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Archiver > GENEALOGY-DNA > 2010-12 > 1292202664


From: "Anatole Klyosov" <>
Subject: Re: [DNA] NW European R1b from Iberia?
Date: Sun, 12 Dec 2010 20:11:04 -0500
References: <mailman.2485.1292191583.2081.genealogy-dna@rootsweb.com>


> From: "Lawrence Mayka" <>
> An interclade age calculation between R-U152 and R-L21 is "clean," in the
> sense that they have a specific interclade MRCA, older than the MRCA of
> either one, and the calculation is an unbiased estimate of that MRCA's
> age,
> regardless of the region from which one draws the samples.
>
> In contrast, an attempted interclade age calculation between R-U152 and
> R-P312* is "messy," in the sense that the actual MRCA depends on the
> choice
> of R-P312* samples. An interclade calculation between the R-U152 and
> R-P312* in Spain is probably estimating the age of a _different_
> individual
> from that of an interclade calculation between the R-U152 and R-P312* in
> Poland. Even for a given region, the calculated estimate may vary
> depending
> on the specific mix of samples.

My response:

The first paragraph is generally correct, the second is inaccurate, if not
to say wrong. This is because the last sentence is applicable to ANY
dataset. Nobody guarantees that R-P312* haplotypes in Poland are ALL
descended from a P312* common ancestor who lived 3600 ybp necessarily in
Poland. This is related to ANY region, whatever it is and whatever subclade
is. All those "regional" estimates should be taken with a grain of salt, and
compared with that of the overall subclade.

That is why a proper methodology should first consider a haplotype tree
including as wide selection of haplotypes for a given subclade or a
haplogroup as possible, including all regions for which haplotypes are
available. Typically, the haplotype tree will show a number of distinct
branches, each one having its base haplotype and its common ancestor. And
ONLY then "Poland" and "Spain" dataset should be considered (also using
haplotype trees). The second, "regional" tree will show where those branches
in Poland might have arrived from, and when.

Instead of using such a general and inaccurate description as in the
quotation above, it would be much better and more productive to take P312*
datasets from Poland and Spain, and illustrate the "statement" in a good
fashion, with data and numbers.

Anatole Klyosov



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