Final answer:
James Hutton and Charles Lyell were influential geologists whose ideas of uniformitarianism and an ancient Earth contributed to Darwin's theory of evolution by natural selection.
Step-by-step explanation:
James Hutton and Charles Lyell were pivotal figures in geology whose ideas contributed significantly to the development of evolutionary theory. Hutton known as one of the founders of modern geology, introduced the concept that geological changes occur gradually over immense periods challenging the predominant view of a young Earth shaped rapidly by catastrophic events.
This concept known as uniformitarianism, was further developed and popularized by Lyell, a friend and significant influence on Charles Darwin. Lyell's work suggested a much older Earth, allowing more time for evolution and provided an analogy for the gradual change in species an idea crucial to Darwin's theory of evolution by natural selection.