THEORY OF EVOLUTION

Theory of Evolution

Theory of Evolution

Evolutionary theory

It can rightly be said that Darwin's theory was by no means the first evolutionary theory in the 19th century. Charles Darwin presented his evolutionary theory in 1859. Darwin didn't invent the idea, however, he did perform research to prove such phenomena existed. Evolution theories are dated back at the periods of ancient Greece. Descent with modification was the notion used at that time which presumed that all things originated from air or water. Immanuel Kant at the start of 19th century argued that individuals originate from single ancestral source and that human organs are developed by the development of social culture. Biological Conceptions of Evolution existed prior to Darwinian Theory, and it was just that Darwin provided a mechanism to prove it (Darwin, 1981, Pp. 28-36). Darwin's grandfather also had his ideas of evolution as he believed that all life might have had a single common ancestor ((Darwin and Matthews, 1972, Pp. 87-94). Lamarck and Darwin had several ideas in common. Both believed that animals evolved over time, though the difference was in the way they achieved this change. Lamarck proposed that animals' genetic material was changed by the environmental pressures animals are exposed to. A giraffe's neck is stretched to reach the highest branch changes the genetic material which is then inherited by its children. Darwin proposed that the genetic material remains fixed for individuals and variations can occur for some individuals. He modified the example by stating that giraffes with longer necks were better fed and had more children and so the gene lasted for generations. Lamarck proposed that adaption takes 6000 years whereas Darwin stated that it takes millions (Fitzpatrick, 2012, pp 15-32).

Voyage on the Beagle

Darwin's voyage on the beagle lasted five years of which eighteen months were spent in seas. It was indeed instrumental in producing the fundamental ideas of his new theory. It allowed him to travel to different parts of the world to investigate and produce fundamental ideas for his new theory. It allowed him to read “Principles of Geology” written by Charles Lyell's ((Burkhardt and Smith et al., 1994, 276-287). It was after this that he concluded that earth's geological history can be correctly understood by uniformitarianism. He analyzed many plant and animal specimens which he then studied for ten years of his life. To counter Lamarck's theory Darwin made the following five observations (Appleman, 2001, Pp. 33-39).

The Galápagos Islands

This was the place where best known discoveries took place. The Theory of Evolution by Natural Selection was the product of these observations and examination of specimens from twenty years. He observed how animals of same kind had differed significantly. Iguanas differed significantly at different islands. Some Iguanas lived underwater and ate sea weed while others remain on land and ate cactuses. As per conditions, the tortoises' shells were adapted. Tortoises that had rounded shells lived near ground and ate plants and those that had long necks to reach plants at higher branches had upward bent shell ...