But that's only if you take a very narrow definition of what "human" is. I think a better definition wouldn't be as limited on the specific isolated organism, b

But that's only if you take a very narrow definition of what "human" is. I think a better definition wouldn't be as limited on the specific isolated organism, but rather on the organism within its environment – and that includes society as well as the actual physical environment. Nature/biology isn't very exclusionary and a lot of things are better looked at as ecosystems. From that perspective, the "human" has definitely changed since a few thousand years ago.