about the yawning...
From Why moths hate thomas edison and other urgent inquiries into the odd nature of nature.
Q:Why is yawning contageous?
A: First let us despense with the antiquated notion that a yawn is the body's attempt to pump extra oxygen into our fatigued systems. Scientists have shown that a person in an oxygen chamber yawns just as much as anyone else. No, yawning seems to be tied to more primal purposes, with contagion at the center of it. A semiautomatic reflex that originates in the brain stem and marks transitions from one mental state to another, yawning is wide-spread throughout the animal kingdom, particularly among carnivores. Watch a pride of lions: when one cat opens its mouth, pretty soon there's an outbreak. Although the precise mechanism for its contagiousness remains unknown, yawning appears to be a piece of ancient genetic wiring meant to help synchronize clan behavior, a form of prelinguistic communication indicating that it's time to move on the the next big thing. Think of it as a way for, say, a Neanderthal to let his comrades know that the nap's over; let's go bag us a woolly mammoth.
guess what the next topic in the book is.....
Q:What purpose do male nipples serve?