Humans are Intelligent and Hierarchical

“You have a mismatched pair of genetic characteristics. Either alone would have been useful, would have aided the survival of your species. But the two together are lethal. It was only a matter of time before they destroyed you." [...] Jdahya made a rustling noise that could have been a sigh, but that did not seem to comer from his mouth or throat. "You are intelligent," he said. "That's the newer of the two characteristics, and the one you might have put to work to save yourselves. You a...

 The Give and Take of Gender on Evolution

Trivers and Willard realized that the same general principle of sex allocation, which determines the gender of nematodes and fish, applies even to those creatures that cannot change sex but that take care of their young. They predicted that animals would be found to have some systematic control over the sex ratio of their own young. Think of it as a competition to have the most grandchildren. If males are polygamous, a successful son can give you far more grandchildren than a successful daugh...