We evolved to eat berries rather than bagels, to live in mud huts rather than condos, to sprint barefoot rather than play football—or did we? Are our bodies and brains truly at odds with modern life? Everyone is fond of paleofantasies, stories about how humans lived eons ago, and we use them to explain why many elements of our lives, from the food we eat to the way we raise our children, seem very distant from what nature intended. Many diets and self-help books are predicated on the notion that our behavior and bodies evolved under a certain set of circumstances, from which we deviate to our peril. Implicit in that idea is the assumption that humans in a modern society aren’t evolving any more, that we have somehow freed ourselves from evolution, or at the very least, that evolution always requires so long to act that we can’t expect to have adapted to our current circumstances. But popular theories about how our ancestors lived—and why we should emulate them—are often based on speculation, not scientific evidence, and they reflect a basic misunderstanding about how evolution works. There was never a time when everything about us—our bodies, our minds, and our behavior—was perfectly in synch with the environment. Evolution is continuous, and all organisms alive today, whether chimpanzees, modern-day hunter-gatherers, or bacteria, are all equally evolved. What really matters is the rate of evolution, which is sometimes fast and sometimes slow. Instead of trying to live like cavemen, we need to understand that process.
Review Marlene Zuk’s biographical statement.