Mother Nature Is Trying to Kill You: A Lively Tour Through the Dark Side of the Natural World

by Riskin, Dan

  X. Interestingly, the North American extinction seems to have been caused by human activity in concert with climate changes that were happening at the same time (Faith 2011; Prescott et al. 2012). Those changes in climate were not caused by humans, though, unlike those happening in the world today.

  XI. To be clear, there are many women who would outcompete the average man in a competition of that kind (my wife, Shelby, can run faster and farther than I can, for example), but on average, men have the upper hand. In a random sample of men and women, you’d expect the fastest 10 percent to be made up of more men than women.

  XII. The Selfish Gene (Dawkins 1976) is among the very best introductions to natural selection out there. The “meat robot” theme I use throughout this book is largely inspired by Dawkins’s shift in perspective from the individual to the DNA molecule. His book is definitely worth a read for that reason alone. As a bonus, it is the book where the term meme was first coined, so it’s interesting to read for that reason too.

  2

  LUST

  Meat Robots Screwing One Another . . . Over

  Maybe you’re worried I exaggerated the influence that DNA has on animals. Maybe you think that whole meat robot idea went a step too far. After all, animals have brains, right? Shouldn’t that put them in a position of control over a twisty microscopic molecule? I know, I’ve made a bold claim, so I’ll let the animal stories speak for themselves. You’ll see that DNA really is in the driver’s seat, and the best evidence of that comes from stories about sex.

  Here’s what makes sex so interesting: animals, including humans, face a trade-off between how long they can live and whether or not they reproduce. If an organism were really in control, it would make decisions that optimized its own survival, and then only have sex if that didn’t shorten its lifespan. But that’s exactly the opposite of what we see in nature. Time and time again, animals do things to pass on their DNA that cause their bodies harm. Animals will even die to have sex. Those animal decisions collectively build a convincing body of evidence that reproduction is even more important than survival; DNA really is in control, and the body really is just a meat robot. A sophisticated meat robot, but a meat robot nonetheless.

  When I was a kid, I found it amazing that animals knew how to mate in the first place. It was no surprise to me that animals instinctively avoided danger, but for some reason I always had a hard time getting my head around the fact that animals instinctively know how to screw. Without training, animals know to thrust certain parts of their bodies against one another in very specific ways, so that sperm will come in contact with an egg. And it’s not just the screwing that comes instinctively either: that horniness drives a male satin bowerbird of Australia to collect anything blue it can find to decorate the ground outside its home—berries, flowers, Bic pen caps, whatever—because blue things will attract a female.I Horniness makes male bighorn sheep smash their heads into one another’s because that’s how they can get a female.II All of that happens instinctively. To me, it’s no surprise that animals are programmed to run away from predators, but I marvel at what they’re programmed to do for sex.

  When I was about ten, I had the same thought about humans. How do they know what to do in bed? I remember thinking that people must have to pass on the secret of how babies are made from generation to generation so that we don’t go extinct. Otherwise, how on earth would anyone ever think to place a penis inside a vagina? Seriously? Who would ever think of that? I imagined scenarios where uneducated teenagers shipwrecked on islands would have no idea what to do. “Even if they did figure out to lie on top of each other,” I thought, “what if they didn’t know to take off their clothes? How would they figure that out?”

  Once I hit puberty I realized my worry had been grossly misplaced. What I’d previously thought of as a very strange ritual between grown-ups had quickly become the only thing I could think about. In junior high my urge to have sex honestly felt about as strong as my urge to stay alive. My DNA had sent new instructions to my meat robot self in the form of raging hormones, and suddenly my whole soul was hell-bent on executing those directions. Girls were suddenly the only thing I cared about. I imagine that’s probably how powerful those urges are for satin bowerbirds and bighorn sheep.

  This chapter is about lust—that DNA-driven, overwhelming urge to make babies that impels animals to hurt one another, hurt themselves, and even sacrifice their own lives. I’ll start by highlighting some of the most heinous sacrifices animals make for reproduction, from being eaten alive to having their clitorises torn open (you can decide which is worse). Along the way, I’ll challenge you to think about your own assumptions about sex and nature. Is there such thing as a natural childbirth? Are homosexual relationships natural? Is rape natural? You’ll quickly see that nature is so immoral, vulgar, and downright wicked, we can’t possibly use nature’s behaviors to set rules for ourselves.

  Here we go.

  No animal makes a more stunning sacrifice for sex than the male antechinus.1 (If you want to say its name properly, make it rhyme with “acts of kindness.”) Antechinuses are cute. They live in Australia and pretty much just look like big-eyed, furry mice, but they’re really marsupials—pouched mammals more closely related to kangaroos and koalas than to mice. What makes antechinuses so unusual, though, is that every single year, they go through a mating season so intense that it kills every single male of the species.

  Mating season is in August and lasts anywhere from three days to a couple of weeks. For a male antechinus that brief period is the only chance he’ll ever get to pass on his genes, so he sacrifices everything to give it his best shot. Testosterone levels skyrocket to ten times normal; sperm production goes into overdrive. As mating season begins, males are so full of sperm that a little bit leaks out of them every time they pee. The males need all that sperm, though, because antechinus mating is like a marathon; copulation lasts for six to twelve hours.

  Hours. (I know, right?)

  That little mouse-sized ball of fur makes love like a tantric stallion. By taking his time, though, he defends that female from the advances of other males: mating season is so short that by staying attached to her for that long, he keeps other males off her for a significant fraction of the whole season. Also, that gives him time to put a significant volume of sperm deep into her reproductive tract. Whether his genes or someone else’s will be passed on all comes down to his performance that week. He’s not out to impress anyone (though I, for one, am very impressed). He’s just doing it because he’s got to pass on his DNA.

  Whether or not that male knows why mating is so important is up for debate, but what is certain is that it’s stressful for him. During mating season, male antechinuses experience off-the-chart levels of stress hormones. Those are the kinds of hormones released by people in the most stressful situations imaginable, for instance when people are displaced from their homes by civil war.III Those hormones, which come from the adrenal glands, tell the whole body how to allocate energy when times are tough: “Stop spending so much on the brain, kidneys, and immune system. Let’s break down our fat reserves. Let’s get our muscles ready for action!” Those hormones can help an animal survive hardships in the short term, but they can also start to hurt the body if the doses are too high for too long.

  To mate with a female, a male antechinus must first win fights with other males, and those high stress levels help him get the extra boost of energy he needs to do that. But somewhere in the evolution of antechinuses, the levels of those hormones that males needed to win those fights got out of control. Males suffer kidney failure, ulcers, immune system breakdown, and a whole whack of other problems all because their stress hormone levels are just too high for their bodies to tolerate. By the end of mating season, every male is dead, having lived less than a year.

  In experiments, researchers have tried cutting off the testes of male antechinuses, and those castrated males survive the mating season without any problems at all. That’s the trade
-off in a nutshell: if you want to mate, you’re going to have to do things that shorten your life. If the male antechinus meat robots were in control, they would skip the stress of sex to live as long as possible, but it’s their DNA behind the wheel, so the meat robots don’t get to make that call.

  A similar self-sacrifice for sex happens to a lot of male spiders, but they don’t die from stress. They’re killed and eaten by females during sex. It’s called female cannibalism, and it happens in many different kinds of spiders. A female spider is almost always a much larger predator than a male, making him pretty much exactly the kind of animal she’d like to eat.IV To have sex with her, a male has to put himself within striking distance—he has no choice about that. So males of some spider species bring food along as a “nuptial gift” when they want to mate. In those cases, the bigger the gift, the longer he gets to mate before she eats him, and the more of her eggs will be his.V That’s a great system for a male when it’s available, but most spider species don’t exchange those gifts, leaving many male spiders out there no other option than to roll the dice and just hope the female isn’t hungry.

  One species of spider with female cannibalism is an orb-weaving spider called Nephilengys, but males of that species have evolved a survival strategy different from gift giving. Instead, they rip off their own penises mid-mating.

  Well, truth be told, it’s not really a penis. It’s called a palp. And it’s not just one palp; he has two of them. And they’re on the sides of his head. Anyway, like any male spider, he mates with a female by inserting his palps into holes in her abdomen and pumping sperm into her. But partway through the mating process, the male Nephilengys spider pulls a quick one on her: he rips off his palps, leaves them sticking into her abdomen, and makes a break for it. He doesn’t always escape—male survival rates are only about 25 percent—but even if she catches and eats him, his palps will keep on pumping sperm into her while she’s distracted by the meal. It’s not the cleanest strategy in the world, but it works.

  If, by some great stroke of luck, the male does manage to escape, things get even more interesting. Now castrated, he waits just beyond the female’s reach for any oncoming males with thoughts of romance. Should a male approach, the castrated male fights the intact intruder as aggressively as he can. Since he’ll never be able to reproduce again, his DNA’s only hope of being passed on lies with the female he just escaped. For his DNA’s sake, the best strategy now is to prevent any other males from mating with her. That way the eggs she lays will carry his DNA, not someone else’s.

  It didn’t take long for researchers looking at these spiders to notice that when fights happened between a castrated male and an intact male, the injured spider almost always won. This made them wonder whether there is something about having his genitals cut off that gives a spider a boost. So they did experiments chasing spiders around a table with paintbrushes until the spiders collapsed from exhaustion. Surprisingly, the researchers found that castrated males had 80 percent higher endurance than intact males. It seems that spiders with their palps intact have the instinct to give up early, since perhaps another female might be available elsewhere. The castrated male doesn’t have other options, so he fights with everything he’s got.2

  Human males have their lives cut short by sex too. Most don’t die from the stress of mating itself, and most aren’t killed and eaten by their female sex partners, but they still pay a price. Specifically, it turns out that for humans, just having male sex hormones in the body shortens life expectancy. Evidence of this effect comes from some fascinating data on castrated men from eighteenth- and nineteenth-century Korea.3 Back then, powerful men with harems would sometimes adopt eunuchs to work as guards or laborers. These men, who were castrated before puberty, were convenient employees to the emperors since they could do the manual labor but wouldn’t try to have sex with women in the house. The eunuchs were perfectly healthy, but they had no testicles, and since testicles are the part of the body that produces testosterone, the eunuchs lived their otherwise normal lives without that hormone in their bodies.

  Here’s the evidence that human men live shorter lives than they would without sex: when you compare eunuchs to intact males of similar socioeconomic status in that same society, the eunuchs lived fifteen to nineteen years longer on average, typically into their seventies. Laborers with their testicles in place were living into their late fifties, whereas one of the eunuchs lived to be 109! This difference, coupled with the fact that females usually live longer than males anyway, strongly suggests that human males have their lifespans cut short by testosterone. Since you can’t make sperm without testosterone, you could say that human males have their lives cut short by sex.

  And as bad as it is for human males, they’ve got nothing on females of the species. Females can’t pass on their DNA without going through pregnancy and childbirth, and although human childbirth is a beautiful and life-changing event, it’s as dangerous as hell.

  In North America, the odds that a fifteen-year-old girl will go on to die from a maternal cause (pregnancy, childbirth, or a failed abortion) is just one in 3,800, but those fantastic odds are due largely to the availability of modern medicine.4 I’m talking about the basics, things like blood pressure monitoring before birth, sterile procedures during birth to avoid infections, antibiotics if infections do occur, and basic drugs to speed up clotting in case a mother bleeds too heavily after the baby’s born. Those simple things improve a woman’s odds of survival a great deal compared to what they are without medicine. As evidence, you can just look at places where those tools aren’t available. The odds of a fifteen-year-old girl in sub-Saharan Africa dying from a pregnancy, childbirth, or a failed abortion at some point in her life is 1 in 150. At first, those better-than-99-percent odds might seem decent, but they’re twenty-five times worse than the North American odds, and when you’re talking about millions of women, those maternal deaths add up very quickly.VI

  Take a moment to think about where you were twenty-four hours ago. Really do this. Stop reading, look at a clock, and figure it out. Think about exactly where you were and what you were doing.

  Got it?

  Since that moment, roughly eight hundred women have died painful and tragic deaths from pregnancy, childbirth, or a failed abortion, and more than 95 percent of those deaths would have been prevented by access to basic modern medicine. That happens every day, and those numbers are a concrete reminder that there’s no Mother Nature looking after us.VII

  We’re animals, and as with other animals, our bodies reflect a trade-off between survival and reproduction. Big-brained humans can compete better than small-brained ones, so the size of the average human baby’s head has reached the very limit of what a mother can handle. If you imagine what childbirth must have been like even just a few generations ago, before painkillers, before antibiotics, nature starts to look pretty rough. Here in the developed world, that can be easy to forget sometimes.

  When my wife, Shelby, and I found out that she was pregnant with Sam, we didn’t even think about the possibility that she might die; we didn’t really have to. If we’d bothered to look it up, we’d have learned that her odds of death were around one-eightieth of a percent. With those odds, we had the luxury to take control of the whole experience. We got to choose from among several options for the childbirth: Shelby could give birth at home or we could go to a hospital; we could have the baby delivered by a midwife or by a doctor; Shelby could use no painkillers at all or have the lower half of her body completely frozen by an epidural. No matter what our decisions, we knew that she and the baby would almost certainly both survive.

  Those decisions, and others like them, were usually presented along a continuum between a “natural childbirth” and a “medicalized childbirth.” Here’s where I want to start challenging your assumptions about sex and nature. Take a moment to think about what defines a “natural” birth. Is it where the baby is born that matters? Is it whether or not drugs are used? Is it who del
ivers the baby that matters? What makes one childbirth more natural than another?

  As Shelby and I got closer and closer to the due date, everyone kept telling us that we could make whatever decisions we wanted, but there was a definite pressure, especially from our friends, to choose the “natural” course wherever possible. People kept saying completely meaningless things like “Women have been having babies for centuries.” (How does that help at all? They’ve been dying in childbirth too!) Worse, several people tried to calm us by saying things like “Nothing should go wrong just so long as Shelby relaxes, gets in touch with her body, and lets things take their natural course.” Or “This is what her body was made for.”

  That is where my issue lies with the entire concept of a natural childbirth.

  If you say, “Things go well when a mother is in touch with her natural self,” you’ve implied that when things go wrong, it might be the woman’s fault for failing to do so. It’s sad enough that more than a quarter of a million women die from maternal causes each year,VIII but to blame even a fraction of them for their own deaths, because they somehow failed to be “natural” enough, is perverse.

  In addition, that hijacking of the word natural puts a woman who does have access to modern technologies in a very difficult position. It erodes her ability to choose what she wants by making certain options at childbirth seem at odds with other decisions in her life. For example, if a woman chooses to eat organic foods, or if she enjoys spending time outside, she may feel pressure to make decisions about childbirth that are also labeled “natural.” Of course, how a baby comes out of you has nothing to do with what you eat or how you exercise, but when things are presented that way, a person can be pushed into a decision that ultimately may not be the best one for them.

  Take epidurals, for example. To say that a woman should be able to handle the pain of childbirth without an epidural because she’s in touch with her natural body seems crazy to me. Giving birth is undoubtedly one of the toughest experiences a human being could ever have, so why should a woman be labeled “unnatural” if she uses modern medicine to help her through? I’m not saying all women should have epidurals. I’m just saying choosing an epidural shouldn’t be seen as some kind of unwomanly act. Labeling an epidural-free childbirth as more “natural” than one with painkillers just isn’t fair. Humans use drugs all the time, for all kinds of reasons, and humans have been using narcotics for centuries. Why is childbirth the only time drugs are suddenly so taboo? My hunch is that it’s because women have epidurals and men don’t. If I have a headache, I take Tylenol, and nobody’s ever called me unnatural for that. Why should a woman facing childbirth suddenly be forced to tough it out?