Archive for April, 2007

Less blog…for now

By Razib Khan | April 30, 2007 7:09 pm

Below is why I haven’t been blogging much….

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CATEGORIZED UNDER: Blog

Changes @ ScienceBlogs

By Razib Khan | April 30, 2007 5:01 pm

Today we debuted the Denialism Blog, while David Dobbs of Smooth Pebbles bids farewell to ScienceBlogs. David offers cogent rationales for why he decided to leave ScienceBlogs (the proximate reason is that he just isn’t posting much as far as bloggers go). One thing to note that is I don’t think a blog is really worthwhile for most people without an intelligent commentariat. I’ve learned a lot from critiques, suggestions and recommendations from comments on my blogs over the past 5 years. Of course, the key is intelligent. Most humans aren’t very smart, so they’re basically just expending the minutes in your life.

CATEGORIZED UNDER: Blog

Bonus Kat

By Razib Khan | April 28, 2007 9:04 pm

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CATEGORIZED UNDER: Blog

Katz

By Razib Khan | April 27, 2007 9:48 am

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CATEGORIZED UNDER: Blog

Round-eyed Chinese?

By Razib Khan | April 26, 2007 3:05 pm

Via Dienekes, a new possible historical genetic story on the horizon: the extent of “European”-origin settlers in pre-modern China. The biography of the individual sequenced:

Yu Hong (d. 592 [C.E.]) was a high-ranking member of a community of Sogdians who had settled on the northern border of China at the beginning of the fourth century. While barely in his teens, Yu Hong began his career in the service of the most powerful nomadic tribe at the time, known as the Ruru, and was posted as an emissary to several countries, including Iran.

Now, the genetics:

…we discuss our analysis of the mitochondrial DNA of human remains excavated from the Yu Hong tomb in Taiyuan, China, dated 1400 years ago. The burial style of this tomb is characteristic of Central Asia at that time. Our analysis shows that Yu Hong belonged to the haplogroup U5, one of the oldest western Eurasian-specific haplogroups, while his wife can be classified as haplogroup G, the type prevalent in East Asia. Our findings show that this man with European lineage arrived in Taiyuan approximately 1400 years ago, and most probably married a local woman. Haplogroup U5 was the first west Eurasian-specific lineage to be found in the central part of ancient China

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CATEGORIZED UNDER: Genetics

ScienceBlogger threatend with legal action vs. Fair Use

By Razib Khan | April 25, 2007 2:14 pm

Final Update: Victory Day! In response to Shelley’s request I’ve removed the text of the original email.

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CATEGORIZED UNDER: Blog

Erick Trinkaus on Neandertal Admixture

By Razib Khan | April 24, 2007 1:30 pm

Erick Trinkaus has a new article in PNAS, European early modern humans and the fate of the Neandertals:

A consideration of the morphological aspects of the earliest modern humans in Europe (more than ~33,000 B.P.) and the subsequent Gravettian human remains indicates that they possess an anatomical pattern congruent with the autapomorphic (derived) morphology of the earliest (Middle Paleolithic) African modern humans. However, they exhibit a variable suite of features that are either distinctive Neandertal traits and/or plesiomorphic (ancestral) aspects that had been lost among the African Middle Paleolithic modern humans…The ubiquitous and variable presence of these morphological features in the European earlier modern human samples can only be parsimoniously explained as a product of modest levels of assimilation of Neandertals into early modern human populations as the latter dispersed across Europe. This interpretation is in agreement with current analyses of recent and past human molecular data.

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CATEGORIZED UNDER: Evolution

Immune to missionaries

By Razib Khan | April 24, 2007 1:07 am

The April 16th issue of The New Yorker had an article by John Colapinto, The puzzling language of an Amazon tribe. It’s in print, so I can’t post it, but the short of it is that the tribe might lack recursion, a hammer blow to Chomskyan universal grammar. Overall the tribe seems to have a rather attenuated tendency toward engaging in abstract thought, and has been incredibly immune to any attempts by Christian missionaries to convert them. At some point in the piece the author notes that occasionally someone will ask a Christian if they’ve ever met this Jesus Christ that they keep talking of, and when they’re told that he died 2,000 years ago all interest disappears. Below, I argued that humans have psychological propensities which bias them toward being religious. If the research about these Amazonians pans out I think you have here a group which is totally insulated by their culture from the attractions of religion because they lack some of the necessary psychological propensities (I suspect, and the article pretty much claims, that those propensities can be developed by tribal members who are raised outside of the group, but that culture constrains cognition in this case). Now, I’ve said that though I’m not religious myself and kind of find the whole behavioral tendency kind of alien and strange, I think that we’ll have to turn humans into autistics for them to truly be “rid of” religion. The Amazonians are not autistic, but, in some ways they are pretty strange, and I don’t know if we want most people to live like them if that’s the price for being grounded in the empirical present instead of delusions of the supernatural.
Update: Here’s a list of unique traits for this people.

CATEGORIZED UNDER: Culture

Monday Kat

By Razib Khan | April 23, 2007 2:27 pm

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CATEGORIZED UNDER: Blog

Levels of analysis of religion, Atran, Boyer & Wilson

By Razib Khan | April 23, 2007 9:26 am

A few weeks ago, Andrew Brown (author of The Darwin Wars) stated:

I’m not sure that Boyer, Atran and Wilson regard their explanations as complementary. I have talked to all three of them about it. My feeling is that while all three of them understand that the explanations might be complementary, they prefer to believe that all the work is done by their preferred model. It’s not clear to me how one could decide this point in principle.

He refers to Scott Atran (In Gods We Trust), Pascal Boyer (Religion Explained) and David S. Wilson (Darwin’s Cathedral). Atran & Boyer are of very similar intellectual outlook, they’re cognitive anthropologists who synthesize psychological and evolutionary paradigms and apply them to anthropological questions. They were both part of Dan Sperber’s salon during the early 1980s in Paris, and work within a ‘naturalistic’ tradition of their discipline which attempts to decompose & reduce anthropological phenomena to make them analytically tractable. In contrast, David S. Wilson in Darwin’s Cathedral is by training an evolutionary biologist who ventures frequently into anthropological territory. All three overlap insofar as they employ methods from a range of fields to explore human social and anthropological questions, though Atran and Boyer emphasize psychology far more than Wilson. In my comments & posts on this weblog I’ve contended that these two models actually are complementary and analyze different levels of religion as a natural phenomenon.

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CATEGORIZED UNDER: Evolution

Trivializing analogies?

By Razib Khan | April 22, 2007 5:58 pm

Chris of Mixing Memory rips into the usual suspects for analogizing atheist activism with the women’s suffrage movement. I have basically taken a sabbatical from these SB intramural debates about religion, Creationism, etc. So I’ll let you comment over there. But, I will offer that I’ve never been jumped for being an atheist, but I have for being a “sand nigger.” So I hope people will maintain some perspective….
Update: Also @ Mike’s & Josh’s.

CATEGORIZED UNDER: Blog

Bonus Kat

By Razib Khan | April 22, 2007 3:16 pm

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CATEGORIZED UNDER: Blog

Genetic conundrum

By Razib Khan | April 20, 2007 10:19 pm

Obviously a sex-linked trait. All males seem to exhibit the trait but none of the females. It can’t just be the lack of something on the X, otherwise some of the females would have exhibited this trait as well. No, perhaps a mutant on the Y which acts in a trans & “dominant” acting manner to repress or abolish something on other chromosomes?

Note: All the males exhibit the phenotype, but none of the females do. If you accept it is a sex-linked trait which manifests because the males don’t have a compensatory copy of the allele inherited from the mother, then all their mothers had to have at least one copy of the “bad” allele. That means that random mating implies that at least 1/4 of the women in the current generation would exhibit the trait (assume that all the mothers are heterozygous), as they would inherit a “bad” copy from both parents. If all the males exhibit the trait, but none of the females do, that would imply something that acts dominantly from the Y chromosome, which only males have.

CATEGORIZED UNDER: Blog

Brother Bru-Bru's African Hot Sauce

By Razib Khan | April 20, 2007 6:42 pm

bru.jpgI was at the local food co-op when I saw Brother Bru Bru’s African Hot Sauce. It said it was “very hot!” on the label, and since some of you had recommended African hot sauces to me earlier I decided to check it out. The label suggests that there were assorted peppers mixed into this concoction. Frankly, for me it was a bit on the mild side. Also, the background sweetness and pungency overwhelmed the heat. Nevertheless, I enjoyed the flavor, even if I was disappointed by tepid spice level. I’m giving it a 4 out of 10, mostly because this was way too mild for a “very hot!” sauce. I mean, the label advertises that it is peddling indigenous wisdom, and the cover has a bug-eyed black guy wearing a tribal necklace. It would have had to be real good to make up for the promises & kind of offensive marketing package, and it just didn’t step up.

CATEGORIZED UNDER: Blog

Born to run?

By Razib Khan | April 20, 2007 6:22 pm

Here is a report on some developments on the hypothesis that humans are very well evolved to run in the heat. A physical anthropologist told me that while cold adapted peoples can acclimate to tropical conditions, heat adapted peoples are not as good at the reverse. That suggested to me that as a tropical species we have deep and extremely powerful adaptations which allow us to tolerate heat, and these adaptations might have other uses that remained advantageous once we moved north into Eurasia.

CATEGORIZED UNDER: Evolution

Kat

By Razib Khan | April 20, 2007 1:11 pm

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CATEGORIZED UNDER: Blog

Outside

By Razib Khan | April 18, 2007 7:30 pm

It’s been a cold & rainy April. This morning I got up and walked down the block to take an unobstructed photo of the mountains which loom over my apartment. When I visit the Midwest I am always struck by the 2-dimensional topography….

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CATEGORIZED UNDER: Blog

Bookie Monster?

By Razib Khan | April 18, 2007 7:21 pm

bookiemonster.jpgToday I was accused of being a “bookie monster.” I suppose it is apt.

CATEGORIZED UNDER: Blog

Why overdominance ain't all that

By Razib Khan | April 18, 2007 5:25 pm

A few days ago I posted about how overdominance, the fitness advantage of a heterozygote (an Aa genotype instead of an AA or aa genotype), can maintain polymorphism (genetic variation) within a population at a locus. Roughly, the equilibrium ratio between the two alleles is determined by their respective fitnesses in the homozygote state. For example, if AA & aa are of equal fitness and of lower fitness than the heterozygote then the final equilibrium frequencies will be 0.5.
Heterozygote advantage is intuitively comprehensible to many people, after all we’ve all heard of “hybrid vigor.” During the genesis of theoretical evolutionary genetics some thinkers promoted the idea that balancing selection of various kinds, including heterozygote advantage, would result in a non-trivial proportion of extant genetic variation within a population. Coalescing around Sewall Wright and Theodosius Dobzhansky this was the “Balance School,” which stood in contrast with the “Classical School” which took its lead from R.A. Fisher, who emphasized directional selection constraining polymorphism and either fixing or eliminating mutant alleles within a population. In 1966 Richard Lewontin and J.L. Hubby published A molecular approach to the study of genic heterozygosity in natural populations. II. Amount of variation and degree of heterozygosity in natural populations of Drosophila pseudoobscura (full paper at link), which showed that the extant of genetic variation as inferred from allozyme diversity was far greater than either the Balance or Classical School has predicted. At first Lewontin & Hubby offered the idea that selection for heterozyogosity might be maintaining the variation that they observed (Lewontin was a student of Dobzhansky), but soon enough they rejected this on theoretical grounds. The logic is simple, so I will first go through the formal motions.
Consider a population whose fitness can modeled as such:

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CATEGORIZED UNDER: Genetics

The fall of Rome

By Razib Khan | April 18, 2007 1:31 pm

I have a review up over at my other weblog of the book The Fall of Rome: And the End of Civilization.

CATEGORIZED UNDER: History
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