Somewhere toward the end of the last ice age, we formed an alliance with wolves: Maybe the ancestors of dogs got food scraps while our own ancestors gained protection from predators and other humans. These social species eventually collaborated on a vast scale, possibly even hunting woolly mammoths...

We zigzag from tree to tree, seeking refuge under the leaf umbrellas. Drizzle turns to deluge as we dash beneath a tall canopy to plot our escape. The sky booms. My dad takes my hand, and I look up to see if he shares my sense of foreboding. But he’s smiling at me, his eyes twinkling. He says...