Bachelor of Science, University Minnesota, 1961. Doctor of Philosophy in Entomology, University California, Berkeley, 1965.
Assistant and Association Professor, University »f Kansas 1965-1968. Association Professor, University of Chicago 1969-1972. Association Professor, and Professor, of Ecology and Evolutionary Biology, University of Michigan 1972-1976.
Pruf. of Biology, University of Pennsylvania, Philadelphia since 1976. Teaching responsibility "ith Organization for Tropical Studies in Costa Rica since 1965. Field research in tropical ecology, supported mainly by grants from National Science Foundation, 1 S.A. since 1963.
MacArthur Fellow 1989.
Served with Member of Parliament, United States Army, 1957. Member British Ecological Society, Ecological Society of America, American Society Naturalists, Association for Tropical Biology, American Association for the Advancement of Science, National Academy of Sciences.