A paleontologist compared fossils of large prehistoric mammals with modern animal species and observed that several fossil forms no longer existed anywhere on Earth. However, the scientist still rejected the idea that species evolve into new species. Which statement best summarizes this scientist’s position?

• A. Species evolve gradually through natural selection over many generations
• B. Fossils are unreliable evidence because ancient organisms still exist unchanged today
• C. Extinction has occurred, but species themselves are fixed and do not transform
• D. Organisms become extinct only when humans interfere with their environments

Answer: (C)