Comment by vanderZwan

Yeah, ages ago I read in a book about evolution that mammalian genes are actually simplified (or optimized, if you will) compared to amphibians because we don't have to accomodate as wide of a temperature range due to being warm-blooded and giving live birth.

I also recall seeing in a documentary that the temperature of crocodile eggs will determine if it's a male or female. Wikipedia seems to back that up:

https://en.wikipedia.org/wiki/Temperature-dependent_sex_dete...