I find it very interesting how some people are willing to accept the concept of Nishtanu Ha-Tevaim (nature has changed) in the broadest sense when discussing Chazal's (allegedly) erroneous scientific information, but yet are so viscerally against the natural concept of evolution.
There are, as we all know, many statements made by Chazal that are not correct according to current scientific understanding. Rabbi Slifkin, in his book Mysterious Creatures, details five ways to approach this contradicition. The first one he focuses on is "Nishtanu Ha-Tevaim," the very nature of nature (so to speak) has changed between the times of Chazal and now. Various cures for maladies that are mentioned in the Gemara are no longer effective, the idea goes, not because they were wrong, but because nature has changed, and so the cures mentioned are no longer effective. Likewise, lice that spontaneously generate no longer do so because of Nishtanu Ha-Tevaim. Half-earthen, half-flesh mice? No longer exist - Nishtanu Ha-Tevaim. And so on...
Of course, I find it very interesting that the same people who will try to bring scientific counter-proofs to evolution, will accept this very counter-scientific reasoning. There really is no scientific proof of the concept of "Nishtanu Ha-Tevaim." There is some anecdotal evidence that is mentioned from time to time (with regard to women's vestos and the like) but that may not be 100% reliable or may be explained by better nutrition/healthcare or improved technology. But, ultimately, the "proof" for Nishtanu Ha-Tevaim really comes down to "well, this-and-this worked in the times of the Gemara and it doesn't now, so nature must have changed." Of course, this really just assumes the premise that Chazal were scientifically infallable to begin with.
However, isn't it possible to view Nishtana Ha-Tevaim as an "evolution of nature?" After all, if nature has changed appreciably in the last two thousand years, who is to say that it is now static? Maybe it is still in the process of changing and continuing to do so. One who holds the doctrine of Nishtanu HaTevaim should probably have to hold of this possibility as well, no? After all, is there *any* Torah source that mentions NHT that also indicates that this changing of nature has stopped? I don't think that there is (although if someone is aware of one, I'd certainly be willing to hear it). As such, there is really no indication that these changes in nature have stopped.
All this, of course, leads to the next question: If one holds that nature itself is changing/evolving, why is it such a sin (so to speak) to maintain that objects *within* nature (animals, plants, etc.) are changing and evolving as well?