The Role of Caffeine in Wakefulness

Caffeine is the molecule that most of us think of with coffee. We don't exactly know the biology of caffeine, like what the natural function of caffeine is. So we have basically co-opted what we think is a plant toxin as a stimulant to wake us up. And actually as human beings, we're really good at co-opting molecules that have evolved to do one thing to do something else.