Which geologist argued for slow, gradual change and the existence of more primitive life in older rocks, and authored a work Darwin read during his voyage?

• A. Lyell
• B. Hutton
• C. Cuvier
• D. Darwin

Answer: (A)

The idea being tested is uniformitarianism—the belief that slow, continuous processes over vast stretches of time shape the Earth and its life. Charles Lyell argued for this gradual change and, through his fossil record in older rocks, suggested that early life forms were more primitive. He wrote Principles of Geology, a work Darwin carried on the Beagle voyage, which helped shape Darwin’s thinking about deep time and gradual evolution. While Hutton also spoke to gradual change, the specific work Darwin read during the voyage was Lyell’s; Cuvier favored sudden, catastrophic events; Darwin himself was the naturalist, not the geologist who authored that influential text.