Richard Levins: Dialectics of Disease

What had started out as a small discussion group that fit comfortably into the small, 11th-floor Takemi conference room in Building 1 had grown into a standing-room-only crowd. Students and faculty were feeling the intellectual equivalent of an adrenaline rush. The idea under discussion was really quite an old one: that changes in the world's ecology can lead to changes in the diseases that afflict the people who inhabit it. But with HIV-AIDS, the Ebola virus and the global rise in tuberculosis all in the news, there was a new urgency to the subject. Some of the School's most dynamic and accomplished faculty were in attendance. Among the most striking was an older man with a wise mien, snow-white hair and beard, and a weathered face. When he spoke, recalls Mary Wilson, that Richard Levins was truly impressive.

"I would sit there sometimes with my mouth open in awe," says Wilson, an assistant professor in the Departments of Population and International Health and Epidemiology. "He would move so easily, so seamlessly, from economics to molecular genetics to political theory to biology. He pulled it together so effortlessly and then would bring in some very practical observations." 

For over two decades, Levins, the John Rock Professor of Population Sciences, has been one of the intellectual giants of the School. A founding theoretician of evolutionary ecology and one of the world's most brilliant biomathematicians, Levins has applied ideas from these fields to the problems of disease causation, particularly infectious disease. In over-simplified terms, he is a scholar of, and advocate for, an ecological approach to public health. 

The 66-year-old professor says this approach is partly a matter of taste: "There are different aesthetics in science. Physicists have an aesthetic for symmetry and simplicity. My own aesthetic is for complexity, anomaly and, asymmetry." Levins' scientific views are also guided by a philosophical outlook rooted in Hegel and Marx that eschews the modern tendency to break systems into their smallest identifiable parts. Instead, Levins sees the world as an ever-moving process and looks for patterns in the whole. 

"When someone asks me what Richard specializes in, I answer, 'complex systems,' says Pamela Anderson, SM '84, SD '91, a Colombia-based researcher and consultant in the School's Department of International Health and Population Sciences and someone who has prized Levins as a mentor for a decade. "Problems in health, agriculture, and the environment all span disciplinary boundaries and require the integration of biological and social phenomenon," says Anderson. "Richard applies his integrated, quantitative, and qualitative thinking on complex systems to all these arenas." 

Levins grew up in Brooklyn's Manhattan Beach section, a comfortable middle-class neighborhood just east of Coney Island, but he was imbued with a radical socialist outlook at a young age. His great-great grandmother rebelled against the orthodox Judaism of her day on the grounds that it was sexist. His father, an attorney, was a member of the Young Communist League. As an eight-year-old, Levins set out to raise money for the Abraham Lincoln Brigade, a contingent of left-wing Americans that fought in the Spanish Civil War. 

"It was an interesting experience," he says, a smile creeping across his face. "After the first meeting or two, we realized that we had no resources for actually contributing to the Abraham Lincoln Brigade and furthermore, we were dependent on our parents for transport." Levins laughs. "So I decided at that point that a political movement needed a material base!" Levins says he grew up "with the sense of the inseparability of science and politics­that is, trying to understand the world in order to change it." 

As an undergraduate at Cornell, Levins split his studies between math and genetics. An active member of the Communist Party, Levins figured opposition to his radical politics would block a career in science. "It was the McCarthy period, and I expected the United States to become more repressive and fascistic," he says. So after he graduated, Levins and his wife, Rosario Morales, moved to her native Puerto Rico to farm and work as labor organizers. 

The 90-acre vegetable farm in the midst of coffee plantation country in the island's Central Mountains was "technically innovative, but barely getting by economically," says Levins. He and his wife had seed sent from all over the world. They used some novel agricultural methods. But two children made the micro-economics of the farm that much more precarious. Sick in bed with hepatitis, Levins began to look over his old math notebooks and decided that maybe he could contribute something to science. In 1956 he returned to New York City as a graduate student in Columbia's zoology department. His family still owns the farm in Puerto Rico, but termites have claimed the farmhouse, and the original 90 acres has shrunk to 35. 

Zoology, and the life sciences more generally, was in the throes of a titanic struggle as Levins resumed his studies. After Watson and Crick described DNA's structure in 1953, biology based on field work and observation was being increasingly dismissed as old hat--unimaginative "stamp collecting" as Harvard's Edward O. Wilson described it in his 1994 autobiography. The way to understand living things, said the up-and-comers, was at the molecular level, through genes and biochemistry. 

Meanwhile, scientists such as G. Evelyn Hutchinson at Yale and Robert MacArthur at the University of Pennsylvania were headed in the opposite direction. Their biology sought to describe life at the population level, and how those populations compete with and compliment one another in an environment. Moreover, they wanted to find underlying mathematical patterns to these interspecies and environmental relationships. With his mathematical gifts and knowledge of genetics, Levins was a welcome addition to this new field, known variously as population biology, population genetics, and evolutionary ecology. 

Levins first major contribution to this new population-level biology was development of the community matrix, a mathematical model for determining how many overlapping species can co-exist in a shared environment. Levins says he developed the community matrix model after a series of intense scientific discussions with MacArthur at a meeting on mathematical biology held at Yale in the early 1960s. The community matrix can be thought of as a table in which the rows and columns are species and other elements of an environment and the entries are calculations for describing the interactions among them. It can be used to derive some of the essential ecological features of an environment­its stability, its sensitivity to change, its vulnerability to catastrophe. Levins eventually trumped his own model with loop analysis, which also deals with species interaction in an environment. 

More generally, Levins helped change how modern biology views the environment from something that was objective, uniform and largely static to a system that is "selected, transformed, and defined" by organisms. Richard Lewontin, the Alexander Agassiz Professor of Zoology at Harvard, who has known Levins for 35 years, says Levins has supplied modern biology with the insight that "there is no element of the environment that is not a consequence of the organisms that construct it." 

Levins was a professor at the University of Chicago before coming to the School in 1975. Over the years, Levins has challenged his students and his colleagues to view disease in ecological terms rather than settling for standard etiologic explanations. In a class, he might ask students to calculate how a gene that increases the nitrogen uptake of wheat plants might affect the economic independence of women. His admirers say one of the amazing things about him is that he often has answers to just that kind of question. "He makes connections better than anyone I know," says Lewontin. 

While at the school, Levins has kept his hand in biology, writing articles for The Quarterly Review of Biology and elsewhere. Integrated pest management, which seeks to minimize the use of pesticides, has been a practical interest. He travels frequently to Cuba, where he has taught, conducted research, and advised government officials on agricultural practices. And he still proudly wears the label communist (to show people, he says, that "we are still around and kicking.") "Dick Levins has a very gentle and generous spirit," says Mary Wilson. "I have never seen him be mean or sarcastic." 

Pamela Anderson says, "He is a true intellectual; he listens to others and he engages their ideas, irrespective of the source." 

That Levins would have interest in new and emerging diseases is only logical. After all, to an evolutionary biologist, a pathogen is just another species seeking a safe haven for life and reproduction. Levins was a key participant in the pivotal Woods Hole meeting in November 1993 that gave fresh currency to the notion that environmental changes resulted in new opportunities for pathogens. Levins says he is delighted at the public attention that new disease research has gotten as it has put to rest the notion that infectious diseases have been conquered. Working with his close colleague Tamara Awerbuch, a lecturer in the Department of Population and International Health, he is in the midst of a Robert Wood Johnson Foundation-funded study asking why public health was caught off-guard by the emergence of diseases like Lyme disease and AIDS. 

Drawn to science by politics and philosophy, Levins has the serenity of someone who has been true to his beliefs. As a young man, he says, he found his "intellectual focus" in dialectics, Marxist philosophy, and "a fascination with complexity." And his most recent cause­the need for an "integrated epidemiology" that would take into account the myriad causes and effects that result in disease­resonates with ideas that a boy from a radical family in Brooklyn was introduced to about a half-century ago. "Something is not quite right in the way our species' current societies are relating to the rest of nature or in the way we attempt to fix what goes wrong," Levins has written recently. "There is a disjunction in science between the exquisite sophistication of the small and the irrationality of the enterprise as a whole."

- Peter Wehrwein

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