There are several individuals that had a major impact on Darwin, but the most important influence was Charles Lyell. Lyell was known for one of the most influential books of our time called The Principles of Geology. Lyell's book stated his theory that the Earth's crust was always changing a small amount over a vast period of time. Lyell's "Uniformitarian" idea was extremely controversial for 1830 and he was criticized and ridiculed for his theory. While Darwin was on his boat The Beagle, he experienced an earthquake and then measured an 8 foot uplift in the land. Darwin took the motto of uniformitarianism, "The present is the key to the past," and he applied it to his research on evolution. Darwin came to the conclusion that just like how the land slowly developed to what we see today, the biological evolution of creatures and life around us took just as much time for organisms to develop into their full potential. Just like Lyell's book not being accepted by the church neither was Darwin theory on evolution. Neither of their ideas were accepted during their lifespan but their contributions and ideas to science live on today.

http://www.pbs.org/wgbh/evolution/library/02/4/l_024_01.html