Some scientists believe we have entered a new geological era that has been named the Anthropocene, in which humans play a profound role in shaping the planet and are a geological force to be reckoned with. According to studies by Erle Ellis ’81, an ecologist at the University of Maryland, Baltimore County, the vast majority of ecosystems on the planet now reflect the presence of people. Click on the following link to listen to an interview with Professor Ellis taped for The Economist online on May 27, 2011, while he was in London for a conference. http://www.economist.com/blogs/multimedia/2011/05/erle_ellis_anthropocene