Theoretical embryology: a route to extinction?

Once upon a time, about thirty years ago, there were two species of developmental biologists. The first of these were the experimentalists. These had been around for more than a hundred years and had descended from predecessors such as Boveri, Morgan and Spemann. In attempting to understand the awesome complexity and reliability of development, they developed explanations verging on vitalism. They built concepts such as epigenesis (the hypothesis that development is essentially a process of elaboration from a simpler start), regulation (the notion that embryos are often able to correct damage done to them either by the environment or by the experimentalists) and fields (the idea that specific domains of embryos are to some extent self organising). These concepts were rather abstract and took little account of either cells or genes. Their experiments, which consisted mainly of transplanting or excising parts of embryos, were published in journals such as Journal of Experimental Zoology and Developmental Biology, and they built their careers as scientists always have. As ever, their fields of investigation evolved through a process of natural selection that was fuelled by fashion.