Complex sentence: Darwin was eminent as a naturalist, geologist, biologist, and author; after working as a physician's assistant and two years as a medical student was educated as a clergyman; and was trained in taxidermy.
Split into simpler sentences: Darwin was eminent as a naturalist, geologist, biologist, and author. After working as a physician's assistant and two years as a medical student, he was educated as a clergyman; he was also trained in taxidermy.