Genetic evolution can be fast or s l o w but when it is fast it is still too slow to protect us from the immediacy of a colliding Comet or from the alternating periods of extreme climate changes during glacial times like those of today.

But what good luck! Those pre-adapted pre-humans (us) evolved words and our isolated words quickly evolved into languages and our languages quickly evolved into cultures and all cultures begin to evolve (those that haven't already died out) and are evolving today. Get it?

Some cultures are bad and some are good, with good and bad being determined by the culture's survival.