What Is Evolution?
Evolution can be scientifically defined as the change in genetic composition of a population over successive generations, which may be caused by natural selection, inbreeding, hybridization or mutation. In more simpler terms, it is a process by which different types of living organisms have developed and diversified from earlier forms during the history of the Earth. Additionally, evolution does not affect individuals, but only large numbers of people or species and may entail either slight or significant changes to a species. If the changes are significant enough and persist over consecutive generations because they are favorable to survival in the environment, a new species may develop. Futhermore, evolution cannot occur without something to evolve from. For example there are approximately 4 million domesticated dogs in Australia alone, but for all the diverse breeds of dog, from St. Barnard to Poodle, from Labrador to Pekinese, they share one common ancestor - the grey wolf. Humans and chimpanzese also evolved from a common ancestor before they went their sperate ways. (Humans did not evolve from apes, it is a common misconception)
Charles DarwinCharles Darwin is best known as the father of evolution. Although the idea of evolution did not begin with Darwin, he (and his fellow naturalist Alfred Russel Wallace) had a major contribution to accurately explaining how it worked.
Charles was born into the Darwin family on February 12th 1809, near Shrewbery on the english border with wales. As a young man he was offered a job from the Admiralty as naturalist aboard HMS Beagle, which was sailing on a scientific expedition to South America. |
Galapagos Island FinchesDarwins Famous Book |
It was expected to last for approximately two years, however it lasted almost five years, taking Darwin right around the world. On September 7 1835 the Beagle reached the remote Galapagos Islands in the Pacific ocean, here the theory of evolution was to be confirmed. When exploring the dry, cactus strewn islands Darwin found 13 different species of finch, which was evident through there diverse beak structures. He eventually realised that animal species do not remain the same perpetually and that all the finches had a common ancestor which had flown to the islands from the mainland. Over time they evolved different beaks, each suited to the foods they found on the islands. This is a clear example of divergent evolution, which will be further discussed on the "Forms of Evolution" page. By analysing the finches Charles Darwin was able to devise his "natural selection" theory of evolution. The theory was that over many generations animals descend from what is known as a common ancestor, changing their form, allowing them to adapt to living in a certain environment. Basically a completely new species was formed. Charles arrived back in England on the 2nd Of October 1836 and began working on the specimens he had collected on his voyage. 19 years later Darwin, heard from another naturalist, Alfred Russel Wallace, who coincidently had formed similar ideas on evolution to Darwin around the same time. A paper was written by both men and was read to a learned society in July 1858 and the next year Darwin published his most famous book called "On the Origin of Species by means of Natural selection." In 1871 he published "The Descent of Man" stating that humans were also the result of evolution. Humans and their other primates: the great apes, had descended from a common ancestor. It was challenging for people to simply accept these ideas as they changed the whole course of human knowledge. Charles studied and wrote for the rest of his life, however he unfortunalty died on April 19 1882 and as an honor to perhaps one of the greatest naturalists of all time he was buried in Westmister Abbey.
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