Biology sets the context, and that is critical, but obesity still boils down to whether a person eats too much or exercises enough.

I regret not working harder to create true friendships with other couples, not seeking out people with whom to go do things and go places - people with whom to have a few crazy, memorable bonding adventures.

When a trait is universal, evolutionary biologists look for a genetic explanation and wonder how that gene or genes might enhance survival or reproductive success.

For humans and animals alike, truly vigorous, wholehearted, spontaneous play is something of a biological frill.

I don't exercise. I'm skinny-fat. I worry about being too skinny.

Exercise has its hazards. Runners are sidelined by shinsplints, freestylists by swimmer's ear, and who hasn't heard of tennis elbow? But the fitness buff of the '90s has a far greater worry. StairMaster Butt.

Though foreign loans are indispensable for the emancipation of the rising capitalist states, they are yet the surest ties by which the old capitalist states maintain their influence, exercise financial control, and exert pressure on the customs, foreign and commercial policy of the young capitalist states.

My father was a research doctor at the National Institutes of Health in the early 1980s, and you couldn't work in the field and not know about D. Carleton Gajdusek, who my father often mentioned.