people are concerned if they open the door to non-Darwinian mechanisms, they will let creationists slip through the door as well.
What non-Darwinian mechanisms could he be talking about?
Well, says Newman, "self-organization represents a challenge to the Darwinian theories of natural selection."
Darwinian orthodoxy, you see, says everything is incremental.
Wikipedia (where most people seem to get their understanding of evolution) says
While the fossils cannot undoubtedly prove common descent, they are highly suggestive of it if they show two patterns:
* older forms are simpler than newer forms;
* the number of species increases with time.
The fossil record certainly meets the first criterion. Among the earliest mammalian fossils, there are no specialized mammals like whales, but we do find fossils of whale-like terrestrial mammals that possessed underdeveloped legs. The second criterion poses a sort of impasse between evolutionary scientists who claim their findings to be incomplete yet compelling and creationists who bemoan them as severely lacking.
These gaps in the fossil record are a problem for the theory of darwinian evolution.
Punctuated Equilibrium is another explanation for the fossil gaps. It fell out of favor for a while, but now the top evolutionary scholars are re-assessing its potential. Like self-organization, punctuated equilibrium creates a problem for the darwin religious sect. You know who they are, they will ask you if you "believe in evolution", or condemn you if you don't "believe in evolution".
Farmers who don't believe in evolution. Oy vay.
End of discussion. - Heather Houlahan
Darwin proposed natural selection as the mechanism for 'Common Descent'. Natural selection has been observed, but is yet to be substantiated as the driving force of species jumps.
When most people talk about evolution today, they really mean "natural selection". When they ask you if you believe in evolution, they are asking you an impossible question. Of course you don't have to believe in natural selection, it has been observed. And since natural selection isn't the only (or even perhaps most critical) force in generating separate species, no one should sign up to believing in 'Darwinian Evolution'. But if you don't? Oy vey.
Epigenetics has thrown another wrench into the previous understandings of natural selection.
And for the final word, the entertaining Fred Reed asks questions that have yet to be answered...
If the faithful of evolution spent as much time examining their theory as they do defending it, they might prove to be right, or partly right, or discover all manner of interesting things heretofore unsuspected.
At any rate, the idea is that slight selective pressure (operational definition, please? Units?) over enough time produces major changes. The idea is appealingly plausible. But, for example:
(1) A fair number of people are deathly allergic to bee stings, going into anaphylactic shock and dying. In any but a protected urban setting, children are virtually certain to be stung many times before reaching puberty. Assured death before reproduction would seem a robust variety of selective pressure.
Yet the allergic haven’t been eliminated from the population. Why is it that miniscule, unobserved mutations over vast stretches of time can produce major changes, while an extraordinarily powerful, observable selective pressure doesn’t? The same reasoning applies to a long list of genetic diseases that kill children before they reach adulthood. (Yes, I too can imagine plausible explanations. Plausibility isn’t evidence.)
(5) If intelligence promotes survival, why did it appear so late? If it doesn’t promote survival, why did it appear at all?
(8) So much of evolution contradicts other parts. Sparrows evolved drab and brown so that predators won’t see them. Cockatoos and guacamayas are gaudy as casinos in Las Vegas so they can find each other and mate. But…but….
So get over Darwin already, and let people question evolution. Maybe we'll actually learn something.