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Archiver > GENEALOGY-DNA > 2008-11 > 1227901959


From: Vincent Vizachero <>
Subject: Re: [DNA] TRMCA for R1b1
Date: Fri, 28 Nov 2008 14:52:39 -0500
References: <C556259C.FA4C%bobhay@optusnet.com.au><0741DF0B-C741-4EEB-B761-C1F995CA28D9@vizachero.com><f3f05ce80811280713j4ec76a5cpda422767c2fa2150@mail.gmail.com><2B633A6B-F35A-4E4F-B341-69C4AE554EF9@vizachero.com><BAY106-DS5AEAC4A917ACDFEF9A5FBBC040@phx.gbl>
In-Reply-To: <BAY106-DS5AEAC4A917ACDFEF9A5FBBC040@phx.gbl>


Tom,

The basic premise of the "old argument" was laid out by Semino et al.
in 2000. I gave a pseudo-detailed rebuttal of that paper at dna-
forums.org in August, and it is probably too lengthy to repeat on an
email list. Here's a link to an archived version of that post:

http://vizachero.com/R1b1/SeminoGotItWrong.html

And a link to the original post:

http://dna-forums.org/index.php?showtopic=4223

Anyway, if you review the literature the paper trail on any citation
generally leads back to Semino 2000 and its the only paper that really
attempts to assemble an argument in any detail whatsoever. Given
that the paper is nearing 8 or 9 years old, hindsight makes it easy to
spot the holes in the argument. My conclusion in August was this:

> All in all, its a pretty weak case. It depends entirely on two
> "findings": ht15 has its highest frequency in western Europe, and
> R1(xR1a) is 30,000 years old.
>
> The first finding is true, but subsequent research has shown that
> the most ancestral forms of R-M269 are in the east primarily and
> have the highest STR diversity there (not in western Europe). This
> one annoys me a bit, because Semino could have and should have known
> about ht35 in April 2000 when she wrote the paper.
>
> The second finding is, to be blunt, dubious at best. She used only
> three STRS, two of them palindromic, and used a bad mutation rate
> estimate to boot. RecLOH was not as well understood in 2000 as it is
> today, so I'm inclined to cut Semino some slack here. The finding is
> bogus, still, but more understandable.
>

Semino lacked the ability to fully characterize what then could only
be described as ht15: STR testing had not been widely adopted in
2000, and M269 had not even been discovered (much less P312 and
U106). Also, as I mention above, her access to reasonable mutation
rate estimates and models was much more poor than we have today. But
her focus on frequency (as opposed to diversity) severely weakens her
case, as does the fact that she is dating R1(xR1a) and using that as a
proxy for the age of (under ISOGG 2008) R1b1b2a1b.

Vince



On Nov 28, 2008, at 1:40 PM, Tom Gull wrote:

> I've seen a lot in these
> forums on the "younger R1b" theory but very little of the factual
> underpinnings for the "R1b was the original European haplogroup in the
> western refugia". Did it all really boil down to "R1b predominates
> now so
> it must have done so then"? Or is there a set of interlocking
> evidence that
> hasn't been refuted yet?


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