The Phylogeny of Octavolateralis Ontogenies: A Reaffirmation of Garstang’s Phylogenetic Hyphothesis

Abstract

The relationship of ontogeny—the development or life history of an individual—to phylogeny—the history of successive biological populations—has been a focus of biological research for almost 200 years, and a number of solutions have been proposed (see Russell 1916; Holmes 1944; de Beer 1958; Gould 1977; Kluge and Strauss 1985, and Northcutt 1990a for reviews). Garstang’s proposal (1922), however, appears to be the most insightful. Garstang realized that phylogeny is usually perceived as a succession of adults, when, in fact, it is the result of changes, through time, in an ancestral life history (those stages and processes that span the development of one zygote to another zygote). Thus in Garstang’s view, subsequent changes in an ancestral ontogeny create phylogeny.