natural selection promoting genes for intelligence has probably been far more ruthless in New Guinea than in more densely populated, politically complex societies, where natural selection for body chemistry was instead more potent.

even for people specifically interested in the shaping of the modern world, a history limited to developments since the emergence of writing cannot provide deep understanding.

History before the emergence of writing around 3,000 B.C. also receives brief treatment, although it constitutes 99.9% of the five-million-year history of the human species.

Why did wealth and power become distributed as they now are, rather than in some other way?

“Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own?”

Within a few thousand years there were no more Neanderthals, who had been evolving as the sole occupants of Europe for hundreds of thousands of years. That sequence strongly suggests that the modern Cro-Magnons somehow used their far superior technology, and their language skills or brains, to infect, kill, or displace the Neanderthals, leaving beh

why did human development proceed at such different rates on different continents?

“History followed different courses for different peoples because of differences among peoples’ environments, not because of biological differences among peoples themselves.”

What use one makes of a historical explanation is a question separate from the explanation itself. Understanding is more often used to try to alter an outcome than to repeat or perpetuate it.