The Evolution of Sex

Let's talk about sex. Not boring, human sex, but the endlessly fascinating, varied and complex forms of reproduction in the rest of the natural world.

Sex in slime molds can involve upwards of three mating types. For some fungi, it's twenty-three thousand. And for algae, every single organism is a potential mate - a veritable bonanza.

Whiptail lizards and California condors are just two among the many species capable of parthenogenesis, or immaculate conception.

Clownfish and cardinals, butterflies and bearded dragons regularly switch between male and female, challenging the notion that sex is binary and fixed.

Dr Lixing Sun has spent decades exploring the world of reproduction, using behavioural experiments, genetic testing and mathematical and computer modelling to push the bounds of what we understand about how the planet is populated. And sex, as it turns out, is far more complex and far more interesting than we ever knew.