GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2006-04 > 1145717339


From: "Ken Nordtvedt" <>
Subject: Re: Mutations (was [DNA] Genealogy as we knew it)
Date: Sat, 22 Apr 2006 08:48:59 -0600
References: <000101c66619$68f3c6e0$6601a8c0@DH870341>


Let's stick with the non-recombining part of the ydna because that's what we
are generally talking about with the STRs and SNPs of y-haplotypes.

With the present idea of SNP mutation rates and estimated number of sites
for an SNP mutation, it is thought that there is almost one SNP mutation on
average for every father/son transition. So since genetic Adam who existed
2000 to 3000 generations ago, each of us contemporary males probably has
accumulated of order a 1000 SNP mutations from Adam's ydna. Those that
occured very recently we share with just a few close male relatives. As we
move further back in time we share those SNP mutations that we have with a
bigger fraction of mankind.

The STRs are a different story. It is estimated there are about 200 STRs in
the entire non-recombining region of the ydna. Suppose we all had 200
marker haplotypes. With an average mutation rate of about 1/400 for each,
then every other father/son transition on average would have an STR
mutation.

But I'm sure the scientists will continue to find different kinds of
mutations (changes) that can occur in the string of ydna and could become
additional tags for our extended haplotypes.

Ken
----- Original Message -----
From: "Michael L. Hébert" <>
To: <>
Sent: Saturday, April 22, 2006 8:31 AM
Subject: RE: Mutations (was [DNA] Genealogy as we knew it)


> Good point. Maybe I will go ahead and use "mutations" and equate it
> simply
> with small changes in the dna. This brings up a question I have. Am I
> correct in assuming that no one inherits a perfect copy of their father's
> Y
> chromosome and that there are mutations in every transmission? If this is
> the case, how much mutation on the entire Y chromosome occurs on average
> going from father to son? I guess that if I can put these genetic
> genealogy
> mutations into the larger context of mutations that occur between every
> father and son, then that softens the blow a bit.
>
> Mike
>
>
> -----Original Message-----
> From: Ken Nordtvedt [mailto:]
> Sent: Saturday, April 22, 2006 8:36 AM
> To:
> Subject: Re: [DNA] Genealogy as we knew it
>
> The "variations" are of course what we get because of the "mutations".
> There may be a euphemism you can find to replace for "mutation", but don't
> go so far with the language to give people a false or poor idea of what is
> going on and why the variations are statistically smaller the closer the
> common ancestor.
>
>
> ==============================
> View and search Historical Newspapers. Read about your ancestors, find
> marriage announcements and more. Learn more:
> http://www.ancestry.com/s13969/rd.ashx
>
>



This thread: