After the asteroid impact at the end of the Cretaceous period that triggered the dinosaurs' extinction and ushered in the Paleocene, leaf-mining insects in the western United States completely disappeared. Only a million years later, at Mexican Hat, in southeastern Montana, fossil leaves show diverse leaf-mining traces from new insects that were not present during the Cretaceous, according to paleontologists.

Responding to the impact that a growing population and changing land use have had on the Chesapeake and Delaware Bays over the past 60 years is the focus of a research project led by Penn State and supported by a $1.4 million grant from NASA.