Natural (and Unnatural) Selection
I’m talking to the kids about the Galapagos Islands because it’s Darwin’s birthday. “No it’s not,” my partner, Michael, interjects. “It’s the hundred and fiftieth anniversary of the publication of The Origin of Species.” Whatever. I am in love with evolution, but what exactly happened out at Galapagos I’m less clear about: Dinosaurs turned into Komodo dragons, which sprouted legs and crewed the S.S. Beagle? Something. I attend to ideas in passionate—if brief—flurries of attention; I can be aghast over a headline I’ve misinterpreted in a newspaper story I haven’t actually read. “They’re replacing school nurses with robots!” I might cry, indignant, and Michael will say, “I think that’s just an article about MIT graduate students.” Oh.
“Distraction is adaptive,” I explain to the children. “If I did only one thing at a time, your lunchboxes would be packed every day with air and then you’d never survive to reproduce now, would you?”
No. They would not. Biologist Ernst Mayr summarized Darwin’s theory this way: “Individuals more suited to the environment are more likely to survive and more likely to reproduce and leave their inheritable traits to future generations, which produces the process of natural selection.” Force open your rusted-over junior-high-school mind, sift through your Duran Duran memorabilia, and call this up. Remember? No, not the smooth and wrinkled peas—that was genetics (Doesn’t “Mendel’s Peas” sound like a vegetarian deli? Or maybe a Hungarian garage band.). Keep sifting. It’s the other thing—the pale peppered moths on dark trees getting picked off by the birds. Remember? Or has “survival of the fittest” kind of blurred into “Manifest Destiny,” and now it gives you a bad white-people-giving-away-free!-small-pox-blankets feeling to recall it? It’s not like that. Nor does survival of the fittest really have a fitness component—it doesn’t mean that your daughter’s ropey and muscled karate instructor will thrive to birth a million babies like a sea turtle while you, with your giant corduroy thighs rubbing together with a shkrrr-shkrrr sound (I’m just imagining here) will drop immediately dead; it’s more like genetic calisthenics. Which is why the term “reproductive success” has nothing to do with foreplay, Tantric ecstasy, or simultaneous climaxing. It’s about whether particular traits help a particular organism live long enough to produce offspring. Your husband could do you from behind while you were bent over to sort the Tupperware drawer. And if you got pregnant and passed along your organizational skills to your offspring? Evolutionary Bingo! Reproductive success.
But for now, the kids and I stick to our conversations about various visible traits and how they might be adaptive, and let me say this: If you live in the world as a student of natural selection, you will never be bored. The children study the eyes of animals to determine if they’re predators or prey. Prey have those nervous side eyes, usually with the big nervous ears, twitching and swiveling all around to see who’s coming to eat them and from where; picture a bunny, a mouse, Bambi’s dead mother. Predators’ eyes stare out from the front of their heads. “The better to chase you with, my dear,” ten-year-old Ben says in his best Big Bad Wolf voice, even though we humans are predators, too (except for maybe your one cousin with the nervous side eyes whom you feel a strange urge to chase).
We stroke our pussycat and analyze him for adaptivity: fur to keep him warm, of course; whiskers to avoid bumping into nighttime doorways; and what about purring? We don’t know. “It makes you want to take care of him,” Ben hypothesizes, which is so totally true. I picture the kittens turning on their irresistible little motors, the mother cat thinking, “Oh, fine,” and rolling over to expose her rows of exhausted teats. I picture my babies smiling up at me at the exact moment I was contemplating how discreetly to rid myself of them; I picture myself weeping instead, spilling over with love, and yoinking a milky boob from my nightgown. They’ve actually studied this—the way babies’ smiles trigger massive hits of dopamine and oxytocin in their parents, biological and adoptive both. Street drugs could kill you, but nature’s drugs might just keep you alive.
“Being cute is adaptive,” six-year-old Birdy says, as if reading my mind. She’s thinking still about the pussycat, but I’m thinking about her: the big eyes, the helpless littleness, the wobbly dependence.
I kiss her plummy cheeks and say, “It is.”
“So is being beautiful,” Ben says, hair falling around his face like dark silk, his lips the color of berries. “Like the male hummingbirds.” We watched one at the feeder all summer: a head sleeked over with emerald feathers, the neck banded in iridescence. I’m sure the girls were going crazy. I picture the scarlet cardinal seducing his fawn-colored mate, male peacocks fanning the riot of their tails, the hot crimson wattles of a cock. Why the human equivalent is a boozy grin from a barstool remains a mystery. At least to me.
But sex is a big part of it, right? All the pleasure-rigged engineering that keeps the species from extinction, all the stinky snatches of body hair like so much pheromonal quicksand, the blood rushing hither and yon in its tumescent quest for continuity. “Enjoy it,” I like to tease Michael, nudely. “I’m going to be done with this after menopause.” If it were adaptive for us to have sex for our entire lives, would our coochies really dry up like that at a certain point? Is Viagra an adaptive invention—everyone’s grandpa running around with a four-hour woody? I don’t know. I don’t understand the relationship between technology and nature. Because as it is, I never feel more special—in the species sense—than when I’m ovulating. That pull towards sex then? It’s pure animal survival. Michael is always thrilled, if a little daunted—that growled “fuck me” emanating adaptively from the very throat of my DNA.
Of course the danger here is that evolutionary arguments, rather than remaining the grand, analytical riddles that they are, get mustered to justify various patterns of domination: Women should suckle everybody; gay people should concede the barren hydraulics of their coupling; pregnancy should end in birth. Gender inequality; the Defense of Marriage Act; threats to Roe v. Wade. Danger, danger, danger. That’s why you have to get kids with the program, and get them there early and inarguably.
“Clearly,” I explain, “we’ve adapted to the point where, whether we’re gay or straight, we understand how to have or not have babies, which is the most healthy thing for human beings.” Reproductive technology is adaptive for replicating the species; reproductive freedom is adaptive for women’s health and population control. It makes perfect sense to the kids, in the same way that justice and helping other people also makes perfect evolutionary sense to them. (We see where rugged individualism has gotten us: a world of drowning polar bears, slave labor, illness, the bogglingly unjust distribution of wealth, of poverty.)
“Also karate,” Birdy says. “Karate is totally adaptive for girls and women because it keeps you”—here she kicks her leg out and aiiiiiiis fiercely—”safe.” Indeed. Mostly, though, we speak not in philosophical abstractions, but in the interest of solving an endless series of evolutionary logic puzzles. Maybe it’s the way other families talk about God: We are awestruck. Milkweed blows far and wide, a botanical Don Juan, we conclude. Acorns thunk straight down beneath the sheltering oaks. “They must grow better if they’re close to their moms, ” Birdy theorizes from my lap. A pomegranate stuns us, its seeds packed together like a ruby-filled auditorium. “Maybe it attracts the birds so that the tree can get them to poop out its seeds all over the place.” Probably it does.
“Poor berries,” Ben sighs. “They didn’t plan on the sewer system, all us humans just flushing their seeds down.” I picture—but don’t mention—the related phenomenon of jizz-soaked teenaged Kleenex, like so much potential life sneezed away. Ben thinks for a minute, toilets flushing over his head like light bulbs, then asks, “What about poop?”
I laugh. “What about poop?” It’s a favorite topic of conversation.
“Why does poop smell bad, do you think?” When I lob over the classic parental Why do you think poop smells bad? he says, “Probably so you won’t eat it.” We picture an entire race of sickened people dying off, their poop smelling like Rice Krispie Treats.
But really? Evolution is nature at its most enchanted: the beaker of science fizzing over with magic. It is logic and mystery, life and death, the omniscience of a god, but without the burning-in-hell morality. Without any morality at all, actually. Ben, considering our resident swivel-headed, night-vision barn owl and the big-eared, nose-twitching mice, muses, “Nature just lets them duke it out. They both adapted for what they need—chasing or getting away—and then they just do their best.”
And so do we, given that we are programmed to be here and then not—to die one day, despite how ferociously attached we may be to life. At the top of a fire tower, after a gorgeous and vigorous hike, Ben wondered recently about death. “It’s funny,” he said. “I mean, it’s obviously adaptive for the species as a whole for people to die. Otherwise you’d just have, like, a bazillion people everywhere, fighting over everything. But then, how did nature select for death? Because dead people? They were dead. They couldn’t exactly pass along the dying trait.” Holy necrophilia. Although he’s more right than he might know: Programmed cell death is one of the least well-understood biological traits; cells don’t have to die, but they do.
“Whoa,” says a fellow hiker, a stranger to us, raising his disturbed eyebrows at my pretty, pink-cheeked son. “Deep.”
When I ask Ben what has prompted this revelation, he says, “Being kind of tempted to jump off the fire tower.” Oh. “But then knowing I would die if I did. I guess it’s adaptive for me personally to not want to die.” I guess it is. I think about teenagers everywhere, the danger that their will to thrive will ebb treacherously away. And I cross my fingers and send up a kind of evolutionary prayer. We may be programmed to desire that our offspring live to reproduce themselves—but it just feels like love.
Author’s Note: I love the idea of Lamarckism: the so-called “soft” theory of evolution that allows for acquired characteristics to be passed on to offspring—a theory that gets regularly debunked and resurrected. I like to willfully misinterpret it to mean that my children, born of two half-Jews, will pass on a genetic love of frying latkes in bacon grease. My father likes to willfully misinterpret it to explain the impatience I inherited from growing up in an impatient household. “Your mother—always craning her nosy head around,” a giraffe probably said to his kid at some point. “You get your long neck from her.”
Brain, Child (Spring 2010)