Bachelor in Biology and Mathematics, Hampshire College, 1978. Doctor of Philosophy in Biology, Massachusetts Institute of Technology, 1984.
Research assistant, University of Pennsylvania, 1977-1978; postdoctoral fellow, University of California, San Francisco, 1984-1987; assistant professor biology, California Institute Technology, Pasadena, 1987-1992; associate professor biology, California Institute Technology, Pasadana, since 1992. Assistant investigator Howard Hughes Medical Institute, 1989-1992, associate investigator, since 1992. Adjunct assistant professor department cell and neurobiology University of Southern California School Medicine, since 1989.
Fellow American Association for the Advancement of Science, American Academy Arts and Sciences. Member American Society Cell Biology, Genetics Society of America, Helminthological Society Washington, Society for Development Biology, Society Nematologists, National Academy of Sciences.