Re: Evolution
Francis Maloney (fjm@ici.net)
Sat, 18 Jul 1998 21:25:39 -0400 I dislike the term micro-evolution. But, as I understand it, it is
something like this: Given genetic variation within a population,
microevolution would be a shift in the overall gene frequencies in
subsequent generations by selective pressure acting on the entire
population or an isolated subset of the population. It would specifically
have to exclude beneficial mutation.
What are the boundaries and are there boundaries to selective
breeding? Logically, it presents a problem for creationists because the
line is hard to draw, the term is ill-defined and the question has not been
investigated. A horse and a donkey can interbreed but produce sterile
offspring. Assuming a common ancestor, have they diverged to the point
where they are no longer of the same "kind"?
On the other hand, shifts in relative gene frequencies certainly are
not evidence of evoution. It was examples like the peppered moth that were
given to me in college to convince me that evolution was a fact that now
make me question it. Given selective pressure favoring dark skin in
tropical climates, many generations will produce dark-skinned people from
light-skinned people. Does this mean dark-skinned people are evolving into
another species?
Also, in response to Glenn's point that it would take too long to test
these issues, it seems that laboratory controlled breeding can be set to
select a trait 100% of the time while natural selection would usually be
only a slight push in favor of a trait, thus requiring significantly longer
than controlled breeding.
Fran Maloney