Paleontology
From Memory Alpha, the free Star Trek reference
Paleontology is the study of the developing history of life.
Commander Chakotay of the starship USS Voyager had a passion for paleontology, and considered becoming a paleontologist himself. He was able to use he skills and knowledge of the subject matter at least twice on Voyager; in 2373, while examining the Distant Origin Theory and in 2376 while searching for a lost Mars spacecraft, Ares IV. (VOY: "Distant Origin", "One Small Step")
