Thanks! That's excellent. Different measurements from populations with varying exposure to snakes certainly seems to weigh in favour of an evolutionary explanation.

> That's a general argument against any complex adaptation.

I know my comment looks remarkably close to typical poorly-informed arguments for ID (eyeballs, even bananas lol), which probably explains the poor reaction to it. There's a lot of fuzzy thinking about evolution all round, and I'm just as guilty of it as the next person.

Thanks for taking the time to give me a good read :).

You're welcome! I actually agree that it feels weird that selection can work effectively on such a long chain of causes between genes and behaviors. It'll be exciting to learn more.