GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2009-12 > 1260604125


From: "Tim Janzen" <>
Subject: Re: [DNA] R-U152 and R-L21 on the European Continent
Date: Fri, 11 Dec 2009 23:48:45 -0800
In-Reply-To: <1965382295.123831260548944880.JavaMail.root@sz0002a.westchester.pa.mail.comcast.net>


Dear Anatole, Ken, and Vince,
Thanks for your comments today. My recollection of our lengthy
discussion this past summer on this topic was that there is a reasonable
probability that John's mutation rate estimates for the slowest mutating
markers are inaccurate to some extent. I would like to go back to the chart
below that I presented in this message
http://archiver.rootsweb.ancestry.com/th/read/GENEALOGY-DNA/2009-07/12473842
75 in July:

Haplogroup TMRCA in years
Node 50 markers YHRD 24-slow slow medium-slow medium medium-fast fast
A/B node: 35089 8808 77394 147246 78635 8396 21794 13847
A/C node: 63495 18739 116242 304294 59912 23270 57241 19203
A/E node: 57130 13854 125948 361737 57458 16200 30445 10476
A/F node: 49312 13807 113808 321089 46486 20235 22255 6530
A/G node: 57469 12193 129701 317200 79527 20022 20878 15035
A/H node: 62347 14074 143096 398629 64638 19601 23412 11063
A/I node: 54443 11550 132353 351809 68182 18508 21409 11278
A/J node: 81744 12558 193603 535755 79287 12341 23725 17049
A/L node: 58009 33480 136617 333747 84388 15231 18448 22513
A/N node: 82927 38295 187740 361372 133969 45063 27563 17185
A/O node: 81833 31636 177607 467354 79509 20438 40433 15476
A/Q node: 61898 39224 139675 336568 88815 22948 23093 11306
A/R node: 63410 36125 146504 322738 111135 17916 24269 14764
A/T node: 71635 22171 163429 361335 117881 16835 26311 22927

The following was one of the observations I made:
"1. The TMRCA for Y Adam could be as much 300,000-400,000 years if the
calculations using the slowest markers are to be believed. I suspect that
the true age of Y Adam was much less than this, probably in the
80,000-150,000 year range. This would suggest that the mutation rate I am
using for one or more of the slowest mutating markers is lower than true
mutation rate for that marker or markers."
I think that most of us who are reasonably knowledgeable about TMRCA
estimates would agree that in all probability Y Adam didn't live between
300,000 and 400,000 years ago as is suggested by the above TMRCA estimates
using only the slow-mutating markers. This would suggest that either John's
mutation rates for these markers aren't highly accurate, that these markers
haven't mutated at a consistent rate since Y Adam lived, or that there is
some other variable we haven't yet accounted for such as "overcounting" as
Anatole suggested. I would appreciate any insights into this that anyone
may have.
I think that the advantage of Anatole's method of looking at the
actual haplotype trees is that he notices major aberrations in the numbers
of mutations and tries to take those into account when generating his TMRCA
estimates. Anatole, you previously mentioned that your best estimate for
the age of Y Adam was about 80,000 years ago. Is that still your current
working estimate for the age of Y Adam?
Sincerely,
Tim

-----Original Message-----
From:
[mailto:] On Behalf Of

Sent: Friday, December 11, 2009 8:29 AM
To:
Cc:


However, there is no problem with the John Chandler's estimated marker
rates, unless you use ONLY slow markers and do not separate branches on a
haplotype tree.

However, when one uses ONLY slow markers, it is a big deal what those
overcountings do. You count many more mutations that  supposed to be, and
make a phantom common ancestor much more ancient. That is what you, Tim,
typically get with your estimations. As you have undoubtedly noticed, your
"slow marker" TCA's always higher compared with that by other methods.

Regards,
Anatole      




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