Human beings are monotypic: we’re the only species within our taxonomic genus. Monotypic genera are relatively rare—it’s unusual for there to be no other species within a genus, especially among higher level complex organisms. (*)
We weren’t always monotypic. We shared Ice Age Europe with Homo neanderthalensis for tens of thousands of years. We shared parts of the planet with H. erectus for much of our early existence. It’s possible we even overlapped somewhat with H. heidelbergensis (I don’t know what the scholarly consensus is on this—recent discoveries have complicated the origins of H. sapiens. There were also many more coexistent relatives during our early evolution.)
For well over half of our existence on this planet as H. sapiens, there were other people out there who were within our taxonomic genus but who weren’t our species.
