My research focuses on the paleontological evidence for early life on Earth, the geochemical evidence for changing Earth surface environments through time, and the relationships between the two. For many years, members of my laboratory have conducted field and laboratory research on the fossil and geochemical records of Proterozoic basins. Most recently, our work has been focused on 1740- ca. 1450 Ma basins in northern Australia and a ca. 2500 Ma basin in South Africa. We have also worked in collaboration with geochemists from the Carnegie Geophysical Laboratory to develop physiologically informative, non-destructive microchemical analyses that can be used to study both ancient fossils on Earth and possible traces of biology on Mars. We have also worked with members of the Spanish Center for Astrobiology to understand how biology and environment shape the iron-rich sediments of the Rio Tinto in Spain. This work will help to guide exploration of hematitic deposits on Mars. Knoll is a member of the science team for NASA's 2003 Mars MER mission.

Facilities and equipment:
The Paleobotanical Laboratory at Harvard contains one of the world's most extensive collections of Proterozoic sedimentary rocks and fossils. These have been the focus of numerous analyses in the past and are available to the community for new types of geobiological investigation.

Courses relevant to Astrobiology:
Biology 107: The Evolution of Plants in Geologic Time EPS 181: Invertebrate Paleontology Biology 208: Issues in Paleobiology

Principal NAI collaborators:
Robert Hazen, George Cody, and Marilyn Vogel: Carnegie Geophysical Labs; Malcolm Walter: Australian Centre for Astrobiology; Ricardo Amils and David Fernandez: Spanish Center for Astrobiology (CAB)