Female moles grow testicles to fight through their brutal underground existence

If any animal understands the horrors of trench warfare, it has to be the mole. Faced with an enemy, there’s no time for pleasantries. No place to hide. Aggression is all that matters.

To help them fight in this brutal world, evolution has granted the female mole a generous dose of ‘roid rage’ by tacking some testicles onto her ovaries – resulting in a unique bit of anatomy called an ovotestis.

Now, researchers have a better understanding of how this fascinating biological change came about.

“The sexual development of mammals is complex, although we have a reasonably good idea on how this process takes place,” says geneticist Darío Lupiáñez from the Max Planck Institute for Molecular Genetics.

“At a certain point, sexual development usually progresses in one direction or another, male or female. We wanted to know how evolution modulates this sequence of developmental events, enabling the intersexual features that

Read More