"Evolutionist and Missionary," the Reverend John Thomas Gulick (1832-1923). Part II: coincident or ontogenetic...

During the last third of the 19th and first third of the 20th centuries, John Thomas Gulick (1832-1923) was one of the most well-known and influential evolutionists. His research on the nonadaptive geographical variation in snails of the genus Achatinella in the valleys of Oahu in the Sandwich Islands (Hawaii) demonstrated the importance of geographical isolation in speciation, anticipating Ernst Mayr's proposal of the founder principle and Sewell Wright's mechanisms of genetic drift and genetic isolation. Gulick mechanisms for species transformation were twofold. Both are known today under different names: geographical isolation--which Gulick called cumulative segregation--and organic selection (the Baldwin effect), which Gulick called coincident or ontogenetic selection, the topic of this paper to accompany a paper on Gulick's concept of cumulative segregation. With coincident selection, Gulick saw organisms as active participants in, and in interaction with, their environment, able to respond to environmental change without the action of, or with minimal and secondary input from, natural selection. Gulick stands in the same relationship to the Baldwin effect (coincident selection) as he does to the geographical isolation (cumulative segregation) and the founder principle (indiscriminate isolation): elucidator, original thinker, anticipator and founding father--truly an evolutionist extraordinaire, whom we should recognize as one of the earliest, most original and most innovative of evolutionary biologists.