Various activities of living organisms stimulated their bodies to change. The giraffe’s neck elongated, the eagle’s beak sharpened, the snake’s tongue forked, and the crocodile increased the strength of its jaw. They practiced something akin to bodybuilding. It wasn’t a conscious effort to work on their figures or teeth; it happened rather by accident—mostly while foraging for food. We can only envy our predecessors. It would be much more enjoyable to sculpt our physiques by buying potatoes, eggs, or a pound of pork neck (with or without the bone) rather than by sweating our guts out at the gym, doing cardio or CrossFit, or dragging weights. Not to mention riding a bike for dozens of miles without moving as much as an inch. (…)