ABSTRACT
Our evolutionary perspective represents a departure from the neo-Darwinist approach, which emphasizes inclusive fitness theory and reproductive-mindedness (Buss, 1995). During the last 15 years, an alternative to neo-Darwinism has been emerging under various names: expanded evolutionary theory (Gould, 1980), constructionist evolution (Gray, 1992), developmental systems theory (Griffiths & Gray, 1994; Oyama, 1991), process evolution (Ho, 1991), or group selection (Wilson & Sober, 1994). Proponents of the latter views argue that significant evolutionary units of analysis cannot be confined merely to the gene or the individual, as is the case for neo-Darwinism. Instead, there are multiple levels of organization upon which selection may occur, resulting in evolutionary dynamics that cannot be reduced to a summary of selection on alternative alleles. Leo W. Buss (1987), a biologist at Yale University, summarized the hierarchical perspective:
The history of life is a history of transitions between different units of selection…. When a transition occurs in the units of selection, synergisms between the higher and lower unit act to create new organizations which may allow the higher unit to interact effectively in the external environment. However, the organization of the higher unit does not simply interact with the external environment; it is also the agent of selection on the lower unit. To the extent that control over replication of the lower unit is required for effective interactions with the external environment, organizations must appear in the higher unit to limit the origin or expression of variation at the lower unit. Any such organization will act to stabilize the higher unit, as it limits the capacity for variants to arise or be expressed, (p. 171)
