ABSTRACT
The concept that changes in individual development are the basis for evolution was raised originally by St. George Mivart in his book On the Genesis of Species (1871). William Bateson also favored the idea but little was done to work out the details until Walter Garstang (1868-1949) and Gavin de Beer (1899-1972) delivered their respective coups de grace to Haeckel’s recapitulation doctrine, and, from another side entirely, Richard Goldschmidt (18781958) hypothesized that changes in early embryonic development would be necessary for evolution to occur. While Garstang and de Beer were interested in showing the importance of various kinds of on-togenetic changes to evolution generally, Goldschmidt, having become convinced of the impossibility of neo-Darwinian microevolution producing a new species, had come to the notion
of a developmental macromutation as essential to the production of the large differences necessary for speciation.
