On 8 May 1900, the English biologist William Bateson was on the way to the Royal Horticultural Society to read a paper on the topic “Problems of Heredity as a Subject for Horticultural Investigation” (Fig. 33.1). Several years later, his wife tells the story: “He had already prepared this paper, but in the train on his way to deliver it, he read Mendel’s actual paper on peas for the first time. As a lecturer he was always cautious, suggesting rather than affirming his own convictions. So ready was he however for the simple Mendelian ratios that he at once incorporated it into his lecture” (B. Bateson 1928, 73). Mendelism had arrived on the scene!

Mendelians and Biometricians

Bateson was one of a number of biological researchers who, in the 1880s, had started their careers as morphologists or embryologists, much interested in evolutionary questions (Ruse 1996). However, it was not long before he and his fellows realized that truly they were getting nowhere. Although, out in the American West, fabulous fossil finds were being made almost daily, overall the fossil record was not strong enough to support detailed investigations of life’s past. Closer to home, Haeckel’s biogenetic law was simply not sufficiently accurate or powerful to allow for reliable tracings of phylogeny. Morphology and embryology did not suffice. In Bateson’s own words: “Morphology was studied because it was the material believed to be most favourable for the elucidation of the problems of evolution, and we all thought that in embryology the quintessence of morphological truth was most palpably presented. Therefore every aspiring zoologist was an embryologist, and the one topic of professional conversation was evolution.” To no avail. “Discussion of evolution came to an end primarily because it was obvious that no progress was being made. Morphology having been explored in its minutest corners, we turned elsewhere” (B. Bateson 1928, 390). Bateson himself turned to the potential building blocks of change, producing a massive tome on the subject in the early 1890s (Materials for the Study of Variation).