monty1104
Premium Platinum
It is, but I highly recommend the book.
https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel
You do see variance in other species, but they fill a far tighter evolutionary niche than we do, so any that don't conform to the physical qualities that niche demands will struggle to reproduce.
Just ordered this on a whim after reading the post. Hope it's as good as you've made it seem