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Archiver > GENEALOGY-DNA > 2006-02 > 1140884604


From: "Alfred A. Aburto Jr." <>
Subject: Re: [DNA] SNP Test Necessary: WEBB-BIRNBACH R1b SuperX HaplotypeStudy Report
Date: Sat, 25 Feb 2006 08:25:40 -0800
References: <200602250337.k1P3br9C012337@mail.rootsweb.com> <43FFD6A6.8050601@sbcglobal.net> <44007833.50408@scs.uiuc.edu>
In-Reply-To: <44007833.50408@scs.uiuc.edu>


> Doug McDonald wrote:

> Alfred A. Aburto Jr. wrote:
>
>> They are not accurate, because they vary with sample size, and also
>> the results vary with samples of the same size (look at the web page
>> results for DYS389I where there is a factor of 2 variation and the
>> sample sizes are comparable). What one would like to see in terms of
>> accuracy are results like, for example, 2.16E-03 +/-0.04 from
>> scientist A, and then another totally independent result like
>> 2.167E-03 +/-0.008 from scientist B and so on ... then in that case
>> you would have accurate and repeatable results. The results at the
>> YHRD web site don't show that behavior.
>
>
>
> yes they do
>
> They are quite consistent, it's just that the individual studies
> have large standard errors.
>

What worries me is that the fundamnetals don't look right. What I mean
is that, in the case I'm thinking about for DYS389I, in the YHRD
results we have Dupuy et al. 2004 with 1766 samples giving a mutation
rate of 2.26E-03, and then Gusmao et al. 2005 with 1793 samples giviing
a mutation rate of 1.11E-03. A factor of 2 difference! The first thing,
before publishing, a scientist must ask is why do I differ from this
other result by this factor of 2? The sample sizes are both "large" at
1766 and 1793 meioses and they are of comparable size, yet there is a
factor of 2 difference. What is it that is causing that? It seems that
the fundamentals are at odds (or something is wrong with them that we
don't understand). So in view of this I wonder how we can say the
composite, or weighed average, is more accurate? This seems wrong to
me... How can we go on when the fundamental and most recent studies
disagree like that?

If you have these reports (Dupuy et al. 2004 & Gusmao et al. 2005) I
would like to look at them and try to understand why there is a lack of
consistency in the results...
Thanks,
Al

[snip,snip]

> Doug McDonald


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