1) "The gorilla must have branched off from our family tree slightly before we separated from the common and pygmy chimpanzees. The chimpanzees, not the gorilla, are our closest relatives. Put another way, the chimpanzees' closest relative is not the gorilla but humans."

2) "[The] most hotly debated problem in the evolution of human reproduction is to explain why we ended up with concealed ovulation, and what good all our mistimed copulations do for us. For scientists, it's no answer just to say that sex is fun. Sure, it's fun, but evolution made it that way. If we weren't getting big benefits from our mistimed copulations, mutant humans who had evolved not to enjoy sex would have taken over the world."

3) "We wouldn't mourn the shrinking cultural diversity of the modern world if it only meant the end of self-mutilation and child suicide. But the societies whose cultural practices have now become dominant were selected just for economic and military success. Those qualities aren't necessarily the ones that foster happiness or promote long-term human survival. Our consumerism and our environmental exploitation serve us well at present but bode ill for the future. Features of American society that already rate as disasters in anyone's book include our treatment of old people, adolescent turmoil, abuse of psychotropic chemicals, and gross inequality. For each of these problem areas, there are (or were before first contact) many New Guinea societies that found far better solutions to the same issue."

4) "Our inherited [proto-Indo-European] roots tend to be for human universals that people surely were already naming thousands of years ago: words for the numbers and human relationships; words for body parts and functions; and ubiquitous objects or concepts like 'sky,' 'night,' 'summer,' and 'cold.' Among the human universals thus reconstructed are such homely acts as 'to break wind,' with two distinct roots in PIE depending on whether one does it loudly or softly."

5) "Although we usually think of the Cro-Magnons as the first bearers of our noblest traits, they also bore the two traits that lie at the root of our current problems: our propensities to murder each other en masse and to destroy our environment. Even before Cro-Magnon times, fossil human skulls punctured by sharp objects and cracked to extract the brains bear witness to murder and cannibalism. The suddenness with which Neanderthals disappeared after Cro-Magnon arrived hints that genocide had now become efficient. Our efficiency at destroying our own resource base is suggested by extinctions of almost all large Australian animals following our colonization of Australia fifty thousand years ago, and of some large Eurasian and African mammals as our hunting technology improved. If the seeds of self-destruction have been so closely linked with the rise of advanced civilizations in other solar systems as well, it becomes easy to understand why we have not been visited by any flying saucers."