if we differentiate between species by not being able to provide fertile descendents. Why do we say neanderthals were a different species from us but also say we got some of their genes via cross reproduction?

Question

if we differentiate between species by not being able to provide fertile descendents. Why do we say neanderthals were a different species from us but also say we got some of their genes via cross reproduction?

In: Biology

Answer 1

Humans and Neanderthals could not freely and easily reproduce, which is a major support to the faction of scientists who consider them to be a different species. It looks like there is no male Neanderthal DNA in the human genome. Only female Neanderthal DNA. It appears that human males and female Neanderthals could mate and produce fertile offspring, but human females and male Neanderthals could not produce fertile offspring.