Category: Science

Ancient DNA samples from Mesolithic Scandinavia show east-west genetic gradient

mesolithic-scandinavia

New pre-print article at BioRxiv, Genomics of Mesolithic Scandinavia reveal colonization routes and high-latitude adaptation, by Günther et al. (2017), from the Uppsala University (group led by Mattias Jakobsson).

Abstract (emphasis mine):

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the last glaciation. However, the origin(s) of the first colonizers and their migration routes remain unclear. We sequenced the genomes, up to 57x coverage, of seven hunter-gatherers excavated across Scandinavia and dated to 9,500-6,000 years before present. Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient

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Islands across the Indonesian archipelago show complex patterns of admixture

austronesian-dna

An open access article Complex patterns of admixture across the Indonesian archipelago, by Hudjashov et al. (2017), has appeared in Molecular Biology and Evolution, and clarifies further the Austronesian (AN) expansion.

Abstract:

Indonesia, an island nation as large as continental Europe, hosts a sizeable proportion of global human diversity, yet remains surprisingly under-characterized genetically. Here, we substantially expand on existing studies by reporting genome-scale data for nearly 500 individuals from 25 populations in Island Southeast Asia, New Guinea and Oceania, notably including previously unsampled islands across the Indonesian archipelago. We use high-resolution analyses of haplotype diversity to reveal fine

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Two more studies on the genetic history of East Asia: Han Chinese and Thailand

chinese-eurasian-drift

A comprehensive map of genetic variation in the world’s largest ethnic group – Han Chinese, by Charleston et al. (2017).

It is believed – based on uniparental markers from modern and ancient DNA samples and array-based genome-wide data – that Han Chinese originated in the Central Plain region of China during prehistoric times, expanding with agriculture and technology northward and southward, to become the largest Chinese ethnic group.

Abstract:

As are most non-European populations around the globe, the Han Chinese are relatively understudied in population and medical genetics studies. From low-coverage whole-genome sequencing of 11,670 Han Chinese women we

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Potential Afroasiatic Urheimat near Lake Megachad

palaeolithic-migrations

The publication of new ancient DNA samples from Africa is near, according to people at the SMBE meeting. As reported by Anthropology.net, a group by Pontus Skoglund has analysed new samples (complementing the study made by Carina Schlebusch), so we will have ancient samples of Africans from 300 to 6,000 years ago. They have been compared to the data of modern African populations, and among their likely conclusions (to be published):

  • Several thousand years ago, likely Tanzanian herders migrated far and wide, reaching Southern Africa centuries before the first farmers.
  • West Africans were likely early contributors to the
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My European Family: The First 54,000 years, by Karin Bojs

steppe-expansion-corded-ware

I have recently read the book My European Family: The First 54,000 years (2015), by Karin Bojs, a known Swedish scientific journalist, former science editor of the Dagens Nyheter.

It is written in a fresh, dynamic style, and contains general introductory knowledge to Genetics, Archaeology, and their relation to language, and is written in a time of great change (2015) for the disciplines involved.

The book is informed, it shows a balanced exercise between responsible science journalism and entertaining content, and it is at times nuanced, going beyond the limits of popular science books. It is not written for … Read the rest “My European Family: The First 54,000 years, by Karin Bojs”

Effective migration in Western Eurasia reveals fine-scale migration surface features

map-effective-migration-eurasia

Interesting poster from SMBE 2017, Maps of effective migration as a summary of global human genetic diversity, by Benjamin Peter, Desislava Petkova, Matthew Stephens & John Novembre, of the JNPopGen group of the University of Chicago.

You can read the full poster in the original PDF, or in compressed image. The following are important excerpts:

Aim: To answer the following questions:

  • Which regions have high/low effective migration?
  • How well is human genetic diversity explained by this pure isolation-by-distance model?
  • How does the explanatory performance of EEMS compare to PCA?

Method: It uses the

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Collapse of the European ice sheet caused chaos in northern and eastern Europe until about 8000 BC

deglaciation-europe-east

A new paper with open access has appeared in Quaternary Science Reviews, authored by Patton et al.: Deglaciation of the Eurasian ice sheet complex, which offers a new model investigating the retreat of this ice sheet and its many impacts.

According to the comments of professor Alun Hubbard, the paper’s second author and a leading glaciologist:

To place it in context, this is almost 10 times the current rates of ice lost from Greenland and Antarctica today. What’s fascinating is that not all Eurasian ice retreat was from surface melting alone. Its northern and western sectors across the

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The over-simplistic “Kossinnian Model”: homogeneous peoples speaking a common language within clearly delimited cultures

proto-greek-mynian-ware

There seems to be a growing trend to over-simplistic assumptions in archaeology and linguistics, led by amateur and professional geneticists alike, due to the recent (only partially deserved) popularity of Human Evolutionary Biology.

These studies are offering ancient DNA samples, whose Y-DNA and mtDNA haplogroups and admixture analyses are showing some new valuable information on ancient cultures and peoples. However, their authors are constantly giving uninformed conclusions.

I have read a good, simple description of the Kossinnian model in the book Balkan Dialogues (Routledge, 2017), which has been shared to be fully read online by co-editor Maria Ivanova.… Read the rest “The over-simplistic “Kossinnian Model”: homogeneous peoples speaking a common language within clearly delimited cultures”

Another nail in the coffin for the Anatolian hypothesis: continuity and isolation in the Caucasus during the Neolithic and Calcholithic, in mtDNA samples

caucasus-armenia

A new paper appeared on Current Biology, by Margaryan et al. (including Morten E. Allentoft): Eight Millennia of Matrilineal Genetic Continuity in the South Caucasus.

Among its conclusions:

The plot clearly shows the clustering of the ancient group together with the modern European, Armenian, and Caucasian populations. We observe none of the typical East Eurasian mtDNA lineages (A, C, D, F, G, and M) among the ancient individuals, and only one individual with haplogroup D is present in the modern Armenian maternal gene pool (Artsakh). As such, the archaeologically and historically attested migrations of Central Asian groups (e.g., Turks

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