Lynn Margulis, Distinguished Professor in the Department of Geosciences at the University of Massachusetts-Amherst and president of Sigma Xi for 2005-06, still works with students and colleagues on her theory of the origin of cilia from symbiotic spirochetes. An avid environmentalist, she investigates extensions of James E. Lovelock's Gaia hypothesis. Address: Department of Geosciences, Morrill Science Center, University of Massachusetts, 611 North Pleasant Street, Amherst, MA 01003-9297. Internet: celeste@geo.umass.edu