sex

Asexual reproduction can produce twice as many offspring as sexual reproduction without the hassle of finding and courting a mate. So why do most complex animals have two sexes? Why not three?

Nature offers species a panoply of ways to determine an organism’s sex. That flexibility suggests we need not be concerned about losing sex chromosomes, but it raises the question of why such a fundamental property is so variable.

Microscopic creatures called bdelloid rotifers have thrived without mating for millions of years. How they did it could reveal why sex is so essential for almost everyone else.

An insight borrowed from computer science suggests that evolution values both fitness and diversity.