Where have all the Neanderthals gone?

Why there aren't any Neanderthals still around these days:

Neanderthals, Neanderthals

Neanderthals are glorious creatures.

They're stronger, smarter, and better than you.

Despite these and other special features,

they haven't got a farther-mucking clue.

They don't know they're better, smarter, stronger.

They're innocent as lambs and cause no harm.

But they can't stay this way for much longer.

Let's act before there's cause for great alarm.

A fallen world is a risky place for unfallen creatures.