It's an enduring puzzle. For hundreds of thousands of years, our ancestors were nomadic, ranging over large territories, hunting and gathering for sustenance. Then, beginning roughly 12,000 years ago, we pivoted. Within a short timeframe—in Asia, Africa, the Middle East, and the Americas—humans...

Maybe your idea of spiders is a bit like mine was. You probably know that they have eight legs, that some are hairy. Perhaps you imagine them spending most of their time sitting in their webs—those classic-looking ones, of course—waiting for snacks to arrive. Maybe you consider them vaguely...