The common view of natural selection is based solely on the individual: A trait allows an organism to out-compete its rivals and is thus passed down to its offspring. To suggest otherwise can provoke ...

The Indigenous peoples of the Bolivian highlands are survivors. For thousands of years they have lived at altitudes of more than two miles, where oxygen is about 35 percent lower than at sea level.

We choose our mates with care. Many of us make bad dating decisions when we’re young—and some of us do when we’re old—but we generally care a great deal about who we have children with. Our options ...