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Archiver > GENEALOGY-DNA > 2005-03 > 1112040571


From: "Ken Nordtvedt" <>
Subject: Re: [DNA] R1a1 - Dating of M17
Date: Mon, 28 Mar 2005 13:09:31 -0700
References: <67.419f075b.2f79bb7c@aol.com>


I think the first folks who derived the ASD formulas believed they could put
in an authentic mutation rate measured in the lab. I don't believe their
goals were only relative ages?

Hence the problem with the fudge factor being used in the literature.

But from the pure computer simulations --- even before worrying about unique
real world shocks to the population --- I think using ASD for relative ages
is on shaky ground. The variance of the ratio --- ASD divided by
generation --- for many simulated runs is too great to measure the ASD ratio
of two populations and then say that yields the ratio of their ages.

I hope the above communicates my belief that there are two separate problems
with the ASD usage.

Ken
----- Original Message -----
From: <>
To: <>
Sent: Monday, March 28, 2005 12:56 PM
Subject: Re: [DNA] R1a1 - Dating of M17


>
>
> True. And also true is that the inital goal of Ken, John's & my recent
> simulation efforts was to do "virtual experiments" to gather data,
specifically to
> analyze the difference between our observed f/s rates & the popular
(1/3rd)
> published population rates.
>
> ASD was intended to give ratio of time of a subpopulation with a parent
> population, not absolute rates, or TMRCA.
>
> Yes, we can incorporate allele length tendencies to mutate up/down, more
> markers & their individual rates, and even, *intentional rare events*,
> real-world input. :-)
>
> Mike ...
> =================================================
>
> In a message dated 3/28/2005 6:39:59 AM Pacific Standard Time,
> writes:
>
> Simulations, unless done intentionally, don't simulate rare
> events, such as are known to have happened in history.
>
> Doug McDonald
>
>
>
>
>
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