How did Principles of Geology influence Charles Darwin?

Charles Lyell’s Principles of Geology profoundly influenced Charles Darwin, shaping both his scientific methodology and his theoretical framework for evolution. Darwin carried the first volume of the work with him on his voyage aboard the HMS Beagle, and he later noted that the book "altered the whole tone of one’s mind," allowing him to view geological phenomena through Lyell’s perspective.123

The influence of Principles of Geology on Darwin was twofold:

• Methodological Approach: Darwin admired Lyell’s superior manner of treating geology, which emphasized natural, observable processes over supernatural explanations. This approach taught Darwin to interpret complex natural history through the lens of consistent, ongoing causes.45
• Theoretical Foundation: Darwin borrowed two critical concepts from Lyell’s uniformitarianism to support his theory of evolution: the idea that geological time is virtually limitless and the understanding that a sequence of minute, gradual changes integrated over vast periods can produce significant transformations in natural entities.1

Darwin drew heavily on both the style and content of Lyell’s work when developing his own revolutionary ideas.6