KC

I was having a discussion with an Intelligent Design creationist on an AOL message board recently about genetic homeostasis, which is the phenomenon (often seen in artifical selection experiments) of populations resisting drastic one-sided selection. This resistance usually is expressed in decreased fitness. The ID's argument was that this was evidence of a 'topping off' point of variability beyond which selection could not operate, and that this was evidence against evolution.

Besides noting his misunderstanding of the nature of genetic homeostasis, I had an amusing idea. I asked him if these results were common in artificial selection (he called it 'Intelligent Selection"). He said yes, and quoted something by Mayr to that effect. I then asked him if artificial selection reflected what we see in nature. He scoffed, and said of course not.

So I then asked him why, if the only observed examples of intelligent design in biology, artificial selection, didn't reflect what we see in nature, then how did he come to the incongruous conclusion that design could be inferred in nature?

I know, it's not a very sophisticated argument, but so far, spluttering has been his only reply.

Cheers,

KC

Late_Cretaceous

In addition to that, if there were constraints on the degree to which organisms could evolve (i.e. limited to microevolution only) would that not doom all organisms to extinction.