Introduction

Abstract

Conventionally and in very introductory presentations, the Evolutionary Synthesis is said to have been initiated with the work of Fisher, Haldane and Wright in the early thirties (Fisher, 1930; Wright, 1932; and Haldane, 1932). It is certainly the case that in the first decades of this century there appeared to be a very fundamental conflict, even a contradiction, between Darwinian natural history, the home of evolutionary speculation, and Mendelian genetics, a rapidly developing experimental science. Darwinians thought of variations so small that continuous evolution of adaptive features could result from them; Mendelians thought of their variations, ‘mutations’, of whatever magnitude, as discontinuous, segregating and, even when expressed in phenotypic ‘blends’, continuing their separate ways in a kind of patchwork ‘germplasm’. Bateson’s journal, Genetics,was said to have been initiated precisely to oppose Darwinism (at least Waddington said so). And then, lo and behold, Fisher, Haldane, and Wright, in different mathematical modes, showed that genetic discontinuities could be handled so as to produce nice continuous curves — the seeming contradiction was no contradiction at all. Experimental genetics, in particular, population genetics, became the underpinning of Darwinian theory, and at the same time and by. the same conceptual move, Darwinian theory became the theoretical explanation of Mendel’s laws. Moreover, even if Mayr and Provine begin their story in 1936, there is no doubt that this triumphant reconciliation, initiated in 1930–1932, was given its classic and foundational expresssion in Dobzhansky’s Genetics and the Origin of Species in 1937 (based rather on Wright’s than on Fisher’s or Haldane’s versions of population genetic algebra).