What might account for rapid cognitive leaps without invoking alien intervention, according to some interpretations?

Answer

Ecological pressures favoring subtle, pre-existing genetic variations

An alternative scientific interpretation suggests that critical junctures in human development, where cognitive capacity suddenly appears advanced, could result from intense ecological pressures selecting for advantageous variations that were already present in the population.

What might account for rapid cognitive leaps without invoking alien intervention, according to some interpretations?
humantheoryaliengeneticmodification