Answers to the Pop-Quiz

Posible answers to the Pop-Quiz Briefly describe two ideas about evolution that were proposed by scientists in the 18th century. They proposed that species could change and that different species may have come from a common ancestor. What ideas in Lyell´s theory of uniformitarianism were important for evolutionary theory? Lyell stated that observable geologic processes, such as the deposition of soil, occur over a long perior}d of time at a uniform rate.

What are the key differences between the theories of gradualism and catastrophism? Gradualism emphasizes slow changes on Earth over long periods of time, while catastrophism emphasizes change through natural disasters. Why are the ideas that Earth undergoes change and is billions of years old important for evolutionary theory? Evolution often happens over long periods of time. The fact that Earth can change over time inspired the idea that organisms can also change. Earth´s great age makes it posible for significant changes to have occurred.