WASHINGTON — You fly more than 100 miles for love. You get rejected. You fly another 100 miles. Another rejection. And another. That’s the high-flying but futile sex life of the male pectoral ...

New evidence suggests that Mother Nature has her own means of handling cheating wives. Researchers have found that a gene responsible for semen viscosity has evolved more rapidly in primate species ...

Some symbioses conform to the traditional one-on-one mode of symbiotic relationships, but it is increasingly understood that many symbioses are more open and consist of multiple associates with ...

A portion of the phylogenetic tree of the squirrel family (Sciuridae) illustrates how promiscuous ancestral species (black dots) gave rise to both monogamous species (blue dots) and polygynous species ...

Mrs. Robinson couldn't avoid seducing Benjamin: it was a biological imperative. (United Artists) Next time your significant other catches you in bed with someone else, try this defense: "Don't take it ...

People often ask what kind of human sexual relationship is most evolutionarily "natural." Is human nature adapted for promiscuity or long-term relationships, for example? And if we're wired for ...

Eyes may be the window to the soul, but our hands may offer a window into romantic faithfulness. In a new study published in Biology Letters, scientists at Oxford University set out to discover ...

“Promiscuous” is a term that is almost always used when speaking about a woman; it is most often pejorative. It refers to a woman—usually a young woman—who has sex frequently and casually. This ...

In environments where mice compete for mates, the rule seems to be survival of the sexiest. Researchers have found that when female mice must compete with one another for mates, they bear sons that ...