GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2010-02 > 1265929606


From: Sasson Margaliot <>
Subject: Re: [DNA] Variance Assessment wrt back and parallel mutations
Date: Fri, 12 Feb 2010 01:06:46 +0200
References: <1197787204.2554981265915596096.JavaMail.root@sz0002a.westchester.pa.mail.comcast.net><725621759BD14562850C4D49F01981A4@john>
In-Reply-To: <725621759BD14562850C4D49F01981A4@john>


John


1) Regarding the issue of "back/parallel mutations", I think Anatole's
methods do not simply ignore the issue, but account for it in some
simplified way, so that for 800 years or so there is no problem, and for
longer periods there is a "correction formula". So it seems to me, you
cannot simply "add 10%".


2) You also mention the issue of AVERAGE GENERATION TIME.

Mutation rates are calibrated with a certain assumption about generation
length, say 30 years.
So the "mutation rates" not literally for generation, but rather for 30
years. So at least for this part of your objections there is a SIMPLE
straightforward answer. You cannot add 20% because of this reson, because it
was "thought through" in advance.


3) As for the age of participants, let's say it is indeed 60 instead of
(apparently) presupposed 30. For 26 generations it is less than 4% (you use
up all 26 generations to get the 10% for back mutation).
So even if you were right about the "back mutations", you would still only
get up to 14% for 800 years (and even less for younger estimates) - not even
close to 50%.


*When a cluster is "symmetric and homogeneous", the robust calculation
methods Anatole exports from Chemistry work well*. (It is "dynamics", not
the college-level statistics). *If some "symmetric and homogeneous"
sub-clusters are there, they must be excluded and considered separately*.

In addition, to farther reduce the probability that some relevant bad
sub-cluster was spaced-out, the "logarithmic formula" is employed.


Hope this helps

Sasson


This thread: