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Archiver > GENEALOGY-DNA > 2009-05 > 1243345726


From: adam bradford <>
Subject: Re: [DNA] revised TMRCA calcuations for the R-L21 results
Date: Tue, 26 May 2009 09:48:46 -0400
References: <2007595302.13582001243295043561.JavaMail.root@sz0093a.westchester.pa.mail.comcast.net><200905260019.n4Q0JtHC019929@mail.rootsweb.com>
In-Reply-To: <200905260019.n4Q0JtHC019929@mail.rootsweb.com>


A continental origin would also be supported by the same data, since the
dates from "western Europe" are essentially identical to those from the
British Isles. There is a difference of only 150 years between the British
Isles 67-marker estimate and the western Europe 67-marker estimate. This
seems almost negligible to me, given the timescale. What is the margin of
error on these estimates?


On Mon, May 25, 2009 at 8:19 PM, Tim Janzen <> wrote:

> Dear Kirsten,
> You make some good points. The age spread between the continental
> haplotypes and the British Isles haplotypes has narrowed since I last ran
> calculations on this topic. We do need more data, but it is interesting
> that the hypothesis that L21 originated in the British Isles is still being
> supported by the data we have.
> Sincerely,
> Tim
>
> -----Original Message-----
> From:
> [mailto:] On Behalf Of
>
> Sent: Monday, May 25, 2009 4:44 PM
> To:
> Subject: Re: [DNA] revised TMRCA calcuations for the R-L21 results
>
> Dear Tim,
>
> The age calculations for Scandinavia and Eastern Europe depend on a very
> small number of haplotypes, and the other calculated ages don't differ by
> very much at all. If my own experiences are any guide, some of the
> diversity
> attributed to the Isles is the result of non-paternity events leading to
> the
> attribution of Continental lines to the Isles. If any Isles individuals
> from
> groups close to the Western Atlantic modal haplotype have been attributed
> to
> Continental locations, you could also have a case of the diversity of
> Continental haplotypes being underestimated, too.
>
> If young-looking Continental clusters could be identified, that would be
> consistent with an Isles origin for R-L21. I would like to see some
> clusters
> with a Continental flavor identified, but I don't think that many people
> have been working on this. When I look at Continental haplotypes, I
> generally don't find them easy to place in clusters at all. If our samples
> are not adequate for placing European haplotypes into clusters, I think
> that
> our confidence intervals for age estimates have to be really large. Still,
> I
> am thankful to you for doing these calculations. At some point, the numbers
> from these calculations are going to tell us more than they do now.
>
> Kirsten
>
>
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