January 30
John P. Dawson
Abstract Title: "A Man, a Plan, a Canal, Panama: Reactions of Azooxanthellate Corals to the Closure of the Central American Isthmus"
  About three million years ago the Central American Isthmus closed
and separated the Atlantic from the Pacific Ocean and subsequently resulted in the onset of northern hemisphere glaciation. In 1986, Jeremy Jackson and Tony Coates formed the Panama Paleontology Project (PPP) with the plan to study the entire biologic and geologic history of the Central American Isthmus. Every year since the PPP's formation, fieldwork has been performed in locations throughout Central America. As a result of their rigorous collecting, systematic paleontology, and stratigraphic work, this group has challenged views of how biodiversity in the fossil record has been studied in the past.

Due to concern over global warming, the ecology, systematics, biogeography, and evolutionary history of zooxanthellate (primarily reef-building) corals have been extensively studied. Azooxanthellate corals, in contrast, have been less well studied. Unlike their zooxanthellate relatives, azooxanthellate corals lack symbiotic algae and are broadly distributed both in water depth and in latitude.

This talk will cover the two major themes in my azooxanthellate coral research: 1) patterns of biogeography and diversity and 2) patterns of morphologic change and evolution. These patterns of stability and change in azooxanthellate corals are associated with the closure of the Central American Isthmus and the onset of northern hemisphere glaciation. In order to elucidate these patterns, I have created diversity and morphologic databases and have used many quantitative tools including multivariate statistics, traditional and geometric morphometrics, and cladistics. In addition, I will compare the patterns of change in azooxanthellate corals over the last 24 million years in the Caribbean to their zooxanthellate relatives.