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Archiver > GENEALOGY-DNA > 2005-08 > 1123013250


From: (John Chandler)
Subject: Re: SMGF [was Re: [DNA] FTDNA Genetic Distance Calculations...]
Date: Tue, 2 Aug 2005 16:07:30 -0400 (EDT)
References: <IGEOKAGLHNEKPCKPADIGAEHKKEAA.bbailey.lowedna@baileyconnection.com>
In-Reply-To: <IGEOKAGLHNEKPCKPADIGAEHKKEAA.bbailey.lowedna@baileyconnection.com>


Bill wrote:
> ...are they transient
> mutations that will
> mutate back (be corrected) the next generation;

Huh??? If such things were expected, the observed father-son mutation
rate would be much higher than the observed pedigree rate.

> or, a mutation that will
> continue to increase the genetic distance
> even further beyond the 21/25 or 32/37 limits.

I agree with Ann. "Genetic distance" should not be confused with
the degree of matching. "21/25" means 21 markers out of 25 agree
exactly while the other four do not agree. This isn't the same
as genetic distance because the amount of disagreement is not
specified. For example, four one-step mismatches would give 21/25
agreement and a genetic distance of 4, but four two-step mismatches
would give the same 21/25 agreement and a genetic distance of 8.

John Chandler

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