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From:
Subject: Re: [DNA] Marker Mutation Rates
Date: Sun, 2 Nov 2003 08:22:49 EST


In a message dated 11/01/03 11:34:43 AM Pacific Standard Time,
writes:

> Is it possible that a fallacy was introduced initially into the thinking
> regarding Y-chromosome marker mutation rates based in part on the fact that
> marker mutations can move back and forth (+1 or -1) over time and was not
> properly taken into consideration by geneticists also using "limited"
> database sizes??


The commonly used mutation rate (.002) merges data from three studies: Kayser
using father-son pairs, Heyer using deep-rooting pedigrees (the kind you're
worried about), and Bianchi using shallow but broad pedigrees from CEPH
families. You can search the archives for those names to find more details, but the
father-son study actually contributed the bulk of the data.

There is also an abstract of a paper present at the Y-STR meeting last fall
which has the biggest data set yet: 1767 father-son pairs times 9 loci, for
15903 opportunities to observe a mutation. There was a total of 37 mutations, for
an overall rate of .0023. The range was .00057 to .0051 for individual loci,
but there's not enough data yet to be confident that we've identified the fast
and the slow markers. Markers which are above average in one study can be
below average in another study. Patrick G was at the meeting and e-mailed us that
the two fastest were DYS390 and DYS391, NOT ones that FTDNA labels as "fast."
To retrieve the abstract, go to http://www.ystr.org and click on the link
for the Y-User Workshop.

There was one father-son pair with mutations at two loci, which should
comfort Jerry Lake -- but remember that was one out of 1767, so you have to test a
lot of people to observe that phenomenon, and not everyone can claim to be the
exception to the norm!

But the bottom line is that the .002 number is reasonably well-supported by
direct father-son observations.

> This type of thinking above, in addition to the fact it appears that the
> earliest ancestors for most of these participants, originated in Virginia,
> North Carolina, South Carolina and Tennessee, was part of the rationale for
> my choosing to provide an alternate merger of the Lindsay DNA Groups 3, 4,
> 5, &8 ( http://www.clanlindsay.com/merger_gps__3,4,5,8.htm ) , with four
> to six marker mis-matches between participants.

I think it's sensible to "group your groups," as they look like they are all
Haplogroup R1b (what we used to call the Hg1, with the Atlantic Modal
Haplotype). None of your groups are an exact match to the AMH on Dennis Garvey's page:

http://freepages.genealogy.rootsweb.com/~dgarvey/DNA/RelGenMarkers.htm

It would be interesting to do a network analysis on your data, with and
without an artificial record with the modal values from R1b. Check the archives for
the keyword Fluxus, the company which has a freeware program on the web. I'd
guess that you'll find that there are too many mutations to place the MRCA in
colonial times.

Ann Turner - GENEALOGY-DNA List Administrator
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