eli5 If it’s suspected that early humans interbred with other species of humans, why would they be considered different species since the offspring were obviously fertile?

Question

eli5 If it’s suspected that early humans interbred with other species of humans, why would they be considered different species since the offspring were obviously fertile?

In: 54

Answer 1

Whether two populations can create fertile offspring is just one aspect to *consider* when defining species. If interbreeding was the only thing to consider, then we’d be shit out of luck for organisms that don’t sexually reproduce.

But also, we simply *don’t have a definition for “species”*

“Species” is mostly a man made concept. Humans like putting things into nice, distinct boxes because it can make things easier to understand and talk about. But the natural world is going to be messier than that.

The wikipedia article for species has two whole sections about how hard it is to define:

* https://en.wikipedia.org/wiki/Species#Definition
* https://en.wikipedia.org/wiki/Species#The_species_problem

And even it’s own article: https://en.wikipedia.org/wiki/Species_concept

This Darwin quote from that article sums things up pretty nicely

> I was much struck how entirely vague and arbitrary is the distinction between species and varieties