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

Speciation is a gradual process that occurs as gene pools slowly drift apart. There’s no single point in time where two groups abruptly stop being able to interbreed; they just become less and less likely to produce viable offspring. The definition of species is fuzzy around the edges because gene pools themselves have no distinct edge.