Indian ancestry maritime Southeast Asia
In the comments, people keep asking about Indonesia, and Java in particular. The reason is pretty simple: before wholesale conversion to Islam maritime Southeast Asia was dominated at the elite level by Indic social and religious forms. I say “Indic” because unlike mainland Southeast Asia Theravada Buddhism did not supplant other Indian religions, and in […]
The Indian admixture into Southeast Asia is not just a function of distance
In the comments to the post below about Indian ancestry in Thailand, some observed that this should not be surprising due to reciprocal gene flow and proximity. Implicitly, I think what is being suggested here is that there is isolation by distance and continuous gene flow. Obviously some of this is true, but there details […]
Thais may have more Indian ancestry than Cambodians and less than Burmese
There were some questions about the Indian ancestry of the Thai. The dataset released by the Reich lab has some Thai. I pulled that data, and some other Southeast Asian groups, and Tamils and Tajiks. The merging only left 62,000 SNPs, but that’s probably enough to answer this question. The PCA above shows the West […]
Humans are basically invasive weeds
One of the somewhat surprising things we have learned over the last decade is that massive admixture and homogenization has occurred between distinct human lineages over the last 10,000 years. By this, I mean that we’re not talking simply about continuous gene-flow between neighboring populations, but massive expansions of small groups and assimilation of very […]
Selection against height in Sardinians
Evidence of polygenic adaptation at height-associated loci in mainland Europeans and Sardinians: Adult height was one of the earliest putative examples of polygenic adaptation in human. By constructing polygenic height scores using effect sizes and frequencies from hundreds of genomic loci robustly associated with height, it was reported that Northern Europeans were genetically taller than […]
Whole genome sequencing comes to Cavalli-Sforza’s data
More than twenty years ago L. L. Cavalli-Sforza published The History and Geography of Human Genes. Based on decades of analysis of ‘classical’ markers, this work lays out results of statistical genetic analyses based on a few hundred genes, as well as displaying Cavalli-Sforza’s encyclopedic ethnographic knowledge. A close look at this book will yield […]
Tutsis are genetically very similar to Masai
Many years ago, before I used ggplot, I did a little analysis of the genetics of the Tutsi. Actually, it was the genetics of a single Tutsi, or more precisely, someone who was 75% Tutsi ancestry (3 out of 4 grandparents). I found that the Tutsi individual seemed quite distinct from the Bantu peoples in […]
Selection for and against pigmentation alleles in South Asia
Recently some British friends were asking about what we knew about South Asian historical genetics now. I explained that it does look like there was some migration in from the Central Asian steppe and West Asia into South Asia during the Holocene. To which one friend responded, “that’s obvious though, many Indians look like brown […]
Genes, memes, and Mundas
The Munda languages of the northeastern quadrant of the Indian subcontinent are quite interesting because they are more closely related to the Austro-Asiatic languages of Southeast Asia than to the Indo-Aryan or Dravidian languages which are spoken by their neighbors. The Munda are usually classified as adivasi, which has connotations of being an ‘original inhabitant’ […]
Very ancient ghosts in the African genome
The above figure is from a preprint (updated from last year), Recovering signals of ghost archaic introgression in African populations. But to truly get a sense of this preprint, I would highly recommend you read the supplementary material. And, to be honest, a publication from 2007, The Joint Allele-Frequency Spectrum in Closely Related Species, as […]
Europe had a lot of demographic turnover because there were never many humans
Now things are coming into focus. Population dynamics and socio-spatial organization of the Aurignacian: Scalable quantitative demographic data for western and central Europe: Demographic estimates are presented for the Aurignacian techno-complex (~42,…
On “big science”, ancient DNA, and David Reich
A lot has happened in the last few days in backchannel conversations and social media in relation to the piece in The New York Times Magazine which put the spotlight on ancient DNA, and David Reich, for the general audience. Unlike Carl Zimmer’s …
Models uncovering African population genetic history
In a deep sense, we know a lot more about the population genetic history of England at the fine-grain than we do about the whole continent of Africa. That’s going to change in the near future, as researchers now realize that the history and emergence of modern humans within the continent was a more complex, […]
How paternity testing is like international trade
Nonpaternity rate % N Switzerland 0.83 1607 USA, Michigan, white 1.49 1417 USA, California, white 2.1 6960 USA, Hawaii 2.3 2839 UK, West London 3.7 2596 Paternity Testing Laboratories UK 16.6 1702 USA, Los Angeles, white 24.9 1393 Sweden 38.7 5018 South Africa, Cape Coloured 40 1156 The results above are from Kermyt Anderson’s How […]
Patterns of genetic diversity within Africa
The violin-plot above is from a new preprint, Runs of Homozygosity in sub-Saharan African populations provide insights into a complex demographic and health history. Here’s the abstract: The study of runs of homozygosity (ROH), contiguous regions in the genome where an individual is homozygous across all sites, can shed light on the demographic history and […]
The golden age of pigmentation is yet to come
Skin color is important and interesting. It is important because people think it is important. Humans often classify each other by complexion, and it has a high social importance in many cultures. This tendency starts at a very young age. When my children are toddlers they’ve all misidentified photographs of black American males with a […]
Hominins are still having sex, caught in flagrante delicto
Assuming you haven’t been sleeping under a rock, you have probably heard that a Nature paper came out on an F1 Neanderthal-Denisovan hybrid. The major new science in my opinion from the results of the genome itself is to be found in the figure above. It confirms that there was a lot of population turnover among Neanderthals, […]
The HGDP in the post-ascertainment era
In the 1990s there was a huge debate around the “Human Genome Diversity Project” (HGDP). By the HGDP I don’t mean what you probably know as the HGDP panel, but a more ambitious attempt to genotype tens of thousands of individuals across the world. In the end activists “won”, and the grand plans came to […]
Complex evolution of pigmentation in modern humans
Last fall Crawford et al., Loci associated with skin pigmentation identified in African populations, was published in Science and made a huge splash. As I’ve been saying recently, and most people agree, much of the remaining “low hanging fruit” in human evolutionary genomics, and to some extent, human medical genetics, is going to be in Africa on […]
India vs. China, genetically diverse vs. homogeneous
About 36% of the world’s population are citizens of the Peoples’ Republic of China and the Republic of India. Including the other nations of South Asia (Pakistan, Bangladesh, etc.), 43% of the population lives in China and/or South Asia. But, as David Reich mentions in Who We Are and How We Got Here China is […]