Evolution of Temperature Controls on Alkenone Biosynthesis

Indiana University, Bloomington IN

Investigators

Abstract

9909857 Brassell This project focuses on the geological record of molecular evolution. Its working hypothesis is that alkenones were first biosynthesized by calcareous nannoplankton in the Cretaceous, but that temperature-controlled synthesis of alkenone unsaturation developed in the Eocene as a response to cooling trends. To answer this postulate the project will investigate the distributions of alkenones in suites of Paleogene and Cretaceous sediments from the Atlantic to determine the timing of the development of the temperature dependence in their biosynthesis by haptophyte algae. The availability of materials from multiple sites facilitates exploration of the timing and geographic extent of specific alkenone adaptations, and provides the opportunity to correlate their characteristics with their source organisms, calcareous nannoplankton, and the timing of significant climatic events.