Marlene Zuk has the ability, all too rare among evolutionary biologists, to look at a snake orgy, or a battle to the death between female bluebirds, or a troop of baboons jockeying for social status, without crying, "It's our story exactly!"
As an evolutionary biologist and a feminist, Zuk says that while each discipline can shed light on the other, feminism "has more to offer biology than biology has to offer feminism." Feminism, after all, can help biologists identify their biases so they can study animal behavior more objectively, whereas in evolutionary biology it seems to be all too easy to go species-shopping for a comparison that will "prove" that women are naturally good with children, or that men are naturally good with howitzers, or that we're designed for polygamy, or that someone else should do the dishes. This kind of selective comparison is particularly common when it comes to matters of sex and sexuality.
Among the subjects Zuk discusses in this spirit are homosexuality in animals, infidelity in apparently monogamous animals, the evolution of the female orgasm, why bonobos have replaced dolphins as the Cool Species We Can Learn From, the evolutionary significance of menstruation, sexual stereotyping, the "myth of the ecofeminist animal," maternal instinct, the zany things animals do with sperm, the alleged Great Chain of Being, the dogmas of dominance hierarchies, and sex differences in math ability.
Zuk herself does much of her research with insects, in part because it is so much easier not to identify with their behavior and indulge in anthropomorphism than it is with chimpanzees, dolphins or other vertebrates.
In her discussion of homosexual behavior in animals, Zuk describes studying crickets and locating males in the grass by listening for their courtship songs. With any luck, she notes, she can find two crickets at a time by this method: the singing male and the object of his serenade, usually a female cricket. In the past, if she found a courting male with another male, she assumed that it was a case of mistaken identity. After reading Bruce Bagemihl's work compiling reports of homosexual behavior in a wide variety of birds and animals, she says, she is not so sure. Perhaps it should be considered homosexuality --- but what does that mean to a cricket? Can we really make the parallel? What about the times when she finds a courting cricket next to a leaf or twig? "Do we call that fetishism?"
An aside: In the spirit of full disclosure, I note that on this subject Zuk quotes a book review by this author, which appeared in this publication. In order to avoid the appearance of cronyism or logrolling I feel the need to insert a savage attack on Zuk at this point: The woman is unsound on the subject of earwigs. She admits to considering earwigs "cute and interesting" and to trying -- unsuccessfully -- to convert her students to this view. Had she ever planted tender lupine seedlings in her garden only to find them hideously chewed up in the morning, and had she gone out in the night to inspect her seedlings by flashlight in a frenzy of grief and concern, only to find earwigs stationed at the tip of each leaflet, remorselessly slashing at the delicate green flesh, I do not think the first word from her lips would have been "cute!" This is classic ivory-tower analysis, unmindful of ground truths the rest of us know from bitter experience. I concede that a mother earwig curled on her eggs is not without a certain charm --- until you consider the sap-splattered career that brought her to this point and the similar destiny of destruction that, when they hatch out, awaits the teeny-tiny miniature earwiglets.
Then there's the little matter of infidelity -- rather, "extra-pair copulations" -- in many species of birds hitherto thought to cleave only unto one another. Zuk writes that the fact that this happens pretty often upsets her students more than any other material covered in the class. Fuzzy animals eating their fuzzy babies, ghastly flesh-eating parasites, close-up photos of earwigs -- apparently none of these is as upsetting as the news that Betty and Billy Bluebird might be indulging in quickies with Jimmy and Jessie Bluebird.
But as Zuk tries to convince her students, "It isn't cheating if there are no rules to break." It's only in cartoons that Betty and Billy stand up before Judge Bluebird or Reverend Bluebird to say their vows. Zuk criticizes the fact that not only the popular press, but also some scientific articles, use terms like "illegitimate" or "wife-sharing." In one example, researchers refer to "female promiscuity" in red-winged blackbirds despite the fact that the females could not have been tangoing alone.
"[T]hese are our categories, not theirs ..." she points out, as her students vibrate in distress.
Zuk's students apparently feel better about her lectures when she mentions bonobos and their sex-packed lifestyle than they do when she's telling them about earwigs or imperfectly monogamous songbirds. In fact, they are riveted by the subject, and Zuk includes a selection of amusing student answers from a quiz given following a lecture in which a mere three minutes (out of 50) were devoted to the Bonobo Way. She notes that the student who wrote about bonobos "fornicating" didn't get the word from her. The sex lives of bonobos, she says, explains why they have more or less replaced dolphins as icons of nature's goodness, and argues that it was ironic that during the era of the Summer of Love advocates of sexual revolution were "championing creatures with invisible genitals."
One of the key issues of sexual revolution, female orgasm, while subject to the analyses of evolutionary biology, is relatively free of animal models, because so little is known about it. We may assume that female bonobos or macaques have orgasms, judging by their behavior, but this is subject to what about that scene in "When Harry Met Sally"? criticisms, among others. So arguments on this subject focus on our own species.
Why do women have orgasms and, if they must have them, why aren't they more -- reliable? You know, like the ones men have?
Why would anyone wonder why women have orgasms? Isn't it obvious that in both women and men, orgasms function as rewards for having sex, which, one should keep in mind, has a spooky tendency to lead to having babies, which leads to perpetuation of the species?
The reason people wonder -- OK, the reason some male scientists wonder -- is that the female orgasm is notoriously different from the male orgasm. More elusive. To some. From this dreadful observation, "... it is a small leap to the conclusion that if females differ from males in their sexual response, they have a problem," writes Zuk.
The late Stephen Jay Gould, among others, argued that the only reason women even have orgasms is that men do, and we're related. In other words, women have clitorises for the same reason men have nipples -- the organ is adaptive in one sex, and the other sex gets a watered-down version as a developmental accident. On the way to crafting a penis, the genes create the clitoris but then, noticing that the embryo is female, abandon the project.
Many women have found this lucky slopover argument annoying. But evolution has given us lots of annoying stuff -- you know, one-way knee joints, the vermiform appendix, no redundancy in the esophagus, thus enabling us to choke to death on the silliest stuff -- so that doesn't prove it isn't so.
But Zuk cites primatologist Sarah Blaffer Hrdy's observation that the clitorises of female primates of different species do not seem to mirror the penises of the same species, in size, shape or placement. In fact both are extremely variable, but not in similar ways. "This does not seem like a case of the clitoris demurely following where the penis has led, evolutionarily speaking," writes Zuk. (See? Annoyed.)
Biologist John Alcock argues the view that the female orgasm is indeed an adaptation in its own right. The fact that it does not result from heterosexual intercourse as reliably as the male orgasm means that women will be inclined to seek better lovers, whose consideration will make them good partners in other ways. "Presumably along the lines of, 'If he makes sure I enjoy sex and have an orgasm he'll be more likely to take the kids to Little League'" writes Zuk, apparently not wholly convinced.
"Why is it less 'efficient' for women to have orgasms before, after and not always during intercourse? Why do they have to have one (or more) every single time a man does? And most of all, why is it such a problem for penis-in-vagina intercourse not to reliably result in orgasms for all women, all of the time?" queries Zuk. She quotes psychologist Carole Wade's sports metaphor: "Sex is not a soccer game. The use of hands is permitted."
"This situation does not appear to be a devastating defect for many women or their partners, but it has distressed numerous biologists," Zuk notes. "It is as though they were concerned mainly with sex for amputees."
Zuk discusses some of the other theories about female orgasm (the more elusive it is, the harder you hunt for it; the longer she lies there in a happy daze, the more likely it is that sperm can get to the egg) and notes how little information we have, not only about orgasm, but even about desire in females of other species. Pigs, for example. I know you've wondered about pigs. Researchers studying female sexual desire in animals usually look for two things, it seems: "cooperation" and "immobilization." Zuk quotes Kim Wallen, author of "The Evolution of Female Sexual Desire," on the pig issue: "Placing a boar's saliva on the snout of an estrous sow produces an immobilization reaction so strong that a human can sit astride her without producing an escape response," and adds austerely that "while this certainly seems as if it would be an endless source of amusement in research facilities, we are left not really knowing what females feel."
There are real difficulties in such research, however, and Zuk writes that it seems meaningless to attempt to monitor sexual arousal in a spider, for example.
But she has one question she'd like answered. "Why do men have orgasms?" Given that men don't have to be pregnant, give birth or breast-feed, to name a few advantages, it seems to Zuk that women are the ones who need a big motivator to have sex, not men.
She notes that assessments of relative sexual desire -- where it is again often assumed that men want it more than women do -- need to be taken in social context, and makes the comparison of the desire for food. The usefulness of hunger is pretty clear and there is no reason to suppose that avoiding starvation and getting adequate nutrition were unimportant to females in the course of evolution. "The fact that many Western women are dieting or have psychological problems about eating does not in the least suggest that males and females are selected to respond to hunger differently. Should we conclude that women have a less intense physical hunger drive than men?"
Zuk has fun with her chapter on the evolutionary significance of menstruation, mocking both the biologist who wrote that the phenomenon of menstruation has "worried man since early times" and writers who treat menstruation as a spiritual phenomenon putting women in touch with the earth/matriarchy/goddesses/dragons. With rationalist glee she cites the work of anthropologists debunking the image of the "menstrual hut" found among some preindustrial peoples as a place for women, free of their daily chores, to kick back, relax, and bond with one another, a sort of Club Red.
In fact, Beverly Strassmann's studies of the Dogon farming people of Mali found that although women don't have to cook for their husbands while staying in the hut, they're still expected to work in the fields; that women say the huts are boring and confining and they don't want to go there, but their husbands insist; that women's use of the huts is determined by their husbands' religious beliefs, not their own; and that perhaps a main function of the huts is to allow men to monitor the reproductive condition of women and know when they conceive.
Evolutionary biology's analyses of female orgasm and menstruation are the exception, in that they are not heavily reliant on animal models. Most sociobiological analyses of human behavior make extensive use of comparisons to other species of animals, like the polygynous male meadow vole, with his great math skills and giant hippocampus and the monogamous prairie voles, with their unisex hippocampus. But when it comes to humans, "Men are far more like women than they are like voles, even male voles," Zuk writes. "This statement seems to require much more vigorous assertion than one might think, perhaps because we are often so intent on scrutinizing the world for differences that support our biases."
Beyond the wish to compare humans to other species, Zuk is bemused by people's attitudes toward different species of animals. She describes an incident when, while working at a Southern California museum in the 1970s, someone brought in a dying loon. The loon died in the arms of the would-be rescuer, who identified himself as Wing Bamboo. Persuaded by Zuk to leave the loon's body behind to become a museum specimen, Bamboo bade it farewell, saying, "Goodbye, Brother Loon." She wondered, she says, why he claimed kinship with a bird he knew nothing about -- she had to tell him its species -- and "why 'brother' and not 'sister'?"
Later in the book she grumbles about the unlikelihood that Wing Bamboo would have made the same effort for Brother Earwig. It seems that we must be careful when thinking about animals, even when we are not consciously making a comparison.
In short, there are serious limits to what we can learn about our own behavior from studying animal behavior. Zuk doesn't see this as a problem, since she's interested in animals (even earwigs) for their own sakes, and finds it restful to look at nature without an agenda. Not only that, "we should not be using animals to guide our ethics in the first place, regardless of which side of the social or political fence we prefer."
Looking at an orgiastic writhing ball of mating snakes, and pondering the fact that female adders mate with many males, Zuk does not conclude that all males are beasts nor that we must reclaim the female as sexually empowered earth-goddess, but that animals are interesting to study and that not all stories have morals. "Sometimes ... snake sex is only about sex in snakes."