In the third chapter of On the Origin of Species, Darwin introduced his concept of natural selection by noting that, given the struggle for existence, “any variation, however slight and from whatever cause proceeding, if it is in any degree profitable to an individual of any species in its infinitely complex relations to other organic beings and to external nature, will tend to the preservation of that individual, and will generally be inherited by its offspring” (Darwin 1859, p.61, my emphasis). That is, all evolution occurs in an ecological context. You would not, however, learn much about the workings of that “infinitely complex” context if you consulted the average biology text, philosopher of biology, or evolutionary biologist. The structure and dynamics of evolution’s ecological context have not been well integrated into evolutionary theory. Population genetic evolutionary theory, most notably, has avoided unravelling ecological complexity by compressing organism-organism and organism-environment relationships into the fitness conferred on an organism by its characters. The center stage in theory could then be occupied by the genetic basis and differential representation of characters within single species. In turn, speciation could become a process of genetic divergence, in which the environment mostly takes the role of raising and lowering barriers to gene flow.
In this series of posts, I bring into focus the challenges of making evolutionary theory more ecological. Or, given that ecological dynamics are implicit in any evolutionary theory, I might say, the challenges of making these dynamics explicit. Writing in the spirit of Lewontin’s essays on organisms as the subject and object of evolution (Lewontin 1983; see also 1982, 1985), I will not present a well-formed program of ecological evolutionary theory, but point to the existence of problems. My aim is to provoke further, much needed, discussion. (Next post in series.)
Lewontin, R. C. (1982). Organism and environment. In Learning, Development, and Culture, ed. H. C. Plotkin, pp. 151-170. New York: John Wiley & Sons.
Lewontin, R. C. (1983). The organism as the subject and object of evolution. Scientia 118: 63-82. Reprinted in The Dialectical Biologist, ed. R. Levins and R. C. Lewontin, pp. 85-106. Cambridge, MA: Harvard University Press.
Lewontin, R. C. (1985). Adaptation. In The Dialectical Biologist, ed. R. Levins and R. C. Lewontin, pp. 65-84. Cambridge, MA: Harvard University Press.
Adapted from “From natural selection to natural construction to disciplining unruly complexity: The challenge of integrating ecology into evolutionary theory,” in R. Singh, K. Krimbas, D. Paul & J. Beatty (eds.), Thinking About Evolution: Historical, Philosophical and Political Perspectives, Cambridge: Cambridge University Press, 377-393, 2000.