Over 160 years ago, Henry David Thoreau initiated a study of flowering times at Walden Pond. Today, a research team including, Charles Davis, Assistant Professor of Organismic and Evolutionary Biology and Curator in the Harvard Herbarium (below,)  has updated Thoreau’s records with current data and integrated them with modern evolutionary biology to reveal how climate change and earlier flowering times have affected Walden’s plants. Those that have greatly declined include many charismatic native wildflower species, while those that have thrived include many nonnative and invasive species. Davis will explore how an integration of historical records combined and cutting edge science can help us potentially mitigate the impacts of climate change on biodiversity. This program, taking place Thursday, November 18 at 6 pm, is free and open to the public, at the Geological Lecture Hall, 24 Oxford Street. Part of the Asa Gray Bicentennial series. For more information, log on to www.hmnh.harvard.edu.