The Amazon molly is a species that cannot reproduce within itself. It needs to go and find a male of another species of fish. The sperm triggers this process of its eggs starting to develop. But that female Amazon molly destroys the sperm and all of the genes inside of it.
For every definition of life, there’s a creature that sends us right back to the drawing board.
This is the third episode in our three-part series, Origins, about the beginnings and boundaries of life on Earth.