Why should there be? The only reason I can think of is if you have a prior religious/metaphysical belief in a specific species (in this case H. Sapiens) having a 'destiny'. If OTOH you see species as contingently arising, well, then: they come, they change, and sometimes they overrun, and go.
Why should descriptions 'help'?
> to which there is no known better alternative
Why should there be? The only reason I can think of is if you have a prior religious/metaphysical belief in a specific species (in this case H. Sapiens) having a 'destiny'. If OTOH you see species as contingently arising, well, then: they come, they change, and sometimes they overrun, and go.