qpAdm best practices and common pitfalls

olalde-2018-qpadm-bell-beaker

The recently published preprint Assessing the Performance of qpAdm, by Harney, Patterson, Reich, & Wakeley at bioRxiv (2020) offers some interesting clues about what previous papers using qpAdm might have done right, and – more importantly – what they might have done wrong.

Since it doesn’t make much sense to repeat what this open access paper says within quotes, I will try to use short sentences or rework them to sum it up, illustrating best practices and common pitfalls with what I believe are corresponding examples with Steppe-related populations to date, with an emphasis on Bell Beakers. Most … Read the rest “qpAdm best practices and common pitfalls”

R1b-rich Proto-Indo-Europeans show genetic continuity in Asia

middle-bronze-age-andronovo-horizon

Another preprint came out at the same time as Wang et al. (2020), from the Jena Lab of the Max Planck Society: A dynamic 6,000-year genetic history of Eurasia’s Eastern Steppe, by Jeong, Warinner, et al. bioRxiv (2020).

NOTE. I have now updated the Ancient DNA Dataset, the Prehistory Atlas – with PDF and GIS files including Y-DNA and mtDNA of all newly reported samples (starting with the Neolithic) – as well as the PCA files with those from Wang et al. (2020).

The conclusions are similar, but with some interesting twists. Relevant excerpts (emphasis mine), … Read the rest “R1b-rich Proto-Indo-Europeans show genetic continuity in Asia”

Fully Steppe-like Proto-Corded Ware Late Trypillians

late-trypillia-corded-ware

The genotypes from Human auditory ossicles as an alternative optimal source of ancient DNA, by Sirak et al. Genome Res. (2020), have been finally published by the Reich Lab, so we can get a sneak peek into what’s coming in future papers about the origins of R1a-rich Proto-Corded Ware and R1b-rich Italo-Venetic peoples.

NOTE. To avoid adding potential errors, I have merged the Reich Lab’s Curated Dataset (v. 42.4, March 1 2020) with these new samples before performing the qpAdm analyses. If you find something different with your files, you should probably check out this simple setting first. Read the rest “Fully Steppe-like Proto-Corded Ware Late Trypillians”

Proto-Anatolians: from the Southern Caucasus or the Balkans?

anatolian-lba-kingdoms-hatti

There has been some renewed interest lately in the origin of Proto-Anatolians, because of the recent lecture by Petra Goedegebuure, associate professor of Hittitology at the University of Chicago: Anatolians on the Move: From Kurgans to Kanesh, given at the Oriental Institute (Feb 5 2020).

I will try to comment on her lecture with a critical view of some of her ideas, keeping in mind reasons for one or the other potential routes, which we can for the moment simplify as Gimbutas’ (1965, 1993) eastern route through the Caucasus vs. Anthony’s (2007, 2015) … Read the rest “Proto-Anatolians: from the Southern Caucasus or the Balkans?”

Earliest R1a-Z93…from Late Trypillia in the Podolian-Volhynian Upland!

chalcolithic-yamnaya-corded-ware

Recently, the preprint by Sirak et al. biorXiv (2019), Human auditory ossicles as an alternative optimal source of ancient DNA, was published in Genome Res. (2020), and the corresponding samples were finally uploaded to ENA.

I have been trying to get my hands on sample GLAV_14, a male from the Late Eneolithic site Glăvăneştii Vechi, classified as Romania Bronze Age (ca. 3500-3000 BC), mtDNA T1a1, referenced as investigated first in the study:

Haas N, Maximilian K. 1958. Anthropological study of the human bones from graves with ochre from Glăvăneștii Vechi, Corlăteni and Stoicani Cetățuie. Soviet Anthropology 4,

Read the rest “Earliest R1a-Z93…from Late Trypillia in the Podolian-Volhynian Upland!”

Spread of Indo-European and Uralic speakers in ADMIXTURE

indo-european-uralic-admixture

The following are updated files for unsupervised ADMIXTURE of most available ancient Eurasian samples with K=7. For reference, see PCA of ancient and modern Eurasian samples.

NOTE. For a precise interpretation of ancestry evolution, be sure to first check the posts on the expansion of “Steppe ancestry”, on the spread of Yamnaya ancestry with Indo-Europeans, and on the evolution of Corded Ware ancestry typical of modern Uralic populations.

ADMIXTURE timeline

This is a YouTube video similar to the one on Indo-Europeans and Y-DNA evolution:

admixture-video-youtube

Some comments

  • I have tried running supervised ADMIXTURE models by selecting
Read the rest “Spread of Indo-European and Uralic speakers in ADMIXTURE”

The expansion of Indo-Europeans in Y-chromosome haplogroups

yamnaya-corded-ware-y-dna-haplogroups

I have compiled for two years now the reported Y-DNA and mtDNA haplogroups of ancient DNA samples published, including also SNPs from analysis of the BAM files by hobbyists.

Y-DNA timeline

Here is a video with a timeline of the evolution of Indo-European speakers, according to what is known today about reconstructed languages, prehistoric cultures and ancient DNA:

NOTE. The video is best viewed in HD 1080p (1920×1080) with a display that allows for this or greater video quality, and a screen big enough to see haplogroup symbols, i.e. tablet or greater. The YouTube link is here. The Read the rest “The expansion of Indo-Europeans in Y-chromosome haplogroups”

“Steppe ancestry” step by step (2019): Mesolithic to Early Bronze Age Eurasia

yamnaya-gac-maykop-corded-ware-bell-beaker

The recent update on the Indo-Anatolian homeland in the Middle Volga region and its evolution as the Indo-Tocharian homeland in the Don–Volga area as described in Anthony (2019) has, at last, a strong scientific foundation, as it relies on previous linguistic and archaeological theories, now coupled with ancient phylogeography and genomic ancestry.

There are still some inconsistencies in the interpretation of the so-called “Steppe ancestry”, though, despite the one and a half years that have passed since we first had access to the closest Pontic–Caspian steppe source populations. Even my post “Steppe ancestry” step by step from a year ago … Read the rest ““Steppe ancestry” step by step (2019): Mesolithic to Early Bronze Age Eurasia”