GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2005-08 > 1123088643


From: "Lowe DNA" <>
Subject: RE: SMGF [was Re: [DNA] FTDNA Genetic Distance Calculations...]
Date: Wed, 3 Aug 2005 12:04:03 -0500
In-Reply-To: <REME20050802160318@alum.mit.edu>


John..

"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."

You lost me completely on this one.??????

Bill

-----Original Message-----
From: John Chandler [mailto:]
Sent: Tuesday, August 02, 2005 3:08 PM
To:
Subject: Re: SMGF [was Re: [DNA] FTDNA Genetic Distance Calculations...]


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


==============================
Census images 1901, 1891, 1881 and 1871, plus so much more.
Ancestry.com's United Kingdom & Ireland Collection. Learn more:
http://www.ancestry.com/s13968/rd.ashx




This thread: