In the mouse, where mutation in the MHC is a commonly observed event, and
where gene conversion is, perhaps, best documented, the motifs are nicely
explained by the identification of MHC-linked donors of the conversion event.
There can always be alternative explanations, however. The question is
which explanations seem to be the most reasonable fit of all the data?
>Also:
>Why wouldn't the motifs be subjected to neutral drift or balancing
>selection, and thus not be the same across the orders?
They may very well be--then one searches for strong homologies and
conservative changes that may not affect the amino acid sequence.
>
>I noticed that the larger the effective population is, the smaller the
>time required for coalescence. Thus, is there any set of assumptions which
>would allow the MHC data to be explained staring from a single pair
>growing to today's population over the past 6 MYR? Any hope for the
>60,000 years of Hugh Ross?
Don't know. You need a population geneticist for this.
>Please be simple, remember I am just a geophysicist.
It's hard to forget :-)
>
>Note to Steve Clark: After tomorrow I will no longer be able to play the
>one-armed man to Jim Bell's Dr. Kimball. :-)
Pretty optimistic of you to think I'd read this far down.
Cheers,
steve
__________________________________________________________________________
Steven S. Clark, Ph.D. Phone: (608) 263-9137
Associate Professor FAX: (608) 263-4226
Dept. of Human Oncology and email: ssclark@facstaff.wisc.edu
UW Comprehensive Cancer Ctr
University of Wisconsin
Madison, WI 53792
"Philosophers consistently see the method of science before their eyes,
and are irresistibly tempted to ask and answer questions in the way science
does. This tendency...leads the philosopher into complete darkness."
Ludwig Wittgestein, The Blue Book, 1933
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