Category: Science

FADS1 and the timing of human adaptation to agriculture

fads1-farmers

Open access FADS1 and the timing of human adaptation to agriculture, by Sara Mathieson & Iain Mathieson, bioRxiv (2018).

Abstract:

Variation at the FADS1/FADS2 gene cluster is functionally associated with differences in lipid metabolism and is often hypothesized to reflect adaptation to an agricultural diet. Here, we test the evidence for this relationship using both modern and ancient DNA data. We document pre-out-of-Africa selection for both the derived and ancestral FADS1 alleles and show that almost all the inhabitants of Europe carried the ancestral allele until the derived allele was introduced approximately 8,500 years ago by Early Neolithic farming

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The Danube Corridor Hypothesis and the Carpathian Basin in the Aurignacian

palaeolithic-migrations

Open access review, The Danube Corridor Hypothesis and the Carpathian Basin: Geological, Environmental and Archaeological Approaches to Characterizing Aurignacian Dynamics, by Wei Chu, J World Prehist (2018).

Abstract (emphasis mine):

Early Upper Paleolithic sites in the Danube catchment have been put forward as evidence that the river was an important conduit for modern humans during their initial settlement of Europe. Central to this model is the Carpathian Basin, a region covering most of the Middle Danube. As the archaeological record of this region is still poorly understood, this paper aims to provide a contextual assessment of the Carpathian Basin’s

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Ancient human parallel lineages within North America contributed to a coastal expansion

americas-dispersal

New paper (behind paywall), Ancient human parallel lineages within North America contributed to a coastal expansion, by Scheib et al. Science (2018) 360(6392):1024-1027.

Abstract:

Little is known regarding the first people to enter the Americas and their genetic legacy. Genomic analysis of the oldest human remains from the Americas showed a direct relationship between a Clovis-related ancestral population and all modern Central and South Americans as well as a deep split separating them from North Americans in Canada. We present 91 ancient human genomes from California and Southwestern Ontario and demonstrate the existence of two distinct ancestries in North

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Reproductive success among ancient Icelanders stratified by ancestry

iceland-pca

New paper (behind paywall), Ancient genomes from Iceland reveal the making of a human population, by Ebenesersdóttir et al. Science (2018) 360(6392):1028-1032.

Abstract and relevant excerpts (emphasis mine):

Opportunities to directly study the founding of a human population and its subsequent evolutionary history are rare. Using genome sequence data from 27 ancient Icelanders, we demonstrate that they are a combination of Norse, Gaelic, and admixed individuals. We further show that these ancient Icelanders are markedly more similar to their source populations in Scandinavia and the British-Irish Isles than to contemporary Icelanders, who have been shaped by 1100 years of

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Contrastive principal component analysis (cPCA) to explore patterns specific to a dataset

Interesting open access paper Exploring patterns enriched in a dataset with contrastive principal component analysis, by Abid, Zhang, Bagaria & Zou, Nature Communications (2018) 9:2134.

Abstract (emphasis mine):

Visualization and exploration of high-dimensional data is a ubiquitous challenge across disciplines. Widely used techniques such as principal component analysis (PCA) aim to identify dominant trends in one dataset. However, in many settings we have datasets collected under different conditions, e.g., a treatment and a control experiment, and we are interested in visualizing and exploring patterns that are specific to one dataset. This paper proposes a method, contrastive principal component analysis

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Steppe and Caucasus Eneolithic: the new keystones of the EHG-CHG-ANE ancestry in steppe groups

indo-uralic-ehg-chg-ane-ancestry

Some interesting excerpts from Wang et al. (2018):

An interesting observation is that steppe zone individuals directly north of the Caucasus (Eneolithic Samara and Eneolithic steppe) had initially not received any gene flow from Anatolian farmers. Instead, the ancestry profile in Eneolithic steppe individuals shows an even mixture of EHG and CHG ancestry, which argues for an effective cultural and genetic border between the contemporaneous Eneolithic populations in the North Caucasus, notably Steppe and Caucasus. Due to the temporal limitations of our dataset, we currently cannot determine whether this ancestry is stemming from an existing natural genetic

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Post-Neolithic Y-chromosome bottleneck explained by cultural hitchhiking and competition between patrilineal clans

Open access study Cultural hitchhiking and competition between patrilineal kin groups explain the post-Neolithic Y-chromosome bottleneck, by Zeng, Aw, and Feldman, Nature Communications (2018).

Abstract (emphasis mine):

In human populations, changes in genetic variation are driven not only by genetic processes, but can also arise from cultural or social changes. An abrupt population bottleneck specific to human males has been inferred across several Old World (Africa, Europe, Asia) populations 5000–7000 BP. Here, bringing together anthropological theory, recent population genomic studies and mathematical models, we propose a sociocultural hypothesis, involving the formation of patrilineal kin groups and intergroup competition among

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East Bell Beakers, an in situ admixture of Yamna settlers and GAC-like groups in Hungary

indo-european-yamnaya-corded-ware

I wanted to repeat what I said last week in two different posts (see on the new Caucasus and Yamna Hungary samples, and on local groups in contact with Yamna settlers).

We already knew that expanding East Bell Beakers had received influence from a population similar to the available Globular Amphorae culture samples.

  1. Without Yamna settlers, but with Yamna Ukraine and East Bell Beaker samples, including an admixed Yamna Bulgaria sample (from Olalde & Mathieson 2017, and then with their Nature 2018 papers), the most likely interpretation was that Yamna settlers had received GAC ancestry probably during
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The new Scicomm’s warhorse is “CHG ancestry = PIE” and the Iranian homeland

invasion-from-the-steppe-yamnaya

Funny reports are popping up due to a recent article in New Scientist (behind paywall), World’s most-spoken languages may have arisen in ancient Iran, which echoes the controversial interpretations of Wang et al. (2018).

I have been waiting to read the printed edition, but that of May 26th doesn’t have the article in it, so it may be a web-only text.

Nevertheless, here are some excerpts about the PIE homeland from a news aggregator that caught my attention (emphasis mine):

The two proposed locations are divided by the Caucasus mountains, which are found between the Black

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