[maskedinvader]

Ah survivor ship bias I think it’s called, that’s one explanation, but how does the original gene mutation work ? How did it survive for apparently so many generations ? Seems to be the kind of mutation that would have not survived if it literally caused you to dance till you die.

[carlmr]

The question is rather if there's sufficient evolutionary pressure to rule this out.

It led to a handful of people dancing till they die, ok, but maybe only in a dense urban setting which wasn't an issue before. Maybe that gene conferred other benefits, like more stamina.

Maybe it's like a lot of disease which don't seem to have benefits but still affect a much larger part of the population.