GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2010-11 > 1289772846
Subject: Re: [DNA] First Neolithic Y-DNA published
Date: Sun, 14 Nov 2010 22:14:06 +0000 (UTC)
From: Sasson Margaliot
>I need you to clarify something for me
>J2 Jews came to Russia, say, 500 years ago.
>Their TMRCA is, say, 4000 years ago. As they were relocated from Levant to
Italy, then to France and Germany, then to Poland and Ukraine, they brought
the diversity with them.
>R1b people probably also were carrying the diversity with them. What is not
clear to me is: why do you equate TMRCA with the time of arrival?
Where did you get (or read, or heard) that I equate TMRCA with the time of arrival?
Let me share with you the first rule of DNA genealogy: You shall not equate TMRCA with the time of arrival, unless you damn sure that it was the time of arrival.
It might well be that a TMRCA of R1b1b2 in the USA is around 6,000 years. Do you think that I take this figure as the time of arrival of "Mayflower" to Plymouth Rock??
DNA genealogy is NOT just TMRCAs. When I claim that R1b1b2 have arrived to Iberia 4800 years before present, it is not just the TMRCA of a number of subclades of R1b1b2. This figure is a middle one in a long chain of figures accompanying the migration route of R1b1 from the Altai region (~ 17,000 ybp) via Central Asia (~6900 ybp), Middle Volga (6,000 ybp), Caucasus (6,000 ybp), Middle East (5,500 ybp) an so forth, and then R1b1b2-L21 in France (4,200 ybp), etc.
In other words, this figure is not just TMRCA, it is a reflection of a complex pattern of evens (including, by the way, a chronology of the Beaker Culture). It is a part of an extended pattern. By the way, this figure used to be lower in my earlier works, it was around 3,700 ybp, until I realized that U106 is a close relative of P312, an they both were the Beaker Cultur and both moved North from Iberia. Their common ancstor lived ~4,800 year ago. That is why their base haplotypes are so similar.
As to your first "statement",
>Their (Jewish J2) TMRCA is, say, 4000 years ago. As they were relocated from Levant to Italy, then to France and Germany, then to Poland and Ukraine, they brought the diversity with them.
it is not quite accurate. Yes, some of them brought the diversity with them. However, there are not so many J2 populations in Poland and Ukraine (and Latvia and Lithuania, and Russia, on that matter) who have their common ancestor 4000 years ago. More commonly, it is 600-650 years ago, or 400 year ago, or 300 years ago. This reflects tough times for the Jews, when they fled to new territories, and "started" new common ancestors. Quite often these ARE times of arrival. There were not so many Jews who fled in droves. They fled in small groups, some times probably even only individuals managed to escape.
To make it short, every TMRCA needs to be analyzed in a historical context, before to claim "the arrival". Do not forget population bottlenecks.
>What is so unique about Altai is its EXCEPTIONAL preservation of
super-ancient state of affairs. Altai also has the forms of Q and C common
with Native Americans, (and Ket language similar to Na-Dene languages in
Altai indeed was an exceptional place. Maybe because haplogroup P arrived there some 50-45 thousand years ago, and produced Q, R, and then R1, R1a, R1b. Probably, the Altaic family of languages is not accidentally Altaic. On some data carrier of Q left for America from there 46,000 years ago (radiocarbon data) to arrive some 30,000 years later. Which makes sense, if to take into account that those times migration took - on average - 0.5-1.0 kilometers a year. Do you have a map and a calculator handy?
Last but not least, Altai was exceptional because R1a have there 21,000 years of "age" and R1b 17,000 years of "age".
>I think the greater diversity of both R1b and R1a is best explained by
exceptionally low level of mixing-up in Altai over thousands of years
You cannot get "a great diversity" by mixing young relatives. Great diversity can be obtained only by mixing great diversity. Or I do not understand what you do mean.
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