GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2008-09 > 1220454563
Subject: Re: [DNA] Proven Credentials
Date: Wed, 03 Sep 2008 15:09:23 +0000
David Faux wrote:
>For example Contu et al. (2008) found a MRCA date of 28,000 years for their R-M269 (possibly R-U152) sample. That is a long way from 4000 years.
It is a strange combination, I have to notice, that is being adherent so much to (some) conservative views in science, and at the same time to repeatedly cite wrong results, accepting them in a surprisingly quick fashion.
O.K., I continue with "ages" of R1b (and clades). Here is a haplotype tree built using Contu et al. (2008) data:
The tree contains at least four branches: (1) Seven identical haplotypes from clearly very recent connon ancestor (they sit directly on the "trunk")
This base (ancestral( haplotype is shown here in the FTDNA format (there are only 8-marker haplotypes in the Contu paper). As one can see, it is a truncated classical Atlantic Modal Haplotype:
(2) An upper right branch of 12 haplotypes, which ancestor haplotype differs by only one mutation from the AMH (11-->10). These 12 haplotypes contain 25 mutations, that is 0.260 mutations per marker. Remember, it is roughly the same number as those I have shown in a different thread. Right, it gives 3,525 years from a common ancestor.
(3) An upper left branch of 16 haplotypes, with 28 mutations from their base haplotype, which differs by two mutations from the AMH (11-->10, 14-->15), and by only one mutation from (2). It has 28 mutations, results in 0.219 mutations per marker (younger, eh?), and gives 2,900 years from a common ancestor.
(4) It is the largest branch, however, one can see that there is nothing ancient in it, it of about the same age as others.
Anyway, when we combine them all (that is not exactly correct, since all the branches are of different sizes), then it results in 180 mutations in all 64 haplotypes, that is 0.352 mutations per marker, or 5,025 years from a common ancestor.
Again, Contu et al have used the same 64 haplotypes, but employed that funny 0.00069 coefficient, and got the number you like so much, that is 22,800 years (not 28,000 years).
You wrote: "It is not credentials but ideas that are most important. However the ideas must have cross validation with other sources or they stand alone".
Is this what you call "cross validation"?