In the animal kingdom, penises can be spiked, split, corkscrewed—even detachable. They're one of the most diverse structures in biology. The human penis is so uniform, it's an anatomical outlier.

Recently, Emma Lavaut and her colleagues from Sorbonne University and Universidad Austral de Chile found that a species of red seaweed, Gracilaria gracilis, uses the isopod crustacean Idotea balthica ...

During mammalian reproduction, millions of sperm undertake a journey that only one will finish. This journey to fertilization has been commonly viewed as a race: a sea of sperm competing to get to the ...