When biologist Tyrone Hayes discovered that a top-selling herbicide messes with sex hormones, its manufacturer went into battle mode. Thus began one of the weirdest feuds in the history of science.
Darnell lives deep in the basement of a life sciences building at the University of California-Berkeley, in a plastic tub on a row of stainless steel shelves. He is an African clawed frog, Xenopus laevis, sometimes called the lab rat of amphibians. Like most of his species, he’s hardy and long-lived, an adept swimmer, a poor crawler, and a voracious eater. He’s a good breeder, too, having produced both children and grandchildren. There is, however, one unusual thing about Darnell.
Genetically, Darnell is male. But after being raised in water contaminated with the herbicide atrazine at a level of 2.5 parts per billion—slightly less than what’s allowed in our drinking water—he developed a female body, inside and out. He is also the mother of his children, having successfully mated with other males and spawned clutches of eggs. Recently he was moved to an atrazine-free tank and has turned lanky, losing the plump, pincushion look of a female frog. But last March, when UC-Berkeley integrative biology professor Tyrone B. Hayes opened him up to take a look, Darnell’s insides were still female. “He still has ovaries, but there’s no eggs in them,” Hayes told me the next day as we stood watching the frog, who swam over and inspected us soberly, then turned and flopped away.
Hayes is a 5-foot-3 fireplug of a man with a gentle voice and an easy grin who favors black suits when he’s on the lecture circuit and sweatshirts and running shorts the rest of the time. He is an unusual breed. You will find few other faculty members who keep their money and identification in a child’s Spider-Man sock rather than a wallet, or run their daily 12-mile commute, or compose raps about their research and perform them at scientific meetings. The pool of endocrinologists and herpetologists who might casually mention lunching on homemade raccoon curry is also minuscule. And most scientists, upon discovering that trace amounts of one of the nation’s top-selling herbicides cause gender-bending abnormalities in frogs, would have been content to publish their results and let the regulators and manufacturers fight it out.
But Hayes is not like other scientists. To be sure, he publishes in all the right journals and presents his work at the key scientific meetings, but he has also spearheaded a public outcry against atrazine, testifying at government hearings, appearing in all forms of media, and even launching AtrazineLovers.com, an anti-atrazine website.