Andrew Knoll, Harvard University
Fossils of shells, bones, tracks and trails record a history of animal evolution more than 600 million years in duration. Earth, however, is some four and a half billion years old, prompting the question of what kinds of life characterized our planet’s youth and middle age. Harvard University’s Andrew Knoll, a professor of Earth and planetary sciences best known for his contributions to Precambrian paleontology and biogeochemistry, addressed this question in his EDGE lecture.