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University of California Press

Sexual Selections

What We Can and Can’t Learn about Sex from Animals

by Marlene Zuk (Author)
Price: $29.95 / £25.00
Publication Date: Jun 2002
Edition: 1st Edition
Title Details:
Rights: World
Pages: 250
ISBN: 9780520937673

Read an Excerpt

Introduction

An Ode to Witlessness

 

" . . . nature, heartless, witless nature . . ."

A.E. Housman

Shortly after I entered graduate school at the University of Michigan, a fellow student came into my office and flung himself into the chair opposite mine. "I don't understand," he said, "how you can have feminist politics and still be interested in all that stuff over in the museum." The museum was the Museum of Zoology, and the "stuff" to which he referred was the burgeoning field of sociobiology, the study of the evolution of social behavior. It had become a flashpoint for vitriolic debate about the ability of science to draw conclusions about animal behavior in general and human behavior in particular. Both sex, meaning the genetic distinction between male and female, and gender, referring to its social and political associations, were a big part of the controversy from the start. Feminists were quick to recognize that a classic application of biology to oppression had been via the old "anatomy is destiny" route, and sociobiology seemed to some like the same restrictions dressed in trendy new genes.

The debate has taken many turns in the years since; some stereotypes have fallen, and some new perspectives have been achieved. One result of the feminist movement is that many more of the scientific participants are now women. The term "sociobiology" became sufficiently politically laden that it has been abandoned by many scientists, who now tend to call studies of the evolutionary basis of behavior in animals "behavioral ecology" and its counterpart in humans "evolutionary psychology." Yet we are as far as ever from consensus on what feminism and biology have to offer each other and whether—and if so, what—we can legitimately expect to learn about ourselves, particularly about aspects of our sexuality, from studies of nonhuman animal behavior.

I am both a feminist and an evolutionary biologist interested in animal behavior. In my work I am interested in mating behavior and the evolution of sexual characteristics, and I am continually struck with the ways in which our biases about gender influence how we view animal behavior. As a feminist, I advocate the social and political equality of men and women. As an animal behaviorist, I want to learn as much as I can about what the animals I observe are actually doing, and why. In both of these aspects of my identity, I find it impossible to ignore that all of us, scientists, social scientists, and the general public, cannot seem to help relating animal behavior to human behavior. The lens of our own self-interest not only frequently distorts what we see when we look at other animals, it also in important ways determines what we do not see, what we are blind to.

This book is about seeing what animals do. It is about the connections, legitimate and illegitimate, between learning about them and learning about ourselves. It is for those wanting to see how our ideas about sex have helped and hindered our ability to see animals clearly, for those wanting to know about some of the new frontiers in behavioral research, and for those who wonder how we could ever do science without trying to understand our social predisposition. It is for biologists, including those who never thought feminism mattered, and for feminists who always knew it did. I hope to convince you that the natural world is much more interesting and varied than we are often willing to recognize, but that if we try to use animal behavior in a simplistic manner to reflect on human behavior, we will, in myriad ways, misperceive both.

One way we do this is to interpret animal behavior in terms of stereotypical ideas about human society. For example, many feminists have complained about sociobiology's supposed portrayal of females as coy, waiting around for the males to fight it out so they could cheerfully go off with the victor, or at the very least playing hard to get until the sex-mad males had demonstrated which one deserved to win. This image, they claimed, came from outdated and sexist ideas about the nature of women. It is equally true that it is a recipe for being less likely to recognize female assertiveness when it occurs among, say, spiders. The discovery that extra-pair copulations are common in many bird species long thought to be strongly pair-bonded, shocked some scientific observers as well as the public; it seemed somehow not just to reflect on, but even to affect our own dubious potential for being monogamous. We both judge these animals by rules for human behavior and at the same time look to them as role models.

We also relate selectively to animals, feeling closer to the cute, fuzzy ones, and elevating some species—dolphins and other cetaceans and, more recently, bonobos, formerly known as pygmy chimpanzees—to the status of icons. Why do we love some species more than others? Why is any one species worthy of our concern? E.O. Wilson, the founder of sociobiology, calls the human love of nature "biophilia," a term that has caught on to express our emotional attachment to animals, landscapes, and wilderness. He and others argue, I believe correctly, that tapping into these feelings is essential to efforts to preserve biodiversity. But not only do some animals capture our hearts while others do not; our gender stereotypes confuse this connection, and we create a hierarchy of what should be loved and preserved in nature that can deflect our attention from "lower" species worthy of study in their own right, and can also backfire on former icons in which we lose interest.

We can appreciate dolphins without making them into animal Einsteins, and we can use them in our ongoing struggle to understand intelligence without making them rank above or below other animals. The evolutionary tree is not a hierarchy. It is tempting for all of us to view animals with which we share a more recent common ancestor as being just like us. Baboons and even bluebirds can look and act an awful lot like people. A good deal of my own research is done with insects, and one of the reasons I like working with them rather than with vertebrates is that it is harder to see myself reflected in their behavior. Identification and anthropomorphism are more difficult with insects, and that is a good thing. I do not want to study animals only to learn about me, though that may happen along the way. I want to learn about the insects.

What, then, is the relationship between feminism and the study of gender in other animals? What do feminism and biology have to offer each other? I think the answer is complex. On the one hand, many assumptions about male dominance in nature are falling before contemporary research; being aware of science's past tendency to view males as the only interesting organisms allows us to curtail it. But on the other hand, trying to use science to further a feminist agenda does not serve us or other animals well. Seeking examples of liberated animal females is another example of twisting the natural world into an order it does not show. It blinds us to the variety in animal behavior and involves us in a male-versus-female argument that leads nowhere.

What I advocate is not detachment, nor domination, nor the existence of a special relationship of women with nature. Feminism, however, has more to offer biology than biology has to offer feminism. Feminism provides us with tools to use in the examination of ourselves and other species that can, if we apply them carefully, help us to remove ourselves from the center of things and struggle to see past our biases to what animals are doing.

 

The Nature and Nurturing of Sociobiology

The sociobiology controversy, recently expertly analyzed by Ullica Segerstråle in her book Defenders of the Truth, is in important ways still with us, despite changes in terminology. The original debate began in the mid-1970s, with the publication of Wilson's Sociobiology: The New Synthesis . Wilson, an entomologist by training and avocation, specializing in the study of ants, devoted the vast majority of the book to nonhuman animals. The last chapter, however, speculated about the evolution of human sociality and suggested that aspects of human life such as warfare and a sexual division of labor had biological roots. It was this thin layer of concluding material that sparked all the furor among those worried about the misuse of science in the name of social policy. Exactly what Wilson meant by biological roots is open to interpretation, but his detractors thought he opened the door to a host of politically repressive ideas by supporting existing inequities between the races, classes, and sexes.

Proponents on either side have included some of the heaviest hitters in science, among them the paleontologist and evolutionary biologist Stephen Jay Gould of Harvard (just a floor away from Wilson himself) and Richard Dawkins from Oxford. The battle, which originally pitted mainly left-wing intellectuals and social scientists against more genetically oriented traditional scientists, has had connections to many other debates about the political motivations of scientists and the social implications of what they do. The conflict ranged both wide and deep, harking back in time to the accusation that IQ tests were inherently racist as well as reaching into the "Science Wars" between traditional scientists and scholars from the humanities. The potential for a genetic basis for violent crime and the implications for affirmative action programs have also been part of the argument, with critics maintaining that if we are led to believe that genetics dictate behavior, then social programs designed to prevent children from developing criminal behavior, or to compensate for previous discrimination, are destined to fail.

Both sex and gender were a big part of the sociobiology controversy from the start, for several reasons. If, for example, the pattern of women staying home while men went out and hunted/climbed the corporate ladder was linked to our biology, the criticism went, the women's movement was doomed. Just as nineteenth-century physicians and scientists had claimed to find biological evidence for the intellectual inferiority of women, in either purported differences in brain size, the demands of menstruation and childbearing, or muscular frailty, so their modern counterparts seemed to be suggesting that evolutionary tendencies shaped hundreds of thousands of years ago made women coy, uninterested in sex, and unwilling to take risks, whether on the playing field or in the stock market. Numerous feminist theorists, including some scientists, such as Anne Fausto-Sterling, a developmental biologist at Brown University, attacked sociobiology as sexist claptrap thinly veiled as science.

Sex also figures in the debate for the simple reason that sex—simple sex, as well as gender—is an integral part of evolution. Anyone explaining the evolution of behavior, particularly in animals but to an arguable extent in people as well, is mainly concerned with two things: food and sex. Natural selection occurs through the differential reproduction of individuals; variants with better abilities to keep warm, resist disease, and fend off predators will leave more offspring, who in turn can also do these things better, than other variants. Food is important because without it organisms cannot live long enough to reproduce, and sex is important because without it most organisms, by definition, do not reproduce at all. One could argue, in fact, that food is important only in the context of sex, since an animal that successfully locates all the ripe fruit in the forest but fails to mate is an evolutionary dead end.

 

The Power to Charm

This part of sex is, however, only the most obvious reason for its significance in evolutionary biology. The more subtle explanation is called sexual selection, and it was developed as a theory to account for differences between males and females, both morphological and behavioral, that seem removed from the immediate necessities of reproduction. Like the idea of natural selection, sexual selection theory is widely accepted among biologists, and also like natural selection, sexual selection has its origin in the work of Charles Darwin.

When Darwin began to develop his ideas about the origin of species, he distinguished between traits used for survival and those used in acquiring mates. He pointed out that while many animals exhibit extreme traits, in some cases these are found in both sexes and turn out to be beneficial in daily life, like the elongated curved bills of Hawaiian honeycreepers, which are used for probing flowers for nectar. Other extreme traits, though, are sex-limited , and Darwin devoted an entire book, The Descent of Man and Selection in Relation to Sex, published in 1871, to explaining them, noting that many of the characteristics seem actually detrimental to survival. In several of the species of birds of paradise, for instance, the male has ornamental feathers so long or elaborate that they impede his flying ability.

Darwin also distinguished between traits such as these, which are strictly speaking not needed to reproduce, and what he called the primary sexual characters —the plumbing, so to speak, that makes males able to produce sperm and females able to produce and nurture eggs. He figured that a trait allowing a female to put a water-resistant shell around an egg, for example, would be unequivocally beneficial to her, and fit under the general category of natural selection. But what about the other traits, the long tails and bright colors and structures like antlers on deer? Darwin called those traits secondary sexual characters, and noted that in many cases they simply could not seem to have arisen through natural selection. A brightly colored set of feathers or a loud song probably makes a male more conspicuous to predators, and either may be physiologically costly to produce. How could the bearers of the traits been favored by selection over their less elaborated counterparts?

Darwin said that sexual selection, a process similar to but distinct from natural selection, had led to their evolution. The secondary sexual characters could evolve in one of two ways. First, they could be useful to one sex, usually males, in fighting for access to members of the other. Hence, the antlers and horns on male ungulates, like bighorn sheep, or on the aptly named male rhinoceros beetles. These are weapons, and they are advantageous because better fighters get more mates and have more offspring. The second way was more problematic. Darwin noted that females often pay attention to traits like long tails and elaborate plumage during courtship, and he concluded that the traits evolved because the females preferred them. Peahens find males with long tails attractive, just as we do. In one of my favorite passages from The Descent of Man Darwin marvels, "We shall further see, and this could never have been anticipated, that the power to charm the female has been in some few instances more important than the power to conquer other males in battle." The sexual selection process, then, consisted of two components: male-male competition, which results in weapons, and female choice, which results in ornaments.

While competition among males for the rights to mate with a female seemed reasonable enough to Darwin's Victorian contemporaries, virtually none of them could swallow the idea that females—of any species, but especially the so-called dumb animals—could possibly do anything so complex as discriminating between males with slightly different plumage colors. Alfred Russel Wallace, who independently arrived at some of the same conclusions about evolution and natural selection that Darwin did, was particularly vehement in his objections. He, and many others, simply found it absurd that females could make the sort of complex aesthetic decision required by Darwin's theory. After all, according to the thinking of his time, even among humans only those of the upper social classes could appreciate aesthetic things like art and music, so it seemed ridiculous to imagine that animals could do something many humans—particularly non-Englishmen—could not. Several authors have also suggested that because females were not supposed to be interested in sex anyway, the idea that they spent time thinking about it made Victorian scientists uncomfortable. Besides, what would be the point of choosing one male over another? If the only difference between them was the secondary sexual trait, why should the female bother? Wallace scoffed, "A young man, when courting, brushes or curls his hair, and has his moustache, beard or whiskers in perfect order, and no doubt his sweetheart admires them; but this does not prove that she marries him on account of ornaments, still less that hair, beard, whiskers and moustache were developed by the continued preference of the female sex" (p. 286).

Largely because of this opposition to the idea of female choice, sexual selection as a theory lay dormant for several decades. The work of the British geneticist R.A. Fisher was a notable exception, but in general even after genetics became incorporated with Darwin's ideas on evolution to form what is called the New Synthesis, the major evolutionary biologists of the early twentieth century—George Gaylord Simpson, Theodosius Dobzhansky, Robert Ledyard Stebbins, and their contemporaries—were largely uninterested in sexual selection. When they discussed extravagant traits at all, they suggested that these arose to allow females to find a mate of the right species. Choosing a male of a different species could have disastrous consequences, because hybrid offspring, if they can develop at all, are often infertile. In general, variation among individuals was not seen as particularly interesting, so long as reproduction continued.

It was not until the 1960s that evolutionary biologists began to reconsider the portrait they had painted of animal social life. Suddenly, it seemed, people realized that males spent an awful lot of time showing off to females during the breeding season, and it became increasingly hard to believe that all the fuss was made merely so that a female cardinal could tell the difference between a male cardinal and a duck.

It would be interesting to speculate about the social and cultural forces that led scientists to reevaluate their views on sexual behavior. Within the field, however, probably the most important new insight came from a paper written by the evolutionary biologist Robert Trivers about thirty years ago. He pointed out that in many species, females and males inherently differ because of how they put resources and effort into the next generation. Females are limited by the number of offspring they can successfully produce and rear. Because they are the sex that supplies the nutrient-rich egg, and often the sex that cares for the young, they have an upper limit set at a relatively low number. They leave the most genes in the next generation by having the highest quality young they can. Which male they mate with can be very important, because a mistake in the form of poor genes or no help with the young can mean that they have lost their whole breeding effort for an entire year. Males, on the other hand, can leave the most genes in the next generation by fertilizing as many females as possible. Because each mating requires relatively little investment from him, a male that mates with many females sires many more young than a male mating with only one female. Hence, males are expected to compete among themselves for access to females, and females are expected to be choosy, and to mate with the best possible male they can.

This, of course, should sound familiar: it is the same division of sexual selection that Darwin originally proposed. But Trivers not only gave it a new rationale. What he did in addition was to bring female choice back to the forefront of sexual selection, and suggest a more modern underlying advantage to it—even though he and others often referred to females as "coy," with the implication that the impetus for sex came largely from males, who fought among themselves to get to the females and allow the choices to occur. Furthermore, ideas about the evolution of behavior had advanced enough that scientists no longer worried about an "aesthetic sense" in animals; it didn't matter how females recognized particular males, just that if they did, and it was beneficial, the genes associated with the trait females were attracted to would become more common in the population than the genes of less-preferred traits. Evolutionary biologists, therefore, could ignore questions about motivation and get to the more testable issue of how discrimination among males might result in the evolution of ornamental traits that did not function either in day-to-day life or in male combat. Female choice made sense.

Current work on female behavior in many species of animals has confirmed Trivers's—and Darwin's—basic idea about female preference for particular types of males being a major force in evolution. Again and again, females have been shown to be able to distinguish small differences among available mates, and to prefer to mate with those individuals bearing the most exaggerated characters. In some cases those males are also more healthy and vigorous, so that ornaments appear to indicate not just attractiveness but the ability to survive. Peacocks, often used as the symbol of sexual selection, provide one of the best-known examples. The British biologist Marion Petrie studied the behavior of flocks of peafowl that were allowed to range freely in a park in England. She discovered that females did indeed prefer males with greater numbers of eyespots on their tail feathers, and that this preference could be manipulated by cutting the eyespots off of some males' tails; females lost interest in the pruned peacocks and became attracted to the untrimmed ones. Even more interesting, she allowed females to mate with males that had variable numbers of eyespots, and then reared all the offspring in communal incubators to control for differences in maternal care. The chicks fathered by the more ornamented males weighed more than the other chicks, an attribute usually connected with better survival in birds. Indeed, when the individually marked chicks were then released into the park and recaptured the following year, the ones with the more attractive fathers also were found to be more likely to evade predators and survive in the semi-natural conditions.

Not all cases are so satisfyingly clear-cut, but modern biologists accept female choice as an important part of sexual selection . What about the accompanying notion that females were therefore coy, uninterested in sexual activity unless it was initiated by the ever-eager males? This has not fared so well. Evidence from insects, birds, primates and other organisms has contradicted the idea of the passive female and suggests instead that females often mate many times, with many different males. Nevertheless, the basic principle that males are limited by the number of eggs they can fertilize (which can potentially be very high) while females are limited by the number of offspring they can produce and, if necessary, rear (which is potentially relatively low), is a general one that leads to differences between the sexes. Sometimes, if males invest a great deal in offspring along with females, these differences will be quite small; sometimes they will be quite large. How the differences are interpreted is another story, and one that forms the basis for this book.

 

Genes: Selfish, Sexy, or Misunderstood?

Sexual selection research has become one of the hottest areas in evolutionary and behavioral biology. Scientists have found enormous variation in Darwin's original scheme, with both males and females behaving in ways that go far beyond Victorian stereotypes. The field has never been without its critics, however, and the criticisms have been made on both social and scientific grounds, with the distinction between the two often blurring. These criticisms were in part what led to my fellow graduate student's assumption that my feminism and my science must necessarily be at odds.

I have never found any basic conflict between my belief in sexual egalitarianism and my interest in sexual behavior among animals, including my endorsement of the theory of sexual selection. Whatever Darwin's personal views on women, he had managed to hit on an enduring concept in biology that has not appeared to depend on one's political views to hold up.

How, then, do feminism and attempts to use evolutionary theory to explain behavior interact? As I mentioned above, one immediate reaction from some was that so-called biological explanations have so often been used to justify unequal treatment of groups, including males and females, that any new efforts should be viewed with suspicion. The critics focused particularly on efforts to apply evolutionary theory to human behavior, but all links between behavior and selection were often seen as tarred with the same brush. Here I will briefly discuss some of the common misconceptions about evolution and behavior as they apply to the controversy.

First, many people are leery of the apparent consciousness attributed to animals and, at times, their genes, during the process of evolution. The idea of female "choice" still suggests a conscious weighing of alternatives, an idea that seems anthropomorphic at best and idiotic at worst when applied to animals, particularly invertebrates, such as insects, which lack sophisticated brain components traditionally associated with decision-making in humans. Even for humans, the idea has been called into question for social reasons; Segerstråle notes (p. 172) that the anthropologist Edmund Leach decried "this curious idea that by and large individuals can somehow choose their mates! In most of the world they can't! Their love affairs are different from their marriages. Their marriages are arranged by their seniors for political reasons."

For evolutionary biologists, however, the process is not as important as the consequences. Selection acts only indirectly on mechanisms, if it can be said to act upon them at all. If we can show a relationship between a trait and a female tendency to mate with those bearing it, sexual selection may be operating. If female beetles, when presented with one male bearing two spots on his back and one with four spots, are more likely to mate with the four-spotted variety, more baby beetles that develop four spots as adults will result. Two-spotted beetles will become less frequent in the population, and, on the assumption that spottiness has no relation to survival, sexual selection via female choice will have caused the evolution of a secondary sexual character, spot number. Although it would be interesting to know the mechanism by which females discriminate among prospective mates, and this has relevance for formulating some models of preference, it does not matter for the sheer demonstration of female choice what went on in the nervous system of the female, much less that she is incapable of formulating a rational thought. Even with humans, what goes on in the mind is often less significant than what results from the behavior. This is not to suggest that studying sexual selection in either humans or animals, but particularly the former, is without problems. We need not, however, confuse conscious decisions with evolutionary outcomes.

The next misconception concerns the related specter that then rears its head: the nature of genetic differences in behavior, a necessary precursor for selection to act on those differences. What does it mean for a behavior to "be genetic"? Does it mean that possession of a particular form of a gene always leads to the execution of a particular behavior? Does it mean merely that the potential for the behavior is there? Here the relationship between mechanism—getting from genes that produce proteins to a response in the nervous system to a stimulus—and consequence, perhaps changes in fertility or attraction to mates of a certain type, is even more difficult. We have known for many years that genetic differences alter behavior, even fairly complex behavior, and most medical practitioners now recognize, for example, that many mental illnesses have a genetic component. Yet the field of behavior genetics, even as applied to nonhumans, has had an uneasy history, haunted by the eugenics movement, unable to shake the accusation of genetic determinism, of suggesting that if genes influence behavior, they must perforce dictate behavior. This is a misconception about the way genes interact with their environment to produce a trait. One misunderstanding has led to another, as the notion of genes dictating behavior segues into what is called the "naturalistic fallacy," the idea that what is natural is good, so if behavior is genetic, and genes are part of our nature, then we can all give up on trying to change the world into a more just place. Finally, arguments have raged about whether such traits as homosexuality or altruism are "genetic or learned," "innate or culturally determined," due to "nature or nurture."

I discuss the inherent problems with the nature-nurture dichotomy in Chapter 3, in the context of the maternal instinct. Suffice it to say here that all behaviors are the result of genes, developmental conditions during embryonic life, and the subsequent environment in which the organism finds itself. If two genetically identical organisms experience different environments, and exhibit two different manifestations of a behavior, one can conclude that the difference is due to the environment. Conversely, if two genetically dissimilar individuals experience the exact same environment, and still show differences in behavior, one can conclude that genes cause the difference. What can be said to be genetic or learned is a difference in a trait, and not the trait as such. Difficulties with actually putting this distinction to a test notwithstanding, it points up the absurdity of arguing over which part of a behavior, whether it is hole-drilling in woodpeckers or homosexuality in humans, is innate or cultural. This is not to say that we can airily dismiss concerns over the influence of the environment and assert that genes are the only subject of interest, any more than we can say that all human behavior is cultural and hence evolution is of little relevance.

Nowhere is this unease about genetic explanations of behavior more apparent than in attempts to explicitly account for the evolution of how we humans behave. Some critics, not just of sociobiology but of scientific approaches to human biology in general, have objected to the idea that people, with our flexible behavior patterns and extensive period of childhood learning, could be considered as just another species. One found such an assumption "arrogant," which is a curious reversal of the more frequent suggestion that it is special pleading to argue that humans have a separate exalted place in nature. Others simply find social and sexual behavior—sometimes all such behavior, sometimes only when it occurs in humans—to be so complex that we cannot ever guess its trajectory through evolutionary time.

My own concern with this problem of humans being "special" takes us back to the sociobiology controversy and feminism. I am perfectly ready to accept that humans are subject to selection in the same way as other organisms, which places me squarely in the sociobiology camp. On the other hand, I recognize that self-awareness, which is so highly evolved in humans, necessarily complicates matters. If one agrees that evolution affects our behavior, then one must surely also agree that evolution influences how we view ourselves, a catch-22 if ever there was one. Self-consciousness allows us to examine our behaviors (as well as those of other animals), but the way we interpret those behaviors influences our abilities to see them clearly.

It is not news that humans selectively look at the world, both their own and that of other organisms. One of the great contributions of the science of animal behavior has been to point out the dangers of such selectivity, particularly when combined with anthropomorphism. A favorite example of mine which illustrates the problem comes from E.L. Thorndike, an animal psychologist at the turn of the twentieth century who formalized the systematic, experimental study of behavior. In a monograph published in 1898, he rather peevishly took to task previous attempts to examine the mental processes of nonhumans. He wrote:

In the first place, most of the books do not give us a psychology, but rather a eulogy, of animals. They have all been about animal intelligence, never about animal stupidity. . . . In the second place the facts have generally been derived from anecdotes. . . . Besides commonly misstating what facts they report, they report only such facts as show the animal at his best. Dogs get lost hundreds of times and no one ever notices it or sends an account of it to a scientific magazine. But let one find his way from Brooklyn to Yonkers and the fact immediately becomes a circulating anecdote. Thousands of cats on thousands of occasions sit helplessly yowling, and no one takes thought of it or writes to his friend, the professor; but let one cat claw at the knob of a door supposedly as a signal to be let out, and straightway this cat becomes the representative of the cat-mind in all the books.
This problem has of course persisted in science, and I will explore its ramifications as they pertain to sexual behavior in several of the following chapters. In the meantime, Thorndike's complaint can quite easily be reworded to reflect ideas about sex roles; if, for example, someone finds that female rabbits or tortoises or houseflies are less active than males, this reinforces stereotypes about passive females, whereas if they discover the reverse, less notice is taken. Furthermore, people may be less likely to notice behavior in the first place if it contradicts a stereotype. As the psychologist Virginia Valian has pointed out, we interpret what we see in terms of "gender schema," ideas about what the sexes are like, physically, mentally, and emotionally. If men are generally viewed as tall, we see them as tall, and tests show that people overestimate height of men and underestimate that of women. If men are generally viewed as capable and authoritative, we will see them that way, too, whereas if women are stereotyped as submissive and incompetent, we will tend to judge them that way even given evidence to the contrary. The result has obvious implications for practical issues like the salaries of men and women in the same occupation, but it also colors our ability to interpret or even detect the behavior of other species as well as humans.

Does rejecting such stereotypes mean rejecting evolutionary explanations of behavior? I do not believe it does. The question is not whether we accept biological explanations or reject them, it is how much and in what ways the explanations suffer from our biases.

 

Witless Nature

According to Segerstråle, both E.O. Wilson and Konrad Lorenz, the Nobel Prize-winning ethologist who developed the notion of young imprinting on their parents, were proponents of the naturalistic fallacy, that what is natural is good. Both felt that universal laws about morality in human behavior arose from the working of nature. Both were concerned that inattention to our evolutionary history could contribute to nuclear war or other catastrophes. This attitude does not, however, automatically arise from an evolutionary perspective on behavior. It is also true that examining nature with an eye toward our human tendency to force it to say certain things can be enlightening all by itself.

A way out of the dilemma concerning the relationship of stereotypes and evolutionary explanations of behavior simultaneously provides a solution to the naturalistic fallacy. It is perhaps best stated in a poem by A.E. Housman, an early twentieth-century Englishman described as a "Romantic pessimist" who is often read in high school literature classes but does not usually serve as a source for information about philosophy of science. The poem, from his Last Poems, is in many ways a celebration of knowing nature, of seeing:

Where over elmy plains the highway
Would mount the hills and shine,
And full of shade the pillared forest
Would murmur and be mine.
It ends with a verse that summarizes a remarkably evolutionary view of the world:

For nature, heartless, witless nature,
Will neither care nor know
What stranger's feet may find the meadow
And trespass there and go,
Nor ask amid the dews of morning
If they are mine or no.
Nature, as he says, is witless. It is not kind, not cruel, not red in tooth and claw, nor benign in its ministrations. It is utterly, absolutely impartial. I myself take this in the most positive possible way, finding it restful that the world comes without an agenda. This does not mean we cannot have our own agendas, just that we cannot claim that ours has been lifted from some higher outside source. Further, witlessness is not at all the same thing as stupidity. It simply suggests that we cannot expect to find a user's manual accompanying the actions of animals. What is natural can't be inherently "good" any more than it can be inherently amusing, or inherently painful. Finding out that some animals kill their young says no more about the ethics of infanticide than finding out that some animals are yellow says about fashion trends.

Witlessness can, however, be extraordinarily illuminating. When we begin to understand the details of animals' lives, the ways in which we have been trying to make generalizations about behavior, about sex roles as well as selfishness, suddenly seems peculiar and useless. It is as if we were embarking for a space station with elaborate plans for improving the design of a sailing vessel or, perhaps, as if we were blasting off with plans for improving soufflés. Nature does not provide object lessons so much as challenges to our assumptions. This is not to say that we can never generalize, because science relies on generality, but that the generalizations need to come from a wider base. To answer my graduate student friend, I can do what I do because nature is witless, in the sense of being impartial. Feminist points of view can help us look at science from a different angle, but they will never be able to change nature, something for which we can all be grateful.

In this book I try to show that although looking at nature can result in different interpretations, this does not mean that all attempts to study the world are just culturally derived exercises relevant only in a certain social context, the way some philosophers and social scientists might have us believe. It is nonetheless true that we and our culture and our history throw up different kinds of barriers to seeing clearly, especially where sex and gender are concerned. How can feminism help? It can give us some tools to use in the examination.

The chapters in Part I examine various sorts of biases with which we often color the world we are looking at and ask in what ways a feminist perspective might make things appear otherwise. Here I am concerned with how stereotypes distort the questions we ask as well as how we answer them. Feminists have identified several ways in which scientists, by taking males as the norm, have limited our views of what females do, and I explore these. Male bias, however, is far from the whole story, and some attempts to counter it lead in unfruitful directions. I therefore also examine useful and nonuseful modes of attacking stereotypes.

Part II is concerned with myths that, on a deeper level than biases, prevent us from seeing what animals do. The principal issue here is that of the scala naturae, the hierarchical view of the natural world, and particularly the animal world, that has long been deeply embedded in Western thought and still informs many aspects of our ways of thinking. The history of how humans have viewed our place in nature comes with baggage that we barely realize we have. Spinning off from it are myths that blind us in more particular ways—about kinship, about communication, about dominance—and here too I ask how turning a feminist light on the inquiry can improve our vision.

Part III specifically takes up four aspects of human behavior—female orgasm, menstruation, homosexuality, and spatial ability—and explores their relationship to evolution, asking whether or to what extent they represent adaptations, as opposed to by-products of selection for some other process, or what we can say about how and why they developed. I examine a range of views as to their possible adaptive significance and the state of research into parallel behaviors—and the lack of them—in nonhuman animals, attempting to assess what we can learn about ourselves from these findings and what is likely to lead us into blind alleys.

The final chapter describes some of the ways animal behavior can be misused in discussions of gender by both "sides" of the battle of the sexes. Though I believe that feminism has more to say to biology than biology does to feminism, I conclude by discussing the role of biology in understanding sex differences and similarities, and suggest that biology can extend the boundaries of our thinking about gender as it can for so many other ideas. Contrary to popular belief, biology does not set limits, it demolishes them.

About the Book

Scientific discoveries about the animal kingdom fuel ideological battles on many fronts, especially battles about sex and gender. We now know that male marmosets help take care of their offspring. Is this heartening news for today's stay-at-home dads? Recent studies show that many female birds once thought to be monogamous actually have chicks that are fathered outside the primary breeding pair. Does this information spell doom for traditional marriages? And bonobo apes take part in female-female sexual encounters. Does this mean that human homosexuality is natural? This highly provocative book clearly shows that these are the wrong kinds of questions to ask about animal behavior. Marlene Zuk, a respected biologist and a feminist, gives an eye-opening tour of some of the latest developments in our knowledge of animal sexuality and evolutionary biology. Sexual Selections exposes the anthropomorphism and gender politics that have colored our understanding of the natural world and shows how feminism can help move us away from our ideological biases.

As she tells many amazing stories about animal behavior--whether of birds and apes or of rats and cockroaches--Zuk takes us to the places where our ideas about nature, gender, and culture collide. Writing in an engaging, conversational style, she discusses such politically charged topics as motherhood, the genetic basis for adultery, the female orgasm, menstruation, and homosexuality. She shows how feminism can give us the tools to examine sensitive issues such as these and to enhance our understanding of the natural world if we avoid using research to champion a feminist agenda and avoid using animals as ideological weapons.

Zuk passionately asks us to learn to see the animal world on its own terms, with its splendid array of diversity and variation. This knowledge will give us a better understanding of animals and can ultimately change our assumptions about what is natural, normal, and even possible.

About the Author

Marlene Zuk is Professor of Biology at the University of California, Riverside, and coeditor, with J.E. Loye, of Bird-Parasite Interactions: Ecology, Evolution, and Behaviour (1991).

Table of Contents

Acknowledgments
Note on Species Names
Introduction: An Ode to Witlessness

Part One. Sexual Stereotypes and the Biases That Bind
1. Sex and the Death of a Loon
2. Substitute Stereotypes: The Myth of the Ecofeminist Animal
3. Selfless Motherhood and Other Unnatural Acts
4. DNA and the Meaning of Marriage
5. The Care and Management of Sperm

Part Two. Unnatural Myths
6. Sex and the Scala Naturae (or, Worms in the Gutter)
7. Bonobos: Dolphins of the New Millennium
8. The Alpha Chicken

Part Three. Human Evolutionary Perspectives
9. Soccer, Adaptation, and Orgasms
10. Sacred or Cellular: The Meaning of Menstruation
11. That’s Not Sex, They’re Just Glad to See Each Other
12. Can Voles Do Math?
Conclusion: Unnatural Boundaries
Selected Readings
References
Index

Reviews

“An engaging, highly readable, and thought-provoking book.”
Red Nova
“Writing in an engaging, coversational style.”
Coastlines
"Zuk's analogies are better than anyone's—pithy, insightful, and funny. Who said feminists lack humor? Zuk made me laugh with deep pleasure more than once, as she reviewed the lessons of feminism for our understanding of non-human animals. Her main point—that studying the lives of non-humans should not be for the lessons they seem to provide for our political purposes, but for the pleasure of knowing nature on its own terms—will be compelling reading for all naturalists, feminists and not-feminists alike."—Patricia Adair Gowaty, editor of Feminism and Evolutionary Biology

"Marlene Zuk uniquely combines a great breadth of knowledge about the behavior of animals with an ability to challenge conventional wisdom. She also writes with a graceful style and a mischievous wit. The result is a bold, fresh and feminist book about how our sex lives evolved."—Matt Ridley, author of Genome

"This is an engaging and much needed book, which I hope will be widely read."—Sarah Blaffer Hrdy, author of Mother Nature: Maternal Instincts and How They Shape the Human Species