Evolution rocks! I love Discovery Channel and have recently watched two really interesting programs involving snakes.

One was showing a certain hot snake that over the years it's primary prey has developed a genetic immunity to that particular snakes venom. They put forth the theory that enough of these rodents got nipped but not killed that at some point they began to develop an immunity and were able to pass it on to their young. (sorry I wish I noted stuff down better as to which snake and which prey...it was some sort of rodent).

Then there was this interesting one about chimps that were completely zoo bred and raised. Never interacted with a snake in their lives but had an instinctive reaction and particular alarm call specifically for snakes. Yet they'd never seen a snake! They even reacted to rubber snakes as if they were live. A specific alarm call went out. The mother chimps took off with their young and the dominant male went over and poked at the rubber snake with a stick and reacted with obvious fear and apprehension....having never in it's life actually seen a snake but knowing exactly how to safely deal with one. How cool is that!