 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.