Final answer:
James Hutton wrote the theory of the Earth in 1785 and established the principle of uniformitarianism, suggesting geological change was gradual due to long-acting processes. Charles Lyell later popularized Hutton's theory in the 19th century, influencing Charles Darwin's ideas on evolution and the significant increase in the presumed age of Earth.
Step-by-step explanation:
The theory of the Earth, established in 1785, which laid the groundwork for the principle of uniformitarianism, was written by James Hutton. Hutton, a Scottish geologist and naturalist, proposed that geological change was gradual, resulting from small changes accumulated over long periods from processes operating just like those of the present day. Hutton's work significantly contrasted with the popular belief at the time, which attributed Earth's geologic features to catastrophic and short-lived events.
The concept of uniformitarianism was later popularized by Charles Lyell, a 19th-century geologist, in his multi-volume work Principles of Geology. Lyell became a significant influence on Charles Darwin and his ideas on evolution. It was Lyell's work that introduced the notion that Earth was much older than previously thought, giving sufficient time for gradual geologic and biological changes, which supported Darwin's theory of natural selection.
While Lyell's contributions were pivotal and he established a more complete view of uniformitarianism, it was Hutton who initially theorized about Earth's features being shaped over immense periods by consistent processes. Hutton's views laid the foundation for the uniformitarian principles that would profoundly influence the scientific understanding of Earth's history and the development of evolutionary biology.