chance and evolution

[Doug Yanega]

>The origin of new mutants as chance may be an assertion rather than a fact.
>Further, if processes such as biased gene conversion are evolutionarily
>signficant (as suggested by some molecular geneticists) then the spread
>and establishment of such mutants does not require natural selection,
>and is certainly not random.
>
>John Grehan

Now you're getting awfully picky. (1) Can you give a citation for biased
gene conversion in any complex multicellular organisms? Bacteria are in a
class by themselves in many respects, and comparing their evolution to that
of multicellular organisms is apples and oranges. If dogs demonstrate
biased gene conversion, then I'll happily recant my original opinion. (2)
No one here has ever stated that natural selection is *required* for
evolution to occur. (3) I fail to see how biased gene conversion would
automatically lead to "spread and establishment" if the mutant allele does
not confer a selective advantage. In the absence of fitness effects (i.e.,
natural selection), the odds of ANY mutant spreading are the same, no
matter whether it was a "directed" mutational event or not.

Peace,


Doug Yanega        Dept. of Entomology         Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
                http://insects.ucr.edu/staff/yanega.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82