Please remember the following:
Evolution means that life changes over time. That is all. There is nothing inherent in the theory of evolution that ascribes a mechanism to that change.
Natural selection is one theory that states that life changes gradually and constantly over time in response to environmental changes. These changes occur because random mutations either a) don’t kill off the species b) give some advantage over the old form. The key points of natural selection are that changes occur gradually and constantly, and that natural pressures favor some random mutations over others.
Punctuated equilibrium is another theory, unrelated to natural selection, that says that changes in life occur rapidly and across all life forms. Pretty much that life goes on pretty much constantly (equilibrium) for a long time, and it is punctuated by massive changes in lots of species all at once over a very short time period. This theory has an advantage over natural selection in that it explains the so called “gaps” in the fossil record. It also fits in well with the “mass-extinctions” evident in the fossil record. The trouble is that it still doesn’t explain the mechanism. There are lots of equally good ideas on why there is this massive change across the board.
Remember, also, that when in doubt, the “simpler” explanation usually works. Natural selection is a theory with less components, but requires us to postulate about species that we haven’t found yet. Punctuated equalibrium is a little complex, but it fits with the way we have discovered stuff NOW. You’ll find that there are about an equal number of adherants to both theories, though many find both inadequate. I’m inclined to believe that the truth is something between the two…
But please remember that this issue does NOT imply any “weakening” in the theory of evolution. Life is not now as it used to be, therefore it must have changed. Thus, evolution…
Jason R Remy
“No amount of legislation can solve America’s problems.”
– Jimmy Carter (1980)