What Neanderthals tells us about modern humans
In Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past David Reich spends a fair amount of time on Neanderthal admixture into modern human lineages. Reich details exactly the process of how his team arrived to analyze the data that Svante Paabo’s group had produced, and […]
Human genomics will uncover a lot of treasure in Southeast Asia
On this week’s podcast on “Isolated Populations” I mentioned offhand to Spencer that I believe it is a bit ridiculous to bracket a host of Southeast Asian populations as “Negritos,” as if they were an amorphous and homogeneous substratum over which the diversity of modern South and Southeast Asian agriculturalists were overlain.There was almost certainly […]
Height differences across Europe could be less effected by selection than we had thought
Like an Old Testament prophet of yore Graham Coop has been prophesying that cryptic population stratification may be a major confounder in analyses for as long as I’ve known him with any degree of familiarity. So it’s no surprise he’s an author on one of two preprints which have rocked the genomics world: Reduced signal […]
The lost 50,000 years of non-African humanity
The figure above is from Efficiently inferring the demographic history of many populations with allele count data. This preprint came out a few months ago, but I was prompted to revisit it after reading Spectrum of Neandertal introgression across modern-day humans indicates multiple episodes of human-Neandertal interbreeding. The latter paper indicates that there were multiple […]
The great bottleneck after the post-Eemian separation
I’ve been thinking about effective population size. Basically it’s the inferred breeding population you estimate in the present, or in many cases the past, based on the genetic variation you see within the population. Another way to say it is that it’s the population size that can explain the genetic drift that you see in […]
The 4,000 year explosion
The figure above shows a most interesting result from a new preprint, FADS1 and the timing of human adaptation to agriculture. It shows the allele frequency change using ancient Eurasian genomes for the derived allele at FADS1. In case you don’t know why FADS1 is important, it’s been implicated in variation long-chain polyunsaturated fatty acids (LC-PUFA) metabolism. The derived allele, […]
Y chromosomal star-phylogenies as inter-group competition between paternal lineages
The figure to the left should be familiar to readers of this weblog. It is taken from A recent bottleneck of Y chromosome diversity coincides with a global change in culture (Kamin et al.). Over the past few years a peculiar fact long suspected or inferred has come into sharp focus: some of the Y […]
Selection is going on with SLC24A5….
On this week’s episode of The Insight, I talked to Matt Hahn about why he wrote his new book, his opinions on “Neutral Theory”, and what he thought about David Reich’s op-ed. Without Spencer’s supervision, I have to admit that I think I lost control and just went “full nerd”. Next week we’re dropping […]
The peoples of the Maghreb have some Pleistocene roots
The Maghreb is an important and interesting place. In the history of Western civilization, the tension between Carthage, the ancient port city based out of modern-day Tunisia, and Rome, is one of the more dramatic and tragic rivalries that has resonances down through the ages. Read Adrian Goldsworthy’s chapter on the Battle of Cannae in […]
The Ancient Neanderthal Mariner
More recent stuff on Neanderthals of interest, Neandertals, Stone Age people may have voyaged the Mediterranean: A decade ago, when excavators claimed to have found stone tools on the Greek island of Crete dating back at least 130,000 years, other archaeologists were stunned—and skeptical. But since then, at that site and others, researchers have quietly […]
There were possibly late archaic introgression events in Eurasia
A few weeks ago I posted on the strong likelihood that there were at least two Denisovan admixture events in Eurasia into modern humans. That’s probably the floor, not the ceiling. We have an Altai Denisovan genome, but the proportion is so low in most of South and Southeast Asia I don’t think we have […]
So merfolk are a real thing now: adaptation to diving
When Rasmus Nielsen presented preliminary work on diving adaptations a few years ago at ASHG I really didn’t know what to think. To be honest it seemed kind of crazy. Everyone was freaking out over it…and I guess I should have. But it just seemed so strange I couldn’t process it. High altitude adaptations, I […]
The maturation of the South Asian genetic landscape
The above is a stylized map from the preprint, The Genomic Formation of South and Central Asia. In broad strokes, it says some things that are very expected, and some things that are not so expected. The abstract is long, but I’ll reproduce it in full: The genetic formation of Central and South Asian populations […]
We’re descended from Lilith and Eve
From the comments: Something that confused me very early on in the book- the San are shown branching off from the rest of humanity prior to Mitochondrial Eve. How can Eve be a common ancestor in this case? Admixture? The commenter is talking about an early portion of Who We Are and How We Got […]
One the eons of salutary neglect
New preprint, Something old, something borrowed: Admixture and adaptation in human evolution. This part jumped out at me: …Indeed, for most traits, the contribution of archaic human alleles to present-day human phenotypic variation is not significantly larger than those of randomly drawn non-introgressed alleles occurring at the same frequency in modern humans. Interestingly, in both […]
Carl Zimmer profile of the Reich group at work
The New York Times has a review up (sort of) of Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past, David Reich Unearths Human History Etched in Bone. But since Carl has been covering the publications coming out of the Reich lab for many years now […]
Turks are Anatolian under the hood, somewhat more Greek than Armenian
My post, Are Turks Armenians Under The Hood?, attracted a little bit of controversy. The main criticism, which was a valid one, is that I did not sample Anatolian Greeks. A reader passed on three Anatolian Greek samples. I also added a Cypriot data set. To my mild surprise, the Anatolian Greeks and Cypriots cluster […]
Demographic replacement in Southeast Asia during the Holocene
Well sometimes you feel silly, and it’s not your fault. Yesterday our podcast on Sundaland went live (we talked about Doggerland and Beringia too!). Though I expressed a fair amount of skepticism, I took the argument that Stephen Oppenheimer presented in Eden of the East, that modern Austronesians are long-term residents of Southeast Asia, seriously. […]
White modern Northern Europeans are genetically more like brown South Asians than brown(ish) ancient Northern Europeans were
The Guardian has a piece by Arathi Prasad, Thanks to Cheddar Man, I feel more comfortable as a brown Briton. Dr. Prasad is a geneticist, so the science is pretty decent (she’s probably seen the documentary ahead of time too). But there is a curious quirk here and it reveals something about human psychology: modern […]
Ancient DNA and Dystruct
There’s a new preprint, Inference of population structure from ancient DNA, which uses explicit demographic models to make inferences about ancestry. I haven’t dug into the guts of the math, but, the outputs are quite interesting. What seems to be obvious is that Western Eurasia has a much richer set of models to choose from […]