BioConcepts

population thinkingPopulationsdenken (ger.)

• A metaphysical or methodological doctrine within biology that emphasizes the relationship between the levels of individuals and populations for the explanation of population level phenomena (such as evolution).  
  category population

  1955

  [One of the most revolutionary changes of concept in biology has been the replacement of typlogical thinking by thinking in terms of populations.

  Mayr, E. (1955). Karl Jordan’s contribution to current concepts in systematics and evolution (Evolution and the Diversity of Life. Cambridge, Mass. 1997, 297-306): 301.]

  1958

  The older philosophies were all typological, going back to Plato’s eidos, etc. – all variations were merely shadows on the cave walls of the eidos and the eidos was the proper thing. This, when translated to the natural sciences, led to establishing the norm or type, and everything else was something to be ignored. Population thinking is to assume there is no such thing as a type or a norm, only a statistical mean or a mode. You’re dealing with a variable phenomenon which is variable for a good many reasons

  Mayr, E. (1958). [Discussion statement]. In: Condensed transcript of the conference. In: Gerard, W. (ed.). Concepts in Biology, 103-195: 164.

  1959

  The assumptions of population thinking are diametrically opposed to those of the typologist. The populationist stresses the uniqueness of everything in the organic world. What is true for the human species—that no two individuals are alike–is equally true for all other species of animals and plants.

  Mayr, E. (1959). Darwin and the evolutionary theory in biology (Evolution and the Diversity of Life, Cambridge, Mass. 1997, 26-29): 27-8.

  1980

  population thinking involves ignoring individuals: it is holistic, not atomistic

  Sober, E. (1980). Evolution, population thinking, and essentialism. Philos. Sci. 57, 350-383: 370; cf. id. (1984). The Nature of Selection: 168.

  1991

  the replacement of essentialism by population thinking, which emphasized the uniqueness of the individual and the critical role of individuality in evolution

  Mayr, E. (1991). One Long Argument. Charles Darwin and the Genesis of Modern Evolutionary Thought: 42.

  2000

  For the purpose of explaining the tendency of life to exhibit ›marvellous adaptations‹ the basic unit of organisation should not be seen as the population but the individual. Individual thinking – not population thinking – is crucial to any understanding of adaptation

  Walsh, D.M. (2000). Chasing shadows: natural selection and adaptation. Stud. Hist. Philos. Biol. Biomed. Sci. 31, 135-153: 151.

  2008

  for Mary and Sober, population thinking is a metaphysical doctrine, emphasizing the reality either of individuals or of populations (if you are like me, you are still a little confused about which one, individuals or populations, is real). For me, population thinking is a methodological doctrine. It tells you that the regularities that occur in populations, such as extinction, speciation, and adaptation, emerge from the collective activities of individuals. […] On my view, population thinkers adopt a bottom-up approach to the cause of population-level regularity while interventionists adopt a top-down approach.

  Ariew, A. (2008). Population thinking. In: Ruse, M. (ed.). The Oxford Handbook of Philos-ophy of Biology, 64-86: 71-2.

  2011

  emphasis on variation is the kernel of Mayr’s population thinking. However, he also articulated a fuller more complex meaning of population thinking that has often been confused with the biological concept of a population that emerged in the early parts of the 20th century. Mayr’s meaning for “population thinking” was highly synthetic and included statistical and philosophical language for which it is hard to find counterparts in Darwin’s writings. In particular, Mayr invoked an ontological component to “population thinking” in which individuals and their variation are real, but the population is an abstraction. Darwin rarely used “population,” and never did so with meanings having anything to do with variation and evolution. “Population” first appeared in the context of variation and inheritance when Francis Galton adopted it to refer to the collection of individuals under investigation.

  Hey, J. (2011). Regarding the confusion between the population concept and Mayr’s “population thinking”. Quarterly Review of Biology 86, 253-264: 261-2.