1. Division of Biological Sciences, The University of Montana
2. Department of Biology, University of Oregon
3. NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida
4. Department of Biology, Washington University, St. Louis, Missouri
5. Department of Chemistry, Washington University, St. Louis, Missouri
6. J. Craig Venter Institute, Rockville, Maryland
7. Present address: Broad Institute, Cambridge, Massachusetts