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Archiver > GENEALOGY-DNA > 2008-05 > 1211253156


From: "Alister John Marsh" <>
Subject: Re: [DNA] S21/S28 Split+m223 stuff
Date: Tue, 20 May 2008 15:12:36 +1200
References: <018701c8b9dc$c8cbeb10$6400a8c0@Ken1><ea3bd9560805191258n7d57e52an52752fc51f79edc4@mail.gmail.com><01f301c8b9ed$119eb2e0$6400a8c0@Ken1><ea3bd9560805191336u212d50bxda454d1c27958f9f@mail.gmail.com><024001c8b9f5$b85eb640$6400a8c0@Ken1><ea3bd9560805191457j17fda021nd57964e0743a802d@mail.gmail.com><026301c8b9fd$d86792b0$6400a8c0@Ken1><00d601c8ba05$6159b150$0100a8c0@john><031b01c8ba08$bbd348f0$6400a8c0@Ken1>
In-Reply-To: <031b01c8ba08$bbd348f0$6400a8c0@Ken1>


Ken,

I admit my posting was based on assumptions. I was putting forward a way of
looking at the issue. I don't think the assumptions can be considered
disproven just yet.

I think that an Ockham's razor approach would find the assumption that S116+
was in Ireland and other places 8,000 years ago would be one of the simpler
ways of explaining the present day distribution of S116+. However, I have
an open mind, and it will be interesting if 8,000 year old Y-DNA is ever
recovered to prove this matter one way or the other.

If S28+ is not long after the common ancestor of S21+ and S28+, an
explanation could be that S28+ is older than 8,000 years. Could it be that
"if" S28+ is 8000+ years old, that your formula would need a "fudge factor"
added?

Your formula is probably reliant on assumptions, such as assumptions that no
Y-STR mutations are detrimental to the long term survival of a Y-line. Your
formula may give misleading results by having large numbers of survivors of
recent branches, and none or very few survivors from very old thin branches
from antiquity, or none from extinct branch lines. Perhaps what your
formula is showing is the time of large expansion of S28+, rather than the
age of S28+?

Do you have "statistical confidence intervals" for your formula? Is the 95%
confidence interval 2000 to 8000 years?

John.




-----Original Message-----
From:
[mailto:] On Behalf Of Ken Nordtvedt
Sent: Tuesday, May 20, 2008 11:33 AM
To:
Subject: Re: [DNA] S21/S28 Split+m223 stuff

Your presumptions that the original post-LGM Irishman was S116+ is not
archaeology or paleo-anything until some 8000 year old bones are dug up in
Ireland and found S116+. Then you would have a case for all your
presumptions. Or do you have some other kind of argument for your
presumption? M423-Isles-B, on the other hand, seems to have a MRCA 6600
years ago, so maybe those guys beat the S116 guys to Ireland? One of these
days I will estimate the MRCA for all four clades of M423-Isles, and that
date could even be earlier. Find those bones with readable ydna.


If all the recent SNP testing is correct, then S116 SNP mutation is trapped
between the MRCA of S21/S28 and the MRCA for S28. I am saying this trapping

region seems very small with the S28 MRCA having an age about the same as
the age of the MRCA of S21/S28. This is of course all subject to the
statistical confidence intervals --- just like I hope everyone by now keeps
in mind even with their simple two haplotype TMRCA estimations. All this
variance stuff for dating nodes and MRCAs is just variation on the good old
two haplotype TMRCA question, but with all the needed mathematical
generalizations and twists needed to deal with many haplotypes.

Ken

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