Category: Genetics
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Beyond the ANI-ASI cline
Long time readers area aware of the thesis of Reconstructing Indian Population History. Indian populations are a two-way admixture of “Ancestral North Indians” and “Ancestral South Indians.” The former are a West Eurasian population. The latter are not, and their closest relatives today are the people of the Andaman Islands, albeit, 10-30,000 years diverged. But…
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The end of genealogical illusions: arise the truth!
One thing that Zack Ajmal’s readers have done enough over at Harappa is closely examine the treasure-trove of data he’s assembled. I decided to “go public” with two obvious inferences which seem to jump out from the data to me at this point: – Syrian Christians from Kerala are not by and large descended from…
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Case closed: blonde Melanesians understood
As a small child perusing old physical anthropology books I would occasionally stumble upon images of people of Oceanian stock with light hair color. I would wonder: is this a biological or cultural feature? In other words, were people bleaching their …
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Her identity by descent made flesh
As I have indicated before, my daughter has a family tree where everyone out to 0.25 coefficient of relatedness has been genotyped by 23andMe. This is convenient in many ways. Before, relatedness was a theory. Now relatedness can be ascertained on the …
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Types of genetics
Molecular genetics Developmental genetics Population genetics Quantitative genetics Phylogenetics Thoughts? Recently had a discussion whether phylogeneticists considered themselves geneticists (qualified “no”). Quantitative genetics really…
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Grandparents as reality, not theory
I am not particularly mystical or sentimental about genetics. I favor openness. But I just started getting my daughter’s results back from 23andMe, and some of her coefficients of relatedness to her grandparents deviated sharply from 0.25. As I h…
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None dare call it eugenics!
Well, almost no one: “The unspoken central reason for the societal taboo and the penal ban on incest is the possibility of hereditary defects — a factor that Strasbourg only hinted at. But the intention behind the eugenic argument is one th…
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Common variant for “IQ gene”?
A few people have forwarded me this paper, Identification of common variants associated with human hippocampal and intracranial volumes: …Whereas many brain imaging phenotypes are highly heritable…identifying and replicating genetic influen…
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Nature Precedings closes up shop
Here’s the announcement: As of April 3rd 2012, we will cease to accept submissions to Nature Precedings. Nature Precedings will then be archived, and the archive will be maintained by NPG, while all hosted content will remain freely accessible to…
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Targaryen genetic load
I have to point you to this post on royal inbreeding in A Song of Ice and Fire. They reference my post on the Habsburgs. Well done! In any case, one possibility is that the Targaryen lineage may have purged their genetic load through inbreeding. The ba…
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The evolution of the human face
The face is an important aspect of our phenotype. So important that facial recognition is one of many innate reflexive cognitive competencies. By this, I mean that you can recognize a face in a gestalt manner, just like you can recognize a set of three marbles. You don’t have to think about it in a…
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Neanderthals came in all colors
There’s a report in Science about a new short paper about Neandertal pigmentation genetics. The context is this. First, in 2007 an ingenuous paper was published which inferred that it may be that Neandertals had red hair, at least based on an N = 2 from two divergent locations. The new study looks at three…
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Natural selection and dopamine receptor genes
Long time readers will be familiar with the large literature in behavior genetics/genomics and dopamine receptor genes. So with that, I point you to a paper exploring the patterns of variation and their relationship to possible natural selection, No Evidence for Strong Recent Positive Selection Favoring the 7 Repeat Allele of VNTR in the DRD4…
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Not just genomics: the creeping future
In 2007 Reihan Salam asked me when the $1,000 genome was going arrive. On paper, probably around this year, or early next. But as I’ve been suggesting it really isn’t that big of a deal (the sticker price isn’t real in any case, someone will want the publicity). Over at The Crux I try and…
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Tigons, ligers, leguars, and jagupards, oh my!
The recent publicity around the gorilla genome highlighted to me that eastern and western gorilla lineages seem to have diverged ~1 million years ago. In the process of trying to figure out hybridity I stumbled upon this matrix from Wikipedia on panthera hybrids: Lion ♀ Tiger ♀ Jaguar ♀ Leopard ♀ Lion Lion Liger Liguar Lipard Tiger Tigon Tiger…
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Beyond trees and European trees
Submitted for your approval, a very important post and preprint from Dr. Joseph Pickrell, Identifying targets of natural selection in human and dog evolution. If you read the preprint there’s a lot of good stuff. Dienekes highlighted the most relevant aspect: representation of genetic relationships with phylogenetic trees mask the likely reality of gene flow…
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The data sets in the dark
Recently I was tipped off to the appearance of a new paper, Genome-Wide Association Study Identifies Chromosome 10q24.32 Variants Associated with Arsenic Metabolism and Toxicity Phenotypes in Bangladesh. This is the section which caught my eye: “Using data on urinary arsenic metabolite concentrations and approximately 300,000 genome-wide single nucleotide polymorphisms (SNPs) for 1,313 arsenic-exposed Bangladeshi…
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Adam’s end was never in the cards
There has been a lot of talk in the media about a new paper which reports that the Y chromosome is not deteriorating, as had been previously inferred from the data. In the 2004 Bryan Sykes wrote Adam’s Curse: A Future Without Men which used this model as a framing device (and naturally elicited great general…
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The race question: are bonobos human?
Recently Jason Antrosio began a dialogue with readers of this weblog on the “race question.” More specifically, he asked that we peruse a 2009 review of the race question in the American Journal of Physical Anthropology. Additionally, he also pointed me to another 2009 paper in Genome Research, Non-Darwinian estimation: My ancestors, my genes’ ancestors.…
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Loss-of-function & variation in load
Greg Cochran pointed out something that I’d been considering about the MacArthur et al. paper: if the average human (OK, non-African human) has ~100 loss-of-function variants, then the standard deviation should be ~10. That’s because the distribution is presumably poisson, and variance = mean, and the square root of the of the variance (~100) is the…