Evolution's Rainbow. Joan Roughgarden
in a cacophonous cellular democracy.
I studied how some cultures value transgender people, found where in the Bible transgender people occur, and learned that people from various cultures organize categories of identity differently. Although all cultures span the same range of human diversity, they have different ways of distinguishing gay, lesbian, and transgender identities.
All these facts were new to me, and even now seem utterly engaging, leading to page after page of I-didn’t-know-that, wow, and really. This book, then, is a memoir of my travels though the academic spaces of ecology and evolution, molecular biology, and anthropology, sociology, and theology. My general conclusion is that each academic discipline has its own means of discriminating against diversity. At first I felt that the book’s main message would be a catalogue of diversity that biologically validates divergent expressions of gender and sexuality. This validating catalogue is indeed important. But as I reflected on my academic sojourn, I increasingly wondered why we didn’t already know about nature’s wonderful diversity in gender and sexuality. I came to see the book’s main message as an indictment of academia for suppressing and denying diversity. I now conclude that all our academic disciplines should go back to school, take refresher courses in their own primary data, and emerge with a reformed, enlarged, and more accurate concept of diversity.
In ecology and evolution, diversity in gender and sexuality is denigrated by sexual selection theory, a perspective that can be traced to Darwin. This theory preaches that males and females obey certain universal templates—the passionate male and the coy female—and that deviations from these templates are anomalies. Yet the facts of nature falsify Darwin’s sexual selection theory. In molecular biology and medicine, diversity is pathologized: difference is considered a disease. Yet the absence of a scientific definition of disease implies that the diagnosis of disease is often a value-loaded exercise in prejudice. And in the social sciences, variation in gender and sexuality is considered irrational, and personal agency is denied. Gender- and sexuality-variant people are thought to be motivated by mindless devotion to primitive gods, or compelled by farfetched psychological urges, or brainwashed by social conventions, and so on: there is always some reason to avoid taking gender- and sexuality-variant people seriously.
The fundamental problem is that our academic disciplines are all rooted in Western culture, which discriminates against diversity. Each discipline finds its own justification for this discrimination. This book blows the whistle on a common pattern of disparaging gender and sexuality variation in academia and predicts foundational difficulties for each discipline.
Although criticism is valuable in its own right, and a critic has no responsibility to suggest solutions, I do suggest improvements when I can. I offer alternatives for interpreting the behavior of animals, interpretations that can be tested and will lead ultimately to more accurate science. I suggest new perspectives on genetics and development that may yield a more successful biotechnology industry. I show that mathematical criteria for the rarity of a genetic disease point to possibly overlooked advantages for genes presently considered defective. I suggest new readings of narratives recorded from gender-variant people across cultures. I call attention to overlooked aspects of the Bible that endorse gender variation.
I do not argue that because gender and sexuality variation occur in animals, this variation is also good for humans. People might anticipate that as a scientist I would say, “Natural equals good.” I do not advocate any version of this fallacy that confuses fact with value. I believe the goodness of a natural trait is the province of ethical reasoning, not science. Infanticide is natural in many animals but wrong in humans. Gender variation and homosexuality are also natural in animals, and perfectly fine in humans. What seems immoral to me is transphobia and homophobia. In the extreme, these phobias may be illnesses requiring therapy, similar to excessive fear of heights or snakes.2
I also do not suggest that people are directly comparable to animals. Indeed, even people in different cultures have life experiences that may not be comparable, and comparing people to animals is even riskier. Still, parallels can sometimes be found between cultures. Rugby is a counterpart to American football but located in a different sports culture. Some aspects of American football, like the way play begins by hiking the ball, are comparable to rugby. Similarly, parallels can sometimes be drawn between how people behave and how animals behave, as though animals offered biological cultures resembling ours. I’m quite willing to anthropomorphize about animals. Not that animals are really like people, but animals are not just machines either. We make an error if we attribute too much human quality to animals, but we underestimate them if we think they’re mechanical robots. I’ve tried to strike a balance here.
I’ve borrowed the word “rainbow” for the title of the book and use it throughout. The word “rainbow” signifies diversity, especially of racial and cultural minorities. The Reverend Jesse Jackson ran for president with the Rainbow Coalition. The rainbow also symbolizes gay liberation.
You probably work with or supervise biologically diverse people. You may be the parent or relative of an unusual child. You may be a teacher, Scout master, coach, minister, legislator, policy analyst, judge, law enforcement officer, journalist, or therapist wondering why your colleagues, clients, or constituencies are so different from the norms we were indoctrinated with as children. You may be a student in college or high school trying to understand diverse classmates. You may be taking a deep breath before coming out yourself, or you may have come out years ago and wish to connect with your roots. You may be studying gender theory and wondering where science fits in, or you may be a woman scientist wondering how to contribute to feminist theory. You may be a conservation biologist wondering how to make biodiversity more relevant to human affairs. You may be a medical student with a professional need for more information about diversity than medical school teaches. You may belong to a discussion group in your place of worship trying to understand how to be inclusive. You may be a young doctoral student shopping for a thesis topic. This book is for all of you.
In Part 1, Animal Rainbows, I begin with my own discipline of ecology and evolution. I’ve written previously on the evolution of sex: why organisms have evolved to reproduce sexually rather than simply by budding, fragmentation, parthenogenesis, or some other nonsexual means.3 Reproduction that uses sex rather than bypassing it is better because species need a balanced portfolio of genes to survive over the long term, and sex continually rebalances a species’ genetic portfolio. Yet, even though this benefit of gene pool mixing is universal, the means of implementing sexual reproduction are incredibly diverse, spanning many styles of bodies, family organizations, and patterns of bonding between and within sexes, each with its own value and its own internal logic.
Part 1 reviews the body plans, genders, family organizations, female and male mate choices, and sexualities of animals, leading to the conclusion that Darwin’s theory of sexual selection is false. I find that competitive tooth-and-claw narratives about nature have been greatly exaggerated, that all sorts of friendships occur among animals, many mediated by sexuality, and that many social roles are signaled by gendered bodily symbols. The great difference in size between an egg and a sperm (a ratio in mass of usually one million to one) is not present to the same degree at the levels of body, behavior, and life history. When a gender binary does exist, the difference is usually slight and sometimes reverses gender stereotypes. Furthermore, there are often more than two genders, with multiple types of males and females. This real-life diversity in gender expression and sexuality challenges basic evolutionary theory.
Darwin is known for three claims: that species are related to one another by sharing descent from common ancestors, that species change through natural selection, and that males and females obey universal templates—the males ardent and the females coy. This third claim results from Darwin’s theory about sexual selection, and this claim, not the first two, is what is specifically under challenge. The picture conveyed by Darwin’s sexual selection theory is both inaccurate in detail and inadequate in scope to address real-world animal diversity. Darwin’s theory of sexual selection is perhaps valid for species like the peacock, whose males have showy ornaments directly used in courtship, but it isn’t a general biological theory of gender roles. Twisting Darwin’s original theory to conform with today’s knowledge renders the theory a tautology. Instead, I submit that the time has come to acknowledge the historical value of Darwin’s