his peers, since that is what they spent much of their time doing. The disenchantment began in Cambridge, where he could never summon up much interest in the lineages or relationships of species. His professors advised him to keep his thoughts on evolution to himself: “You might think these things, but you mustn’t say them,” one warned.
Isolated in Dundee, however, Thompson could give his originality its head and, untroubled by career success, work on what he liked. In 1894 he presented a paper to the British Association meeting in Oxford titled “Some Difficulties of Darwinism,” in which he expressed doubt that, among other things, the vibrant colors of hummingbirds could come about through a dour struggle for existence. Thompson, in contrast, saw the plumage as the product of a benign environment. The hummingbird’s livery, he suggested, was the product of “laws of growth,” operating unchecked by natural selection. He also sought to banish natural selection from the shape of birds’ eggs, arguing that the narrow, pointed eggs of the guillemot, a seabird that nests on cliff ledges, were formed by pressure from muscles in the mother’s oviduct. This contrasted with, although it does not contradict, the evolutionary explanation that this shape gives the eggs a tight turning circle and stops them from rolling off their ledge. One of Thompson’s old Cambridge professors was in the chair. “He did not hide his impatience and disapproval,” Thompson later recalled. “There were no difficulties in Darwinism, either to him or any sensible man in those days.” In truth, Thompson’s notions about evolution and natural selection have not aged well. But his efforts to formulate new laws to put in the place of natural selection took him down many fruitful paths. In the process he pioneered a different type of biological thinking and a new type of biological explanation.
The seeds of mathematical and physical thinking germinated in Thompson’s mind in the late 1880s. In October 1889 he wrote to Mary Lily Walker, a former student: “I have taken to Mathematics, and believe I have discovered some unsuspected wonders in regard to the Spirals of the Foraminifera!”