June 07, 2016

Neolithic Aegean genomes

I had covered this paper when it went on the bioRxiv, but the final version has been published in PNAS in open access.

PNAS doi: 10.1073/pnas.1523951113

Early farmers from across Europe directly descended from Neolithic Aegeans

Zuzana Hofmanová, Susanne Kreutzer et al.




sykes.1 said...

Eurogenes blog is crapping all over this paper.

eurologist said...

As I have mentioned previously, some derived alleles for so-called "skin de-pigmentation" may instead allow for tanning: the ability to be light-skinned in winter months, but yet darken during the summer - almost a prerequisite for field workers in a wide range of latitudes, and more so than for hunter-gatherers in densely forested areas.

Also, as I previously pointed out, you can still see high counts of male G2a along the river systems that connect the NW Balkans with northern Italy/ Tyrol, Austria, and S Bavaria.

"Furthermore, in this analysis modern samples from Europe and surrounding regions are inferred to be relatively more genetically related to the Aegean Neolithic genomes than to the Neolithic genomes from Germany and Hungary. These patterns are indicative of founder effects in the German and possibly Hungarian Neolithic samples from a source that appears to be most genetically similar to the Aegean Neolithic samples (specifically, Bar31) and that distinguishes them from the ancestors of modern groups."

Another interpretation is that more recent migrations, specifically during the Bronze Age, have increased the diversity of Aegean genomic signatures in Central Europe.

"Although archaeological evidence indicates a cultural break in many Aegean and West Anatolian settlements around 5,700/5,600 cal BCE..."

Yes, of course - caused by the opening of the Bosporus. However, since Aegeans were seafarers, eventually the connection with Anatolia resumed.

"The distribution of obsidian from the Cycladic islands, as well as similarities in material culture, suggest extensive interactions since the Mesolithic and a coeval Neolithic on both sides of the Aegean."

I have long advocated for the Southern Balkans/ Aegean to be the population origin of early European Neolithic farmers. But I have also maintained that pre-Bosporus-opening there would have been little genetic difference to NW Anatolians. To complete the story, we now need Neolithic DNA from a variety of Anatolian and, generally, SW Asian sites. I believe there is still a possibility of specific *ancient* (not modern) markers from the northern Levant to show up exclusively along the Mediterranean route, including Cyprus and Crete. We'll have to wait and see.

batman said...

How do the authors (using dna and dna only) define the direction of the spread, from Anatolia to Europe, rather than the other way around?

Tom Bridgeland said...

One way is by age of the earliest found representative. Oldest samples in the area of origin, newer samples along the route of dispersal. Need lots of samples to get a good idea of the flow.

batman said...

So how do these geneticians establish that the oldest samples of the most early farmers are from the Egean - and not from Balkan, Italy or northern Europe?

Can't see that this paper actually demonstrate what they claim to prove.