Anyone who wants to see "evolution in action" should take a look at beings
that reproduce quickly. Obviously, any one human being cannot see his own
species evolve; we don't live for enough generations. But consider these
examples of rapid evolution:

1. Insects (like Hawaii's banana moth) that apparently developed after a
new food source arrived (in this case, bananas, which are not native to
Hawaii, although the moth's ancestor was native).

2. Insects that adapt to pesticides (like DDT) that never occurred in
nature--a new challenge, a new response.

3. Bacteria that adapt to antibiotics like penicillin, making the
antibiotics useless for treating some diseases.

And the best example of all:

4. Viruses (like HIV) that reproduce so rapidly and inaccurately that they
mutate into new strains <<during the course of an individual person's
illness>>, making them next to impossible for the immune system to
eradicate.

The old argument that "Mutations are always harmful to the organism"
clearly does not work in these cases.

Mollusks? I'm sure they're evolving all the time, but unless people pay
close attention, we won't notice it. The cases above are those of medically
and economically important species, which is why we know something about
them.

Andrew K. Rindsberg
Geological Survey of Alabama