copulation

For the first time, researchers have documented interspecies sexual behavior between a male Japanese macaque and a female sika deer.

Biologist Carin Bondar delivers a TED talk about the wilder side of sex.

Fossils of an extinct, armored fish challenge current understanding of when copulation and internal fertilization evolved in jawed vertebrates.

For centuries, scientists have been trying to understand the mechanics of human intercourse. MRI technology made it possible for them to get an inside view.

Penises and vaginas are not just simple sperm delivery and reception organs. They have been perfected by eons of sexual conflict.
 

The disproportionately endowed carabid beetle reveals that the size of female—and not just male—genitalia influences insemination success.

Meet the retired chemical engineer who has made quite the impression on paleoentomology by uncovering ancient secrets of insect coitus.

July 2014's selection of notable quotes

Not to be outdone by vertebrates, invertebrates employ a suite of interesting structures and behaviors to accomplish procreation.

Observe the sinuous sensuality of mating brook lampreys (Lampetra planeri).

Meet Pek Van Andel, who conducted the famous MRI sex experiment, and see his research in action.

Female spiders prefer sperm from males with gifts, a study shows.

Women may be able to store viable sperm for longer than a week, thus contributing to apparent variability in pregnancy lengths.

In Chapter 3, “From Mating to Conception,” author Robert Martin explores the question of why humans and other primates frequently engage in sexual intercourse when females are not fertile.