If Homo sapiens and Neanderthals are different species, how did they interbreed and produce the fertile offspring needed for modern humans to have some Neanderthal DNA?

Question

I was told that two seperate species couldn’t interbreed and produce fertile offspring, so I don’t understand how we ended up with some Neanderthal DNA.

In: Biology

Answer 1

The same way horses and donkeys reproduce mules, their genetics are just close enough to mix but just different enough to have to be considered different species, not just an adaptation