I investigate environmental changes in the geologic and historic past, and also the extent to which they have affected evolution and paleobiogeography, including changes in evolutionary rates, communities, and organismal morphology. The originations and extinctions of fossil taxa and their ecology/paleoecology are used to identify evolutionary, paleoceanographic, paleoclimatic and tectonic trends through time. Current research projects are listed below.
PANAMA PALEONTOLOGY PROJECT, the web site for a long-term, multinational research project
NEOGENE EVOLUTION OF TROPICAL AMERICAN BENTHIC FORAMINIFERA
The Neogene emergence of the Isthmus of Panama separated tropical Eastern Pacific and Western Atlantic waters and biotas. Fieldwork in Central America and South America is establishing a stratigraphic and paleoenvironmental framework to assess the biogeographic and evolutionary changes in tropical American Neogene benthic foraminifera.
UPLIFT OF THE ISTHMUS OF PANAMA
I am using the paleoecology and stable isotopes of foraminifera to identify evolutionary shallow-water and deep-water paleoceanographic and tectonic changes associated with the early Miocene to early Pliocene emergence of the Isthmus of Panama.
ENVIRONMENTAL CHANGES IN FLORIDA BAY
Florida Bay is part of the environmentally challenged Everglades National Park. This is an investigation of the amount of variation in coastal environmental conditions that is naturally occurring. Several approaches to reconstructing the historical record of environmnetal change include variations in salinity and seagrass abundance, which is highly correlated with environmental water quality. The project collected sediment cores and applied proxies of salinity, distance from shore and seagrass abundance as indicators of the environmental water quality and sea level change over the past hundred to four thousand years. The results from foraminifera and diatoms are being combined with those of experts in sedimentology, geochronology and geochemistry.
RESEARCH IN THE FIELD, pictures from Central America, South America and South Florida