On this date, Charles Darwin gave his first talk before the Royal Geological Society in London. All the experts in geology were there and this was his big opportunity to prove himself to his peers. The topic of Darwin’s paper was the gradual rising of South America over eons of time. He concluded that as land masses rise upward, the nearby ocean floor subsides, and that the animals on the rising continent somehow or another adapt to these very slow changes (at this time Darwin had no idea how this happened). This theory represented a shift away from Lyell’s theory which stated that animals cannot adapt, but rather die out and are replaced with new species. This was one of the earliest signs that Darwin was beginning to develop his own theories, going beyond his mentors. His talk was received very well by nearly all the geologists there.
C.R. Darwin, “Observations of proofs of recent elevation on the coast of Chili, made during the survey of His Majesty’s Ship Beagle commanded by Capt. FitzRoy R.N.,” Proceedings of the Geological Society of London 2 (Read 4 January 1837): 446-449.