Effects of the Uplift of the Isthmus of Panama on the Ecology, Evolution, and Extinction of Mollusks
Seth Finnegan, Professor
Integrative Biology
Closed. This professor is continuing with Fall 2023 apprentices on this project; no new apprentices needed for Spring 2024.
The rise of the Isthmus of Panama ~3 million years ago was arguably the most important biotic and oceanographic event of the past 60 million years. By connecting North and South America, the rise of the Isthmus caused the Great American interchange of terrestrial plant and animal species. In the oceans, the rise of the Isthmus had the opposite effect: the Caribbean Sea was cut off from the tropical eastern Pacific Ocean, and formerly continuous marine populations were severed. Prior to the rise of the Isthmus of Panama, the environment of the proto-Caribbean resembled that of the modern-day tropical eastern Pacific, with upwelling of cold, nutrient-rich bottom waters causing strong interannual and seasonal variations in temperature and planktonic productivity. The modern Caribbean does not experience upwelling, and hence temperatures are nearly constant and planktonic productivity very low. Hence, Caribbean species have evolved (or gone extinct) in a radically changed environment for the past 3 million years.
Role: This project will examine how the rise of the Isthmus of Panama affected the evolution and ecology of one major group by looking at the rich fossil record of mollusks (bivalves and gastropods). Mollusks are abundant and very well preserved in marine sedimentary rocks from Central America that span the interval during which uplift of the isthmus occurred. The student will examine fossil and/or modern collections to characterize the trophic structure, size-frequency distribution, and (in some cases) the age structure of mollusk communities from before, during, and after the uplift of the Isthmus. The collections will also be used to study evidence of predation by crustaceans and drilling gastropods. The student may also examine species stratigraphic ranges (oldest and youngest fossil occurrences) and ecological characteristics to determine how the species that went extinct following uplift of the isthmus differed from those that survived.
Hours: to be negotiated
Related website: http://finneganlab.org
Biological & Health Sciences