GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2005-09 > 1126897936
From: Robert Stafford <>
Subject: Re: [DNA] Better or Best Y-DNA Test
Date: Fri, 16 Sep 2005 12:12:16 -0700 (PDT)
Some calculations were posted back in April on the likelihood of parallel mutations. There is roughly a 50/50 chance of a parallel mutation when you have ten mutations among people with a common ancestor.
We had several reports of parallel mutations in the past and I saw several possible ones on the fiery four in the projects I looked at. Whether the documentation was wrong or not is always hard to know in someone else's family. However, there have been enough reported that everyone should be alert to them.
The fastest markers will be the most likely to have parallel mutations. Initially, relative likelihoods seem to be roughly proportional to the squares of the mutation rates. However, I am not familiar enough with the calculations to be certain about it.
I haven't completely followed the discussions of CDYa/b and its volatility
and susceptibility to parallel mutations -- which raises the questions of how
the heck do we know these markers are more susceptible to parallel mutations
than other markers are? Do we really have enough documented Surname groups
to answer this question?