History followed different courses for different peoples because of differences among peoples' environments, not because of biological differences among peoples themselves

Ahead of me lies the familiar litany: weakening of the heart, hardening of the arteries, increasing brittleness of bones, decreases in kidney filtration rates, lower resistance of the immune system, and loss of memory. The list could be extended almost indefinitely. Evolution seems indeed to have arranged things so that all our systems deteriorate, and that we invest in repair only as much as we are worth.

Recent discoveries about apes suggest, however, that a gorilla or common chimp stands at least as good a chance being murdered as the average human.

Lest those islands still seem to you too remote in space and time to be relevant to our modern societies, just think about the risks... of our increasing globalization and increasing worldwide economic interdependence.

Much of human history has consisted of unequal conflicts between the haves and the have-nots.

Put another way, the chimpanzees' closest relative is not the gorilla but humans.

Why were there far more species of domesticated animals in Eurasia than in the Americas? The Americas harbor over a thousand native wild mammal species, so you might initially suppose that the Americas offered plenty of starting material for domestication.