Professor of History & Philosophy of Biology Department of Biological Sciences Dartmouth College
Hanover, New Hampshire
As a young college student in the early 1980s, Michael Dietrich picked up philosopher Philip Kitcher’s newest book, Abusing Science, an account of the evolution/creationism debate. By the time he turned the last page, Dietrich knew he wanted to study with Kitcher, then a professor at the University of Minnesota, and successfully applied to work with him.

When the aspiring philosopher arrived in Minnesota, eager to begin, Kitcher asked him what audience he intended to write for. When Dietrich said biologists, Kitcher replied, “No biologist is going to take you seriously unless you really know your science.” Kitcher challenged him to take a biology class every term and get the top grade in each class. Dietrich complied, and packed his schedule...

“What is great about a controversy is that people are more open about what’s going on, and you have more access to discussions and arguments.”

Dietrich admits he didn’t always get the top score—“there were some really smart biologists in my classes,” he says with a laugh—but maintains that the technical background was key to his later success. “I couldn’t have done what I do today unless I had gone back and gotten that training,” says Dietrich, now a philosopher and historian of science at Dartmouth College in Hanover, New Hampshire.

The editor of three books and author of dozens of articles and book chapters, Dietrich has made a name for himself by illuminating some of the most intriguing and overlooked controversies in the history of biology, including a debate on a common theory in molecular evolution, the history of the molecular clock, and the life of a heretical geneticist who claimed there was no such thing as a gene.

Here, Dietrich shares why biology’s “oddballs” fascinate him, what it’s like to be a historian surrounded by scientists, and the key reason why students should be encouraged to think about the nature and practice of science.


The wrong kind of biology. Raised in various countries because of his father’s military career, Dietrich finally settled in Virginia for his later high school years and then entered Virginia Tech as an undergraduate in 1981. “The very first term on campus I was a biology major, but I took a philosophy class and enjoyed it, so I decided to do a double major in philosophy and biology. But at the time there was almost no overlap between biology and philosophy. There was a philosophy of science class, but really that was mostly about physics—I ended up learning a lot about Galileo. It wasn’t until my senior year that Virginia Tech hired a philosopher of biology and I had my first philosophy of biology class. It was great, but I realized I had taken all the wrong kinds of biology. Philosophy of biology, it turned out, was primarily concerned with issues of evolution, and I had studied microbiology with an interest in industrial microbiology. That was about as far as you could get from evolutionary philosophical issues. I had a lot of catching up to do.”

Remaining neutral. In 1985, Dietrich began his graduate work studying with Kitcher in Minnesota. But he wasn’t there for long. “After a record snowy winter, [Kitcher] said, ‘I’ve got a job in San Diego. Who wants to go?’ I said, ‘Me!’” Dietrich accompanied his mentor to the University of California, San Diego, where he studied the controversial history of the neutral theory of molecular evolution, posited in 1968, which argued that the vast majority of substitutions in a species’ genome are neutral with respect to natural selection—they do not affect the fitness of an individual or population. For years, evolutionists and biologists had hotly debated how important and widespread neutral variation was, so it was a perfect topic for the budding philosopher to study: “At the time philosophers, historians, and sociologists were keenly interested in controversy, because we wanted to understand how scientists made judgments about theories,” says Dietrich. “What was, and still is, great about a controversy is that during a controversy people are more open about what’s going on, and you have more access to discussions and arguments.”

Hot topic. Dietrich reconstructed the historical events of the neutral theory controversy using archival research and interviews with still-living participants, including Harvard evolutionary biologist Richard Lewontin. The result was Dietrich’s “first big article,” published in 1994 in the Journal of the History of Biology after he had begun working as a professor at the University of California, Davis. In the paper, Dietrich argued that biologists were getting the roots of the controversy wrong: the neutral theory was not a direct continuation of an earlier dispute that was transformed by protein electrophoresis studies, as purported by Lewontin and others, but had an important set of roots in the biochemical analyses of proteins and their rates of change. “It took [Lewontin] and me probably about 10 years to work through our differences on that, but in the end, he nobly said that he thought that my view agreed with more of the facts than his did,” says Dietrich.

The heretic. Dietrich’s fascination with controversy continued to lead him to new study subjects. “I became interested in a controversial geneticist named Richard Goldschmidt. His papers were all at Berkeley, and as a historian you’re always looking for that trove of wonderful historical material.” Goldschmidt had been director of the Kaiser Wilhelm Institute of Biology in Berlin, but was forced to flee his country before World War II because he was Jewish. He settled in Berkeley in 1936. Dietrich began studying Goldschmidt’s life, including why the scientific community considered his ideas heretical. “The first thing [Goldschmidt] does when he comes to Berkeley is to declare there are no genes and that evolution has to occur by large sudden leaps. This immediately made him into a biological heretic. He was never a shy guy, and much more willing than cautious Americans to theorize. He was willing to do a couple of experiments and then create a whole new unifying theory of genetics. To Americans, that was just shocking.”

The heretic’s revival. Dietrich began writing Goldschmidt’s biography around 2000, but as he researched the twists and turns of Goldschmidt’s contemporary and posthumous reputation (he died in 1958), the straightforward story soon morphed into something else. “In the 1970s and ’80s, Stephen Jay Gould tried to resurrect Goldschmidt: he had Goldschmidt’s major book on evolution reissued by Yale University Press, and also tied Goldschmidt’s ideas to his own theory of punctuated equilibrium. It brought Goldschmidt back into public awareness.” In addition, a new generation of evo-devo biologists began to revisit Goldschmidt’s ideas about integrating genetics, evolution, and development. “Eventually I realized the thing motivating my research wasn’t so much the fine details of his life as how he was received by other biologists. So now the first two-thirds of the book goes through Goldschmidt’s life and the last third is about his reputation after death.” Dietrich is finishing the book and expects to publish next year.

Making a move. In 1997, while Dietrich was on sabbatical at Harvard, his spouse, Laura Lovett, a professor of American history, was offered a job at the University of Tennessee at Chattanooga. Instead of returning to Davis and commuting across the country, Dietrich applied for and got a job at Dartmouth College. “We thought, ‘At least we’re in the same time zone!’ We were apart like that for about 3 years—we racked up a lot of frequent-flier miles—until she got a tenure-track job at the University of Massachusetts, Amherst. That was much better.”


In the lion’s den. At Dartmouth, instead of being surrounded by historians and philosophers as he was at UC Davis, Dietrich is employed as a member of the biology department. “It’s a little unusual, as I am the only historian embedded within a bunch of biologists. But it’s been great. It’s changed the way I think about biology quite a bit. Coming and living among a bunch of biologists, watching what they do day in and day out, gives me a much finer appreciation for the everyday life and culture of biology. Overall, I get a much more nuanced view than I would get just studying people’s papers and correspondence. And even the kind of work I do has become more technical—I publish more in science journals than I ever did before. That’s a good thing; I reach a broader audience.” In 2009, for example, Dietrich collaborated with two Dartmouth scientists on a study of microRNAs in the evolution of body plans, work subsequently published in BioEssays.

“I think the history of science is a grand history of failures. It keeps science moving. Once you get too comfortable, you’re not moving anymore.”

Better together. Collaborations now make up a significant part of Dietrich’s career. “Biologists collaborate all the time. Philosophers don’t. So the biologists here showed me how to manage collaborations, and now I’ve started initiating them, not just with biologists but with other philosophers and historians.” For example, philosophers Roberta Millstein of UC Davis and Robert Skipper of the University of Cincinnati, together with Dietrich, have been writing about the role of chance in evolution, but from slightly different perspectives. “Now we’re completing a collaborative book on the place of random drift in biology, called Survival of the Luckiest. It’s part philosophy and part history. We just got together over the summer to start revising and rewriting it. Writing together has actually been pretty easy. We just use a lot of Track Changes.”

Into outsiders. Dietrich’s passion for heretics like Goldschmidt has spilled over into other work; he is coeditor of two anthologies about biology outsiders. “Ten years ago, Oren Harman, an Israeli historian of genetics, published a great book on [geneticist Cyril] Darlington that I reviewed, and we decided to start collaborating.” The two edited a book called Rebels, Mavericks, and Heretics in Biology (Yale University Press). “It was basically the two of us picking out all the oddballs in biology, some of them successful, some of them abject failures. We came up with a list of all these interesting people, then went out and matched them up with historians that we thought would do an excellent job writing about them.” After the success of that book, the duo published a second anthology, Outsider Scientists, about eighteen researchers who were not trained as biologists but went on to make an impact in the life sciences. “We found mathematicians, computer scientists, linguists, anthropologists, and more, then tried to distill out what was it that allowed those people to come into biology and make important innovations.” That book was published in December 2013. (See TS review here.)

Hoarders. In between the two anthologies, Dietrich was called to deal with a dusty old basement. “When I got to Dartmouth, the biology department hadn’t really thrown things away, so there were two rooms in the basement: one filled with microscopes and another, called the bone room, filled with animal specimens. They said, ‘You like old stuff. Come tell us what to do with this stuff.’ I went through it, and it became clear that every microscope the department had ever had was still there in the basement, plus a great collection of models used in teaching. Sadly for them, I said, ‘We have to keep everything.’” Dietrich invited a team of art historians, philosophers, and historians of science to review the material. The end results were an exhibit in the university’s art museum, a permanent installation of exhibit cases in a new biology building, and a book on visual culture and pedagogy.


Crazy commute. Dietrich’s daily drive from his home in Amherst, Massachusetts, to his work in Hanover, New Hampshire, is about two hours each way. “I spend too much time in the car. Often I’ll just gather my thoughts on the drive up, because I’m usually driving right before class. And on the way back I’ll listen to music.”

Required thinking. Dietrich teaches classes in both ethics and the history and philosophy of science. “Most graduate students are required to take some ethics training, usually required by the NIH and NSF. I think philosophy classes also wouldn’t hurt—they would definitely give students a richer understanding of what they’re doing—but I’d be surprised if most places started requiring that. It’s not likely to happen.”

Keep moving. “I think there is no final answer to who is right or wrong [in the history of science]. In that sense, I’m a fallibilist: I think the history of science is a grand history of failures, and that’s a great thing. It keeps science moving. Once you get too comfortable, you’re not moving anymore.”

What’s trending now. Dietrich is editor in chief of the Journal of the History of Biology, a gig that keeps him attuned to the field. “There’s always been a Darwin industry, and that has shown no signs of slowing. But there are a lot of new interesting areas to read about. We’re publishing a lot of essays on the history of immunology and the history of aging research. And a lot of fairly recent history—the history of cloning, for example, is starting to be written.”

Greatest Hits

  • Reconstructed the history of the controversy about the neutral theory of molecular evolution.
  • Published two collections of essays on outsiders in biology: one on biology’s iconoclasts and a second on innovators trained in nonbiological fields.
  • Organized an art exhibit and later published a book on visual pedagogy in biology.
  • Studies the life and reputation of biological heretic Richard Goldschmidt.

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