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Archiver > GENEALOGY-DNA > 2003-12 > 1070804526
From:
Subject: Re: [DNA] Query on Haplogroups
Date: Sun, 7 Dec 2003 08:42:06 EST
In a message dated 12/06/03 4:24:47 PM Pacific Standard Time,
writes:
> Let's take my situation: I SNP tested positive for Y Haplogroup G, and
> has 12 markers STR tested (from Family Tree DNA). Now, comparing my
> results to othere people who have had BOTH SNP and STR test for their given
> sample, I find the following: I am a 3 step difference from an O1 male,
> in terms of my STRs. And I am a 4 step difference from another G male, in
> terms of STRs.
>
> 1) Can I say with 100% confidense that my closeness to the O1 male is due to
> Identical by State" (IBS) or Convergent Evolution, rather than Identical by
> Descent (IBD)?
With that many differences, you're so far away from "identical" that the word
loses its punch. But yes, given your SNP test, your greater similarity to an
O1 person is accidental, or IBS. I think the lesson here is that you can't be
very confident about the "best guess" of a haplogroup when there are that many
differences.
> 2) In other words, when comparing different Haplogroups, at what point can
> you be sure something is IBS vs. IBD? Do the lines get more blurry when
> comparing sub-Haplogroups, such as R1b3 vs. R1b4, since they are much more
> closely related?
You can never be sure without knowing the haplotypes of every generation, but
the finer the subdivisions, the more likely it is that the haplotypes are
IBD. For example, the identical haplotypes in R1b6 and R1b8 that I mentioned in
another message today COULD be IBD from a common R1b ancestor.
Ann Turner - GENEALOGY-DNA List Administrator
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