When conquered pre-Greece took captive her rude Hellene conqueror
When I was a child in the 1980s I was captivated by Michael Wood’s documentary In Search of the Trojan War (he also wrote a book with the same name). I had read a fair amount of Greek mythology, prose translations of the Iliad, as well as ancient history. The contrast between the Classical Greeks, […]
When conquered pre-Greece took captive her rude Hellene conqueror
When I was a child in the 1980s I was captivated by Michael Wood’s documentary In Search of the Trojan War (he also wrote a book with the same name). I had read a fair amount of Greek mythology, prose translations of the Iliad, as well as ancient history. The contrast between the Classical Greeks, […]
The Beaker is breaking!
The link is up, The Beaker Phenomenon And The Genomic Transformation Of Northwest Europe, but the paper is still processing: I’ll update the post when I can read the paper.
Synergistic epistasis as a solution for human existence
Epistasis is one of those terms in biology which has multiple meanings, to the point that even biologists can get turned around (see this 2008 review, Epistasis — the essential role of gene interactions in the structure and evolution of genetic systems, for a little background). Most generically epistasis is the interaction of genes in […]
Africa’s great demographic transformation
Stonehenge has been a preoccupation for moderns since the Victorian period. It was built over 5,000 years ago, and its usage in some fashion continued down to about 2,500 years ago. For a long while it had been associated with the Celts, but more recently there has been some suspicion that its roots must be […]
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 […]
“Out of Africa” bottleneck is what really matters for mutations
At least in relation to mutational load, if you read a new preprint in biorxiv, The demographic history and mutational load of African hunter-gatherers and farmers: The distribution of deleterious genetic variation across human populations is a key issue in evolutionary biology and medical genetics. However, the impact of different modes of subsistence on recent […]
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 […]
Aryan marauders from the steppe came to India, yes they did!
Its seems every post on Indian genetics elicits dissents from loquacious commenters who are woolly on the details of the science, but convinced in their opinions (yes, they operate through uncertainty and obfuscation in their rhetoric, but you know where the axe is lodged). This post is an attempt to answer some questions so I […]
Oxford Nanopore finally giving hope to biologist’s dreams
I don’t talk too much about genomic technology because it changes so fast. Being up-to-date on the latest machines and tools often requires regular deep-dives right now, though I believe at some point technological improvements will plateau as the data returned will be cheap and high quality enough that there won’t be much to gain on the […]
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 […]
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 humans have so many pulse admixtures
The Blank Slate is one of my favorite books (though I’d say The Language Instinct is unjustly overshadowed by it). There is obviously a substantial biological basis in human behavior which is mediated by genetics. When The Blank Slate came out in the early 2000s one could envisage a situation in 2017 when empirically informed […]
Sex bias in migration from the steppe (revisited)
Last fall I blogged a preprint which eventually came out as a paper in PNAS, Ancient X chromosomes reveal contrasting sex bias in Neolithic and Bronze Age Eurasian migrations. The upshot is that the authors found that there was far less steppe ancestry on the X chromosomes of Bronze Age Central Europeans than across the whole […]
How Tibetans can function at high altitudes
About seven years ago I wrote two posts about how Tibetans manage to function at very high altitudes. And it’s not just physiological functioning, that is, fitness straightforwardly understood. High altitudes can cause a sharp reduction in reproductive fitness because women can not carry pregnancies to term. In other words, high altitude is a very strong selection […]
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 […]
Adaptation is ancient: the story of Duffy
Anyone with a passing familiar with human population genetics will know of the Duffy system, and the fact that there is a huge difference between Sub-Saharan Africans and other populations on this locus. Specifically, the classical Duffy allele exhibits a nearly disjoint distribution from Africa to non-Africa. It was naturally one of the illustrations in […]
Ancestry inference won’t tell you things you don’t care about (but could)
The figure above is from Noah Rosenberg’s relatively famous paper, Clines, Clusters, and the Effect of Study Design on the Inference of Human Population Structure. The context of the publication is that it was one of the first prominent attempts to use genome-wide data on a various of human populations (specifically, from the HGDP data set) […]
Your ancestry inference is precise and accurate(ish)
For about three years I consulted for Family Tree DNA. It was a great experience, and I met a lot of cool people through that connection. But perhaps the most interesting aspect was the fact that I can understand the various pressures that direct-to-consumer genomics firms face from the demand side. The science is one […]