Corals in Space and Time

Book excerpt: As concerns about the change in global climate and the loss of biodiversity have mounted, attention has focused on the depletion of the ozone layer and the destruction of tropical rainforests. But recently scientists have identified another seriously endangered ecosystem: coral reefs. In Corals in Space and Time, J.E.N. Veron provides a richly detailed study of corals that will inform investigations of these fragile ecosystems. Drawing on twenty-five years of research, Veron brings together extensive field observations about the taxonomy, biogeography, paleontology, and biology of corals. After introducing coral taxonomy and biogeography, as well as relevant aspects of coral biology for the non-specialist, he provides an interpretation of the fossil record and paleoclimates, an analysis of modern coral distribution, and a discussion of the evolutionary nature and origins of coral species. Revealing a sharp conflict between empirical observations about the geographical variation within species, Veron introduces a non-Darwinian theory of coral evolution. He proposes that the evolution of coral species is driven not primarily by natural selection, but by constantly shifting patterns of ocean circulation, which produce changing variations of genetic connectivity. This mechanism of speciation and hybridization has far-reaching consequences for the study of all types of corals and potentially many other groups of organisms as well.