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Archiver > GENEALOGY-DNA > 2009-07 > 1247412387


From: Al Aburto <>
Subject: Re: [DNA] R1b Origins (was OurEuropeangeographicalblock. . .)
Date: Sun, 12 Jul 2009 08:26:27 -0700
References: <473458.72439.qm@web81103.mail.mud.yahoo.com>
In-Reply-To: <473458.72439.qm@web81103.mail.mud.yahoo.com>


> Gary Felix wrote:
> Al,
> you said
>
>> However, the dates didn't line up with other evidence.
>>
>
> Do you mean historical events? This is of course reasonable and a means of calibration. It would seem to me that you would throw out the method not run with it by tripling it or refining it unless refining it cause consistency with the historical events.
>
> Gary
> Mexico DNA Project Admin.
>


Yes, Zhivotovsky et al (2004) uses 800 years BP for example as the
timing of the Maoris arrival in New Zealand to obtain an average
effective mutation rate of 0.000312 mutations per 25 years over 7 Y-STRs
(loci).

However consider that Semino et al (2004) estimates the age of J2 as
~18500 years ago (from present) using Zhivotovsky et al (2004) average
mutation rate with only 8 Y-STRs. Also, although I do not remember
exactly!, sorry :-(, Tim Janzen estimates a similar age for J2 using a
much faster average mutation rate with 52 markers instead. The fudge
factor that Zhivotovsky et al (2004) derived may be a function of the
number of markers used (too few) but there appears to be a lack of
understanding the basics (I don't know for certainty myself, I'm just
offering my thoughts here --- I could be mistaken --- I don't consider
myself an "expert" by any means)...
Al

PS: Hopefully Tim will jump in and give his average mutation rate for
the 52 marker set and the corresponding J2 age ...


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