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Archiver > GENEALOGY-DNA > 2004-12 > 1104299197


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Subject: Re: [DNA] Can 385a,b = 14,15 be 15/14?
Date: Wed, 29 Dec 2004 05:46:37 +0000


Ken:

There are more estimates of the emergence of R1a than fleas on a camel. No one appears to know, or at least there is no consensus. For example Karafet prefers 7500 years BP, and Zerjal reports circa 2550 to 3800 years BP. Wells looks to 10 to 15,000 years BP. Who to believe?

David F.



-------------- Original message --------------

> Ah, eastern Germany. I suspect R1a is rather decent in that region and
> rather sparce in western Germany, with the all-Germany average a bit
> misleading for both extremes --- in other words a decent gradient from west
> to east in Germany. While I1a does not change that much from east to west,
> the R1a increases at the expense of decreasing R1b.
>
> I did not know people think the R1b/R1a split was so recent? I thought it
> was pre-LGM and still considered a 6 step change from the first modal value,
> presumably R1b's, hard to explain even with that longer time interval.
> Using McDonald's original mutation rates of 1/300 for 385a and same for
> 385b, the characteristic time to get 3 steps of mutation is 900 generations
> which is about 25,000 years if they all went in same direction.
> Characteristic time is somewhat longer when accounting for all back and
> forth possibilities.
>
> Anyway; the effect on this doubling of the number of objectively separate
> underlying populations within the overall I1a distribution is great. The
> phylogenetic tree must be redesigned.
>


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