Saturday, March 4, 2017

More ancient Eastern European mtDNA



Two new papers with ancient Baltic mtDNA: Saag et al. 2017 and Mittnik et al. 2017, were posted at bioRxiv yesterday. Together the two produced 29 new mtDNA samples from ancient Baltic hunter gatherers, 9 from Baltic Corded Ware, and 17 from the Baltic Bronze age. The new data has been added to my European Hunter Gatherers and Bronze age North Europe mtDNA spreadsheets.

The news results contain only a few pieces of interesting information.

  • Two Baltic HGs don’t belong to mHG U; H11a and K1b2
  • One Baltic HG belongs to “Saami” U5b1b1a
  • 47% of Bronze age individuals belong to mHG H
  • No Siberian mtDNA.

Regarding the Baltic hunter gatherer H11a and K1b2, both mHGs today are more or less European specific today. H11a peaks in Poles, not in a particular large region, which is interesting. Also K1b2 is well documented in Europe but to my knowledge only one non European(Armenia) is known to carry it.

In a post I made about Finnish mtDNA a few months ago I speculated that mHG U5b1b1a descends from ancient NorthEast European hunter gatherers. Well now there’s good evidence that is the case: Kretuonas4 an ancient NorthEast European hunter gatherer of the Narva culture belonged to U5b1b1a. Today U5b1b1a is NorthEast European specific but has also been found in locations such as England, Spain, and Turkey.

The new data suggests Baltic mHG frequencies changed in a big way after the Late Neolithic. Can you guess how? If you read my blog you should know. This will help you; Natural Selection Did It!. mHG H frequencies skyrocketed. I’ve been speculating for a while that for some reason in Bronze age Europe natural selection drove mHG H frequencies upand the frequencies of other mHGs like T2 and K down. mtDNA data from Iron age Poland, Scandinavia, and Spain also display high frequencies of H unlike earlier people from the same locations. My natural selection hypothesis is looking stronger and stronger.

Lastly not a single individual in these two studies belonged to an Siberian mtDNA haplogroup. As far as I know  the autosomal DNA from these ancient individuals don't suggest they had any Siberian-like ancestry either. So it looks like Siberian ancestry, possibly along with yHG N1c and Uralic languages, arrived in the Baltic during the Bronze age or later. Siberian mtDNA(C5b1, Z, D) dating 3,500 years old was found in Karelia. So maybe Siberian ancestry existed in some parts of NorthEastern Europe during the Bronze age and then it gradually expanded. 

4 comments:

  1. I've read that mtDNA H has more resistance to sepsis. Perhaps this was a factor. I love your mtDNA spreadsheets! Thank you!

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  2. Interesting that Mittnik et al. 2017 mentioned that CCC & Samara Yamnaya have some shared gene flow. And P.I.E. & Uralic languages have some early loan words suggesting a close homeland. This is another result that points to the P.I.E. homeland as the Pontic-Caspian Steppe and the Yamnaya Culture as the migratory folks that spread the language.

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  3. If the increase was due to migration it seems we're running out of places that this repository of contributing high frequency H can be found, unless it's buried in the North Black Sea.
    If you went with migration, where would you place this maternal contribution??

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    1. SouthEast Europe is my only guess because it's the only location in which more than 30% of Neolithic mtDNA samples belong to H. Infact about 60% of Neolithic Romanian mtDNA samples belong to H. But not enough ancient mtDNA has been sequenced to determine what region(s) a H heavy migration could have originated from.

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