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sex

During fertilization, eggs may play an unexpected role in choosing which sperm offer the best genetic match.
genetics

Choosy Eggs May Pick Sperm for Their Genes, Defying Mendel’s Law

The oldest law of genetics says that gametes combine randomly, but experiments hint that sometimes eggs select sperm actively for their genetic assets.

Chameleons
insights puzzle

Solution: ‘Why Are There Two Sexes?’

The mathematical concept of parity and the fatal flaw of serial multiplication can help explain why having two sexes usually works better than having one or three.

Missing Mutations Suggest a Reason for Sex
molecular biology

Missing Mutations Suggest a Reason for Sex

Sex might help natural selection purge excessive mistakes from our genes.

Chameleons
insights puzzle

Why Are There Two Sexes?

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?

Biology

The Incredible Shrinking Sex Chromosome

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.

evolution

Ancient Survivors Could Redefine Sex

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.

evolution

The Game Theory of Life

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