Inbreeding causing issues in Osama bin Laden’s family
I didn’t figure I would have to say much about 9/11 really that others could not say (aside from perhaps you should read Marc Sageman’s Understanding Terror Networks if you want an ethnography of the Salafi jihadist movement which lead to al-Qaeda). But The Daily Best has a profile of one of Osama bin Laden’s […]
Why do percentage estimates of “ancestry” vary so much?
When looking at the results in Ancestry DNA, 23andMe, and Family Tree DNA my “East Asian” percentage is: – 19% – 13% – 6% What’s going on here? In science we often make a distinction between precision and accuracy. Precision is how much your results vary when you re-run an experiment or measurement. Basically, can […]
Ancient Europeans: isolated, always on the edge of extinction
A few years ago I suggested to the paleoanthropologist Chris Stringer that the first modern humans who arrived in Europe did not contribute appreciable ancestry to modern populations in the continent (appreciable as in 1% or more of the genome).* It seems I may have been right according to results from a 2016 paper, The […]
Castes are not just of mind
Before Nicholas Dirks was a controversial chancellor of UC Berkeley, he was a well regarded historian of South Asia. He wrote Castes of Mind: Colonialism and the Making of Modern India. I read it, along with other books on the topic in the middle 2000s. Here is Amazon summary from Library Journal: Is India’s caste […]
The great Bantu expansion was massive
Lots of stuff at SMBE of interest to me. I went to the Evolution meeting last year, and it was a little thin on genetics for me. And I go to ASHG pretty much every year, but there’s a lot of medical stuff that is not to my taste. SMBE was really pretty much my […]
SLC24A5 is very important, but we don’t know why
The golden of pigmentation genetics started in 2005 with SLC24A5, a putative cation exchanger, affects pigmentation in zebrafish and humans. Prior to that pigmentation genetics was really to a great extent coat color genetics, done in mice and other organisms which have a lot of pelage variation. Of course there was work on humans, mostly […]
The fad for dietary adaptations is not going away
Food is a big deal for humans. Without it we die. Unlike some animals (here’s looking at you pandas) we’re omnivorous. We eat fruit, nuts, greens, meat, fish, and even fungus. Some of us even eat things which give off signals of being dangerous or unpalatable, whether it be hot sauce or lutefisk. This ability […]
The Bronze age demographic transformation of Britiain
In Norman Davies’ the excellent The Isles: A History, he mentions offhand that unlike the Irish the British to a great extent have forgotten their own mythology. This is one reason that J. R. R. Tolkien created Middle Earth, they gave the Anglo-Saxons the same sort of mythos that the Irish and Norse had. But […]
So what’s point of demographic models which leave you scratching your head
There’s a new paper on Tibetan adaptation to high altitudes, Evolutionary history of Tibetans inferred from whole-genome sequencing. The focus of the paper is on the fact that more genes than have previously been analyzed seem to be the targets of natural selection. And I buy most of their analyses (not sure about the estimate […]
Beyond “Out of Africa” and multiregionalism: a new synthesis?
For several decades before the present era there have been debates between proponents of the recent African origin of modern humans, and the multiregionalist model. Though molecular methods in a genetic framework have come of the fore of late these were originally paleontological theories, with Chris Stringer and Milford Wolpoff being the two most prominent public exponents of […]
The logic of human destiny was inevitable 1 million years ago
Robert Wright’s best book, Nonzero: The Logic of Human Destiny, was published near 20 years ago. At the time I was moderately skeptical of his thesis. It was too teleological for my tastes. And, it does pander to a bias in human psychology whereby we look to find meaning in the universe. But this is […]
Mouse fidelity comes down to the genes
While birds tend to be at least nominally monogamous, this is not the case with mammals. This strikes some people as strange because humans seem to be monogamous, at least socially, and often we take ourselves to be typically mammalian. But of course we’re not. Like many primates we’re visual creatures, rather than relying in […]
Women hate going to India
For some reason women do not seem to migrate much into South Asia. In the late 2000s I, along with others, noticed a strange discrepancy in the Y and mtDNA lineages which trace one’s direct male and female lines: in South Asia the male lineages were likely to cluster with populations to the north an […]
Genetic variation in human populations and individuals
I’m old enough to remember when we didn’t have a good sense of how many genes humans had. I vaguely recall numbers around 100,000 at first, which in hindsight seems rather like a round and large number. A guess. Then it went to 40,000 in the early 2000s and then further until it converged to […]
Why only one migrant per generation keeps divergence at bay
The best thing about population genetics is that because it’s a way of thinking and modeling the world it can be quite versatile. If Thinking Like An Economist is a way to analyze the world rationally, thinking like a population geneticist allows you to have the big picture on the past, present, and future, of […]
The future shall, and should, be sequenced
Last fall I talked about a preprint, Human demographic history impacts genetic risk prediction across diverse populations. It’s now published in AJHG, with the same informative title, Human Demographic History Impacts Genetic Risk Prediction across Diverse Populations. Even though talked about this before, I thought it would be useful to highlight again. To recap, GWAS is […]
Why the future won’t be genetically homogeneous
While reading The Founders of Evolutionary Genetics I encountered a chapter where the late James F. Crow admitted that he had a new insight every time he reread R. A. Fisher’s The Genetical Theory of Natural Selection. This prompted me to put down The Founders of Evolutionary Genetics after finishing Crow’s chapter and pick up […]
Mitochondrial Eve: a de facto deception?
The above image, and the one to the left, are screenshots from my father’s 23andMe profile. Interestingly, his mtDNA haplogroup is not particularly common among ethnic Bengalis, who are more than ~80% on a branch of M. This reality is clear in the map above which illustrates the Central Asian distribution my father’s mtDNA lineage. […]
Buddy, can you spare some ascertainment?
The above map shows the population coverage for the Geno 2.0 SNP-chip, put out by the Genographic Project. Their paper outlining the utility and rationale by the chip is now out on arXiv. I saw this map last summer, when Spencer Wells hosted a webinar on the launch of Geno 2.0, and it was the […]
Unveiling the genealogical lattice
To understand nature in all its complexity we have to cut down the riotous variety down to size. For ease of comprehension we formalize with math, verbalize with analogies, and visualize with representations. These approximations of reality are not reality, but when we look through the glass darkly they give us filaments of essential insight. […]