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Archiver > GENEALOGY-DNA > 2002-10 > 1033876867


From: "Gary Rea" <>
Subject: Re: [DNA] Mutations
Date: Sat, 5 Oct 2002 23:01:07 -0500
References: <JCHBN.021005.145703.RC0@CUVMB.CC.COLUMBIA.EDU>


John, isn't the change of a particular marker that repeats twice a useful
means of determining the time between events? For example, Bennett Greenspan
(of FTDNA) has told me that my match, by two step mutations, to someone in
the FTDNA database having Russian ancestry probably means our MRCA lived
"many thousands of years ago," to quote Greenspan. Is this statement not
accurate? It's my understanding that mutations, although they can occur at
any point along the timeline, usually occur at a rate of roughly every one
thousand or so years. At least, that's what I read somewhere (probably on
this list).

Gary

----- Original Message -----
From: "John F. Chandler" <>
To: <>
Sent: Saturday, October 05, 2002 1:57 PM
Subject: Re: [DNA] Mutations


> All,
> There is a widespread tendency to use the term "two-step mutation"
> very loosely. Its strict meaning is a particular event in which the
> length of a particular marker changed by two repeats, but a lot of
> people also use the same term when referring to a total distance of
> two steps anywhere between two haplotypes. You cannot assume that the
> term has been used correctly by someone asking for help in interpreting
> new DNA results. Please make allowances for this uncertainty when
> offering such assistance.
>
> John Chandler
>
> ______________________________

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