The continuing tangling of the human tree
Last summer I made a thoughtless and silly error in relation to a model of human population history when asked by a reader the question: “which population is most distantly related to Africans?” I contended that all non-African populations…
Beware of one tree!
Sometimes in the comments of this weblog people get into heated disagreements about one figure and its proper interpretation. I don’t get much involved most of the time because different visualization techniques often differ on the margin, so get…
The evolutionary effect of the sky gods
Last week I reviewed ideas about the effect of “exogenous shocks” to an ecosystem of creatures, and how it might reshape their evolutionary trajectory. These sorts of issues are well known in their generality. They have implications from th…
Visualization of genetic distances, part n
Zack Ajmal has been taking his Reference 3 data set for a stroll over at the Harappa Ancestry Project. Or, more accurately, he’s been driving his computer to crunch up ADMIXTURE results ascending up a later of K’s. Because it is the Harappa…
Where in the world did anatomically modern humans come from?
The Pith: I review a recent paper which argues for a southern African origin of modern humanity. I argue that the statistical inference shouldn’t be trusted as the final word. This paper reinforces previously known facts, but does not add much th…
Why siblings differ differently
The Pith: In this post I examine how looking at genomic data can clarify exactly how closely related siblings really are, instead of just assuming that they’re about 50% similar. I contrast this randomness among siblings to the hard & fast de…
“Asian” in all the right places
mtDNA haplogroup G1a2
The pith: In this post I examine the most recent results from 23andMe for my family in the context of familial and regional (Bengal) history. I also use these results to offer up a framework for the ethnognesis of the eastern Ben…
A ‘leaky’ model
John Farrell pointed me to this Anne Gibbons’ piece, A New View Of the Birth of Homo sapiens. Here’s some interesting passages:
The new picture most resembles so-called assimilation models, which got relatively little attention over the yea…
The scions of Shem?
The media is reporting rather breathlessly a new find out of Arabia which seems to push much further back the presence of anatomically modern humans in this region (more accurately, the archaeology was so sparse that assessments of human habitation see…
After the evolutionary revolution
Image credit: Luna04
My post The paradigm is dead, long live the paradigm! expressed to some extent my befuddlement at the current state of human evolutionary genetics and paleoanthropology. After the review of the paper of possible elevated admixtur…
Visualizing variation, input → output
I have noted a few times that one thing you have to be careful about in two dimensional plots which show genetic variance is that the dimensions in which the data are projected upon are often generated from the data itself. So adding more data can chan…
Neandertal admixture, revisiting results after shaken priors
After 2010′s world-shaking revolutions in our understanding of modern human origins, the admixture of Eurasian hominins with neo-Africans, I assumed there was going to be a revisionist look at results which seemed to point to mixing between diffe…
The genomic heritage of French Canadians
Image Credit: Anirudh Koul
One of the great things about the mass personal genomic revolution is that it allows people to have direct access to their own information. This is important for the more than 90% of the human population which has sketchy ge…
The rise of genetic architecture
In science, like most things, one prefers simple over complex whenever possible. You keep adding variables until the explanatory juice starts hitting diminishing marginal returns. So cystic fibrosis is due to a mutation at one gene, and the disease exp…
Ancestry in the Americas
The populations of the African Diaspora have a particular interest in the new genomics, and its relationship to ancestry. Unlike other post-Columbian Diasporas they have sketchy, at best, knowledge of the regions from which their ancestors arrived. This probably explains the popularity of Roots and Henry Louis Gates Jr.’s various genealogical projects which have utilized […]
Of association & evolution
Two of the main avenues of research which I track rather closely in this space are genome-wide association studies (GWAS), which attempt to establish a connection between a trait/disease and particular genetic markers, and inquiries into the evolutionary parameters which shape the structure of variation within the human genome. Often with specific relation to a particular […]
Visualizing West Eurasia
Over at his blog Dienekes Pontikos has taken some public data sets and his own Dodecad samples and generated a massive MDS plot of West Eurasian populations. The MDS is fine as it goes. It illustrates clearly that when you visualize an individual on a plot defined by the two largest dimensions of variation in […]
Hobbit DNA in 2011
I predicted earlier that Hobbit DNA would be extracted in 2011. It was pretty much an educated guess based on various omissions I sensed in papers in 2010. But it seems that an attempt is going to be made: Scientists are planning an attempt to extract DNA from the ‘hobbit’ Homo floresiensis, the 1-metre-tall extinct distant […]
Profiling hair color by DNA
Hair Color of Unknown Offenders Is No Longer a Secret: The research findings demonstrate that on the basis of DNA information it is possible to determine with an accuracy of more than 90 percent whether a person has red hair, with a similarly high accuracy whether a person has black hair, and with an accuracy […]
Are Turks acculturated Armenians?
To the left you see a zoom in of a PCA which Dienekes produced for a post, Structure in West Asian Indo-European groups. The focus of the post is the peculiar genetic relationship of Kurds, an Iranian-speaking people, with Iranians proper, as well as Armenians (Indo-European) and Turks (not Indo-European). As you can see in […]