Question

How did Lyell’s “Principles of Geology” influence Darwin?

Answer 1

Hint: Charles Lyell, a Scottish geologist, wrote the book titled “Principles of Geology”. His book explained that the Earth was formed gradually and the processes occurred in the very beginning so that life forms could survive and propagate, and are still functioning the way it is.
His work on this doctrine of uniformitarianism is his best-known work. Apart from this, he also talked about human history, geological dynamics, evolution, etc.

Complete answer:
Charles Darwin was a naturalist, well known for his evolutionary theory. The key takeaway points of his theory were- gradualism, natural selection, population speciation, and common ancestors. He had read the book “Principles of Geology” during his voyage.

Darwin observed these rock formations in one of the islands that he stopped at, and that gave him some idea about the geological history of the island. He could at that point understand Lyell’s point of view. He applied this understanding to the rest of his travels. When he came back to London, he started writing his first paper based on his observations while travelling.

The theory that every life form on earth evolved from a common ancestor was widely accepted. It was also believed that random changes occur in every generation that led to speciation. The latter statement was not well received because it could not explain how just by random changes we have such varied and complex life forms.

This was explained by Darwin. He proposed that random changes occur in individuals over some time (gradualism), however, it is nature that can choose which life form or individual will survive and reproduce. This is called natural selection and the selection of the traits in the organism is ordered. These changes are heritable and help the next generations to survive.

Note: While Darwin was influenced by Charles Lyell’s work, initially Lyell had very different views on evolution. Lyell, like his peers of that time, did not believe that random mutations could bring about evolution and believed in the permanence of species. However, he did encourage Darwin to publish on “the origin of species”. Later, after reading Darwin’s work he accepted the theory of natural selection.