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Archiver > GENEALOGY-DNA > 2006-10 > 1159804974


From: "Alfred A. Aburto Jr." <>
Subject: Re: [DNA] MLE
Date: Mon, 02 Oct 2006 09:02:54 -0700
References: <005f01c6e3dd$e0b56660$5102a8c0@PC238587905109>
In-Reply-To: <005f01c6e3dd$e0b56660$5102a8c0@PC238587905109>


Chris,

> Chris wrote:

>I note several sites ie smgf give MLE's. ie most likely estimate. How is this calculated please (please note I'm no mathematician).
>
>Many thanks,
>Chris
>
>

The MLE (Maximum Likelihood Estimate as it is called), in generations,
is determined by:

MLE = ln(n/k) / (2*mu)

"ln" is the symbol for "natural logorithm"

"n" is the number of markers

"k" is the number of markers whose values match.

"mu" is the mutation rate in generations (generally a nominal value of
0.002 is used).
It looks like the mutation rate used at SMGF depends upon the markers
used. One
could work this out though by looking at 1 marker mismatch cases (I
haven't done it).

On SMGF if you have a 36/37 match (k=36, n=37) then the
MLE = ln(37/36)/(0.004) ~ 6.8 generations (round to 7).

On SMGF DYS464 is not counted for the TMRCA estimates.
Al

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