Ya, human extinction though what precisely? Failing to reproduce? Not likely as ugly people "do it" all the time, they just get drunker than [bleep] first, much of the time... Stupid people also reproduce as well, more prolificly than do many a smart person.
As for walley attempting to smile, he needs much more practice... Because that does look like a grimmice. We are what now - nearly 8 billion beings ang getting more populas.. Though not apperently stronger..