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Archiver > GENEALOGY-DNA > 2009-09 > 1252436119


From: "Ken Nordtvedt" <>
Subject: Re: [DNA] SNP Mutation Rate from WTY-I
Date: Tue, 8 Sep 2009 12:55:19 -0600
References: <005b01ca3097$079a0610$6400a8c0@Ken1><7826808.68846.1252435218665.JavaMail.www@wwinf1h19>


That all depends on how many more do the WTY. There are maybe 15 I1 yet to
report but in the pipeline. Each could conceivably search a virgin 4000
years of branch line, but certainly the average will be less as MRCAs
between these 15 occur more recently. Most of those 4000 years will be
sufficiently downstream from the I1 MRCA that any snp from there will be
taking on private-like features and be derived for only small fraction of
the I1 population. So I'd guess maybe a few useful I1 snps will occur. 400
generations per snp means 12,000 years per snp.

There is an I2a* Western person waiting for results. His branch line is
20,000 years long, so I'd say he has a good chance for one or two snps. If
they fall in the 2500 years or so since the MRCA for I2a* Western, we'll be
lucky. Otherwise, such new snps will simply give I2a* a snp tag which it
does not have at present, being defined as P37.2+(x all downstream snps),
but that splits no haplotype populations not presently split.

There's a teeny chance I2a* donor could find a snp so specially located it
could resolve the order of branching between I2a*, I2a1, and I2a2, but
that's a real long shot.

Ken
----- Original Message -----
From: "Didier VERNADE" <>
To: <>
Cc: <>
Sent: Tuesday, September 08, 2009 12:40 PM
Subject: re: [DNA] SNP Mutation Rate from WTY-I


>
> That's the present state of WTY results for I haplogroup. Now it's unclear
> to me how many more SNPs you are expecting (for I haplogroup) on the WTY
> DNA segment.
>
>
>>
>>
>> I now count discovery of 9 snps throughout all of haplogroup I so far
>> from WTY participants. I used my warpedfounderstree for haplogroup I to
>> measure how many generations of branch length have been covered in these
>> searches. I come up with 3600 generations, indicating an average of 400
>> generations per discovered snp.
>>
>> The coverage per participant has been meeting the 100,000 sites which was
>> Dr Krahn's goal for the searches.
>>
>> The above would imply an average mutation rate per nucleotide site over
>> this particular sampled region of the y being:
>>
>> 1 / [ 400 x 100,000 ] = 2.5 10^(-8) per generation
>>
>> Realizing that the statistics is not yet robust, this rate falls right in
>> the middle of various claimed rates for SNPs, and therefore these results
>> lend some support for the time depths to nodes in the warpedfounderstree
>> which were arrived at using STR variance or GD methods and Chandler STR
>> mutation rates for the 50 slowest STRs out of the 75 available STRs.
>>
>> Warpedfounderstree for haplogroup I can be seen as powerpoint file at:
>>
>> http://knordtvedt.home.bresnan.net
>>
>> The snp per 400 generations can be multiplied by 260 to get the average
>> density of snps per generation on any branch of the y tree if the entire
>> 26 million sites of the y were to be sequenced. That's .65 mutations per
>> father/son transmission.
>>
>>
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>
>
>



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