings are adaptive responses to negative environmental factors, like pain, which would cause us to avoid them. But my observation is that people who suffer from these problems usually have no idea as to their cause, or what to do to overcome them. In my opinion it's more properly seen as a spurious emotional response to unexpected circumstances, much like a computer program given unexpected input – the output is spurious because the inputs haven't been accounted for.

It is well known that our taste for sweets and fats, an advantage in a world poor in these nutrients, has lead, in lands of plenty, to the current epidemic of obesity. We have no natural restraint (or not enough) to keep us from overeating simply because this circumstance was too rare to make developing such restraint evolutionarily advantageous. Something similar has happened to the social nutrient of the tribe. It used to be geography that circumscribed the tribe, and economics which bound it together. Tribal units were physically isolated from one another, villages were distant, and cooperation essential to survival. (The distances need not be great, I think a half-hour walk is enough.) Now the speed of our cars, the density of our cities, and the complexity of our economy have erased these boundaries.

From my vantage point, these things seem obvious (though not necessarily true!), probably because my vantage point is unusual in the modern world: it is distinctly tribal. My ancestors have been urban for thousands of years, and it is perhaps because of this that they developed cultural defenses to high-density living, creating a tribal life through cultural institutions. (Or perhaps not, in any case, the institutions exist.) But let us examine more closely the psychological notion of a tribe. A tribe is a group of people who act, to some degree, altruistically. Barring unusual circumstances, any group of people whose members interact with each other, will become a tribe. The commenters of this blog are a tribe: I am quite sure that they are more likely to be altruistic toward each other than toward people chosen at random. But from a psychological point of view, that is not the defining characteristic. Rather, the most important characteristic of the tribe is that it gives the individual an identity. People who have a weak identity are likely to do crazy things to get one, like become a Nazi, or just become depressed. On the other hand, one who is immersed in his tribe lives with a certain kind of tranquility, a life without the modern plagues of ennui, isolation and depression, though it may be full of ordinary boredom, loneliness, and unhappiness. (The difference between the two: one is chronic, the other causal hence adaptive.) When I look out at modern life, the closest thing to a tribe that I see is the workplace - and this is a poor substitute for the real thing, like eating cake instead of food: filling but not nutritious.

Given enough time, I suppose that humankind could evolve from dogdom to cathood, become a solitary creature that meets only to work and mate. I don't think this is likely. Another, easier, strategy is available: to augment our genes with memes, and create tribes strong enough to withstand the hardships of our habitat. I think the change will become clear in the next few generations. We are already seeing it now.

Some candidates for the tribes of the future: Observant Jews, Evangelical Christians, Mormons, Parsis (though I hear that they're having a problem with fertility, an essential feature for survival), Sikhs, Jains, Marwaris (certainly other Hindu castes as well, that I don't know about), Japanese (I have heard that the true religion of Japan is Japanism), Falun Gong (other Chinese sects?), Druse, Ismailis (I would include Islamists, but my impression is that they're not demographically well-defined - maybe Islam as a whole should be on the list?)... Others?

Cross-posted at Rishon Rishon.

Posted by David Boxenhorn at 02:51 AM | | TrackBack


HLA again...and again....

Though our society (that is American society) makes a great rhetorical show of cherishing "diversity," I've said several times that it is on the HLA locii that this takes real form (see here or here). The polymorphic diversity seems peculiar on such essential genes implicated in the coding of crucial components of the immune system. They shoud have been "fixed" long ago in the variants which code for the most "fit" phenotypes. But, as this article suggests, the diversity of the HLA locii is another twist in the great game between parasites and their prey (sex is likely another arrow in the quiver of multicelluar organisms against their foes). In Narrow Roads of Gene Land William Hamilton even suggests that balancing selection, that is, advantage to novel heterozygote conformations, might not be where the advantage lay, rather the long term fitness is paramount in that parasites will sweep through populations cyclically and any one defense is never absolutely perfect. A mixed strategy, if at any one time suboptimal, might be the most prudent. But in any case, the crucial point about the aforementioned BBC article is that it points out that a particular HLA variant on a particular gene might be more efficient at zeroing in on the HIV virus. Remember, this kaleidoscopic formation of genes transcends the bounds of species and predates our separation from our great ape kin, it's got to be doing something right....

Of course, to some extent this is old news.

Addendum: Nature, which is publishing the research mentioned in the article above, has a gene map of the MHC (PDF) molecule. For immune system nerds only....

Posted by razib at 01:51 AM | | TrackBack

December 08, 2004



Getting physical....

We focus on bioscience on this blog, but I found this article on String Theory worth the read...though obviously I can't comment on it, my brother is the physicist.

Posted by razib at 10:38 PM | | TrackBack


"Stickin' it" to Steve

Courtesy of "PC" Myers, the American Prospect blog, Tapped, has a hilarious piece on our friend Steve Sailer that the good doctor very strangely describes as a "smack down."

There is not a single substantive issue raised; the whole piece is nothing but hysterical biophobia and name-calling.

Update: I failed to notice that Steve had already taken this up on his blog. As he said about attacks on him (and I might add, against people who write on these issues generally):

The defining characteristic of anti-Sailerist diatribes is multitudinous quotations from my writings with no attempt at refutation of the truth of any of my statements -- the reader is simply supposed to be shocked, SHOCKED that anyone would dare write such politically incorrect things.

No truer words spoken.

Update #2: PC has taken Steve to task on the baby-gap yet again.

Posted by God Fearing Atheist at 03:52 PM | | TrackBack


Apples, oranges, masjids & churches

Via Pearsall Helms, via Pandagon, I stumbled upon this blog entry which suggests that Saudis are less religious than Americans (or other Arabs for that matter). The evidence?


...but I was quite surprised to see that American led this list with 45% of its citizens attending services at least once a week. Jordan was right behind at 44, Egypt and Morocco at 43, Turkey at 38, Saudi Arabia 28, and Iran 27...The question of how religious countries are is, of course, more complicated but service attendance is the old standby measure.

...Percentage of citizens who consider themselves religious: 98% Egyptians; 85% Jordanians; 82% Iranians; 81% Americans; and 62% of Saudis.


Yes, a warning sticker should be put on this sort of survey data. In The Churching of America Roger Finke and Rodney Stark offer the following statistics for American church membership:

1776......17% 1850......34% 1860......37% 1870......35% 1890......45% 1995......65%

From this are we to conclude that the United States was a godless republic at its founding? Does this explain the relative religious heterodoxy of early American presidents like John Adams or Thomas Jefferson in contrast to the pious platitudes toward orthodoxy which are mandatory for any contemporary candidate for executive office?1

I think a more nuanced answer is that in a republic of agrarian farmers church membership is something that is less salient because of the relative isolation of individuals on rural farmsteads or hamlets. The lack of affiliation is simply a function of transporation constraints, that is, church membership tracks the rise of the movement of Americans to urban centers where congregational worship is more natural (recall that Christianity was at its founding an urban religion, the people of the countryside were pagani). Additionally, one has to recall that many of the American states had established churches during the early republic, this does not point to a secular population at all. Thomas Jefferson's assertion: "It does me no injury for my neighbor to say there are twenty gods, or no God," was not a statement that would likely be an expression of the normative attitude toward pluralism. In contrast, a common hostility toward Roman Catholicism (a deviation from Protestant convention far less egregious than "twenty gods" or "no God") persisted deep into this century as (a hostility which began its long recession with the rise of normative Protestant congregational membership in much of America).

The digression above is just to point out that such simple comparisons like this do not map well on to the American common sense understanding of what it means to be "religious" or "nonreligious" (frankly, this often difficult to tease apart in a intranational, as opposed to international, context2). Simple juxtapositions are problematic because they neglect the peculiarities of context. The significance of assenting that one is "religious" has to be weighted with full knowledge of what it means to be religious in that given society. For example, my parents are socially conservative religious people in the United States, but in Bangladesh they are liberal to moderate in their religious and social orientation. Also, on a specific minor note, one might wonder as to the sex ratio of the people being surveyed in some of these nations, in Saudi society I am skeptical that women would attend "religious services" in a formal manner at the same rate, so male:male comparisons might be more informative.

Take home message: simple evidentiary talking points are hard to extract from this sort of data, whether you are on the Right or Left, without caveats, qualifications and analysis.

1 - For me the most persuasive explanation of the relative heterodoxy of the early presidents in comparison to the baseline orthodoxy is that limited sufferage meant that traditional elite openness to doctrinal heterodoxy was reflected at the polls.

2 - To go back to church membership, the Catholic Church tends to have laxer standards in terms of counting people as on the "rolls" of a particular parish or congregation. At the other extreme some Protestant denominations are very strict about purging those who do not maintain fidelity in terms of attendence.

Posted by razib at 03:18 PM | | TrackBack


The Bible as the Source of Scientific Truths

We're all familiar with the creationist movement taking its cues from the Bible and their battlefronts in the school districts, most recently in Dover, Pennsylvania.

Then, perhaps feeling emboldended, or simply wanting to open another front, the Biblical interpretation of the Universe was extended to geology, specifically arguing about the formation of the Grand Canyon. What's next, well the Dover activists, could be looking to reform mathematical constants: Hat tip to Kimberly Swygert

The Dover school board has raised eyebrows and ire across Pennsylvania and the country after requiring math teachers to offer 3 as an acceptable value of Pi. . . ."That's all well and good," said Maureen Callister, Dover school board member, "But what about God? Doesn't he have a say?" Callister cited the Bible, First Kings chapter 7, verse 23, where it says, "He [King Solomon] proceeded to make the molten sea ten cubits from its brim to its other brim, [...] and it took a line of thirty cubits to circle all around it." "If 3 is a good enough 'pi' for the Almighty, then it ought to be good enough for us," stated Callister.

"Listen, I go to church on Sundays, I tithe, I don't need this," said Timothy Ernesto, a 10th grade math teacher in the district, "I need to get these kids ready for the rest of their lives, the SAT's, the ACT, the whole alphabet soup of testing they'll face before college. On top of all that, I have to teach an 'alternate reality' flavor of mathematics? I'm going to need my summer off!"

"We firmly believe that God already explained himself adequately, and he doesn't need us to second-guess him," defended Callister, "Besides, who ever really uses this stuff after school, anyway?"

(The above is quoted from a satirical site, much like the Onion.)

Here are a few links on the history of rejigging Pi. Indiana's attempt, and Kevin Drum's review of the history of Pi from way back in 1996.

Posted by TangoMan at 02:04 PM | | TrackBack


Jell-O: The Drug

Do you ever read about teachers complaining that the public doesn't give them the respect that they feel they deserve? Well, here's the latest evidence that there's something terribly wrong, most likely a cognitive deficit, in the profession:

A girl, 8, was suspended for nine days for bringing to school what appeared to be about 30 "Jell-O shots." Under the school's ban on the possession or distribution of a lookalike, the girl's suspension will stand even though the gelatin contained no alcohol, a school official said.

OK, the principal can ascertain the severity of the situation by asking the girl how she came to bring the shots to school. Did she take them from home without her mother knowing? (good chance of alcohol and a good call on the principals part) No, her mother told her to bring them to school. What is the probability that the mother told the girl to sell alcohol shots to 4th graders? Not likely. Since when did little cups of Jell-O become a lookalike drug to 9 year olds. Does Bill Cosby's pitching Jell-O now make him a lookalike drug pusher?

Update:How about suspending teachers for the lookalike curricula they pass off or suspending kids for drinking water which looks like vodka.

Let's have a little fun with the lookalike criteria . . . any ideas?

Posted by TangoMan at 11:36 AM | | TrackBack


Galton's Fallacy

A few months ago I posted on the subject of Galton’s Fallacy. In recent years this term has come into use among academic economists to designate a certain fallacy about growth rates. It is named after Francis Galton because Galton (allegedly) was one of the first to commit it. My post examined what was meant by the term and whether or not Galton was guilty of the fallacy. I also looked more generally at fallacies associated with regression to the mean. I found there was a lot of confusion about what Galton’s Fallacy was, but whatever fallacies Galton may have committed, Galton’s Fallacy was not among them!

I know that people often come to GNXP via search engines, so occasionally I do a search for topics I have posted on, to see if they are catching the attention of the searchers. Usually I find they do quite well - for example, my recent post on kin selection came up as result no. 10 on that subject. I dare say this is more due to the number of links to GNXP than to any enthusiasm for my own meanderings, but whatever the reason, it is nice.

I am immodest enough to think that my piece on Galton’s Fallacy is one of my better efforts, and potentially useful to others, so I was disappointed to find that it didn’t show up in search results on the most popular search engine, even though another post of mine which merely mentioned Galton’s fallacy in passing did show up. So I wonder if some quirk of wording or layout was responsible.

The purpose of the present post is therefore:

a) another attempt at catching the attention of people interested in Galton’s Fallacy, and

b) an experiment to see if a shorter post, with frequent references to Galton and Galton’s Fallacy, does better at tickling the fancy of the search engine.

For those who want to know more about Galton’s Fallacy, or Galton, or fallacies in general, my original post on Galton’s Fallacy is here!

Posted by David B at 07:49 AM | | TrackBack

December 07, 2004



Tiger, tiger....

I can't help it, I must link to this PLOS paper on Tiger phylogenetics. Tigers are cool! Two things of note, people might be surprised that Tigers probably showed up in India around 12,000 years ago, that is, Homo sapiens predates the dark lord of the jungle. Additionally, it seems that the coalescence of the various Tiger mtDNA lineages corresponds with the Toba explosion in Sumatra, which has also been implicated in a population bottleneck among humans (in The Real Eve the Toba event is a watershed in human genetic history).

Posted by razib at 10:42 PM | | TrackBack


Pass the Potato Chips

I firmly believe that the best things in life are sugar, salt, and fat. Sugar is the gas that makes your body run, salt is an essential mineral without which you'd keel over, and fat...well, fat just tastes good. Salt gets a bad rap, though. We wince in horror when Emeril tosses a handful of it into his latest recipe, we scold people who eat it straight from the shaker (take my word for it on this one), and we feel potato chip guilt---because we know the lowly potato chip is nothing more than a vehicle for the administration of the forbidden mineral.

But I'll never turn down a potato chip again, because salt is actually completely harmless for the majority of munchers. Earlier this year, JunkScience reported on the federal government's ongoing and groundless Salt Assault. I just spotted the news in their 2004 Junk Science Awards, where the salt assault placed at #9.

Here's the blurb:

In early 2004, a panel of the National Academy of Science’s Institute of Medicine urged that the recommended daily allowance of sodium be drastically reduced by almost 40% and that the average American’s actual sodium consumption be slashed by more than 60% -- even though 10 major studies conducted since 1995 have all concluded that lower sodium diets don’t produce health benefits and may pose risks for some. Why the extreme recommendation? Political correctness run amok. Read more...

The PC effect comes in because the munching minority who happen to be slightly more sensitive to dietary salt (and therefore more likely to suffer slight elevations of blood pressure) than the rest of us are (did you guess?) African-Americans.

But because the panel didn’t think that singling out African-Americans was an effective public health strategy, it decided to “overcompensate” and make the recommendation for the general population ¯ thereby shifting the burden to the food industry to reduce salt content in foods. African Americans, then, couldn’t help but eat less salt.

Setting aside for the moment my personal loss of potato chips caused by the decades-long salt superstition, I think the panel's approach was counterproductive. Singling out African-Americans would be the more effective strategy. People are more likely to listen to a message that's directed to them. I never really believed the salt hype, but if someone had told me that Luso-Americans (Portuguese Americans) in particular had an issue with salt, I would have been more likely to take them seriously.

I could go on, but I'm going to go make some malassadas (Portuguese fried dough) instead.

Posted by jemima at 03:48 PM | | TrackBack


Genetically Modified Super Coca?

[crossposted from GeneticFuture.org]

Apparently, there's speculation that the Columbian drug cartels have been working on genetically modified coca plants. Whether GM technology is being used or not, it does appear that new crops are popping up that are herbicide resistant and produce eight times the yield of cocaine:

From a Reuters release:

BOGOTA, Colombia (Reuters) - Giant coca plants said to resist herbicides and yield eight times more cocaine may be due to extra fertilizer, not a drug cartel's genetic modification program, a scientist said on Tuesday.

A Colombian police intelligence dossier quoted in the Financial Times said smugglers apparently received help from foreign scientists to develop a herbicide-resistant tree that yields eight times more cocaine than normal shrubs.

But a toxicologist who studied the plants for the police said he knew of no evidence that showed whether the plants were genetically modified or merely grew big because they received an unusually large amount of fertilizer.

...

"We regularly hear rumors that narcotraffickers are working to create a transgenic form of coca, but there is no scientific proof that they have undertaken such research," Phyllis Powers, Director of the Narcotics Affairs Section of the U.S. Embassy in Bogota, said at the time.

Well it doesn't look like we've got giant GM coca monster plants yet... but it's not at all inconceivable. When you look at plants that have pharmocological value to humans, the evolution of those plants often gets kicked into overdrive.

A really (really!) great read is The Botany of Desire - A Plant's-Eye View of the World by Michael Pollan. In it, he talks about how one way of looking the evolution of plants is to consider how they have "used" humans. This is in the sense of how a flower "uses" a bumblebee. The bumblebee thinks it's just using the flower to satisfy its needs, but the flower thinks it's just the other way around. Michael Pollan considers how four plants -- the potato, the tulip, the apple, and marijuana -- have used humans to advance their own agenda.

When you think about it, marijuana has done this amazing job of using humans to extend its reach through the biosphere. I doubt any plant has ever expanded its habitat as quickly as pot has in the last thirty years. It grows in pitch-black basements, in frozen Scandanavian cities, and it will no doubt be grown in space someday.

Yes, this all happens with the help of humans and our technology, but to deny that we play a part in natural evolution would be like denying that bees play that same role. Have you ever seen how a beehive works? They have technology too!

Posted by canton at 02:59 PM | | TrackBack


It's a Ring thing

A puzzle for Wagnerian geneticists (if such exist): what is the coefficient of relationship between Siegfried and Brünnhilde?


For the benefit of non-Wagnerians, Siegfried is the son of Siegmund and Sieglinde, the twin offspring of Wotan (in the guise of Wälse) and an unnamed mortal woman. Brünnhilde is the daughter of Wotan and the Earth goddess Erda. So far as we know, Wotan, Erda and the mortal woman are not inbred or related to each other.

……………
I was reading about kin selection, Hamilton’s Rule, etc, while listening to Wagner (as one does), and it occurred to me that it would be amusing to work out the coefficient of relationship between Siegfried and Brünnhilde. This would be easy enough if they were both outbred, but Siegfried is inbred (which incidentally may explain why he is such a moron), and elementary books on genetics (e.g. John Maynard Smith’s Evolutionary Genetics) usually dodge the complications of inbreeding. But I thought it would be easy enough to find a fuller treatment somewhere, and I looked at a few other books. This proved a frustrating experience, as there is a confusing diversity of terminology for measures of relationship used by different authors.

However, I thought I had hit paydirt in E.O Wilson’s Sociobiology, which gives a general formula for the coefficient of relationship between two individuals, allowing for inbreeding, in the form: rAB = 2fAB/root[(fA+1)(fB+1)], where A and B are two individuals, fAB is the coefficient of kinship between them, fA is the coefficient of inbreeding of A, and fB is the coefficient of inbreeding of B. The coefficient of kinship is the probability that a gene randomly selected from A is identical by descent (ibd) to a randomly selected gene at the same locus in B. This is a symmetrical relationship (fAB = fBA), and it is possible to calculate it whenever the ancestry of two individuals can be traced back to their closest common ancestors, who are either outbred or have a known level of inbreeding. In the case of Siegfried and Brünnhilde, fAB = 1/8. The coefficient of inbreeding for an individual is the probability that a gene randomly selected from that individual is ibd to his other gene at the same locus, in other words, homozygous at that locus by virtue of descent from a recent common ancestor. Since the two genes at the same locus in an individual are randomly selected from the individual’s parents (one from each parent), the coefficient of inbreeding for an individual is equal to the coefficient of kinship between the individual’s parents. Siegmund and Sieglinde are full siblings, with a coefficient of kinship of ¼, so the coefficient of inbreeding for Siegfried is also ¼. Brünnhilde, on the other hand, is outbred, with a coefficient of inbreeding of 0. Using Wilson’s formula (which is taken from Sewall Wright), if Siegfried is A and Brünnhilde B, rAB = 2x1/8/root1.25 = approx .225.

So far so good. However, Wilson gave no explanation of the basis for his formula, and I was curious to know more. The good news is that in Robert Trivers’s Social Evolution I found a plausible justification for a formula of relationship allowing for inbreeding. The bad news is that it is different from Wilson’s! Trivers’s formula for the ’degree of relatedness’ is 2fAB/(fA+1), where fA and fAB have the same meaning as before, and where A is the individual performing an action, and B is the individual receiving its effect. So if the roles are reversed, the formula would be 2fAB/(fB+1), which takes a different value from 2fAB/(fA+1) if A and B have different coefficients of inbreeding. Both versions also have different values from Wilson’s formula in this case. Of course, different authors may reasonably use different formulae for different purposes, but Wilson and Trivers use their different (and sometimes conflicting) formulae for the same purpose, namely as the value of r in Hamilton’s Rule.

So which is right, and why? It took me a while to get to the bottom of this, but to cut a long story short(ish), when Hamilton originally introduced Hamilton’s Rule in 1964 he proposed that Sewall Wright’s coefficient of relationship would usually be the appropriate value for ’r’ in his Rule. Then in the early 1970s he proposed a modification (the formula used by Trivers) which gives different values in the case of inbreeding (see Narrow Roads of Gene Land, vol. 1, p. 179 and 272-3). The formula still depends on various assumptions for its validity. Notably, it assumes additive gene effects, and it disregards the effects of selection on the relative frequency of genes within pedigrees. This means that Hamilton’s Rule is only an approximation (as was recognised from the outset in 1964). To see this point, consider a gene that causes an individual to dispense altruism to his nephews at the expense of his personal fitness. Such a gene can only be found in the nephews (at higher frequencies than in the general population) if it is also found in one of their parents (the brother or sister of the altruist). But this means it will reduce their parent’s fitness, so there will be fewer nephews with the gene in question than might be expected. (Putting it another way, brothers or sisters of the altruist who do not carry the gene for altruism will have more offspring than those who do.) To allow for this would require the formula to be modified for every different kind of pedigree, so disregarding selection is a necessary simplification, OK?

Subject to these assumptions, Hamilton and Trivers both give justifications of the formula which are quite persuasive, but not strictly proofs. I will attempt a more direct justification. (I also assume that all the parties involved - gods as well as humans - are diploids).

Hamilton’s Rule can be expressed in the form br > c, where b is the fitness benefit to the recipient of an action, c is the fitness cost to the actor, and r is the appropriate measure of relationship between actor and recipient. What we want is a formula for r which makes the Rule true in cases involving inbreeding. The Rule will be true if the increase in the number of ibd genes for altruism passed on by the recipient is greater than the reduction in the number of ibd genes for altruism passed on by the actor. The increase or decrease in the number of ibd genes passed on is the increase or decrease in the number of offspring times the expected number of ibd altruism genes per offspring. The increase in the number of offspring of the recipient due to the gene for altruism [Note 1] is expressed by b, while the decrease in the number of offspring of the actor is expressed by c. Since both parties are diploids (by assumption) the expected number of ibd altruism genes per offspring will be half the number in the parent, so the Rule br > c takes the form b½(expected number of ibd altruism genes in recipient) > c½(expected number of ibd altruism genes in actor). The coefficient r is therefore equal to (expected number of ibd altruism genes in recipient)/(expected number of ibd altruism genes in actor). The probability that a randomly chosen gene in the recipient is ibd to a given gene at the same locus in the actor is given by the coefficient of kinship (fAB) between them. [Note 2] Since there are two genes at that locus in the recipient, the average expected number of genes in the recipient ibd with a given gene in the actor will be 2fAB. [Note 3] As to the number of ibd genes for altruism in the actor, we are considering the effect of a particular gene for altruism, so we know that there is at least one copy, and the probability that the other gene at the same locus is ibd with that gene is given by the coefficient of inbreeding, [Note 4] which is fA for the actor. The expected number of ibd genes for altruism in the actor is therefore fA+1. Putting these results together, we have r = 2fAB/(fA+1). QED.

Returning to Siegfried and Brünnhilde, if Siegfried is the actor r = .25/1.25 = .2, and if Brünnhilde is the actor r = .25/1 = .25. We might therefore expect Brünnhilde to behave better towards Siegfried than vice versa, which is indeed the case. (OK, even allowing for Hagen’s trickery, Siegfried was still a shit. What kind of ‘hero‘ takes a ring from a woman by force and then lies about it?)


Note 1
If there is more than one ibd gene for altruism in the actor, by assumption their effect is additive. We can therefore treat each gene as having its own distinct effect without worrying about the effect of the other one, if any.

Note 2
As usually defined, the coefficient of kinship is the probability that a gene randomly selected from A is identical by descent to a randomly selected gene at the same locus in B. But in this case we are selecting a gene in A which we know to be a gene for altruism, so the selection is not strictly random. Does this not invalidate the argument? I think the answer is that what matters is not whether the selection is strictly random, but whether the method of selection affects the probabilities. In this case the fact that we are selecting a gene for altruism does affect the probabilities, via the possible effects of selection, but by assumption we have agreed to disregard these.

Note 3
We are considering the average expected number of ibd genes in the recipient. For this purpose it is legitimate to calculate the expected number simply as probability per copy at a locus (i.e. average number in a large sample of copies) times number of copies at the same locus (i.e. 2 in the case of diploids). This gives the expected number per individual as 2fAB, whether or not the individual is inbred. This should not be confused with the question whether any (one or more) genes in the recipient are ibd with a selected gene in the actor. For outbred recipients, since each individual has at most one copy of the gene, the probability that he has any copy of the gene is the same as the probable number of copies per recipient, i.e. 2fAB. In the case of inbred recipients the probability would be somewhat lower than 2fAB (in fact 2fAB-fB), because some recipients would have two copies, and the same total number of ibd genes in the population of recipients would be concentrated in fewer individuals. Where both parties are outbred diploids, the coefficient of relationship reduces to 2fAB and can fairly be described as the probability that a randomly selected gene in one is shared by the other as a result of common ancestry, or equivalently as the proportion of all their genes which they share as a result of common ancestry, e.g. for full siblings ½, or for uncle and nephew ¼. Where one or both parties are inbred (or where they have a different ploidy, as with haplodiploid insects) these expressions are ambiguous and should be avoided. I have gone into this tedious detail because I have found many authors confusing in their terminology, and it took me some effort to work things out.

Note 4
The same qualm about non-random selection arises here: see Note 2.

Posted by David B at 06:04 AM | | TrackBack

December 06, 2004



Journey of Men...continued

A year ago I reviewed Spencer Wells' Journey of Man, and that post remains one of the most popular if access logs tell any tale. In any case, today I stumbled upon this long article in Discover that profiles Wells' & his research. I've pasted the full text below.

An interesting tidbit to come out of this piece is that the fact that Spencer Wells is a graduate of Dick Lewontin's lab in Harvard! After working with flies he went west to join Cavalli-Sforza's gang and delved into human genetics. This is perhaps the most interesting selection from a GNXP angle:


Man does not evolve by natural selection alone. Darwin even believed that sexual selection-in choosing mates, we choose the genes we pass on to the next generation-was a more important source of "differences in external appearance between the races of man." That idea has never really been tested, says Wells. In recent decades geneticists, beginning with Richard Lewontin, Wells's adviser, have clearly showed how insignificant the genetic differences among races are: The diversity within any single population is far, far greater. "But, by God," says Wells, "I can tell the difference between somebody who comes from the Outer Hebrides and someone who comes from Cambodia. They look different."

The last line echoes Vincent Sarich, we look different! Well, looks aren't everything (though his faux Redford locks and complexion probably didn't hurt Spencer in getting him documentary time)...but as I note in my review of Journey of Man, when Spencer refers to the seminal impact that Central Asia might have had on the suite of human cultural tendencies in his book he sounds more like an adaptationist thinker like William Calvin than a man in the Gould-Lewontin tradition of Adaptation-is-verboten-in-humans (at least in "non-superficial" matters). In fact, he references Calvin and arch-adaptationist Steven Pinker in the "Further Reading" section (see 5 Leaps and Bounds).

I'm very curious to see what Spencer will have to say about sexual selection (his Chinese American wife suggests he is a practioner of the OA strategy). Geoffrey Miller, another young photogenic scientist, has a headstart in this area....

The Hidden History of Men A research team braves Central Asia to capture a surprising genetic record of human migration and military conquest
By Robert Kunzig
DISCOVER Vol. 25 No. 12 | December 2004 | Anthropology

One day last fall, in the home freezer of Spencer Wells, there were these
things: a large leg of lamb, a few quarts of milk, and underneath, DNA
samples from 2,500 people in Central Asia. Wells is an anthropological
geneticist and an energetic collector of DNA, especially Y chromosomes. He
lived then in an old stone house outside Geneva, but he was raised in
Lubbock, Texas. His own Y chromosome, like his name, hails from
Connecticut-an ancestor was governor there in the 17th century. Before that,
Wells's chromosome came from southern England, and before that, maybe 30,000 years ago, it came from Central Asia. From then and there to here and now, it was passed on, like an indelible stain, by a thousand fathers to a
thousand sons, one after the other, until it ended up in Wells's father, a
Lubbock lawyer, and then in Wells.

M168: 50,000 years ago
M130: 50,000 years ago
M89: 45,000 years ago
M9: 40,000 years ago
M45: 35,000 years ago
M173: 30,000 years ago
M20: 30,000 years ago
M242: 20,000 years ago
M3: 10,000 years ago
M172: 10,000 years ago
M17: 10,000 years ago
M122: 10,000 years ago

The DNA samples in the freezer, then, are samples of Wells's own roots-and
of those of a good part of humanity. Before Wells collected the samples, the
region was pretty much terra incognita, genetically speaking. Now some
geneticists see it as a second font of human diversity. In Wells's view, the
grasslands of Central Asia, so reminiscent of the East African savannas with
their abundance of big game, are where the human race fattened up after it
left Africa, 50,000 or 60,000 years ago. "It was essentially a meat locker,"
he says. "Loads of food. And that allowed them to build up the population
density to then go out and move westward and then eastward."

The westward branch of humanity entered Europe; the eastward branch
eventually crossed the Bering Strait and entered North America, and there
the two branches met again in 1492. By that time they had come to seem very
different from each other. Traces of how human beings had fanned out across
the planet, acquiring superficial racial differences along the way, are
written in our DNA and especially in the Y chromosome.

Before long, the record of that ancient migration will begin to vanish. Our
ancestors took tens of thousands of years to spread around the planet;
people today move from Lubbock to Geneva or from Tamil Nadu to Texas in
hours. In the process they wipe out genetic clues to the past. Think of our
genes as the vestiges of an ancient library in which geneticists are trying
to piece together and decipher the books; now think of that ruin being paved
over for a new airport. Archaeologists would want to mount a rescue
dig-exactly what anthropological geneticists are doing these days. That,
along with a young man's taste for adventure, is what has repeatedly sent
Wells bouncing across the Central Asian steppes in a Land Rover. The DNA he
has brought back records not just our distant history but also our more
recent past-and in particular what happened around 800 years ago, when a
prodigious fornicator named Genghis Khan splashed into the gene pool like a
cannonball.

Wells is a tall, handsome man in his thirties, with strawberry blond hair
and a chiseled face that quickly turns ruddy in the sun. Words stream out of
him without a trace of a Texas accent-after Lubbock and before Geneva he
went to Harvard and Stanford. He felt bottled up in Lubbock, he says, and is
drawn to places like India, where you step out of a taxicab to face cows and
crowds and people of many colors speaking strange languages: "It's
incredible, and it's overwhelming. I love the feeling of being immersed."

At Harvard, where he got his Ph.D., Wells studied fruit flies with Richard
Lewontin and became interested in understanding the reasons for genetic
variation within a particular group. A population crashes due to disease,
for instance, and is then restarted by a few individuals, or a few
individuals migrate to a new, uninhabited region and start a new population.
In both cases the genes of the founders become prevalent in the new
population, even if they confer no particular selective advantage. "So much
of what we see in the DNA, in genetic variation, is due to population
events," says Wells. "Which is great, but I'm not interested in the
population history of fruit flies. I am, however, very interested in the
population history of humans."

Lewontin's advice was to go west, to Stanford, to work with Luigi Luca
Cavalli-Sforza, the father of anthropological genetics. When Wells arrived
at Stanford in 1994, Cavalli-Sforza's lab was just plunging into studies of
the Y chromosome. Two researchers there, Peter Underhill and Peter Oefner,
had recently invented a technique for rapidly finding DNA mutations-markers-at the same point in the genomes of two different people. The invention proved useful for tracing human migration. Most spontaneous mutations do neither harm nor good but simply accumulate in the genome, one at a time, as they are passed from one generation to the next. A mutation shared by everybody, therefore, must have arisen in everybody's common
ancestor. The mutation marks the trunk of that population's family tree.
Each successive mutation identifies a branching point, right out to the
twigs at the tip of the tree, which represent individual humans.
Forensic geneticists use large numbers of markers to isolate and identify
one of those twigs in a murder case. Population geneticists focus mostly on
the bigger branches. A mutation that is near-universal in Asia, for
instance, but near-absent in Africa is most likely a sign that somewhere in
deep time a small group of founders with that marker left Africa and started
a new population in Asia.

What complicates the picture, as it complicates so many things, is sex. DNA
comes in chromosomes, and chromosomes come in matched pairs, and when a body makes a sperm cell or an egg, the two chromosomes in a pair recombine,
exchanging large chunks of DNA. Over time, each chromosome becomes a
patchwork of contributions from innumerable ancestors, both male and female.
A recombined chromosome might tell you, for example, that your Ice Age
ancestors came from Central Asia and a later ancestor was governor of
Connecticut, but it would be missing their passage through England. Its
story wouldn't make much sense.

That's why the Y chromosome has become the chromosome of choice for
anthropological genetics. Unlike all the others, it has no matching
partner, and only at its tips does it swap bits with the X chromosome.
Remember: Men inherit a Y chromosome from their father and an X chromosome from their mother; women inherit an X from each parent. As a result the Y passes on largely intact from father to son, ad infinitum, each man adding at most a new mutation or two. The Y chromosome in every man on Earth today is thought to be more than 99.99 percent the same as the one carried by a common ancestor who lived 50,000 or 60,000 years ago. The tiny differences
are the markers that record the spread of the human species around the
planet-and which Underhill and Oefner's invention made much easier to
identify.

HISTORY OF Y'S GUYS

The X and Y chromosomes carry the genes that determine sex. Men have one X, inherited from their mothers, and one Y, inherited from their fathers. Only
5 percent of the Y chromosome's DNA mingles with the X chromosome. The Y
thus provides an unadulterated record of inheritance from father to son over
generations. By analyzing Y chromosome samples from around the world,
geneticists infer how and when humans originated in Africa and how they
colonized the globe.

In the 1990s the Stanford group and Michael Hammer of the University of
Arizona showed that "Adam" lived in Africa: The Y chromosome tree has its
trunk and roots there. Earlier work with mitochondrial DNA-a nonchromosomal
kind that escapes recombination, passing intact from mother to daughter-had
shown that "Eve" lived in Africa too. Beginning around 50,000 years ago, the
genetic evidence suggests, modern humans first migrated out of Africa. In
his book, The Journey of Man, Wells sketches what is known of the subsequent
story, but a lot of it is pretty murky.

As early as 1991, Cavalli-Sforza proposed the Human Genome Diversity
Project: an effort to collect DNA samples from hundreds of populations
worldwide. To Cavalli-Sforza and other geneticists who joined him, the
proposal was altruistic in creating a record for all humanity of its history
at a time when many of the world's smaller populations were facing
absorption into a globalized culture. Some groups reacted with outrage at
the suggestion that they donate their blood to Western science-it smacked of
exploitation. Cavalli-Sforza's idea became hugely controversial, and the
U.S. government never funded it. The research hasn't stopped, however. It
has simply trickled on in a less organized way, driven in part by
entrepreneurial scientists like Wells.

Cavalli-Sforza encouraged his young colleagues to pick an area of the world
in which to do fieldwork. Wells picked Central Asia-"a black box-we knew
nothing about it." Central Asia, to Wells, means the region from the Black
Sea in the west to Lake Baikal farther east. It includes all the former
Soviet "stans," from Turkmenistan to Tajikistan and on into Mongolia. It is
a region of endless steppes cut by soaring mountains. It is, even today, an
intimidating expanse of bad roads and many languages.

Wells's first expedition was to Uzbekistan, where in 1996 he and Ruslan
Ruzibakiev, an immunologist at the Academy of Sciences in Tashkent, sampled
DNA from 550 Uzbeks. There are more than 100 different ethnic groups in
Uzbekistan. The chief result, Wells recalls, was that they needed to survey
a much wider region if they wanted to understand the diversity of Y
chromosomes.

That wider survey took place in 1998, and though it covered a lot of ground,
Big Science it wasn't. It was five men crammed into a Land Rover, along with
many boxes of syringes, tourniquets, and chemicals for extracting DNA from
blood. A small research grant from the Alfred P. Sloan Foundation paid for
the equipment, but the Land Rover itself was donated by the vehicle's
manufacturer. "We chipped in a little bit of our own money for living
expenses," says Wells. "We also had friends who were very interested in
this, who would give us a few hundred dollars here and there, which we
collected in a big pot."

One morning in April they drove through the Channel Tunnel to France. They
didn't stop to collect samples until they hit Georgia, because Europe's DNA
is old hat. After that they didn't stop collecting until they had been to
Kyrgyzstan and back, a total of 25,000 miles. They slept in borrowed rooms
or offices, and even in yurts; they bonded with their local facilitators
over streams of vodka. They had small adventures. A potentate in Uzbekistan
insisted on driving the Land Rover; he gunned it and, top heavy with gear,
it promptly rolled over. The man then hailed a passing car and left Wells
and his companions nursing their bruises. Later, in Kyrgyzstan, a policeman
tried to shake them down on the pretense that the Land Rover's color, red,
was illegal. Wells stood firm.

One problem they did not have, he says, was getting blood donors. Local
research contacts did a lot of the footwork, and the inmates of urban
hospitals, both patients and staff, proved a rich source of blood. But Wells
and his crew also visited factories and villages, sometimes going door to
door. On occasion they found themselves staying for a dinner of, say, sheep
intestines and koumiss, which is fermented mare's milk. "It's one of the
worst things I've ever tasted," says Tatiana Zerjal, a graduate student who
joined the expedition for a month in Uzbekistan and Kyrgyzstan.

To each donor or group of donors, Wells gave what he calls his blood speech,
explaining DNA, the purpose of the expedition, their role in it, and then
asking for "informed consent." On the television version of The Journey of
Man, for which Wells traveled the world in 2002, retracing some of his
earlier steps, he visits a man in southeastern Kazakhstan whose blood had
been sampled on the 1998 expedition and who has turned out to have an
important Y chromosome marker called M45. At a festive dinner, Wells gives
him the blood speech again and concludes with a toast: "To your very
important blood, which has brought us together." The man seems happy and
relieved: As Wells candidly explains, he thought Wells had come back to tell
him he had cancer.

Scenes like that demonstrate that truly informed consent can be an elusive
goal in anthropological genetics, and yet it seems clear that Wells has done
no harm to the man and has done our knowledge of the past a lot of good. M45
is an important branching point on the human family tree. One branch leads
to M173, which is a mutation shared by most people of Western European
descent. The other branch leads to M3, which is shared by most Native
Americans. European and Native American men also have M45, but in Central
Asia there are men, like Wells's Kazakh dinner companion, who have M45 but
neither of the two later mutations-they have a large range of different ones
instead. That indicates Central Asia is where M45 originated and where both
Europeans and Native Americans originated, from a single source.

By counting the number of mutations that have happened since M45, Wells and
his colleagues estimate that M45 is about 35,000 to 40,000 years old. The
European marker, M173, happened roughly 30,000 years ago, which is when the first cave paintings appeared in France. M3 is present only in Native
Americans, and so it must have happened after humans first crossed the
Bering Strait and arrived in the Americas. Archaeologists have long debated
the timing of that momentous event; most favor a date of around 13,000 or
14,000 years ago, but a few have held out for one as early as 30,000 years
ago.

Wells argues that 30,000 years ago has to be the wrong date. The evidence is
another marker, M242, that he and Mark Seielstad of Harvard identified. It
arose after M45 but before M3, in the Asian population that was bound for
America; Native Americans have M242, and so do some people still living in
Central Asia. The Ice Age ancestors of Native Americans must have had that
marker when they crossed the Bering Strait, and so the time of M242's first
appearance puts an upper limit on the time of their passage. "We can
definitely rule out a date prior to 20,000 years ago," says Wells.

Hammer and his Arizona colleagues, anthropologists Stephen Zegura and
Tatiana Karafet, have recently confirmed that result. Their own Y chromosome
collections tell them that the genetic separation of the Asian and American
populations occurred no earlier than 17,000 years ago. And they think they
have narrowed down a source region, an Asian ancestral home for Native
Americans-the Altai Mountains of southwestern Siberia and western Mongolia.

The Altai is a remote region of 14,000-foot alps, deep river valleys, and
large high-altitude lakes. "I think that has been a place where people have
been for a long time," Hammer says, "and have spawned many descendant
populations. And I think some of those descendants ended up in the
Americas."

The Paleolithic migration into Europe, like the Paleolithic migration into
North America, may have also departed from the Altai region, although it may
have been from elsewhere in Central Asia or other locations. After 1492, in
any case, those two great rivers of humanity, which had diverged 30,000
years earlier, began to converge again in America, and their waters
commingled. Hammer estimates that 17 percent of Native American men today
have Y chromosomes inherited from Europeans. (In African American men the
European admixture may be from 5 to 30 percent.) These percentages show that history, and not just natural selection, has a big effect on the human gene
pool-and that conquerors tend to spread their Y chromosomes.

Spencer Wells and his team covered about 25,000 miles in their 1998 genetic
survey of Central Asia. The map on the opposite page traces the expedition
(red). The inset map shows the entire route and their return through
northern Europe. The orange shading represents the approximate extent of
Genghis Khan's empire at the time of his death in 1227. Wells's results show
the presence of a particular Y chromosome variant in about 8 percent of the
sampled male population in Central Asia. Because that variant originated in
Mongolia not too long ago, Wells and his team contend that its prevalence in
Central Asians reflects the influx of Genghis Khan and his powerful kin.

Genghis Khan was born east of the Altai Mountains, at the northern edge of
the vast Mongolian steppe in 1162. His biographers agree, unsurprisingly,
that he was driven by a lust for power. He was also driven by lust. Rashid
ad-Din, vizier to a later khan, quotes Genghis as having said, "Man's
greatest good fortune is to chase and defeat his enemy, seize his total
possessions . . . use the bodies of his women as a nightshirt and support,
gazing upon and kissing their rosy breasts, sucking their lips which are as
sweet as the berries of their breasts." Rashid says Genghis brought a new
wife home from every campaign, maintaining a harem of 500. His interest in
sex was enduring. In his sixties and ailing, he crossed the Gobi Desert to
massacre the Tanguts and died on that campaign. According to one legend, he
was killed by the Tangut queen, Kurbelzhin, who injured his sex organ during
intercourse.

The conqueror's body was carried back to Mongolia, but his tomb has never
been found. A team of archaeologists led by John Woods of the University of
Chicago has spent several summers searching for it. It is not just the
physical remains of Genghis Khan that are missing, says Woods. Although he
fathered a huge empire, there is no artifact that can be definitively linked
to him. There may be something else, however. The idea first came to Tatiana
Zerjal while she was looking at an odd pattern on her computer screen.

After the 1998 expedition with Wells, Zerjal returned to Oxford, where her
adviser, geneticist Chris Tyler-Smith, then had his lab. While Wells
screened the Central Asian Y chromosomes for single-nucleotide mutations
such as M45, Zerjal searched for a different DNA variable called a
microsatellite. A microsatellite is a short, repetitious sequence of
DNA-CACACACA, for instance-in which the number of repetitions can change
from one generation to the next and often does.

When a Y chromosome is passed from father to son, the chance that a specific
single nucleotide will change from, say, T (thymine) to A (adenine) is on
the order of one in a few tens of millions. But the chance that a given
microsatellite will change from, say, 11 CA (cytosine and adenine) repeats
to 12 is on the order of one in a few hundred. That's why a particular
pattern of microsatellites can profile a particular individual-to show, for
instance, as Tyler-Smith and Zerjal had done shortly before embarking on
their Central Asian work, that Thomas Jefferson had fathered a son by his
slave Sally Hemings and that his Y chromosome had been passed down to a man living in Pennsylvania today. In the human family tree, says Tyler-Smith,
"the single-nucleotide polymorphisms give you the trunk and the main
branches. The microsatellites give you the twigs at the end."

As Zerjal screened Central Asian Y chromosomes for 16 different
microsatellites, one combination showed up repeatedly. It was far more
common than expected, and men all over Central Asia had it-which is also not
what you'd expect. "Suddenly, I thought, 'Wow, this is Genghis Khan,' " says
Zerjal. At first, Tyler-Smith says, "We thought it was more or less a joke."

But as Zerjal worked through more than 2,000 Y chromosomes, the joke
wouldn't die. On her computer diagram of how the chromosomes might be
related, fully 8 percent of them clustered together in a starlike pattern,
meaning they had either the identical set of microsatellites or one that
differed at just one of the 16 locuses. Those mutations were most diverse in
Mongolia, indicating that the original star-cluster chromosome had come from
there. And judging from the small number of mutations it had accumulated, it
came from there only about a thousand years ago.

It could not have spread so fast and so far by chance, yet natural selection
made a poor explanation: The full sequence of the Y chromosome has been
determined, but it doesn't seem to do much except make the bearer male.
Zerjal and Tyler-Smith started reading up on Mongolian history. They noticed
that the vast range of the distinctive star-cluster chromosome corresponded
almost exactly to the extent of Genghis Khan's empire. The only outlier is a
small ethnic group called the Hazaras, who live in northern Pakistan, which
Genghis never conquered. The puzzling chromosomes are more frequent in the
Hazaras today than in any other population, even the Mongols. But the
Hazaras migrated into Pakistan from neighboring Afghanistan only in the 19th
century, and they brought with them an interesting oral tradition: They
claim to be direct descendants of one of Genghis Khan's battalions. Some
even claim, with genealogies to back them up, to be direct descendants of
Genghis Khan himself. The Hazaras don't refute the case, says Tyler-Smith;
they cinch it. "It was a conclusion that was forced upon us."

That doesn't mean those Central Asian men have inherited some interesting
trait from Genghis Khan, like his fierceness or his lust. To the extent that
such traits are genetic at all, they probably involve many genes, none of
which is likely to be on the Y chromosome. And although the rest of Genghis
Khan's genome has certainly, if Zerjal and Tyler-Smith are right, made an
outsize contribution to the Central Asian gene pool, it has been chopped to
bits and mixed in so thoroughly over the centuries by genetic recombination
that no one today is likely to have his whole suite of genes for any
particular trait. What they have, in his intact Y chromosome, is more like
an invisible birthmark.

Genghis Khan was not necessarily the first to have it; its rough age of
1,000 years suggests he inherited it from an ancestor, perhaps a
great-great-great-grandfather. Nor was he the only one to spread it: His
brothers, sons, grandsons, and some of his cousins would have had the same Y
chromosome. His sons and grandsons ruled the empire he built; one grandson,
Kublai, was emperor of China. Presumably they enjoyed sexual opportunities
similar to Genghis's, and some were just as vigorous about exterminating
competition. According to one chronicle written a century after Genghis's
birth, there were more than 20,000 people of his lineage "living in the
comfort of wealth and affluence."

To some geneticists, the whole story seems incredible. "It's complete
conjecture!" says Underhill. "There are no living relatives of Genghis Khan
that anyone can document, as they did for Thomas Jefferson. And the other
problem I have is they estimate the age of that lineage to be about a
thousand years-it could be easily 3,000 years old, depending on which
mutation rate you use. You could have 3,000 years of this chromosome
dispersing across Central Asia. You don't need to invoke Genghis Khan
screwing every woman in sight. It just doesn't compute with me."

"What is the alternative?" asks Tyler-Smith. "We know from the genetics that
this pattern originated in Mongolia or nearby a thousand years ago or some
similar time. So the alternative to its being spread by Genghis Khan is that
his Y chromosome, despite his reported 20,000 descendants, is not visible in
the genetic record now, but that of another person has spread in this
unprecedented way. To me that is just less plausible. I think it was his
military ability that allowed it to spread. If it hadn't been for that, it
would have been just another low-frequency chromosome."

The fastest and most famous case of evolution by natural selection is the
case of the British peppered moths: In the 19th century, as mills and
factories began to darken the air with soot, a rare all-black mutant quickly
became more common in Britain than the normal white moth with black spots
because it was less conspicuous to predators. Genghis Khan's Y chromosome,
says Tyler-Smith, spread at a comparable rate through Central Asia. "It
shows that a kind of social selection can operate in humans, whereby people
inherit status and the reproductive advantage that goes along with that," he
says. "It can have a large effect on the genetics."

Man does not evolve by natural selection alone. Darwin even believed that
sexual selection-in choosing mates, we choose the genes we pass on to the
next generation-was a more important source of "differences in external
appearance between the races of man." That idea has never really been
tested, says Wells. In recent decades geneticists, beginning with Richard
Lewontin, Wells's adviser, have clearly showed how insignificant the genetic
differences among races are: The diversity within any single population is
far, far greater. "But, by God," says Wells, "I can tell the difference
between somebody who comes from the Outer Hebrides and someone who comes from Cambodia. They look different." Science has yet to explain that.

How humans settled the planet, in prehistoric and historic times, and how
they came to be so diverse, are interesting questions for anthropological
geneticists to tackle, if only those questions can be freed from their
association, in some people's minds, with racism and colonialism, and if
only the geneticists can get enough support. But they face another more
difficult problem: globalization. People today are feverishly uprooting
themselves and their Y chromosomes, moving, as it were, from Cambodia to the Outer Hebrides, from their yurts into the nearest multiethnic city. All the
lineages Wells has found in Asia, he likes to say, could probably be found
in a single nightclub in New York City's East Village, engaged in precoital
rituals. "Socially, I think it's fantastic," Wells says. "It just makes my
life bloody difficult." A geneticist taking samples in that nightclub would
be like a wine lover who never gets to see the labels: He would find
tremendous diversity, but without geographic context it would be
meaningless. He would be powerless to understand the fantastic migrations
that had brought all those different people to that one place and time.

We are headed toward a world in which we will have erased the historical
record in our genes just as we have acquired the means to read it. For
several years now Wells has been trying to organize an effort to do on a
global scale what he already did in Central Asia-similar to the ill-starred
Human Genome Diversity Project. The idea is simply to preserve a genetic
snapshot of humanity. "It's the sort of thing where, once you lose the
information, you're never going to get it back," he says. "It is our single,
unique human history, and it would be nice to know what that is as we hurtle
into the future and start to change our own genetics.

"The clock is ticking. We need to get out there and do some more sampling."

Posted by razib at 09:27 PM | | TrackBack


Tall tales of the shire

The Sydney Morning Herald has a piece about the Flores "Hobbits" and their possible survival into modern times (username: gnxppublic, password: publicgnxp). Nothing Steve didn't pass on. I wouldn't bet against more recent bones being found. I've cut & pasted the full story below for convenience.

Related: Our earlier commentary.

Chief Epiradus Dhoi Lewa has a strange tale to tell. Sitting in his bamboo and wooden home at the foot of an active volcano on the remote Indonesian island of Flores, he recalls how people from his village were able to capture a tiny woman with long, pendulous breasts three weeks ago.

"They said she was very little and very pretty," he says, holding his hand at waist height. "Some people saw her very close up."

The villagers of Boawae believe the strange woman came down from a cave on the steaming mountain where short, hairy people they call Ebu Gogo lived long ago.

"Maybe some Ebu Gogo are still there," the 70-year-old chief told the Herald through an interpreter in Boawae last week.

The locals' descriptions of Ebu Gogo as about a metre tall, with pot bellies and long arms match the features of a new species of human "hobbits" whose bones were recently unearthed by Australian and Indonesian researchers in a different part of Flores in a cave known as Liang Bua.

The unexpected discovery of this tiny Homo floresiensis, who existed until at least 12,000 years ago at Liang Bua, before being apparently wiped out by a volcanic eruption, was hailed as one of the most important archaeological finds in decades when it was announced in October.
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The chief adds that the mysterious little woman in Boawae somehow "escaped" her captors, and the local police said they knew nothing of her existence when he quizzed them.

The prospect that some hobbits still exist in pockets of thick, fertile jungle on Flores is extremely unlikely, says Douglas Hobbs, a member of the team that discovered Homo floresiensis. But it is possible they survived near Boawae until 300 or so years ago, when the chief's ancestors moved into the area, he says.

The detailed stories that the villagers tell about the legendary Ebu Gogo on the volcano have convinced the Australian and Indonesian team to search for bones of hobbits in this cave when they return to the rugged island next year, says Hobbs, an emeritus archaeologist with the University of New England, who discussed excavation plans with the chief last week.

Getting to the cave on the 2100-metre-high Ebulobo volcano, however, will be no simple matter for the team led by Professor Mike Morwood of UNE. The blood of a pig must first be spilt in this society where Catholic faith is melded with animist beliefs and ancestor worship.

The sacrifice and the feast will please the ancestors and bring many villagers together to talk about the cave, says the chief, whose picture of his grandfather, the king, in traditional head-dress, sits framed on the wall next to images of Jesus.
Grandfather of Chief Epiradus Dhoi Lewa of Boawae.

Grandfather of Chief Epiradus Dhoi Lewa of Boawae.

If the right rituals are followed, "then we will be able to find the road to the hole again", he says.

A Dutch palaeontologist, Dr Gert van den Bergh, a member of the team, was first shown the cave at a distance more than a decade ago, after hearing folk tales of the Ebu Gogo, which means "grandmother who eats everything".

People living around the volcano told him a consistent story of the hairy creatures that devoured whatever they could grasp in their long fingers. The villagers tolerated the stealing of food until the Ebu Gogo began to snatch babies and eat them too. They then set upon the little people, forcing them out of the cave with bales of burning grass.

Van den Bergh dismissed the tales as akin to those of leprechauns and elves, until the hobbit bones were found.

While the search for more bones is being planned, a political furore has broken out after a leading Indonesian palaeoanthropologist - with no connection to the find - last week "borrowed" all the delicate remains from six hobbits found at Liang Bua against the wishes of local and Australian team members. Professor Teuku Jacob, of Gadjah Mada University, who has challenged the view that Homo floresiensis is a new species, had previously taken the skull and bones of the most complete specimen, a 30-year-old female hobbit, from the Indonesian Centre for Archaeology in Jakarta, where they had been kept.

Professor Morwood said it was wrong that the team who found the remains were unable to analyse them first. "It is not good for the Indonesian researchers nor their institution."

However, he said Professor Jacob had signed an agreement to return all the bones by January 1.

Posted by razib at 06:13 PM | | TrackBack


The Eastern Establishment

Weddings & Celebrations in The New York Times has a simple (though primitive) search feature. I decided to enter a few terms and see what I can up with. Here are the results:

Rabbi/4694
Roman Catholic/2474
Episcopal/2069
Presbyterian/1013
Methodist/458
Unitarian/344
Baptist/246
Lutheran/216
Hindu/129
Quaker/51
Buddhist/31
Muslim/14
Mormon/4

First, I did some fudging, I used "rabbi" in place of "Jewish," since if there was a Jewish service I'm assuming a rabbi was present. Now, I'm pretty sure there are 9333 weddings listed since 1996 (bride and bridegroom queries come up that number). Many of the Jewish weddings seemed to also have a Christian service, while many of the Hindu ones were done in concert with Christian or Jewish services, so there is a great deal of overlap in these groups. But, playing with the numbers....

Ratio of eddings to percentage of American population....

Rabbi 38.69
Roman Catholic 1.08
Episcopal 13.04
Presbyterian 4.02
Methodist 0.72
Unitarian 12.29
Baptist 0.16
Lutheran 0.50
Hindu 3.46
Quaker 5.46
Buddhist 0.66
Muslim 0.30
Mormon 0.03

The overrepresentation of Jews is no surprise. Also, the old status ranking of Episcopalian -> Presbyterian -> Methodist holds. I suspect Quaker and Unitarian ceremonies are overrepresented partly because so many of the marriages cross denominational boundaries and both these groups tend to be perceived as "neutral" or liberal about such matters. The Hindu presence is partly a function of the relatively high SES of many Hindu Americans and their geographic concentration in the New York City area. A reverse geographic effect surely afflicts Mormons.

Posted by razib at 12:50 PM | | TrackBack


What clade are you in?

Look at this phylogenetic tree:

Do you notice that "turtles" are in a separate clade from the other reptiles and birds? When I noticed this years ago I thought it was pretty strange, but I had a sketchy understanding of the difference between morphological similarities and genetic affinity.

Now, going up the tree toward reptiles you get this:

Birds are in the same clade as crocodiles and their "extinct relatives" (guess who!), while lizards and snakes are up another branch. Let's keep moving up the first branch....

A few steps ahead, and you end up here:

We've left crocodiles behind. Keep going up and you'll reach the end of the line.


  • Eoraptor

  • Herrerasauridae

  • Ceratosauria (Dilophosaurus, Ceratosaurus, and relatives)

  • Tetanurae


    • Torvosauridae

    • Spinosauridae

    • Allosauroidea

    • Coelurosauria (tyrannosaurs, Oviraptor, Velociraptor, birds, and relatives)



Birds & T-rex, together at last. Many of you know about paraphyletic groups, and even if you didn't know that particular term, the general idea is pretty intuitive. I only point this out to suggest that studies which sketch out cladistic relationships might not always jive with our morphological preconceptions. Now that you have powerful computers crunching the 3-D data of skull & bones this isn't as much of a problem, but the issue still remains, morphology or data from neutral markers?1

A few years ago I posted an email Henry Harpending sent me about being careful about weighting neutral vs. functional markers. That is, even if two groups mix their neutral markers, selection forces, whether it be environmental or sociological, can still serve to erect robust phenotypic distinctions between the two groups. After a few thousand years two groups which inhabit sharply different but adjacent biomes might have an extremely confounded ancestry, but their functionally constrained genome might still restict phenotypic expression to "optimally" adapted forms. One could also imagine a sociocultural tradition enforcing some phenotypic shibboleth that might also result in the perpetuation of a particular modal type.

Examples? Henry offers the Khoisan/Bantu division as one that is clearly discernable phenotypically (and on locii that are functionally crucial and shaped by selection forces), but less clear when looking at neutral mtDNA markers. Similarly, there is some evidence that three centuries of social forces in Brazil might have maintained two distinct phenotypic races despite the fact that both groups overlap considerably in terms of their neutral ancestrally informative markers.

This relates to my common theme of proximate vs. ultimate. The phenotype is an expression of the proximate adaptations to the environment, while the neutral markers in the genotype carry the signatures of demographic expansion and or bottlenecks the genes have been through due to the fitness of the individuals who carry them. These two issues are often confused and treated as identical in many contexts. From a common sense perspective our "folk biology," likely shaped by our EEA, reinterprets morphological input in terms of broad taxonomical categories that seem cross-culturally robust. Sometimes miscategorizations occur because of this tendency, for example, the idea that whales are fish, or less naively, that crocodiles and lizards have more of an affinity than crocodiles and birds. Our cognitive templates are insensitive to reality in any direct sense, rather, they are influenced and framed by the contexts in which our fitness was impacted by decisions we made based on the predispositions we were endowed with.

These issues crop up on the context of humans in various ways. I have criticized Kevin MacDonald for simply assuming that genetic ends are in and of themselves are somehow meaningful without any supporting norms or conjectures. White nationalists themselves have gotten into these disputes, as those who emphasize phenotypic identity (proximate) confront those who emphasize ancestry (the ultimate). I can't help but feel they are missing the point of it all.

Traditionally an assumption of rough aproximation between proximate human traits and ultimate ancestral relationship has held because of geographic distance. Today, these truths do not necessarily hold, especially in mobile modern societies. With the spread of cosmetic surgery and the looming genetic engineering revolution phenotype might be far more of an issue of individual volition and preference. Since humans can not intuit ancestry in any other way by mere inspection this will throw up another barrier between the cognitive tools at our disposal and the reality that encapsulates us.

I have to admit that these discussions about humans strike me as somewhat strange. Though I've known of the issues about turtles & other reptiles, their supposed morphological affinity, and their phylogenetic distance, since I was a child, never did I consider reformulating these issues in light of humans. In my head I suppose I had stuck a wall between macroevolution and microevolution, and in particular was not open to microevolution among human beings.

I have read quite a bit of the new historically oriented human population genetics. You get the impression from this material that human beings were shaped to final completion in Africa, from which they issued full formed. The author of The Real Eve makes this explicit. Then, he proceeds to write a chapter on the specialized adaptations of East Asians that led to their particular physique. Humans are animals like any other, shaped by microevolution. In less than 10,000 years the Neolithic revolution has reshaped the lactose metabolization propensities of some populations, reduced susceptibility to alcoholism and drunkeness in other groups and also led to increased population densities which fueled the emergence of a whole host of endemic rhinoviruses.2

An animal like any other, which means the simplistic gruel based on NRY & mtDNA must be tempered by the reality that humans are a functionally varied species. True, there is great overlap, but the dark and the fair and the tall and the short are part of a broad and varied range. The reality of genetic relationships are salient to us, but I predict that though genetic testing will become affordable and cheap, and basic information about your distance on a host of locii from a person you meet might be had (hopefully assuming some consent on the part of both individuals), phenotype will be more important, that plasticity of human morphology and the range of lifestyles will increase. For thousands of years humans have already clustered around the transcending cultural phenotype of universal religions, in the future we might see an increased importance in other niche tribes.

Look at this blog, many of the readers band together not by genetic relation, physical appearence or shared faith in a god or gods, rather, many GNXP readers have a fixation on ideas and their mental manipulation, a value on mental dexterity and its worth that is simply abnormal. Our phenotype, our morphologically significant feature, is all psychological, under the hood. Someday perhaps a phenotypic race, Homo sapeins eggheadus will rise forth....

Things are only going to get weirder.

Related: The George Schuyler novel Black No More is an expression of the craziness that can ensue when proximate features become extremely plastic.

1 - Obviously the tree was not all based on modern wet lab methods, though the relationship between living classes like birds & reptiles have been more thoroughly elucidated.

2 - I have read that the common colds generally need a particular population density threshold to become endemic. This suggests that many isolated populations, like the Andanman Islanders, might die from exposure to rhinovirus. The "demic diffusions" of the past brought on by agriculture might have been enabled by plagues which acted as selective sweeps on the edge of a demographic wave that swept over the world.

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December 05, 2004



In honor of "aleph"

FIND A SWEDISH WOMAN (among others).

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Francis Collins & IQ

Check out this transcript of Francis Collins, control-f "IQ."

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Kohanim far and wide

DNA Clears the Fog Over Latino Links to Judaism in New Mexico. I am pretty shocked. I had found the model presented in The Atlantic Monthly piece, Mistaken Identity? The Case of New Mexico's "Hidden Jews", that the "hidden Jews" in the Southwest were actually Judaizers who had been influenced by Seventh Day Adventist missionaries (who arrived after the Civil War) persuasive.1 Additionally, I found it plausible that their claims of Jewish ancestry were attempts to deflect the reality that "Hispanos" of the Southwest had a great deal of indigenous blood (assertions made by ethnologists based on physical inspection). I have read in places like Caracas Jewish heritage is prestigous precisely because it suggests no admixture with blacks or indigenous people.

Well, many of these Jews were tested, and they displayed the Cohen Modal Haplotype that indicates a relationship to the Jewish priestly class at an extremely high frequency. This almost certainly implies that a large community of Marronos did escape to the Southwest, large enough to have left a genetic imprint. Like the Lemba Jews or the Bene Israel of Bombay, no doubt they have been greatly impacted by admixture. Additionally, it also offers up evidence of the salience of sociohistorical conditions, because without the presence of numerous, prestigous and powerful Askhenazi community in close proximity I doubt that the "Jewishness" of these people would have been rediscovered and nourished by some. Rather, like the Kaifeng Jews they might have melted into the genetic background and been absorbed.2

Addendum: Here is a fierce rebuttal to The Atlantic Monthly piece that has be taken seriously now. Here is a more "scholarly" review of the situation. It is clear that the editors of The Atlantic Monthly were looking for a sexy story and the writers gave them one. It is interesting that the second link suggests that the issue of crypto-Jews is insoluable (making references to our "postmodern age" and focusing on the motivations of the researchers who are proponents of crypto-Jewishness), totally unaware of the advances in genetic science even in 2002....

1 - I have a bias for what seem to be prosaic and less "sexy" answers.

2 - My study of of the Cochin Jewish community of India suggests its orthodox vibrancy is a direct function of periodic reenforcement by Jews from the West, as late as the 16th century Jews fleeing pogroms in Central Europe made their way to Cochin, not to mention Middle Eastern Jews. In contrast, the Bene Israel of Bombay were practicing an attenuated form of pre-Talmudic Judaism and seemed on the verge of absorption into their social milieu (recontact with the world Jewry had reversed this trend).

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