What is Species Selection?

Abstract

The possibility of selection among species has been debated for a long time and from different points of view (e.g., Fisher, 1929; Wright, 1956; Grant, 1963; Lewontin, 1970; Eldredge and Gould, 1972; Stanley, 1975, 1979; Gould and Eldredge, 1977; Hull, 1980; Eldredge and Cracraft, 1980; Vrba, 1980, 1983; Arnold and Fristrup, 1982; Gould, 1982). A new and interesting perspective on the causes of species diversification was provided by the recent suggestion of extrinsic control (Cracraft, 1982): phylogenies may systematically differ in speciation and extinction rates, not because they differ in heritable characters, but purely as a result of different geologic and climatic histories. In the same paper Cracraft discussed the concepts of selection, species selection and the effect hypothesis of macroevolution (Vrba, 1980; also 1983). I disagree with his treatment of these last topics. The immediate focus of my critique is Cracraft's (1982) discussion of the relationship between patterns in the fossil record and long-term processes. But the basic issues raised are the subject of a wider debate on the nature and role of selection in evolution which is current among biologists in diverse subdisciplines.