GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2009-12 > 1260735277
From: Vincent Vizachero <>
Subject: Re: [DNA] R-U152 and R-L21 on the European Continent
Date: Sun, 13 Dec 2009 15:14:37 -0500
I think it bears pointing out the advantage of adjusting the marker
set (the approach Tim and I use) as opposed to adopting an "effective"
rate approach (a la Zhiv et al.).
The problem Tim and I are solving (or trying to) is mutational
saturation: the fact that over longer time frames some markers
accumulate variance in a non-linear manner due to range constraints.
The Zhiv approach is to apply a "factor" to the real mutation rate,
but that still leaves you in a position of trying to estimate a non-
linear curve with a linear equation.
Ken is right to observe that right now we are engaging in a bit of
circular reasoning, because right now the only way to know which
markers to leave out is to "know" what kind of TMRCA estimate you
should end up with. I think we have bootstrapped it as well as can be
done using independent estimates for the TMRCA of Y-Adam and other
major nodes (e.g. from Karafet et al.), but I do agree with Ken that
we'd much rather have a less circular approach. And a whole lot more
markers with the right parameters so our confidence intervals weren't
But since Zhiv et al. were ignoring some pretty glaring assumptions,
the approach that Tim has described is certainly far more nuanced than
the one advocated by Zhiv et al.
On Dec 13, 2009, at 2:19 PM, Tim Janzen wrote:
> The average mutation rate for the remaining 24 markers is .00040.
> Zhivotovsky et al (2004) use .00069. The 24 markers in my "24 Slow"
> are listed below.
|Re: [DNA] R-U152 and R-L21 on the European Continent by Vincent Vizachero <>|