I received a Ph.D. in Paleontology from the University of California at Davis in 1978. Shortly after finishing my degree, I was employed as museum scientist by the Geology Department at Davis. My job was to assemble collections of minerals, rocks and fossils to help teach courses in geology and paleontology and to support the research being carried out by the faculty. During my time at Davis, I learned a lot about how to classify natural materials and also a lot about how nature is organized. While a museum scientist, I also taught courses in geology and paleontology. My favorite course was a field course in marine paleoecology (study of the ecology of fossil life). I taught this course at the university's marine station at Bodega Bay, in northern California. The course lasted six weeks and my students were able to go out to the field almost everyday and observe and carry out experiments on living marine communities. We tried to understand not only living creatures, but how they become fossilized. In the second half of the course we visited many different places in California where we could study the fossil record of marine life and reconstruct how the ancient marine species lived and interacted.

After five years as museum scientist I decided to try another career and left Davis to join Exxon as a petroleum geologist. My job with Exxon was to find oil. I focused my search on the offshore marine areas of southern California. Using many different methods that enable geologists to visualize the study of rocks underground, I was able to determine the most likely places to drill for oil and gas. It was exciting and during my five-year stay with Exxon I found between five and 10-million barrels of oil.

After leaving the petroleum industry I returned to academics. Although I enjoyed finding oil, I really missed teaching. I was able to land a job teaching Oceanography, Earth Science and Paleontology at UCLA in southern California. I was there for five years and during that time also developed my present interests in the very early history of life and the solar system. This brought me to NASA in 1991 on a research fellowship from the National Research Council. The project I came to NASA to do focused on developing methods to better interpret the fossil record of very small microorganisms. It was quite a change from my early years as a paleontologist where I focused on larger organisms with hard skeletons of bone or shell. Now I had to worry about how very small organisms with no skeletons could become fossils.