There's been a lot of speculation about where and when the last of the Neanderthals died, and basically the picture painted is one of a relatively small tribe that is irreversibly wiped out after an extreme weather event or bad hunting accident.

I wonder what is the smallest population of humans that would have the creativity and knowledge about agricultural and mechanical technology needed to survive under tough conditions. There's a theory that the human population experienced a bottleneck of around 15,000 individuals, 75,000 years ago. I would think that a community of that size would have a tough time keeping modern technology going, unless it happened to be a university town--preferably an agricultural university. A solid combination of engineers and ag experts could probably survive some pretty extreme conditions...not sure what the political science department would contribute, though!