Part II is about origins: how do new traits arise from old phenotypes? People of all ages are fascinated by the question of origins. Origins are the common concern of evolutionists and creationists, of ethnic historians, of Mormon geneologists and the Daughters of the American Revolution, of adopted children searching for their biological parents— indeed, of all who have wondered where Johnny got his patience, his sense of humor, or his big nose. Darwin was a clever publicist when he titled his most famous book The Origin of Species. He touched deep human chords by discussing not only the origin of species but the origin of marvellously complex morphological and psychological traits—specialized limbs, sexual behavior, intelligence, heroism, and the vertebrate eye, to mention just a few. Research on selection and adaptation may tell us why a trait persisted and spread, but it will not tell us where a trait came from. This is why evolutionary biology inevitably intersects with developmental biology, and why satisfactory explanations of ultimate (evolutionary) causation must always include both proximate causes and the study of selection. Novel traits originate via the transformation of ancestral phenotypes during development. This transformational aspect of evolutionary change has been oddly neglected in modern evolutionary biology, even though it is an integral part of human curiosity about origins in other fields. From classical mythology to modern-day childrens’ books, origins are explained in terms of transformations of the phenotype, alongside attention to developmental mechanisms and adaptive functions. Consider this excerpt from The Apeman’s Secret (Dixon, 1980), a Hardy Boys adventure book: . . . [T]he Apeman hated cruelty of any kind. Whenever he saw crooks or villians do something nasty to a helpless victim, he would fly into a rage. This would change his body chemistry and cause him to revert to the savage state. . . .
The Nature and Characteristics of the Gods in Classical Mythology
