🚀 go-pugleaf

Yuri Kuchinsky wrote:
> 
> Peter Ashby (p-ashby@nimr.MAPS.mrc.ac.uk) wrote on 2 Oct 1998 20:07:08 GMT:
> : In article <6v35uf$9bv$1@whisper.globalserve.net>, yuku@globalserve.net
> : (Yuri Kuchinsky) wrote:
> 
> : > You're being dishonest again. Group B does not just disappear "easily".
> 

[SNIP]

	Could someone please summarize, succinctly, the genetic data in these
arguments. On the one hand we have some reference to a low
representation of B blood groups (genetic isolates tend to have these
biases), on the other some mtDNA evidence that I seem to have missed
(perhpaps my newsfeed did not pick it up). What comprised the mtDNA
data? What were the conclusions from the mtDNA data (I infer that it
provides a link to the Asian population rather than that of the
Americas). 

	We seem to be getting an awful lot of hot air about this. As has been
pointed out, allele frequencies at a particular locus are rather poor
evidence of relatedness due to fluctuations over the time spans
involved, one would have to take frequencies from a whole array of
nuclear genes into consideration to ensure that selection at a given
locus was not influential. Even then founder effects _could_ play havoc
with the outcome when comparing distant relationships  in a pairwise
manner (i.e. over long periods of time), and without intermediate data.
As has also been pointed out, mtDNA evidence tends to be more useful for
establishing distant relationships since it is prone to fewer selective
pressures (most of the selective pressures occurred during the
developement of early eukaryotes when mitochondria lost a number of
genes whose function was assumeed by nuclear genes, leading to a rather
minimal, asexual genome), and is transmitted linealy without
recombination from mother to offspring.

	
Gerard
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Gerard Tromp, Ph.D.
CMMG, Wayne State University    vox:	313-577-8773
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