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On the Originality of Species

Biologist Joan Roughgarden has studied nature’s ‘exceptions’ and thinks the rule needs to change. That means challenging Darwin on sex.

Photo: Barbara Ries

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By Bob Moser

In 1997, on the rarest kind of San Francisco summer day—warm and bright—Joan Roughgarden joined a crowd of 500,000 for her first Gay Pride parade. For the queer community, one’s “virgin” Pride march is an emotional initiation rite, at once a public announcement and a celebration of personal liberation. For Roughgarden, the day was even more freighted with significance. After living 51 years as Jonathan Roughgarden, after teaching 25 years at Stanford, after becoming one of the country’s most respected biologists and ecologists, she was about to take a year’s sabbatical to transition into living the rest of her life as Joan.

“I didn’t know what would happen then,” she recalls. “I didn’t know if I was going to have my job, if I would end up waitressing or end up dead.”

It’s hard to fathom the swirl of anxiety and giddiness Roughgarden felt as the marchers cavorted up Market Street. But even amid that swirl, her biologist’s brain kicked into gear. “Up until that time, I didn’t have firsthand knowledge of how many gay and lesbian and transgendered people there are,” she says. “They were six persons deep on either sidewalk, stretching for miles. I looked at this tumultuous, gargantuan group of people and said, ‘There they are! There we are!’ And then I said, ‘But aren’t we all impossible? Doesn’t science, doesn’t Darwin’s theory of sexual selection, tell us we shouldn’t exist?’ And then I said, ‘Well, if science says so many people are wrong, maybe it’s not the people that are wrong—it’s the science that’s wrong.’

“That’s when I resolved to look into it.”

Seven years later, Roughgarden is still at Stanford, still among the elite scientists whose papers and books are must reading. It’s been that way for almost three decades, since Roughgarden came to the Farm and established herself as a rare combination: a dedicated field biologist who’s also an influential ecological theorist, creating mathematical models to explain how ecosystems work. Roughgarden’s wide-ranging interests have produced pioneering research on barnacles and Caribbean lizards, along with textbooks on population genetics, evolutionary ecology and the environment. She’s also been instrumental in uniting ecology and economics, helping communities find practical solutions to environmental quandaries.

“She doesn’t plow the same furrows as everybody else,” says Paul Armsworth, PhD ’04, who worked with Roughgarden on his doctorate combining ecology and economics. “She’s always happiest slightly on the fringes, doing novel, creative and controversial work.”

Now, the spark that ignited Roughgarden’s curiosity seven years ago has produced her most audacious work. Intended for both general and scholarly readers, Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People challenges academia’s traditional views of gender and sexuality.

Published this May by UC Press, Evolution’s Rainbow calls for the “outright abandonment of Darwin’s sexual selection theory” and posits a new theory of “social selection” to take its place. Where Darwin saw competition as the essential reproductive strategy, Roughgarden sees cooperation as the key. Her basic tenet is that animal species “interact socially to acquire opportunities for reproduction.” Sex can be social as well as reproductive, she argues. Genders can be multiple and changeable—partly because animals must cooperate not only to reproduce, but also to keep offspring alive. And animals choose between same-sex and between-sex partners to improve their own net reproductive success.

For most biologists, that would be more than enough for one book. For Roughgarden, it’s merely the first step in a multipronged assault not only on conventional biology and ecology, but also on medicine, genetics, psychology, anthropology, history and even Bible studies. “Each discipline has its own tenets that suppress diversity,” Roughgarden says. “But if you actually read their primary literature, there’s all this diversity and inclusion. It’s almost like there is a tacit agreement to look the other way. That’s why this was such an exciting book to write, because I knew I was going to raise the stakes.”

There’s little doubt that Evolution’s Rainbow will fire lively debates on campuses everywhere. The question is how well Roughgarden’s reputation will weather her foray into disputes both inside and outside her fields of expertise.

“I feel like I’m not just pushing the envelope,” she says with a chuckle. “I’m out of the envelope.”

Roughgarden is bent over a table in her Herrin Laboratory office, conferring intently with one of her two current doctoral advisees. “I’m about to go out in the field,” Lauren Buckley says apologetically, “so I’m bugging her all the time.”

Her adviser seems anything but bugged. “Are you sure those are all your questions?” Roughgarden asks as Buckley makes to leave. She is bound for islands in the Caribbean, where Roughgarden will join her in a few weeks to study how lizards partition space—“basically, how lizards negotiate real estate,” Roughgarden explains.

Some discussion follows on the creatures’ “initiation temperature.” Their body heat lowers when they sleep, and they must warm up, by the sun or other means, before they can become active.

“So you’re going to catch them, refrigerate them, and then you’re going to heat them up and let them move?” Roughgarden leans back, considering. Abruptly, she sits up. “I don’t like it at all,” the self-confessed “animal chauvinist” says. “I know control types like it, but I think you’re better seeing at what temperatures they start to move out in nature.”

“Someone said you have no way of knowing what the lizards’ preferred temperature is unless you put them on treadmills,” Buckley ventures.

Roughgarden rocks back, quaking with amusement. It’s enough of an answer, and Buckley starts laughing too. “I never thought I’d be thinking about putting lizards on treadmills!” she exclaims.

Buckley didn’t foresee Roughgarden’s zeal, either. Shortly before the two were slated to track lizards on Monserrat, a volcano erupted, covering everything in more than a foot of ash. Acidic rain was falling, and their lodging had been destroyed. Buckley figured the trip was off. Her adviser begged to differ. “Joan did not want to pass up the opportunity to see how the lizards would respond to a novel disturbance,” Buckley says. Next thing she knew, she and Roughgarden were picking their way through the wreckage, with Roughgarden “constantly processing observations and developing hypotheses” about how her beloved lizards were coping.

Back in Herrin Hall, Roughgarden slides a couple of 5X8 prints across the table. “Look at this!” she exclaims, pointing to a miniature turtle with a rainbow shell. The other print shows a vibrant lizard with a butterfly perched on its snout. “I just brought them back from Hawaii,” she says.

They’ll fit right in. In one of the drabbest buildings on campus, Roughgarden’s office is an island of color. One long wall features a lineup of bright lizard art, an elephant composed of rainbow squares and a couple of fish in reds, blues, purples and yellows. Completing the effect, directly across from Roughgarden’s desk, hangs a splashy poster of “Dancing Mickey” (as in Mouse).

“I like colors,” Roughgarden says. Many scientists—indeed, many people—take solace in binaries: male and female, gay and straight, sperm and egg, black and white. Roughgarden takes heart from the complicated beauties of shadings, gradations, mixtures. It’s why she has so little patience for geneticists’ quixotic attempts to find a single, magic-bullet “gay gene.” And it’s why she has a major beef with Darwin, whose sexual-selection theory, she believes, encouraged his successors to ignore the sexual and gender diversity right in front of their eyes.

She knows her thesis won’t be an easy sell. “So many institutions are committed to the idea that the sole or natural purpose of sex is procreation,” she says. “And that’s just clearly false. I don’t know what they’re going to do when a foundational tenet like that is incorrect.”

Fight back, most likely.

Sexual selection was the last of Darwin’s “big three” theories, and the only one Roughgarden is challenging. After establishing that species are related to one another by common descent from ancestors, Darwin proposed that species change by natural selection, or “survival of the fittest.” He then came up with the idea that, in Roughgarden’s terms, “males and females obey universal templates: the passionate male and the coy female.” With the “rarest of exceptions,” Darwin declared, males compete to win females, while the female role is to choose the fittest male for reproduction.

Roughgarden asserts that Darwin’s theory doesn’t cover the gender-bending and sex-switching behaviors that have been discovered since the 1970s in fish, bird and mammal societies. The “final torpedo,” she believes, is the mounting evidence of homosexual behavior in perhaps 300 species of animals. “According to Darwin, homosexuality is anomalous,” she explains, because “a homosexual mating can’t produce offspring. But if the only function of sex were reproductive, it’d be a very, very inefficient process. A [ratio of a] thousand or so copulations per conception is typical. Genetic traits are just not that inefficient in nature. There’s got to be another purpose for sex.”

Roughgarden devotes nearly 200 pages of Evolution’s Rainbow to cataloguing the incidence of what she calls “the gee-whiz of vertebrate diversity.” Using generous doses of wit, Roughgarden describes such fascinating creatures as gender-changing damselflies, lesbian lizards, gay male swans rearing young, and macho bighorn sheep that scientists consider “aberrant” and “effeminate” if they’re not homosexual.

We meet an “intersex female bear” that “mates and gives birth through the tip of her penis.” We meet little coral-reef bass that are “simultaneous hermaphrodites”—both sexes at the same time. And, most memorably, we make the acquaintance of male bullfrogs, which come in two different genders: calling (croaking) males and silent males.

“Joan will have to work awfully hard to convince people that sexual selection theory is broke and needs fixing,” says Robert Warner, a longtime professor at UC-Santa Barbara. “I’m not sure the arguments she makes are complete enough to spawn a revolution.”

Warner was one of the first biologists to take gender diversity seriously, conducting a groundbreaking study of sex-changing fish in the 1970s. He got to know Roughgarden and her ideas well during her transition year, when she lived in Santa Barbara and worked with him on a scientific advisory panel for the Channel Island Reserves. “She’s a lot of fun to argue with,” Warner says.

Given the evidence, Warner agrees with Roughgarden on at least one point: “There’s a good amount of gender diversity and switching roles.” But he also concurs with most biologists, including some who’ve studied gender and sexual diversity extensively, that it’s premature to scrap Darwin’s theory and replace it with social selection. “Joan has been well known in the past for being very careful, marshaling the evidence and building her arguments,” he says. “Her work really moves the field forward. But in this [book], there may be an overrepresentation of this theme of cooperation and mutual contracts in animal societies. I think there is just as much of the conflict and competition that Darwin was describing.”

There is no consensus about the extent of same-sex behavior. Roughgarden draws on Bruce Bagemihl’s 1999 book, Biological Exuberance: Animal Homosexuality and Natural Diversity, which reports homosexual behavior in some 450 species. But like many researchers, Paul Vasey, a University of Lethbridge (Alberta) psychologist who has spent 12 years studying sexual behavior in Japanese macaques, believes homosexuality is “not as widespread as has been publicized.” While he’s documented “a vast amount of sexual diversity” in the macaques, including long-term sexual relationships between females, Vasey doesn’t think their behavior is typical of other species. “I believe that homosexuality has been observed in a few hundred species, but that doesn’t mean that homosexuality is frequent,” he says. “Based on available data, Darwin’s theory needs to be modified, not abandoned.”

Warner believes that most “anomalous” sexual behavior can be explained within the framework of Darwin’s emphasis on reproduction. “Some of the behaviors that look like homosexuality,” Warner says, “are tactics that in the long run increase reproductive fitness—[such as] decreasing aggression, increasing care of offspring.”

Roughgarden agrees that “the reporting has been spotty” on homosexuality in most species. But she notes that her book focuses on the dozen or so that are well documented. “Besides, there are also those that are still totally unreported. I know there are a lot of those, because I’ll ask investigators, ‘Have you seen this?’ And they’ll say, ‘Oh, yes, I have.’ And I’ll say, ‘Did you write it up?’ And they’ll say, ‘Oh, no, I didn’t.’ ”

The scientific dust-up over Evolution’s Rainbow could be just as tooth-and-claw as Darwin’s theory itself. “In any area of science,” says Patricia Jones, a Stanford vice provost and colleague of Roughgarden’s in the biological sciences department for 25 years, “there are paradigms that are everybody’s best interpretation of existing data. To change these paradigms takes a revolution in thinking. And when they’re on topics that cross over into things as complicated as sex and gender roles, it becomes even more controversial because it’s not just science anymore.”

It’s not just science for Roughgarden, who says the need to ditch sexual selection transcends biology. This theory “has promoted social injustice,” she writes, so “we’d be better off both scientifically and ethically if we jettisoned it.”

That line of thinking led Roughgarden to conclude that Evolution’s Rainbow needed to stretch into other disciplines. “I realized that it’s pointless to make the case for diversity just on the basis of science. Somebody can come along and say, ‘That’s against my religion,’ and dismiss you. It’s like working with your head in the sand.”

Roughgarden has always championed interdisciplinary studies. In addition to combining economics and ecology, she was the first director of Stanford’s earth systems program, a mix of sciences and humanities. While writing her new book, she pulled together the Committee on Cultural and Biological Diversity, which sponsored speakers and discussions aimed at “addressing the gap between the humanities and the sciences by focusing on gender and sexuality.” Her dream is to expand that effort into a diversity studies program employing both cultural and scientific standpoints. “We need to know how to talk about both dimensions of diversity in the same breath,” Roughgarden says.

Evolution’s Rainbow became a model for that approach. As Roughgarden delved into other fields, “I could start to see this consistency. The biologist might not know anything about anthropology, and the anthropologist might not know anything about theology, and yet the bottom line would be the same [to them]: diversity doesn’t matter; diversity is exceptional or unimportant or mistaken or defective.”

Roughgarden is at her most passionate when she tackles “threats to diversity” from medicine and genetic engineering She challenges the theory, popularized by Richard Dawkins in his landmark 1976 book, The Selfish Gene, that the evolutionary success of a gene results from its outreproducing other genes even if it hurts the organism it resides in. “We are born selfish,” Dawkins declares. Roughgarden counters that a gene can only accomplish its function by negotiating and compromising with other genes; it must be a “genial gene” to succeed. “That’s my one soundbite-level phrase,” she laughs. “I hope it’ll stick.”

All her arguments revolve around the “inherently cooperative and relational nature of life” that she sees. Roughgarden packs her guided tour through the social sciences with evidence of human gender diversity. She cites the special status of “two-spirit” transgendered people in Native American traditions; a million transgendered people (called Hijra) in India; a Mexican tribe that embraced intersex people until Western doctors arrived; the theory that Joan of Arc was burned at the stake because of her transgenderism. But in a culture where The Passion of the Christ is headline news, Roughgarden’s sallies into the Bible probably will raise the most eyebrows.

“I’m Episcopalian,” she says, “and when I was coming out, I was very interested in what the Bible had to say. I started to look at the passages that pertain to sexuality. It was amazing how little there was about gay people. I thought, ‘Conservative Christians are making a case against gay people on the basis of that?’

She did turn up plenty of biblical passages about eunuchs, a category some scholars believe is equivalent to transgendered people. “The Bible is really up-front about the inclusion of eunuchs, in both the Old and New testaments. Jesus himself speaks directly about that. The Bible is yet another text that’s been appropriated to suppress diversity, and yet many passages are very affirming.”

Nobody has to tell Roughgarden that Evolution’s Rainbow won’t be judged solely on its merits. “That’s the thing I’m most worried about, that the book is so out there that people will think, ‘Oh, just another San Francisco radical.’ ” A transgendered San Francisco radical championing the “naturalness” of gender and sexual diversity, at that.

Rather than play defense, Roughgarden decided to tackle the issue head-on. “I’ve exposed right up front that I’m transgendered, that this is where I’m coming from, and that this is a book of advocacy,” she says. “I see myself in here as a lawyer advocating a case for diversity.” Because the book is written for a general audience, Roughgarden felt more at liberty to insert her voice. “If the other side is wrong, I wanted to be able to just say so. Or, if I only think the other side is wrong, I wanted to lay out the arguments and invite the reader to agree or not.”

Julie Kennedy, a longtime earth systems colleague, thinks Roughgarden’s fellow biologists will be less concerned with her mission than with her ideas. “Joan is extremely well-respected in the biology field,” Kennedy says, “and I don’t think the book will be challenged [for its mission] by her colleagues. They know that whenever you do science, there’s an agenda—a subjectivity to what questions you’re asking, and to why you’re interested in a particular problem in the first place. But with the average Joe Blows out there, I don’t know. It might be a different story.”

If the jousting gets too intense, Roughgarden has given some thought to making Evolution’s Rainbow the culmination of her academic career and to peeling off in a new direction. “Maybe after the book comes out I’ll just go hide, go stealth and live happily ever after in a spa in Italy.”

Fat chance, say friends and colleagues. They expect Roughgarden to continue championing academic diversity, and they can’t imagine her leaving science behind. Roughgarden has considered going into local politics full time. She ran for district supervisor in San Francisco in 2000, mostly to promote her idea of gracing the Bay Area with a Diversity Plaza that would be the West Coast’s answer to the Statue of Liberty. In a crowded field of candidates, Roughgarden fared better than she expected. “I had by far the most votes per dollar spent. I’m still deeply moved by that. I love people, and love campaigning. But I’m not convinced it’s the best way for me to make a difference. I think I can make more of a contribution overturning academic prejudices than I can make running for office and fixing potholes.”

That mission gained ground following a controversial study published last year by Michael Bailey, chair of Northwestern University’s psychology department. The Man Who Would Be Queen is subtitled “The Science of Gender-Bending and Transsexualism,” but Bailey draws conclusions from interviews with six transsexuals in Chicago. He dismisses the idea that transsexualism has more to do with gender identity than sexual proclivities as “false” and writes that male-to-female transsexuals are either “extremely feminine gay men” or “autogynephilic” men who are “erotically obsessed with the image of themselves as women.” Homosexual transsexuals “might be especially well-suited to prostitution” and are “especially motivated” to shoplift, Bailey adds. They “are not very successful at finding desirable men willing to commit to them.”

After Bailey lectured on his theories at Stanford, Roughgarden wrote a strong op-ed in the Daily, and the controversy led to an alliance of transgender academics and activists. “It took Bailey to come along and bring us together,” says Lynn Conway, emeritus professor of engineering at the University of Michigan. “We’re not going to be ashamed and hide and take whatever these so-called scientists say about us anymore.”

The alliance successfully prodded Northwestern to launch a formal investigation into Bailey’s research methods following interviewees’ complaints that they never agreed to be research subjects. And now activists are championing Evolution’s Rainbow, and its writer, as a counterweight to Bailey’s assertion that “homosexuality is evolutionarily maladaptive.”

“The timing of her book is so significant,” says Conway. “Joan represents a real scientific challenge to Bailey and crew, to all the famous tenured professors at great universities who really believe this stuff.”

Read a November 2009 update on this story.

Bob Moser, a senior writer for the Southern Poverty Law Center in Montgomery, Ala., was a 2000-01 John S. Knight Fellow at Stanford.

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