Is This the Real Life...Or Is This Just (Paleo)Fantasy?
...or, what bug sex, blue-eyed babies, and a big glass of milk can teach us about human evolution and its role in our present and our future
True confession: when you are a writer, sometimes you get an assignment that makes you hold your head and groan. Which is pretty much what I did when I heard the word "paleofantasy." The idea of paleo-anything made me want to weep tears of done-to-death.
But then, however, I sat down with Dr. Marlene Zuk, author of Paleofantasy: What Evolution Really Tells Us About Sex, Diet and How We Live and instructor for the upcoming short course Paleofantasy: Our Evolutionary Past and Future (Feb. 25), and realized that every once in a while, those initial assumptions about an assignment are wrong.
For one, this "paleo-" topic has nothing to do with telling me how horrible my diet is or how I should give up jogging and take up some sort of activity where I sling a 80-pound, oddly shaped basket of lead around my waist and do wind sprints because it's more like the cavemen's form of exercise.
"It isn't a diet book," she says. "And it's not going to be a 'diet' course. It's not a how-to guide for eating, exercise, parenting, or anything like that--despite what the people who write online reviews without reading the book would have you think," she continues with a smile.
What the book is, and what she hopes the course will be, is an examination of evolution--and the myths and misconceptions about it. Something that may SEEM fairly straightforward on the surface, but in reality is anything but. "Yes, absolutely there are things we can learn from our ancestors...but there are also things we can't. There's a lot of misinformation floating around, or people using snippets of evolutionary history (pseudoscience) to justify all sorts of behavior."
The example that sparked her latest book is the proliferation of "paleo" lifestyle trends, or "the belief that our bodies haven't evolved to keep up with technology, and that we're getting all these diseases and ailments because we're out of sync with nature/our real selves, so the best way to live is to adopt the eating habits or exercise patterns or childrearing practices of the hunter-gatherers from tens of thousands of years ago."
The idea that human evolution was all wrapped up and done millennia ago (and even if it weren't, evolution only makes minuscule changes over millions of years ANYWAY), and we would be healthier and happier if we lived more like our ancient ancestors, is in direct contradiction to Zuk's research work (and, yes, her studying bug sex).
"That's the 'fantasy' part," she says. "This idea that we'd be better off reverting to some halcyon time. That and the idea that we haven't evolved since ancient times."
Zuk expounds, "sure, to some extent we aren't adapted to 'modern life'--we aren't built to sit at computers all day. But we're not ideally built for eating and talking, either. Because of the way our larynx has moved way down in the trachea, and the way our epiglottis works (both reasons why we can speak), and the fact that our windpipe and esophagus are so close together...we run the risk of choking on our food--something that doesn't happen with other animals. They don't aspirate their food.
"But where do you draw the line? You don't see people saying 'Well, we're not perfectly suited for bipedal ambulation and for talking.' How far back do you want to go? Should we all go back to living like amoebas? To the primordial soup? We're not perfectly suited for ANYTHING--evolution doesn't work that way."
How evolution DOES work, says Zuk, is similar to a broken zipper--it mostly lines up, or lines up well enough to get the job done, but it's not a perfect fit all the way. "It's a tinkerer, not an engineer," she explains further. "Always building on to what is there, and occasionally having to jury-rig things. But it's a continual process. There isn't some ideal stopping point. It's not like engineering a computer chip or bridge or something with a specific design you can match, and when you get there you're done."
It's a continual process--and not one that is only evident on a glacial scale. In fact, some evolutionary adaptations have happened relatively rapidly, Zuk points out. "The main example I give is lactase persistence [the ability to digest milk past infancy].Following the domestication of cows [around 7,000 years ago], the gene for this flourished--now something like 35 percent of the population can digest it."
She adds that blue eyes are another recent evolutionary development--as recently as 6,000 years ago, they were virtually nonexistent. They then arose, probably by random mutation, and proliferated to where they are now quite common.
Rapid changes like these happen in all species, of course, and the new field of experimental evolution is allowing researchers to study the process firsthand. Which brings us back to the topic of Zuk's own research and the mating habits of certain members of the insect world.
"I do get a lot of people asking me about that--asking what on earth is someone who wrote a book about bug sex [her previous book is Sex on Six Legs:Lessons on Life, Love, and Language from the Insect World] doing myth-busting our evolutionary history? But while they sound like disparate ideas on the surface, the connection is pretty direct," she explains.
"My work looks at how quickly evolution can happen. Right now, we're looking at a species of cricket that has developed a wing mutation that stops them from chirping--they stopped chirping because their calls for a mate were also attracting a parasite. So, they evolved in fewer than 20 generations, to be silent. That's a remarkably short time span--in human terms, it would be a period of only a few hundred years."
Zuk says that her work on rapid evolution, coupled with the research showing how certain traits in humans (like lactase persistence and blue eyes) have evolved quickly, made her increasingly more cognizant of all the "paleo press"--everything from the diets extolling the virtues of grain-free living to exercise regimens like Cross-Fit that center around activities that supposedly mimic ancient man's "exercise" in the wild (throwing boulders, sprinting from predators, etc.).
It wasn't the specifics of the diets or workouts themselves that Zuk had issues with, necessarily, but rather the science (or lack of science) used to justify (and market) them. "I am not here to tell you how to eat or work out. That was never my intention. And by all means, if you are eating a grain-free, raw-veggie rich, high-protein diet and find your skin clears up or you lose weight or any of that...then good for you.
But there is a danger to saying 'Well, because we didn't do X, Y, and Z in the Paleolithic area, we shouldn't do it now.' I am not discarding our evolutionary heritage in considering our health--I think there's a value to that. But I think that people should make decisions about what to eat and how to exercise based on data, not theories about what our fore-bearers may have done millennia ago.
"Living on potato chips and Coke is not a good idea. We all agree on that. But at this point, there isn't even evidence that everyone was eating the same 'right thing' 15,000 years ago. What people ate varied by where they lived. And recent research suggests that maybe they did eat more starch and carbs than we initially thought."
All the more reason, Zuk believes, to "re-think" evolution--or, rather, to consider what it can (and cannot) tell us, and then how we can use that information in our lives.
"There's more to understanding evolution than learning what Australopithecus was like," she says. "The goal of the book--and what I'd like to tackle [in the LearningLife short course] is how do we think about evolution. How does it affect what is happening to us right now? Or what will happen? How will it affect our children and grandchildren? We're not done with it."
She concludes, "Humans have a tendency to see what we want to see or expect to see...[and to] rationalize what we already want to do. Understanding some of these concepts can change the way you do things, the way you think about thing. About concepts of variability, of differences, of what's 'natural.' If we're really successful, I think it can also help people question their intuition--look for and ask for data when making decisions...not just make assumptions."