“There’s a cost to living; there’s a cost to doing everything. That cost depends on the speed at which we’re living, to some degree. If we are living our lives at a very fast rate, we tend to wear out sooner. There is a strong relationship between metabolic rate—the rate at which we’re taking in oxygen and burning up food—and lifespan. Under good conditions, we focus most of our resources on sexual maturation. I’m speaking not so much about humans as animals in general. But this goes beyond the animal kingdom.” – Nautilus