For primates, males’ fancier ornaments are linked with smaller testes, according to a new comparative study.

Members of species with shells they must hold onto for survival have larger sexual tubes than those with less precious private property.

The exaggerated horns and elongated forelegs of male flower beetles, which use these appendages as weapons in combat for females, do not slow down the insects in a race.

The male proboscis monkey’s large nose probably evolved in response to female preference and competition between males.

The lizards may be signaling one another using fluorescent cues that we can’t see.

Andean highlander genomes possess cardiovascular-related variants, while populations from other regions evolved different solutions to manage the lack of oxygen.

A protective coating on ocellated wrasse eggs helps female fish select sperm from nest-building males.

A study reveals why some male fruit flies produce sex cells that are 20 times the length of their bodies.

Sex assignment in bearded dragons can flip from one based on chromosomes to one driven by temperature, researchers report.

A review of The Scientist’s 2014 special issues, highlighting trending areas of research across the life sciences

Extending her initial studies of social wasps, Mary Jane West-Eberhard has spent her career probing the evolutionary relationship between social behavior and developmental flexibility.

Sex is an inherently fascinating aspect of life. As researchers learn more and more about it, surprises regularly emerge.

Meet some of the people featured in the July 2014 issue of The Scientist

Sexual selection doesn’t end when females choose a mate. Females and males of many animal species employ an array of tactics to stack the deck in their reproductive favor.

Watch flightless dung beetles (Circellium bacchus), sneaky copulators and crap connoisseurs, do their thing in South Africa.

Scientists propose that hominin facial bones evolved for protection against the powerful blows of combat.

Two island populations of male crickets independently evolved to evade parasites by keeping quiet, and have come up with a way to sneak matings with females that still seek the male courtship song.

Humans evolved the ability to walk on two legs because it allowed them to more accurately size up prospective mates. Or did they?

In Chapter 7, “The Way We Walk,” author Henry Gee describes the first steps taken by the ancestors of Homo sapiens.