Here's a kind of twist on the subject.
If the "evolutionary record" actually contains any truth to it (and, personally, I'm not fully in agreement with ANY popular theory out there of our origins) then people have been people for what, 150-250 thousand years or so.
Sound good?
And let's say that this curent period of history in which we now live incorporates about....10,000 years or so.
Then conceivably we (human beings) could have risen and fallen, as a species, anywhere up to two dozen times or so.
I'm not fully convinced that this has happened, hell, even more than once.
But it sure as hell is fun to ponder.