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Archiver > GENEALOGY-DNA > 2004-01 > 1072995981


From: David Faux <>
Subject: [DNA] MRCA calculations useless for individual cases
Date: Thu, 1 Jan 2004 14:26:24 -0800 (PST)
In-Reply-To: <NGBBJAIJELIPIIJLDFIKMEMHCPAA.MHARPER8@houston.rr.com>


Michael and all:

Your situation is another of the many for which using the standard .002 / marker / transmission rate (or any figure for that matter), and even making adjustments for "fast moving" markers is not only a waste of time for genealogists, but is dangerous in that if affords the illusion of scientific precision. It can only be used as a rule of thumb - even then I personally do not give it any credence in genealogical investigations, only when looking at "deep ancestry" to perhaps estimate the length of time for divergence of an individual haplotype from the haplotype of "the patriarch" (as estimated by Dennis Garvey's modal values for R1b) who is the ancestor of all R1b types.

I am sure that I will raise the hackles of many here, but I have patiently listened to the hundreds of postings on this List addressing the topic which presume its validity for genealogical inquiries, and still have not changed my opinion one iota - the MRCR concept is useless. One only has to look at the range (e.g., 16 generations plus or minus 10 generations) to see how absurd it is to say that this one number in the middle should be chosen - why not the 6 generations if it is more convenient? This MRCR concept can be used to support or disconfirm virtually any hypothesis - use it as you will. It means nothing to me in my genealogical - DNA studies.

I have probably stepped on someone's sacred cow. I expect that the fur will fly (I have probably not been very PC either - my back is acting up again, perhaps I can press this into service as an excuse).

David F.

Michael Harper8 <> wrote:
Well if we take Gary Childress recent post on the Wirral study as a starting point, then 16 generations would seem in the ball park, i.e. starting from abt. 1400. However, since I have two mutations from my known third cousin in 4 generations (8 transmission events), the lack of mutations in 16 generations seems peculiar.

Michael Harper
-----Original Message-----
From: David Faux [mailto:]
Sent: Thursday, January 01, 2004 3:31 PM
To: Michael Harper8
Subject: RE: [DNA] DAVISSON results in - R1a


Unknown, since I put little credence in present very general estimtes of mutation rates since they apply to populations not individual families. Only genealogy and geographical proximity can help you.

I know that there are many on this List who believe that the MRCA calculations can be applied to individual cases, but I am not one of them. The result can be entirely misleading.

David F.




Dr. David K. Faux, P.O. Box 192, Seal Beach, CA, 90740, USA



www.davidkfaux.org


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