Evo-devo

The birth of evo-devo and a second synthesis

In 1977, a revolution in thinking about evolution and developmental biology began, with the arrival of recombinant DNA technology in genetics, the book Ontogeny and Phylogeny by Stephen J. Gould and the paper "Evolution and Tinkering" by François Jacob. Gould laid to rest Haeckel's interpretation of evolutionary embryology, while Jacob set out an alternative theory. This led to a second synthesis, at last including embryology as well as molecular genetics, phylogeny, and evolutionary biology to form evo-devo. In 1978, Edward B. Lewis discovered homeotic genes that regulate embryonic development in Drosophila fruit flies, which like all insects are arthropods, one of the major phyla of invertebrate animals. Bill McGinnis quickly discovered homeotic gene sequences, homeoboxes, in animals in other phyla, in vertebrates such as frogs, birds, and mammals; they were later also found in fungi such as yeasts, and in plants. There were evidently strong similarities in the genes that controlled development across all the eukaryotes. In 1980, Christiane Nüsslein-Volhard and Eric Wieschaus described gap genes which help to create the segmentation pattern in fruit fly embryos; they and Lewis won a Nobel Prize for their work in 1995.