Darwin’s ideas about organic evolution were drawn from the existing forces of knowledge on evolution developed by Lyell, Malthus, and Lamarck. Although Darwin was not the first thinker about the concept of evolution, he was a revolutionary in developing a theory of evolution that was consistent.
The distinctive element of the evolutionary theory conceived by Darwin is the way he viewed species. Darwin considered variation among individuals of a species to be natural. He further argued that variation, far from being problematic, actually provides the explanation for the existence of distinct species. Darwin adopted elements from Malthus’s theory on population growth and stated that only those members of a population that are capable of adapting through variations survive. Thus, over generations, adaptive variations will accumulate in the population and this results in constant variations within species through time. According to Darwin species are non-static and progressive in nature.
Darwin’s view about specie’s was very different from his contemporaries. Rather than defining species in idealistic terms that involved rejecting deviations and differences within species, Darwin viewed species as ever changing. Carolus Linnaeus classified organisms based on the their degree of similarity. Linnaeus believed that each species existed in an ideal form. He considered variations as problematic and imperfect. Darwin on the other hand was a great believer in the idea of materialism and applied it to his idea of evolution. Darwin’s view about species also differed from Lamarck’s. Although Lamarck advocated that species do change over time but importantly his theory of transformism was different from Darwin’s and modern theory of evolution.
In the midst of the brewing debate over the early theories of evolution came the most compelling theory by Charles Darwin. Darwin explained the variation in species through natural selection, which was the core of his theory of evolution.
The realizations about natural world provided the context for Darwin’s theory of evolution. His theory was supported by evidence from a wide variety of scientific disciplines, including paleontology, geology, genetics and developmental biology. Darwin observed firsthand the power of earthquakes in shaping the landscape in Chile. Hutton and Lyell’s uniformitarianism led Darwin to recognize the dynamic nature of earth’s geology and hence he hypothesized that evolution is a long, gradual process. Furthermore, after reading Cuvier’s studies of fossil and introspecting fossils in South America he observed that these fossils resembled animals native to South America. This suggested to Darwin that an earlier species has transformed in to modern species through a succession of species over time. Adding to this was the Malthusian theory of population, Darwin wrote “it at once struck me that under these circumstances (environmental conditions) favorable variations would tend...