Adjunct Professor of Computer Science, University of Oklahoma, January 2000 to present.
Supervisor (Invited Researcher), ATR Human Information Processing Research Laboratories, January 4, 1999 to February 28, 2001.
Professor, Department of Zoology, University of Oklahoma, August 1998 to present.
Member of the External Faculty of the Santa Fe Institute, November 1993 to present.
Invited Researcher, ATR (Advanced Telecommunications Research Institute International) Human Information Processing Research Laboratories, August 1993 to August 1998.
Associate Professor, University of Delaware, Computer and Information Sciences, January 1993 to August 1998.
Associate Professor, University of Delaware, Biology Department, September 1990 to August 1998.
Assistant Professor, University of Delaware, Biology Department, September 1981 to August 1990
Visiting professor at Départment D'Informatique, École Polytechnique Fédérale de Lausanne, Switzerland, October 1, 1996 to November 13, 1996.
Consultant, Inter-American Development Bank, January - July 1993.
Visiting Professor, Santa Fe Institute, July 199l; Feb. -- Aug. 1992;
Owner and operator, Finca El Bejuco Biological Station, Costa Rica, 1982 to present
Director of University of Delaware's Semester in Costa Rica Program, Spring 1988
Michigan Fellow, July 1981 to June 1982
Field Assistant to Dr. E. O. Wilson, 8/1978--8/1979, 12/1979--1/1980 and 12/1980--1/1981
Station Manager for Finca La Selva, August 1978 to August 1979
Organizer and Host of the weekly ``Society for Expeditionary Biology'' seminar series, held in the Harvard Biological Laboratories spring 1978, 1979--1980, & 1980--1981
Visiting Scientist on summer of 1977 OTS course
Research Assistant to Dr. Donald Strong at Finca La Selva, summers of 1974--1976
Assistant to Dr. Daniel Simberloff 1973--75
Environmental Consultant to FSU Department of Physical Planning 1972