Alyce smiled. “Isn’t that stereotyping, Joan? But, well, primate behavioral studies in the wild take — took — decades of observation, because that’s how long the animals themselves take to live out their lives. So you need patience, and an ability to observe without interfering. Maybe those are female traits. Or maybe it was just nice to get away from all the usual male hierarchies in academia. The forest is a lot more civilized.”

“Still,” Joan said, “it’s a powerful tradition. Goodall, Birute Galdikas, Dian Fossey.”

“I’m the last of a dying breed.”

“Like your chimps,” said Bex, with surprising brutality. She smiled at their silence. “They’re all gone from the forests now, aren’t they? Wiped out by climate change.”

Alyce shook her head. “No, actually. It was the bushmeat trade.” Briefly she told Bex how, toward the end, she had worked in Cameroon, as the loggers had worked their way out into the virgin rain forest, and the hunters had followed.

“Wasn’t it illegal?” Bex asked. “I thought all those old species were protected.”

“Of course it was illegal. But bushmeat was money. Oh, the locals had always taken apes. A gorilla was prestige meat; if your father-in-law visited, you couldn’t give him chicken. But when the European loggers arrived, it got much worse. Bushmeat actually became a faddish food.”

The black hole theory of extinction, Joan thought: all life, everything, ultimately disappears into the black holes in the centers of human faces. But what next? Will we keep on eating our way out through the great tree of life until there’s nothing left but us and the blue-green algae?

“But,” said Bex reasonably, “there are still chimps and gorillas in the zoos, right?”

“Not all the species made it,” Alyce said. “Even the populations we did save, like the common chimps, don’t breed well in captivity. Too smart for that. Look: The chimps are our closest surviving relatives. In the wild they lived in families. They used tools. They mounted wars. Kanzi, the chimp who learned a little sign language, was a bonobo chimp. Did you ever hear of her? And now the bonobos are extinct. Extinct. That means gone forever. How can we understand ourselves if we never understood them?”