RE: Peppered Moths and Evolution

Tim Ikeda (tikeda@sprintmail.com)
Wed, 11 Nov 1998 20:51:52 -0500

In this discussion, some participants mentioned that the changes
in moth populations represent the effects of natural selection.
I think that is likely true. However, I also think Art has a point
in that it is difficult to be certain of this because the specific
agent or method of selection is clearly not as well understood as was
once thought.

Art writes:
"[...] This is the major example in every biology textbook of
how evolution works. If it is not correct, that ought to be
cause for something besides a stifled yawn...."

I agree. It's an excellent example of how difficult it is to
untangle environmental influences and determine the particular
"direction" of evolutionary change. I'd doubt that evolutionary
changes are ever as simple as described in the original peppered
moth hypothesis. That's an important lesson in biology.

Oh, here's another scientific "triumph" that may also fall someday:
The idea that bees determine the location of good nectar sources
through an elaborate dance. The alternate explanation? Smell.
The "bee dance" hypothesis has a problem in that despite a bee's
dancing, flowers which are downwind of the hive don't seem to
get found as well as those upwind.

Regards,
Tim Ikeda
tikeda@sprintmail.hormel.com (despam address before use)