EXPERIMENTAL EMBRYOLOGY AND THE SYNTHESIS

In this chapter I examine the early interactions between embryology and the Evolutionary Synthesis. Section 9.2 sketches some of the accomplishments of experimental embryology. Section 9.3 covers criticisms that some embryologists directed against the Mendelian–chromosomal theory of heredity, and through that the Synthesis. Section 9.4 proceeds to the potentially Synthesis-friendly work by embryologists and other developmental theorists, and the Synthesis reactions to this work. Section 9.5 covers the position of development within the Synthesis up to about 1959.

Scott Gilbert is a developmental biologist, an evo–devo practitioner, and a trained historian of science. Many of his historical writings argue for the relevance of the tradition of experimental embryology to modern biology. Gilbert claims that, during the mid-twentieth century, embryology began to be unfairly depicted as old-fashioned and metaphysically flawed. He traces the beginnings of this disparagement of embryology to two reformed embryologists, William Bateson and T. H. Morgan (Gilbert 1998). The grounds for Morgan's sudden disapproval of his own former field are complex. They surely involved his hopes for the new genetic paradigm, and probably also the institutional and financial support that genetics came to receive in the United States (Allen 1985). I suspect they also involve what I have called Morgan's quasi-positivism. Morgan expresses this influence in a paper on the rise of genetics. In this paper, he separates science from philosophy and metaphysics, which are to be discarded “not because they are wrong, but because they are useless.“