PD
>Which cautions us as to how far we should infer the evolution from apes
>to man based on pseudogenes.
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Sure, caution is warranted when one must decide between alternative hypothesis
to explain an observation. But my point was that you laid out three
alternatives to
account for pseudogene conservation in primates. These were.......
>1. Pseudogenes are remnants of evolutionary mistakes (inactivated by
>mutation rather than being eliminated)
>
>2. Pseudogenes are genes that are in the act of evolving (perhaps one
>day to be activated and expressed)
>3. While not expressed, pseudogenes play an essential role in the
>expression of their normal counterparts.
Then you went on to point out..........
>These multiple explanations caution us as to how much weight one should
>give to the pseudogene concept when developing one's model. One can
>easily chose one particular explanation from several proposed by
>geneticists as an assumption from which to build a supporting argument.
I don't entirely agree with the statement that, "One can easily chose one
particular
explanation from several proposed........"
This sounds as if all explanations have the same probability, where in fact
they may
not. In the example of pseudogenes, I pointed out that hypothesis #2 is
unlikely since
genes that are not expressed probably do not confer a trait on which
selection can work.
Hypothesis #3 is also of minimal probability give our state of knowledge
since there is
nothing that I know of to suggest that it is true. This hypothesis falls
under the rubric of
speculation, rather than being based on biological knowledge. Thus, the
probability that
hypothesis #1 explains the observation is much greater than the
probabilities that #s 2 or
3 explain the observation.
So, we are wise to use caution, but we are also wise to pick the most
probable explanation.
Cheers,
Steve
While there may be alternative ways to explain pseudogenes, they don't all
have equal probability of being the correct answer as I have illustrated above.
__________________________________________________________________________
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 Center
CSC K4-432
600 Highland Ave.
Madison, WI 53792
"It is the glory of God to conceal a matter, but the glory of kings to
search out a matter." Proverbs
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