Complex sentence: Parkinson's interest gradually turned from medicine to nature, specifically the relatively new field of geology, and paleontology, and he began collecting specimens and drawings of fossils in the latter part of the eighteenth century.
Split into simpler sentences: Parkinson's interest gradually turned from medicine to nature, specifically the relatively new field of geology, and paleontology. He began collecting specimens and drawings of fossils in the latter part of the eighteenth century.