tag:blogger.com,1999:blog-7315236707728759521.post4813436845730162258..comments2024-03-27T22:28:06.861-06:00Comments on Dispatches From Turtle Island: Do Yamnaya Autosomal Genetics Derive From Caucasian Mail Order Brides?Andrew Oh-Willekehttp://www.blogger.com/profile/02537151821869153861noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-7315236707728759521.post-58694547185547321222017-05-24T16:44:59.760-06:002017-05-24T16:44:59.760-06:00"Y-DNA R1b-M269 is also found in many steppe ..."Y-DNA R1b-M269 is also found in many steppe individuals who have EHG and/or CHG ancestry, but lack WHG ancestry."<br /><br />EHG is 50% WHG. None of those individuals lack WHG ancestry. That's my point.<br /><br />"The empirical link...."<br /><br />Yes. And the link between R1b-M269's ancestors to WHG and not the steppe is just as strong. Hence why I'm arguing that R1b-M269 came from WHG - because its ancestors did. And to be clear - it's really R1b-P310 that's common in Western Europe, and that excludes Yamnaya's R1b-Z2103, which is most common among non-IE Uralic and Altaic speaking populations (though older IE populations may have been assimilated).<br /><br />So there's two scenarios supported by the data here IMHO.<br /><br />Scenario 1: R1b-P310 arrived in non-Iberian Bell Beakers from a steppe IE population related to Yamnaya. These IE speakers came to complete dominate the Bell Beaker DNA on the Y-chromosome but ended up speaking the Bell Beaker's language and adopting their culture.<br /><br />What's unexplained:<br /><br />Both the Bell Beaker culture and early IE seem to have been transmitted mostly by men. So how would Yamnaya completely wipe out the Bell Beakers' male side of the gene pool but adopt the culture of Bell Beaker women, particularly when the expansion of both Bell Beaker culture and IE cultures seems to have been male mediated? This is the crux of why I think scenario 2 is more likely - I doubt that their would be cultural and linguistic continuity of the Y-chromosome pool had such a sudden and complete turnover.<br /><br />The IE-speakers that Bell Beakers actually interacted with were Corded Ware Culture too, and they seem overwhelmingly dominated by R1a. Will future samples find groups of CWC that are predominantly R1b? Will they find a CWC male that is R1b-P310 that pre-dates any interaction with the Bell Beakers? That would be the smoking gun.<br /><br />Scenario 2: The resurgence of WHG ancestry and R1b and I2 frequencies that occurred throughout Europe during the Middle Neolithic also affected people a little bit further east on the steppe. So the R1b-Z2103 in Yamnaya is actually not via EHG, but more directly from WHG, probably somewhere in the Danube basin. These men assimilate into Yamnaya and coexist alongside males with R1a, Q, and older R1b clades from EHG.<br /><br />What's unexplained:<br /><br />What is the full story of the WHG resurgence? Will we find P310 from a male Bell Beaker who lacks steppe admixture? That would be the smoking gun.<br /><br />"And, WHG ancestry is widespread in populations such as first wave Neolithic people and Mesolithic populations, in which the derived Y-DNA R1b (e.g. R1b-M269) is completely absent."<br /><br />Finding only highly derived R1b is a sign that you're looking at a population that comes after the bottleneck/expansion of R1b, not before. An ancestral population should have the greater diversity. <br /><br />Consider this - we only have 7 Y-chromosomes for Iberian Bell Beakers. Of those 7, 2 were R1b, 3 were I2a2 or I2a2a, 1 was I2a1a1, and 1 was G2.<br /><br />Of those two R1b Iberian Bell Beakers, all we know is that one was R1b1a(xL23), and the other was R1b1. They weren't able to test either of those for R1b-M269, and only the first one were they able to exclude any mutations downstream from R1b1a. We don't actually know that R1b-M269 is absent, even for that small of a sample.<br /><br />If Iberian Bell Beakers are the source of R1b-P310, then one would expect R1b to be pretty diverse in their homeland. If that's the case we may need a larger sample size too (or to catch a P310 male outside of Iberia but prior to mixing with steppe peoples).<br /><br />What does seem to be known already though is that long before Bell Beakers expanded outside of Iberia, WHG had almost obliterated any first farmer Y-DNA they had. And that seems to have been happening independently in Neolithic populations in Britain and Germany too.Ryanhttps://www.blogger.com/profile/07906194112935320590noreply@blogger.comtag:blogger.com,1999:blog-7315236707728759521.post-4811952587003546602017-05-24T09:58:54.756-06:002017-05-24T09:58:54.756-06:00The empirical link in both modern and ancient DNA ...The empirical link in both modern and ancient DNA between Y-DNA R1b (the derived version found, e.g., in Western Europe and the Yamnaya, not the more basal R1b-V88), and autosomal steppe ancestry is extremely strong, even if not 100% perfect. And, WHG ancestry is widespread in populations such as first wave Neolithic people and Mesolithic populations, in which the derived Y-DNA R1b (e.g. R1b-M269) is completely absent.<br /><br />Y-DNA R1b-M269 is also found in many steppe individuals who have EHG and/or CHG ancestry, but lack WHG ancestry.andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-7315236707728759521.post-84175985250928818282017-05-23T20:08:21.508-06:002017-05-23T20:08:21.508-06:00"One possibility is that Southern steppe peop..."One possibility is that Southern steppe people were not originally Indo-Europeans and had a strongly Caucasian influenced language (possibly related to Minoan and Basque), but that northern steppe people were Indo-Europeans. The fact that early Iberian Bell Beaker culture people seem to largely lack steppe ancestry, even though non-Iberian Bell Beaker people have it to a great degree, however, complicates the story."<br /><br />I think the simpler explanation is that Iberian Bell Beakers moved to central Europe and assimilated Corded Ware Culture locals before having a secondary expansion. That would fit with all of the data. People just assume it's only IE speakers who went around assimilating others, but I see no reason for that to necessarily be the case.<br /><br />I suspect though that Yamnaya got its Indo-European language from it's ANE heritage, whereas it got its R1b Y-chromosomes from its WHG heritage. I think R1a and Q are the markers that were linked to IE's older ancestors, not R1b, which would have arrived in Europe quite a bit earlier.<br /><br />Consider that all the ancient samples we have of R1b are only from populations with WHG ancestry. It's the only common factor between them. Many lack any appreciable Steppe ancestry, so I don't think it makes sense to view R1b and steppe ancestry is very closely tied. There's R1b Iberian Bell Beakers who lack steppe ancestry even.<br /><br />I think the data fits with Bell Beakers initially carrying high frequencies of I2 and R1b spreading to central Europe with a relatively modest autosomal impact, and through a series of founder effects one clade of R1b becomes dominant in the group that reaches Central Europe and mixes with CWC. Then a secondary, more demographically important expansion comes from that mixed group (and IE speakeres influenced by Bell Beakers do their own expansion as the Unetice culture.<br /><br />The Bell Beakers were almost entirely WHG on their Y-chromosomes though. I think the bigger question is this WHG resurgence in the middle Neolithic that seems to have impacted everywhere from Portugal to the Ukraine. What caused that? Is there some WHG network/culture that the Bell Beakers just managed to make use of even?<br />Ryanhttps://www.blogger.com/profile/07906194112935320590noreply@blogger.com