In his newest book, Here on Earth, Tim Flannery, Australian scientist and author, offers a sweeping account of the dual evolutionary history of Earth and the life it supports. Beginning with the birth of stars to the creation of water and the accident of simple life forms, Flannery documents life up through the 2-million-year rise of our human species and ponders our future as a “superorganism” capable of either sustaining or destroying the planet’s ecosystems. This Thursday, April 21 Harvard Museum of Natural History program begins at 6 pm. Free and open to the public, Geological Lecture Hall, 24 Oxford Street. For more information log on to www.hmnh.harvard.edu.