The modern evolutionary synthesis arose out of the conjunction of the Mendelian theory of inheritance and the neo-Darwinian theory of population change early in the 20th century.1 In the nearly 100 years since its inception, the modern evolutionary synthesis has grown to encompass practically all fields of comparative biology—ecology, ethology, paleontology, systematics, cell biology, physiology, genetics, development. Theodosius Dobzhansky’s dictum—“nothing in biology makes sense except in the light of evolution” (...