Darwin Was No Geologist
Charles Darwin's ignorance of geology, a science he never studied, probably resulted in the biological errors he made in formulating his theory of biological evolution.
As he sailed on the Beagle to the Pacific, Charles Darwin read Charles Lyell's book, Principles of Geology. That book, of course, theorized that the Earth's geology was the result of the slow processes we see today working over millions of years. On the way to the Galapagos he had a 16-day stopover in Argentina. He spent some of the time exploring the valley of the lower Santa Cruz River. He later wondered in his journal how the small and lazy Santa Cruz River could have carved the 300-foot-deep valley. But he allowed that Lyell's idea of long ages could solve that problem.
Later, at the Galapagos, he tried to explain plant and animal diversity based on those same long ages. Today, geologists believe that melting glaciers at the headwaters of the river formed a huge lake behind a natural dam. When that dam broke, the rushing lake water quickly cut a spillway that became the valley through which the Santa Cruz River gently flows today.
It appears as though Darwin's assumption that Lyell knew what he was talking about when he wrote of long geological ages influenced his biological interpretations.