Wynne-Edwards, Vero Copner
WYNNE-EDWARDS, VERO COPNER
(b. Leeds, United Kingdom, 4 July 1906;
d. Banchory, Aberdeenshire, United Kingdom, 5 January 1997)
ecology, evolution, social behavior, population biology.
As a pioneer in the study of social behavior, Wynne-Edwards focused debate on the question of the level at which natural selection acted. Contrary to the increasingly reductionist focus of evolutionary biology on individual organisms and subsequently genes, Wynne-Edwards argued that an explanation of the evolution of social behavior required the mechanism of natural selection acting on groups of organisms rather than individuals or genes. This theory, most comprehensively described in his 1962 book Animal Dispersion in Relation to Social Behavior, became the target of sharp critique and generated an extended response from the community of evolutionary theorists. Although Wynne-Edwards’s formulation of the theory of group selection was never accepted into the mainstream of evolutionary biology, later models of group selection have continued the debate about the levels of selection that was crystallized by Wynne-Edwards’s work.
Early Life and Education. Wynne-Edwards was born in Leeds, the fifth of six children of the Reverend Canon John Rosindale Wynne-Edwards, headmaster of the Leeds grammar school, and his wife Lillian Agnes, née Streat-field. As a young boy growing up in the Yorkshire Dales, Wynne-Edwards developed a deep fondness for natural history. His early exposure to natural history was not much different from the experience of young English naturalists a century before; he was an avid collector and list maker. His first success as a young naturalist was the 1918 junior botany prize from Leeds for his collection of named wildflowers and ferns. He received a copy of Gilbert White’s eighteenth-century classic The Natural History of Selbourne (1789), which led Wynne-Edwards to his next project, “The Flora of Austwick,” which he completed that summer.
In January 1920, at age thirteen, Wynne-Edwards was sent to boarding school at Rugby. It was here he became interested in astronomy and further developed his love of natural history in the school’s museum, herbarium, and natural history society. At Rugby, Wynne-Edwards attended lectures by august visitors such as Sir Ernest Shackleton on the eve of his final Antarctic expedition and Julian Huxley, a renowned biologist, that inspired him with visions of the adventurous scientific life. In 1924 he prepared to leave Rugby with visions of Himalayan expeditions to study alpine flora and fauna; his father, however, had more traditional plans for him. In the end, Wynne-Edwards entered New College, Oxford, in 1925 to read zoology with the hope of having Huxley as tutor.
Although Huxley was to leave for the chair of zoology at King’s College London after Wynne-Edwards’s his first year, Oxford remained a propitious choice. The comparative anatomist Edwin S. Goodrich was Linacre Professor and head of the zoology department and had assembled at Oxford an unrivaled collection of biologists. Wynne-Edwards read comparative anatomy with Goodrich, embryology and experimental zoology with Gavin de Beer, genetics with Edmund B. Ford, and ecology with Charles Elton. Reflecting on his experience at Oxford in 1985 Wynne-Edwards wrote,
Looking back fifty-five years later, I know how often I have been glad to have studied every phylum of the animal kingdom in detail, and thus acquired enormously more straight zoological knowledge than comes the way of students nowadays.… The apparent narrowness of the Oxford degree never seemed a handicap in my career in university teaching and research. The biological revolution has of course been running at flood level all my life, and we have never stopped having to study new subjects, often in widely diverse fields, just to keep up with our work. (pp. 489–490)
Given the scope of Wynne-Edwards’s later theorizing, this breadth of training was indeed fortunate. It was, however, the ecologist Elton who had the most significant and long-lasting influence on Wynne-Edwards’s scientific career. It was during Wynne-Edwards’s first year as a student that Elton had begun his studies on periodic rodent population cycles in Bagley wood. These studies, along with a consulting position as biologist for the Hudson’s Bay Company, set the foundation for the establishment of the Bureau of Animal Population at Oxford (Elton’s institutional home for the rest of his career) and fired an interest in animal populations that would dominate WynneEdwards’s career and lead to the development of his most significant and controversial contribution to science, his theory of group selection.
Wynne-Edwards completed his studies at Oxford in 1927 with first-class honors. Initially, he took a position at the Marine Biological Laboratory at Plymouth, studying the distinct male morphs of the marine crustacean Jassa falcata. Although this project foundered, Wynne-Edwards was simultaneously pursuing an interest in the roosting behavior of starlings. The starling study marked the beginning of a lifelong fascination with birds and their social behavior and dispersion patterns.
After two years at Plymouth, he took a job as assistant lecturer at Bristol University and married his Oxford classmate Jeannie Morris. The position at Bristol was short lived; within months of his arrival he received an offer for a position as assistant professor at McGill University in Montreal. In September 1930, Jeannie and Wynne-Edwards emigrated to Canada.
Professional Life: Canada. For Wynne-Edwards the voyage from England to Canada was not merely a mode of transport to his new position; rather, it was an opportunity for research. Through the course of the transit, he kept numerical logs of the various species of birds he saw. As he later reported: “The data threw new light for me on seabird ecology” (1985, p. 494). He decided to make several more transatlantic data collection trips and ultimately published an article describing the basic pattern of inshore (coastal), offshore (to the edge of the continental shelf), and pelagic (deep-water) zones of seabird distribution. The resulting article, “On the Habits and Distribution of Birds on the North Atlantic” (1935), won the Walker Prize of the Boston Society of Natural History and established the arrival of a sharp new zoologist at McGill.
Wynne-Edwards remained at McGill through the end of World War II. During his fifteen years in Canada he became deeply familiar with Canadian natural history. He participated in multiple field expeditions to Newfoundland, Labrador, and the Arctic. He conducted faunal surveys of the St. Lawrence River and its tributaries for the Canadian Fishery Research Board, and in 1944 and 1945 he surveyed the Mackenzie and Yukon rivers in the Yukon Territory. The results of these expeditions tended initially to be of greater interest to government agencies than to research scientists. Ultimately, however, Wynne-Edwards would put his survey results to use in developing his theory of group selection.
At the end of the war, Wynne-Edwards was presented another fortuitous opportunity; the Regius Chair for Natural History at Aberdeen University in Northern Scotland had become available. After his return from the Yukon, Wynne-Edwards applied and ultimately was appointed to the chair in 1946.
Professional Life: Scotland. The move to Aberdeen University allowed Wynne-Edwards to continue his interest in population ecology; pursue his love of skiing, hiking, and birding; and to develop the Zoology Department at Aberdeen into a center for ecological research. He also continued to serve as a scientific member of various government advisory committees, such as the Nature Conservancy, and the Natural Environment Research Council (NERC), which he chaired from 1968 to 1971. As he pointed out in his autobiographical memoir, these administrative duties “kept me in close contact with scientists working at sea and at the bench, and added very opportunely to my intellectual stock in trade in the important decade of 1952–62” (1985, p. 501). Indeed, it was during that decade that Wynne-Edwards developed the theory of group selection that would make him famous (or infamous as the case may be).
The seeds of the theory were sown in an offer he received to review Oxford ornithologist David Lack’s 1954 book The Natural Regulation of Animal Numbers. In his review, Wynne-Edwards praised the value of this broad ranging work but took Lack to task for some of the hypothetical assertions. He pointed out that on Lack’s view natality is the independent variable and that mortality adjusts itself (through density-dependent effects) to match it. Wynne-Edwards quoted Lack asserting, “Natural selection cannot favour smaller egg-number as such” (Wynne-Edwards, 1955a, p. 433). This, in particular, is one of the hypothetical assertions that Wynne-Edwards questioned. He countered that Lack had mistaken fecundity for fitness and that this was deeply problematic. If indeed the most fecund are not the most fit, then over time the “stock will very likely fall on evil days” (Wynne-Edwards, 1955a, p. 434).
Further, according to Wynne-Edwards, selection could just as readily favor a lower as a higher reproductive rate, differentially permitting survival of those populations that continue to live in harmony with their environments. Wynne-Edwards’s claim that selection could favor lower reproductive rates was a restatement of the controversial theory he had introduced the previous summer at the eleventh International Ornithological Congress in Basel, Switzerland. In the paper, Wynne-Edwards argued for a “collective response” by a social group to general conditions of food productivity rather than the individual response of a male bird claiming territory as suggested by Lack. In the concluding paragraph Wynne-Edwards wrote:
The theory that slowly breeding birds have evolved a series of interrelated adaptations, giving them a great measure of autonomic control of their numbers, permits, at any rate, a rational explanation to be offered of many hitherto unconsidered features of their breeding biology. It shows that if they were adapted to impose their own limit on the number and size of their breeding colonies (as an alternative to limiting the minimum size of individual breeding territories) they could combine optimum feeding conditions with maximum numbers. (1955b, p. 547)
This paper described the theory that Wynne-Edwards would elaborate in his 1962 book and would spend the rest of his career defending. Between 1955 and 1962 Wynne-Edwards did not publish a great deal, rather, he continued to collect evidence for his theory and work on the book.
A Life’s Work. Animal Dispersion in Relation to Social Behavior was published in 1962 and vaulted Wynne-Edwards to the forefront of evolutionary biology and ecology. The book synthesized his years of field experience in Canada and the United Kingdom, his knowledge of population management policies of various environmental agencies, and his love of natural history into a theory of group selection that challenged a growing consensus among biologists that Darwin’s mechanism of natural selection worked exclusively at the level of the individual organism or below (i.e., on the gene). The book was born of the interest that Elton had sparked almost forty years earlier in population biology and provoked by the elegant work of Lack that Wynne-Edwards sought to challenge.
For example, Wynne-Edwards and Lack were at odds over the evolutionary explanation of brook size. Lack argued the individual breeding pairs were selected to raise as many offspring as the food supply would allow. Wynne-Edwards argued that selection acted on groups of breeding pairs (i.e., colonies) and maintained the breeding level below the threshold of available food. Wynne-Edwards argued that Lack’s explanation would lead to overexploitation of the food resource by the individual pairs ending in the extinction of that population. While on his model, groups of breeding pairs were selected to maintain their population at a level that would ensure long-term success of the population.
The realization of the theory of group selection was consistent with Wynne-Edwards’s earliest work on starling roosts, as well as his work in the late 1930s on nonbreeding behavior in sexually mature fulmars (sea birds). In Animal Dispersion he offered explanations of these phenomena that were significantly different from the prevailing individual-level explanations at the beginning of Charles Darwin’s second century. According to Wynne-Edwards, the proper understanding of these, among many other social behaviors, required his theory of group selection. He was careful at the outset of the book to distinguish his theory from the traditional “Darwinian heritage” (read neo-Darwinism). He cited the standard interpretation of natural selection, which occurs at two levels, the individual (intraspecific) and the species (interspecific) levels, and argued that neither of these covered the social adaptations of interest.
On his account, it takes a group of individuals to maintain social conventions. He cited the work of geneticists Theodosius Dobzhansky and Sewall Wright as supportive of the notion that social grouping is of the utmost importance to evolution and the distribution of populations. In the first chapter Wynne-Edwards laid out the theory in no uncertain terms.
Evolution at this level can be ascribed, therefore, to what is here termed group-selection—still an intra-specific process, and, for everything concerning population dynamics, much more important than selection at the individual level. The latter is concerned with the physiology and attainments of the individual as such, the former with the viability of the stock or race as a whole. Where the two conflict, as they do when the short-term advantage of the individual undermines the future safety of the race, group selection is bound to win, because the race will suffer and decline, and be supplanted by another in which antisocial advancement of the individual is more rigidly inhibited. (1962, p. 20)
This unequivocal statement of Wynne-Edwards’s theory, which was expanded upon at length in the 650 pages of the book, led to a quick and ultimately devastating response from the community of evolutionary biologists. Among the most influential of these critics were William Hamilton, John Maynard Smith, George C. Williams, and David Lack. By the mid-1960s with the development of Hamilton’s kin-selection model and the theory of inclusive fitness, the focus of selection had shifted to the level of the gene and Wynne-Edwards’s theory of group selection was largely rejected.
In 1966, Williams published the now classic Adaptation and Natural Selection where he argued convincingly that although group selection might be theoretically possible it was practically unimportant. Individual level selection was more efficient, quicker, and would always undermine group selection except in extremely limited circumstances. The influence of Williams’s book on evolutionary theory would be difficult to exaggerate and its effect on Wynne-Edwards was telling. Although Wynne-Edwards continued to publish in support of his theory throughout the 1960s and early 1970s, by the mid-1970s he was ready to capitulate. After his retirement from Aberdeen in 1974 Wynne-Edwards nearly gave up on group selection. At a 1977 conference on Population Control by Social Behavior Wynne-Edwards gave the opening paper and said:
In the past 15 years many theoreticians have wrestled with it, and in particular with the specific problem of the evolution of altruism. The general consensus of theoretical biologists at present is that credible models cannot be devised, by which the slow march of group selection could overtake the much faster spread of selfish genes that bring gains in individual fitness. I therefore accept their opinion. (1978, p. 19)
This recantation was short lived. Soon thereafter Wynne-Edwards began work on a second book that he claimed would answer the criticisms that had been leveled against his theory.
Wynne-Edwards’s second book, Evolution through Group Selection (1986), was met largely with silence. Many of the reviews dismissed the book as one of advocacy rather than science. What is not generally recognized is that Wynne-Edwards had modified his position to some degree (Pollock, 1989). He had become convinced that his theory was consistent with the early models of Sewall Wright, and most importantly that group selection and individual-level selection did not necessarily work in opposite directions. Into his late eighties, Wynne-Edwards continued to publish and advocate for the importance of group selection to evolution. Moreover, he continued to emphasize the connection of his own work to Wright's. In a 1991 article in the Ecologist he cited Wright’s review of George Gaylord Simpson’s Tempo and Mode in Evolution, writing:
Neo-Darwinian evolutionists, however, hold firmly to the belief that natural selection can operate only on individual organisms, and that all the adaptations and advances which evolution has witnessed must have arisen by that process alone.… Theoretical defects on this scale again point to the existence of a second, slower process of innovation and natural selection, with self-perpetuating groups or sub-populations as the separate units on which selection works. The theoretical conditions required to make group selection work have been well understood for many years. [(i.e., Wright, 1945)]. (Wynne-Edwards, 1991, p. 138)
Wynne-Edwards had also begun to incorporate some of the more recent research on group selection that had been conducted by Michael Wade and David Sloan Wilson.
Wynne-Edwards published his last article, “A Rationale for Group Selection,” in the Journal of Theoretical Biology in 1993, at the age of eighty-six. Perhaps not surprisingly, he reiterated his support for the importance of group selection theory. Interestingly, the response to the review article was generally positive. Although the theory of group selection remains outside the mainstream of evolutionary biology, Wynne-Edwards’s contribution should not be underestimated. The debate over group selection has outlived its most prominent proponent. Evolutionary biology has benefited from the focus on the question of the level at which natural selection occurs, which was precipitated by Wynne-Edwards’s formulation of the theory of group selection. Wynne-Edwards’s advocacy of group selection theory ought not to be his only legacy; he was also influential in the synthesis between ecology, evolution, and animal behavior that occurred in the latter half of the twentieth century.
In the course of his career Wynne-Edwards received many awards and honorary degrees. He was elected a Fellow of the Royal Society in 1970 and appointed Commander of the British Empire in 1973. Wynne-Edwards spent his retirement in Banchory, Aberdeenshire, where he lived with his wife Jeannie until his death in 1997. His family attests that he had his binoculars and his bird logs at the ready to the end.
The Wynne-Edwards collection is stored in the Queen’s University Archive, Kingston, Ontario, Canada.
WORKS BY WYNNE-EDWARDS
“On the Habits and Distribution of Birds on the North Atlantic.” Proceedings of the Boston Society of Natural History 40, no. 4 (1935): 233–346.
“The Dynamics of Animal Populations.” Discovery: A Monthly Popular Journal of Knowledge(October 1955a): 433–436.
“Low Reproductive Rates in Birds, Especially Sea-Birds.” Acta of the XI International Congress of Ornithology (1955b): 540–547.
Animal Dispersion in Relation to Social Behavior. Edinburgh: Oliver and Boyd, 1962.
“Intrinsic Population Control: An Introduction.” In Population Control by Social Behaviour, edited by F. J. Ebling and D. M. Stoddart. London: Institute of Biology, 1978.
“Backstage and Upstage with ‘Animal Dispersion.’” In Leaders in the Study of Animal Behavior: Autobiographical Perspectives, edited by Donald Dewsbury. London and Toronto: Associated University Presses, 1985.
Evolution through Group Selection. Oxford: Blackwell Scientific Publications, 1986.
“Ecology Denies Neo-Darwinism.” Ecologist 21 (1991): 136–141.
“A Rationale for Group Selection.” Journal of Theoretical Biology 162 (1993): 1–22.
Borrello, Mark E. “Synthesis and Selection: Wynne-Edwards’ Challenge to David Lack.” Journal of the History of Biology 36 (2003): 531–566.
———. “Mutual Aid and Animal Dispersion: An Historical Analysis of Alternatives to Darwin.” Perspectives in Biology and Medicine 47, no. 1 (2004): 15–31.
———. “Dogma, Heresy and Conversion: Wynne-Edwards’s Crusade and the Levels of Selection Debate.” In Rebels of Life: Iconoclastic Biologists of the Twentieth Century, edited by Oren Harman and Michael Dietrich. New Haven, CT: Yale University Press, (in press).
———. “Shifting Balance and Balancing Selection: A Group Selectionist’s Interpretation of Wright and Dobzhansky.” In Descended from Darwin: Insights into American Evolutionary Studies 1925–1950, edited by Joseph Cain. Philadelphia: American Philosophical Society Press, (in press).
Pollock, Gregory B. “Suspending Disbelief—Of Wynne-Edwards and His Reception.” Journal of Evolutionary Biology 2 (1989): 205–221.
Sober, Elliott, and David S. Wilson. Unto Others: The Evolution and Psychology of Unselfish Behavior. Cambridge, MA: Harvard University Press, 1998.
Wade, Michael J. “Experimental Study of Group Selection.” Evolution 31 (1977): 134–153.
———. “A Critical Review of the Models of Group Selection.” Quarterly Review of Biology 53 (1978): 101–114.
———. “Soft Selection, Hard Selection, Kin Selection and Group Selection.” American Naturalist 125 (1985): 61–73.
———. “The Group Selection Controversy: History and Current Status.” Annual Review of Ecology and Systematics 14 (1983): 159–187.
Wright, Sewall. “Tempo and Mode in Evolution: A Critical Review.” Ecology 26 (1945): 415–419.
Mark E. Borrello