Consequences
A well known example is the mule, which is bred by a donkey and a horse can be born relatively healthy. However, it will always be infertile, preventing it from producing young of it’s own.
But there are other species which defy the deformities of interbreeding, which give us clues as to how the Denisovan and Neanderthal managed to mix. Here are 5 that shed some light on the mystery.