Darwin’s theory of evolution: Survival of nature’s fit!

Abstract

Abstract: Even after 200 years after his birth, Charles Robert Darwin and his work are still central to any discussion on evolution. What is the relevance of evolution as Darwin perceived it? What were the pre-Darwinian, Darwinian and post-Darwinian pictures? Among the ancient pre-Darwinian theories Aristotle’s ‘Scala Naturale’ and the ‘Special Creation’ theory are perhaps the most important, whereas Lamark’s theory of ‘Evolution’ and Lyell’s theory of ‘Uniformitarianism’ are perhaps the most important modern ones, before Darwin’s work. His voyage of circumnavigation on the Beagle lead to pertinent observations: the similarities of structures between fossils and living forms in the same area; the presence of related but different species in adjacent areas of the same continent; the resemblance of species on isolated islands to those of the nearest continent and differences between species on closely adjacent islands of the Galapagos Archipelago in relation to their modes of life and feeding ; natural selection and survival of the fittest. The conclusions arising out of these and other observations were published as “The Origin of Species by means of natural selection or the preservation of Favored Races in the Struggle for Life”. But Darwin’s theory could not explain how the variations favored by natural selection initially arose or were inherited; the lack of intermediate forms and the long time frame needed for the changes to occur were two further objections to it. However, in the post-Darwinian era beginning with the rediscovery of Mendelism to modern day molecular biology, and the inputs from radioactive dating, these and other queries have not only been answered but they also strongly vindicate Darwin’s theory that has indeed stood the test of time and has emerged as the most convincing and fittest of all!