The Origin of Species Even though Darwin’s ideas were considered revolutionary in Victorian England, natural evolution was no novel concept when in 1859 he published On the Origin of Species. Some philosophers and scientists of the eighteenth and nineteenth centuries had already been toying with the idea that species were not stable– that is, that they could change and, over time, become new species. Scientists like the French naturalist Jean-Baptiste Lamarck (1744–1829) and Charles Darwin’s grandfather, Erasmus Darwin (1731–1802), had been explor- ing the idea for years. However, no one had been able to convincingly suggest a natural mechanism that could be driving evolution, and so natural evolution had remained a fringe idea. Apparently, Darwin was not an adherent of evolution (or what it implies) in his younger years. Rather, at least according to official biog- raphies, he was a strong believer in the Bible, trained in Christian the- ology. As he later described, “I did not then in the least doubt the strict and literal truth of every word in the Bible.” 1 And according to the Bible, creation had taken place just a few thousands– and not millions– of years earlier, when over a period of six days God had created each spe- cies– each type of plant, animal, and human being– separately. Darwin is supposed to have changed his outlook, however, while undertaking a five-year voyage (1831–1836) to some of the remotest cor- ners of earth as a naturalist aboard the HMS Beagle. His travels took him to the bottom of South America and to the windswept shores of the Galapagos Islands in the Pacific Ocean, 970 kilometers off the coast of Ecuador. There he encountered much that didn’t fit his understand-ing of Biblical creation. He saw geological wonders– volcanoes and rock strata– that pointed to an earth much older than the six thousand years the Bible allowed. Of course, he had already encountered the idea that the earth was more ancient than he had previously supposed when he read British geologist Charles Lyell’s Principles of Geology, the first volume of which was published just a year before Darwin set out. In Principles Lyell proposed that the earth’s geological structure was a result not of a recent creation ut hlow natural forces operating almost invisibly over millions and millions of years. Darwin felt what he saw on his voyage confirmed Lyell’s hypothesis. Aside from geological questions, Darwin also found himself puzzled by the geographical distribution of species. That the Galapagos alone hosted many distinct yet obviously related species of plants and ani-mals scattered over a few small islands sowed in his mind the seeds of the idea of organic evolution. He wrote in his journal, “It is the cir-cumstance, that several of the islands possess their own species of the tortoise, mocking-thrush, finches, and numerous plants, these species having the same general habits, occupying analogous situations, and obviously filling the same place in the natural economy of this archi-pelago, that strikes me with wonder.” 2If species had been created separately, then why had God created different yet very similar species for each of the small islands, the smallest of which were, in Darwin’s words, barely more than “points of rock”? It would have made more sense if completely different species inhabited each island. This phenomenon, something Darwin began to notice everywhere he traveled, led him to think that perhaps the species had not been created separately at all but had evolved from a common ancestor in the distant past. When Darwin returned to England in 1836 he continued to ponder the issue and gradually became convinced of organic evolution. In 1844 he wrote a friend, “At last gleams of light have come, and I am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a murder) immutable.”3 As other naturalists of Darwin’s time also observed the geographi-cal distribution of species, they too became convinced of evolution. One such naturalist was Alfred Russel Wallace (1823–1913), a young correspondent of Darwin’s who now and then sent Darwin plant and animal specimens from his travels in Borneo. Wallace shares with Darwin the honor of having proposed the theory of evolution, because while Darwin had written down his thoughts privately, he had never published his theory. Wallace had found the time to spell out his ideas on evolution through natural selection while he was bedridden with malaria in Borneo. He detailed his thoughts in a paper he sent to Darwin, asking him to send on both the letter and the paper to Charles Lyell, whom Wallace did not know. It is said that Darwin was dismayed to receive Wallace’s paper 4 – Darwin had been quietly working on the same ideas for twenty years by this time. Now the younger Wallace was about to receive credit for the theory Darwin considered his own. Of course, there were differences between Darwin’s conception and Wallace’s conception. Darwin had focused on the uniqueness of spe-cies and Wallace on the driving force of natural selection. But both had drawn their ideas from Malthus’s paper on population economics. When Darwin mentioned Wallace’s letter to Charles Lyell, Lyell encour-aged him to copublish the theory with Wallace. Wallace readily agreed to share the spotlight, and on July 1, 1858, their joint paper was pre- sented to the Linnean Society of London. This was the official birth of the theory of evolution through natural selection.The theory drew little notice at first– it was only one of several papers read at the Linnean Society that summer– but it came more into the light a year later when, on November 22, Darwin published On the Origin of Species. The book was an overnight bestseller and some-what eclipsed Wallace’s role in the theory’s development. From then on, the theory of evolution has been almost exclusively attributed to Charles Darwin

NEXT