Molecular clocks, marine geminate species, and research in Panama
Oris Sanjur, Ph.D.
Smithsonian Tropical Research Institution
Friday, February 4, 2005
Pacific Forum – Noon
"Geminate" marine species separated by the Central American Isthmus provide a great opportunity to study the molecular evolution of taxa that have been separated approximately 3 millions years. The rise of the Panamanian Isthmus rendered the continuous range of marine taxa into two large populations, resulting in many pairs of closely related marine species. Because they are numerous, phylogenetically diverse, and are thought to have been separated by the same geologic event, the geminate species pairs provide a remarkably array of organisms in which to investigate nucleotide substitution processes and rate variation in molecular clocks. We use around 20 marine sister taxa separated by the rise of the Panamanian Isthmus to test the molecular clock hypothesis, using one nuclear and four mitochondrial genes. We compare nucleotide substitutions processes across genes, and provide a discussion on differences in substitution rates among these genes.I will also present a brief introduction to the Smithsonian Tropical Research Institute, its areas of research, and the facilities.