The Caveman Controversy
In her new book, Paleofantasy, Marlene Zuk dared to debunk a lifestyle that advocates eating, exercising, and even mating like our ancestors. Now the outspoken insect-sex researcher has adversaries, who say she’s the one whose thinking needs to evolve.
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It was an unlikely confrontation between experts from two very different academic worlds, and their disagreement has only intensified since the publication of Zuk’s new book Paleofantasy: What Evolution Really Tells Us About Sex, Diet, and How We Live.
Zuk’s office on the U of M’s St. Paul campus is filled with books about insects and evolution, including her own Sex on Six Legs, which came out in 2011. When I show up, she has just finished eating a lunch of cheese, crackers, and carrots. Zuk refuses to tell me what kind of cheese or what kind of crackers, insisting that the details have nothing to do with her book, which is not a diet book.
Zuk wears her brown hair cut short, and her no-nonsense demeanor is friendly but focused. She seems like the sort of person who would rather talk about why the sky is blue than chitchat about the weather. Scientific questions fascinate Zuk, whose rapid-fire sentences are packed with information and punctuated with wry humor. At one point, she tells me she used to think all biologists should study parasitoids, organisms that feed off of their hosts and often end up killing them. “It is an extraordinary life cycle,” she says, and then doles out a little advice with a matter-of-fact, scientist’s manner. “Now I think everybody, whether they are biologists or not, should work on parasitoids at some point. It should just be, like, a requirement in life.”
For 30 years, most of them spent at the University of California–Riverside, Zuk has been studying birds, insects, and other animals for insights into what makes males and females different and how parasites influence reproduction, with her most recent focus on cricket evolution and mating behaviors. In Paleofantasy, Zuk turns her evolutionary lens on our own species, arguing that there is no such thing as a single “natural” way to eat, exercise, make love, raise babies, live, die, or anything else. The notion of an idyllic time when ancient humans and their genes lived in perfect harmony with the earth is fundamentally hogwash, Zuk argues. There has often been a mismatch between our bodies and the environments we inhabit. And perhaps most importantly, as the world has continued to change, so too has our DNA—more quickly than scientists long thought possible. Our genes don’t necessarily suggest anything about our lifestyles, she says, much less that we should live like cavemen. (While we modern humans share most of our genes in common with our Stone Age ancestors, in fact, there’s also significant overlap with chimpanzees, and even bacteria and sea anemones.) The world is different now, and so are we.
In Zuk’s mind, her book is purely an attempt to correct misguided ideas about how evolution works by highlighting exciting new research on rapid genetic change throughout the animal kingdom. But its provocative title and its chapters on food have sparked debate, even ire. After the first round of Internet commenters posted their thoughts on the tome, Zuk stopped reading the blogs. “I was taken aback by how all these people who didn’t read the book took it as a big attack on their diet,” she says. “Really, it’s not what the book was about. People can eat whatever they like. I just don’t care about people’s diets.”
What she does care about are crickets. Zuk loved animals as a kid, but she grew up in Los Angeles, where wildlife is scarce. (One thing she appreciates about insects is their ubiquity—they’re accessible to just about everyone.) Alongside other projects, she has been delving into questions about how crickets find each other to mate and how parasites can alter their characteristic chirping. Zuk leads me down a hallway to a room lined with loud-humming, refrigerator-shaped machines. When she opens one of the doors with routine practicality, a cacophony of chirps escapes, evoking a post-sunset evening at summer camp. The dozens of plastic containers before us don’t contain the lab staff’s sandwiches and fruit salad. Instead, they host colonies of crickets and the rabbit feed the creatures eat.
“Isn’t that awesome?” she asks, perking up. “I love watching them call!” She takes a moment to point out a female that’s looking around for a place to lay her eggs and some just-hatched tiny babies. “I always think they look almost like little ants with curly antennae,” she says. “Aren’t they cute? Very cute.”