What's up in

sex

insights puzzle

How to Design (or at Least Model) Mixed Dog Breeds

July 31, 2020

Readers simulated the genetics of dog breeding to solve a puzzle about mixed breed percentages and sexual reproduction.

insights puzzle

How to Breed a Pomsky and Other Questions About Dogs and Sex

June 18, 2020

Solve a puzzle about mixed dog breeds, sexual reproduction and the COVID-19 pandemic.

Video of two slipper-shaped paramecia engaged in a sexual process called conjugation.
evolution

Why Sex? Biologists Find New Explanations.

April 23, 2020

Why did sex evolve? Theories usually focus on the diversity of future generations, but some researchers find compelling explanations in the immediate benefits to individuals.

Photo of the female penis structure of the cave insect Neotrogla aurora.
Abstractions blog

Why Evolution Reversed These Insects’ Sex Organs

January 30, 2019

Among these cave insects, the females evolved to have penises — twice. The reasons challenge common assumptions about sex.

Abstractions blog

Why Nature Prefers Couples, Even for Yeast

July 17, 2018

Some species have the equivalent of many more than two sexes, but most do not. A new model suggests the reason depends on how often they mate.

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

November 15, 2017

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?’

July 28, 2017

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

July 13, 2017

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

Chameleons
insights puzzle

Why Are There Two Sexes?

July 7, 2017

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?