Charles Darwin’s book, On the Origin of Species (1859,) introduced the scientific theory that populations evolve over the course of generations through a process of natural selection.
The Galapagos Islands are associated with Charles Darwin’s theory of evolution; however, “(Hawaiʻi) is where modern evolution started, and people don’t know it.” (Jones, Star-Bulletin)
John Thomas Gulick did the first modern evolutionary study on Hawaiian land snails. Gulick discovered dramatic differences in snails in valleys only short distances apart and developed a theory about speciation, or new species emerging through evolution. (Altonn)
Gulick had been a collector of land snails since his teen years and became a convert to evolutionary thinking even before reading On the Origin of Species.
An acute observer, he noticed that many species and varieties of snails were often restricted to very geographically-limited ranges. (Smith)
He came “to place great emphasis upon every form of isolation or prevention of mingling, and also to emphasize the great significance for evolution of many factors that are of internal origin, such as the unknown intricacies of the process of heredity, and the effects of new choices made by the evolving creatures…” (Addison Gulick; Smith)
“In Manoa there were a number of kukui trees which were the favorite places of one species of the shells. A little beyond, in Makiki, a half mile or so, hardly that, there was a different species.”
“In Pauoa there was a still different species, while in Nuʻuanu there were landshells of allied form, but which had changed their habits, living on the hau trees in preference to the kukui trees, which were the favorites of the Manoa shells. This was in 1852 and 1853.”
“I knew that these shells didn’t come from Noah’s ark. They couldn’t have even come from the other islands. Right here in Manoa we had what you might call a special creation. In Makiki Valley we had another special creation. And yet we had every reason to believe that all were allied. (Gulick, Mid-Pacific Magazine, January 1912)
“I began to have the idea that I had found a place of creation. I found out that the shells had no ability to travel from valley to valley. Those which lived on ridges were diffused over a larger area, but would have perished in the valleys. Those in the valleys could not have lived on the ridges.”
“If heavy rains washed some down from the valleys to the plains, they died in a few hours, or a few days at the most. If they were washed out to sea, of course they did not live. We tried to keep Manoa Valley shells alive at the school, but could not do it. They were as completely isolated in each locality as if they had been on separate islands.” (Gulick, Mid-Pacific Magazine, January 1912)
Gulick was among the first to recognize the critical role for geographical separation in the diversification of ecologically similar Hawaiian land snails. His ideas were discussed by Darwin, as well as leaders in the Modern Evolutionary Synthesis who saw an important role for geographical isolation in speciation. (Rundell)
“Darwin’s book, ‘Origin of Species,’ was published in ‘59, the year I left college. My mind was ripe for it and had already got started on this subject. I accepted largely the theories of evolution. I accepted natural selection, but in addition I saw the necessity of isolation.” (Gulick, Mid-Pacific Magazine, January 1912)
Gulick’s theory of the species-differentiating effects of isolation was regarded by many as a more complete theory of speciation than Darwin’s and others as correcting a fundamental deficiency in Darwin’s theory, namely how groups of organisms diversify one from another.
With his concepts of cumulative segregation (geographical isolation), indiscriminate isolation (the Founder effect) and coincident selection (the Baldwin effect), we should recognize Gulick as one of the earliest and most original and innovative evolutionary biologists. (Hall)
Gulick extended his ideas to societal evolution in human beings. (Smith)
While a leading biologist, an interesting aspect of Gulick’s beliefs is that he was a son of a Hawaiʻi missionary, and was a missionary himself, going to China and Japan under the American Board of Commissions for Foreign Missions (ABCFM – the same organization who sponsored the Hawaiʻi missions.)
Gulick was born March 13, 1832, at Waimea, Kauai, son of Peter Johnson and Fanny (Thomas) Gulick. He first married Emily De la Cour September 3, 1864, at Hong Kong, China, who died in childbirth in 1875 (no children,) then remarried Frances A Stevens May 31, 1880, at Osaka, Japan (they had two children, Addison and Louise.)
Gulick continued a family tradition by attending theological school and then did missionary work in China and Japan for over thirty-five years. But he also carried on a parallel career as a naturalist and, somewhat strange to say, Darwinian evolutionist. (Smith)
One of the world’s foremost scientists, Gulick, peer of Darwin, whose theories he accepted and advanced, and while a missionary still espoused the cause of Darwin and added to the doctrine of evolution the theory of isolation. (Mid-Pacific Magazine, January 1912)
Later in 1905, Gulick returned to Hawaiʻi and sold his shell collection to Charles Montague Cooke, Jr the new curator of the Bernice P Bishop Museum. He remained there until his death, on April 14, 1923 in Honolulu. He and his second wife are buried in the Mission Houses cemetery.