The Genetic Evolution of Flexible Strategies

West-Eberhard (1987a, 1987b, 1988) has suggested that (1) students of the evolution of insect eusociality fall into two groups, "geneticists" and "naturalists," and (2) the "naturalists" take account of environmental conditions mediating the expression of altruistic behavior whereas the "geneticists" do not. Her writings are also interpretable as arguing that (3) evolution may proceed epigenetically, without genetic innovation. All three statements are false: models about the evolution of insect eusociality explicitly include contextual statements and are often made by persons who also make thorough empirical studies of natural populations, and the evolution of responsiveness to particular cues eliciting worker behavior cannot be understood without genetic models for the evolution of the genetic architecture of the developmental systems involved. Although models may begin as simple intuitive statements, they have to be made quantitative to test their true explanatory power and to delimit their applicability to the observations they are supposed to explain. It behooves modelers to make their models understandable and applicable and empiricists to obey Darwin's exhortation (Gruber and Barrett 1974, p. 123) to "let theory guide your observations." That the modelers and empiricists studying social insects are often the same people should make this eminently practicable. Following Sober (1987, p. 50), the controversy can be seen to be more apparent than real, involving a confusion between source laws (about the relationship between life pattern and fitness consequences) and consequence laws (about the resulting evolutionary changes).