Richard Levins, 1930-2016

February 12, 2016 • 11:00 am

by Greg Mayer

Richard ‘Dick’ Levins, the John Rock Professor of Population Sciences at the Harvard School of Public Health, died on January 19 of this year. He was one of the most influential population biologists of the 20th century, and a close colleague and associate of Dick Lewontin, Jerry’s doctoral advisor.

Richard Levins, 1930-2016
Richard Levins, 1930-2016

Levins was an early and active participant in the group of biologists that, in the early 1960s, worked to unite ecology, evolutionary biology, and genetics into a unified and theoretically-rich science of the biology of populations. Included among this group was Dick Lewontin, Larry Slobodkin, E.O. Wilson, and, perhaps most saliently for Levins, Robert MacArthur.

Both Levins and MacArthur were skilled in mathematical theory, and both wanted to develop a unified, general, and realistic theory of ecology and evolution. They collaborated on a number of seminal papers, and Levins (1966) wrote an important exposition and defense of the style of modeling that he and MacArthur favored, and which proliferated throughout population biology. The self-conscious unification of ecology and evolutionary biology in which Levins participated was an important event in the history of the field, but it has received little attention from historians. Sharon Kingsland touches on it in her Modeling Nature, but the most extensive treatment I know of is in E.O. Wilson’s memoir, Naturalist (though see note below.)

Wilson had a spectacular falling out with Levins and Lewontin in the 70s, so other accounts would be welcome. Some flavor of the movement, its goals, and participants, can be found in the 1968 symposium volume Population Biology and Evolution, edited by Lewontin, which included contributions by Levins, MacArthur, and Slobodkin, and which was favorably reviewed by Wilson in Science.

Though both Levins and MacArthur were accomplished theoreticians, both also had a natural-historical side (MacArthur, famously, “really knew his warblers“), and it is in fact Levins’ empirical side that first attracted my attention. Levins had a farm in Puerto Rico, and later was professor at the University of Puerto Rico. While there, he had a collaboration of many years with Harold Heatwole, documenting the biogeography of the biota of Puerto Rico and the nearby Virgin Islands, which involved substantial field work.

Levins was most interested in the insects, while Heatwole is a herpetologist. As Heatwole put it, this field work taught Dick “to love ants for themselves.” (There is no good online list of Levins’ papers, but those written with Heatwole are listed at the latter’s website.)Their 1981 paper with Michael Byer is rich in data and modestly synthetic, with a good bibliography. Their work was of great interest to me, as my dissertation field work was concentrated in the Virgin Islands, and my 2012 paper cited below is basically an update of the herpetological data parts of their 1981 paper.

But there was also one important theoretical paper, “On the distribution of organisms on islands”, that came out of their island collaboration. Published in 1963 in the Caribbean Journal of Science, it contains, in capsule form, the equilibrium theory of island biogeography, deriving the species species richness of an island biota from the balance of extinction and colonization.

This is of course, the theory made famous by, and now universally associated with, MacArthur and Wilson, who also first published on it in 1963, but in the more prestigious journal Evolution. The Levins and Heatwole paper has been almost universally overlooked. (Ilkka Hanski and I have cited it.) This could be a lesson in choosing your publication outlets wisely, but, in fairness to MacArthur and Wilson, their paper was more comprehensive, and explored more ramifications. Given the close connections among Levins and the latter two, it would be interesting to know how the ideas developed so as to result in near simultaneous publication of the same basic idea.

Levins did later develop some of the theory from his and Heatwole’s paper into the theory of metapopulations, which looks at a species’ distribution over a region as a “population of populations”– some populations going extinct, while new ones form by colonization, leading to a dynamic landscape of the species’ presence and absence. In fact, the basic metapopualtion model is to this day called the “Levins Model”.

When I was a graduate student, including doing some work in Lewontin’s lab in the Museum of Comparative Zoology, Levins had students based with Lewontin at the MCZ, but, being across the Charles River at the School of Public Health himself, I rarely saw him, and never discussed with him either his field work in Puerto Rico and the Virgin Islands, or the circumstances surrounding the development and publication of his and Heatwole’s version of the equilibrium theory of island biogeography, a failing which, to this day, I regret.

Levins was a lifelong communist, which was evident in his activities with groups such as Science for the People, and his affinity for Cuba and North Vietnam. I could not detect any hint of his political philosophy in his biological work, but John Maynard Smith, perhaps the greatest British evolutionary biologist of the second half of the 20th century, and himself an ex-Marxist who became disillusioned by communism, thought otherwise:

Levins was a Marxist before he was a biologist, and all his work shows it. His book Evolution in a Changing Environment, although it avoids the usual jargon, is the work of a conscious Marxist. I also think that it was a major contribution to ecology…. It is perhaps ironic that he made extensive use of mathematical techniques borrowed from capitalist economic theory: I cannot criticise because I have done the same. Since that time, he has worked more on applications of ecological theory. The essays in this book [The Dialectical Biologist] on pesticides, on Latin community health, and on applied biology in the Third World, reflect these interests. They illustrate the power of Marxism in the right hands. I have long thought of Levins as a rare example of a scientist whose work has been strengthened by adherence to a philosophy – Marxism or any other – and this book has confirmed that view.

Like Ernst Mayr before him– a synthesist of an earlier generation– Levins was able to participate in a symposium and celebration of his life’s achievements– “The Truth is the Whole”– organized at Harvard by his colleagues and students in the year before his death. Reminiscences by a number of his colleagues have been posted at the symposium website.

Richard Levins in Maricao, Puerto Rico, in the early 1950s (from
Dick Levins in Maricao, Puerto Rico, in the early 1950s (from

Heatwole, H. R. Levins and M.D. Byer. 1981. Biogeography of the Puerto Rican Bank. Atoll Research Bulletin 251. pdf

Kingsland, S. 1985. Modeling Nature. University of Chicago Press, Chicago.

Levins, R. 1966. The strategy of model building in population biology. American Scientist 54:421-431. pdf

Levins, R. 1968. Evolution in Changing Environments. Princeton University Press, Princeton, N.J.

Levins, R. and H. Heatwole. 1963. On the distribution of organisms on islands. Caribbean Journal of Science 3:173-177.

Levins, R. and R.C. Lewontin. 1985. The Dialectical Biologist. Harvard University press, Cambridge, Mass.

Levins, R., and R.H. MacArthur. 1966. The maintenance of genetic polymorphism in a spatially heterogeneous environment: variations on a theme by Howard Levene. American Naturalist 100:585–589.

Lewontin, R.C., ed. 1968. Population Biology and Evolution. Syracuse University Press, Syracuse, N.Y.

MacArthur, R.H., and R. Levins. 1967. The limiting similarity, convergence and divergence of coexisting species. American Naturalist 101:377–385.

Mayer, G.C. 2012. Island lists of West Indian amphibians and reptiles. Puerto Rico and the Virgin Islands. Bulletin of the Florida Museum of Natural History 51:136-147. pdf

Maynard Smith, J. 1986. Molecules are not enough [review of The Dialectical Biologist]. London Review of Books 8(2):8-9. link

Wilson, E.O. 1994. Naturalist. Warner Books, New York.

Wilson, E.O. 1969. The new population biology [review of Population Biology and Evolution]. Science 163:1184-1185.

* N.B. This book– Slack, N.G. 2010. G. Evelyn Hutchinson and the Invention of Modern Ecology. Yale University Press, New Haven, Conn.– may treat this important episode: Hutchinson was MacArthur’s thesis advisor, but I have not read it.

14 thoughts on “Richard Levins, 1930-2016

  1. I’ve never heard of Levins. Thanks for the introduction.

    Levins liked the insects and was a lifelong communist. Makes sense to me as colonial insects seem to be the perfect communist community.

  2. “the theory of metapopulations, which looks at a species’ distribution over a region as a “population of populations”– some populations going extinct, while new ones form by colonization, …”

    This sound a bit like E. O. Wilson’s sociobiology and perhaps group selection. Given that Wilson and Levins had a falling out, I suspect it had to do with some of these ideas.

  3. Great piece, Greg, thank you. I didn’t know about the Levins-Heatwole island biogeog convergence. (Somewhat akin to the Wallace-Darwin convergence, I suppose. Scientific ideas are products of time, place, milieu.

    1. Andrew– Yes, the Wallace-Darwin comparison had occurred to me too. In the island biogeography case, the time, place and milieu are even more closely connected, and the participants knew each other better than Darwin and Wallace. But Levins and Heatwole were in Puerto Rico, and Wilson (in Naturalist) says the group he called the “Marlboro Circle” which included him, Levins, and MacArthur (among others) gathered for the first time in July 1964, so the two 1963 papers may be truly independent origins of the same idea.


    2. I’ve heard of Levins and even read The Dialectical Biologist, and I’m even more familiar with Heatwole as an Australian herpetologist and ecologist (first through his 1976 book Reptile Ecology), but have never heard of the 1963 island biogeography paper. Google Scholar knows of 20 citations, but cannot find the article.

  4. A warm and informative obituary. He sounds like a guy I’d have loved to meet. and an asset to any pub quiz team!

  5. Is a species that undergoes a population explosion over a long period, and thus is more genetically diverse, less likely or more likely to avoid extinction than a stable one with lower diversity?

  6. Warm thanks for this thoughtful piece, Greg.

    When I was growing up in ecology I did indeed perceive Levins (along with the others you list) as a 1960s founder of modern community ecology — they set an agenda that was captured in the Krebs and Ricklefs textbooks (first editions 1972-3) and has remained the mainline way of formulating questions about assemblages up to the present.

    Population biology — fusion of pop ecology with pop genet — hasn’t really been a success in my view, though certainly it made sense on the surface, what with many of the variables being shared.

    Seems to me that Levins (and other marxists) didn’t need to feel embarrassment about using microeconomics. The living world (unlike human economies) actually is an arena where standard microeconomic assumptions are met — many independent small firms rather than monopolies and oligopolies, variants being tried out all the time, no tax breaks or insurance or price-collaboration, DNA-lineages go out of business pretty briskly if their carbon-budget goes into the red.

  7. Thanks for an interesting insight article! It took me a while to get around to it, but it (and the thread) was well worth the wait.

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