Systematics, Paleontology, and the Modern Synthesis

Ernst Mayr, a systematist and founding father of the synthetic theory, has recently (Mayr 1980b) assessed the role played by the field of systematics in general in the emergence of the synthesis. Mayr (1980a, 1980b; 1982, chapter 12) actively opposes the conventional supposition that the synthesis is the product of three phases of development: (1) resolution of early difficulties raised in the early days of genetics, largely through the work of Fisher, Haldane, and Wright; (2) the publication of Dobzhansky’s Genetics and the Origin of Species (1937a), which fused concepts of the genetics of populations with the mainstream of Darwinian thought; and (3) the demonstration by systematists (e.g., Mayr 1942), paleontologists (e.g., Simpson 1944), and practitioners of various other biological disciplines that the data of their respective fields are consistent with genetic principles. (See, for example, Shapere 1980, p. 398, for such a view of the historical development of the synthesis.) It is Mayr’s view (e.g., 1980a, 1980b) that these various nongenetics disciplines played a more vital, vigorous and active role than such “me-too-ism” implied by phase 3 above in the conventional view. There is, no doubt, something to be said for this claim, though the historical question per se is not germane to the present inquiry. But Mayr’s (1980b, pp. 127 ff) list of the contributions he feels systematists made directly to the new synthesis is relevant as it suggests a guide to our understanding of Mayr’s own important contribution—Systematics and the Origin of Species (1942, reprinted in 1982). Mayr lists the following contributions of systematics to the emerging synthesis: (1) “population thinking,” (2) “the immense variability of populations,” (3) “the gradualness of evolution,” (4) “the genetic nature of gradual evolution,” (5) “geographic speciation,” (6) “the adaptive nature of observed variation,” (7) “belief in the importance of natural selection,” and (8) the notion (shared with paleontologists) that “macroevolutionary phenomena” are interpretable in terms of “gradual evolution” (i.e., as opposed to saltational models—Mayr 1980b, p. 134). All these topics, and more, are well developed in the pages of Mayr’s Systematics and the Origin of Species.