GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2005-12 > 1133466610
From: Robert Stafford <>
Subject: Re: [DNA] upgrades
Date: Thu, 1 Dec 2005 11:50:10 -0800 (PST)
Generally, I just use the number of matches and then examine the two-steppers separately. For the single-copy markers that RG uses and the time spans that we normally are able to document, they seem to be unusual. The only multi-step mutation that we found among 35 people with documented genealogies was at DYS385. It was likely a recLOH event.
Chris <> wrote:
Dear Bob and others,
Thanks for your replies.
"Are you PCA7Y and the other person T84DA?" Yes you are quite right. I'm
not expecting a close realtionship here being as I understand it a genetic
distance of 4. We match on 29 markers out of 32.
"Did you subtract 1 from your RG value for Y-GATA-H4? It would be unusual
for close matches with a common surname to have a 2-step difference on it."
. I didn't but does having a two step difference in your mind decrease the
possibility of a connection within the time frame of surnames?
I know there are arguments regarding the mutation rates used by FTDNA but
using their rates this gives a probability is 50% that the TMRCA is no
longer than 12 generations. And 95% 25 generations. I am aware that some
argues that this should be multiplied by anything from one to two and a half
I didn't subtract one, but note that Y-DNA Comparison Utility does do this
in certain formats eg the SMGF database configuration.
> Bob Stafford
> Chris wrote:
> Hi Folks,
> I had my 43 marker test via Relative Genetics. I've just found, on
> Ysearch, an individual with the same surname and a very distant match.
> However they tested with Family Tree DNA. They tested on 37 markers. But
> being different companies we can only compare on 32 markers.
> The question is there a company which would test me for FTDNA's 5 markers
> (not covered by Relative Genetics). And this matching individual on the
> markers I've tested on (Relative Genetics) but they have not been tested
> on with FTDNA?
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