Dr. Ross MacPhee is the former chairman of the Department of Mammalogy at the American Museum of Natural History, where he has been curator since 1988. Known for his paleomammalogical research on island extinctions, he has focused his most recent work on extinctions occurring during the past 50,000 years, or "Near Time." He is the author of the new book "End of the Megafauna: The Fate of the World's Hugest, Fiercest, and Strangest Animals" (Norton, 2019). Dr. MacPhee has also collaborated with geneticists and molecular biologists to develop the new tool of "ancient DNA" for studying the ultimate collapse of Pleistocene mammals.