These physical changes were empirical as Darwin saw after he experienced an earthquake in Chile and the Earth’s crust rose. The uniformitarian theory influenced Darwin’s natural selection theory, because he thought the changes observed in the Earth’s structure could also be observed in animals, which had evolved through small variations during a lot of years. Darwin thought just as natural forces like earthquakes affected the Earth’s formation, there were natural processes such as inheritance and competition that would moderately affect the characteristics of a species. 

This shortage would cause a decrease in the population, due to problems like famine, and the population would stay moderated until the cycle repeated itself. Darwin recognized that animals, like humans, depended on resources like food and competed for them between each other. To avoid losing this competition or facing issues like starvation, the best genes of a species would be maintained throughout its bloodline  for a better chance at surviving. 

Lamarck influenced Darwin’s evolution theory by acknowledging that the environment changes and because animals want to survive, they adapt themselves and eliminate those traits that are making them weaker. However, Lamarck made the drastic assumption that the elimination of weaker traits would transform organs, and these organs would be inherited by the kids. Darwin did not believe that “better” organs were inherited by the children rather that the best genes were preserved for the whole species through natural selection. 

For example, when an earthquake happens the Earth’s crust lifts up, which eventually forms mountains. Uniformitarianism influenced and supported Darwin’s theory of evolution because it pointed at the fact that the Earth was ancient. Darwin thought, during this long time of earth’s existence, it wouldn’t make sense that species would stay the same as they had been in the beginning, they would either evolve with the fittest genes or go extinct. 

Both excited to prove that natural selection was real, wrote a paper together and published it. A year later, in 1859, Darwin published the infamous book called the Origin of Species explaining evolution and the process of natural selection. Writing the paper with Wallace the year before, who was like a mentor to Darwin, was the base for a successful career.