We’ve certainly heard more than five around here. But this group is set up as a sort of slide show. How here’s the theory that makes a lot of sense:
5. … Computer modeling indicates that the continuous migration of modern humans from Africa to Eurasia meant they were always going to replace Neanderthals, regardless of the other factors that certainly didn’t help them survive. It was a numbers game, and the numbers weren’t there for the Neanderthals.
“What Killed the Neanderthals” at Inverse.com
In other words, it wasn’t something exotic that was wrong with the Neanderthals after all those millennia but the fact that other, larger groups were always moving out of Africa and thus either absorbing them or pushing them along. Something the same seems to have happened in North America half a millennium ago.
It’s nice when human paleontology theories can actually make ssense.
See also: Neanderthal Man: The long-lost relative turns up again, this time with documents
and
A deep and abiding need for Neanderthals to be stupid. Why?