J. William Schopf, Distinguished Professor of Paleobiology at the University of California, Los Angeles, is the recipient of the NAS Award in Early Earth and Life Sciences, presented this year with the Charles Doolittle Walcott Medal. Schopf is being honored for his studies of the microscopic fossils that represent the earliest forms of life on Earth and for his generous and inspirational leadership of large, collaborative research groups. These "Precambrian Paleobiology Research Groups" brought together scientists from multiple scientific disciplines and focused their efforts to yield new ideas and information. Their work has stimulated countless further studies of the earliest history of life on Earth. The Walcott Medal is presented every five years with a $10,000 prize and recognizes contributions to research on Cambrian or Precambrian life.