Dissertation Research: Morphological Variation and Macroevolution in the Ostracode genus Poseidonamicus

University Of Chicago, Chicago IL

Investigators

Abstract

This project explores the manner in which morphology has evolved over the course of the 40 million year history of the deep-sea ostracode genus Poseidonamicus. Fossil and modern specimens will be studied using scanning electron microscopy. Features of the ostracode carapace will be measured using the digital images obtained, and patterns of morphological change over time will be reconstructed. From these data, it will be determined if features that are more variable within populations are also more likely to evolve. This study will be one of the first to use the fossil record to determine if patterns of variation affect the direction of long-term evolutionary change. While the evolutionary importance of these patterns is well understood over the course of a few generations, it is not clear whether trait variability matters for long-term evolution. Several researchers have suggested that patterns of variation should act to bias or constrain the course of evolution, even over long time stretches of time. The proposed research uses the evolutionary history of a taxon with a rich fossil record to test these suggestions.