Evolution as Fact and Theory Essay

Submitted By ryanbush56
Words: 656
Pages: 3

Ryan Bush
4-26-12
Mr. Beaty

Evolution is any change across any successive generation in their heritage. Charles Darwin theorized evolution by a thing called natural selection. It includes three facts of a population. One, more offspring are produced than can possibly survive. Two, traits vary among species leading to different rate that they can reproduce and survive. Three, different traits to survive are heritable. So when a generation dies the ones that lived the longest and had the better traits to live pass them down to their offspring, resulting in their offspring being able to have those genes and survive better. All of the organisms today are believed to have slowly changed from one common ancestor and have changed their way into what they could survive best at. Darwin had many influences on his study of evolution there were many key players such as Lamarck, Malthus, Lyle and Wallace. Lamarck proposed that organisms try to change their traits in their lifetime so that eventually the genes they altered would be passed down to their offspring. Lamarck got this theory from giraffes. Lamarck thought that the giraffes did not have long enough necks, so they could not reach the food in top of the trees they wanted. So the first ancestor of the giraffe stretched and stretched and stretched his neck to reach for food. Then his offspring repeated the same process resulting in their neck growing longer and longer through each generation. This gave Darwin a good idea of how organisms can change to adapt to their environment, but he still did not think it happened during the organisms life. Thomas Malthus proposed that with populations increasing more and more it would result in total war, famine, and anarchy is humans to try and survive. It would put a “roof” on the population growth and it would stop. Humans would strive out of their way to get food. Malthus basically meant that only the strong will survive and reproduce to pass on their genes of being able to tough things out and live better than other individuals. Darwin saw how this was true in animals also. He noticed that an organism better equipped with genes to get certain foods it needs, or able to survive better than this organism without those traits would. Lyle changed Darwin's thinking that small changes over time would lead to big differences in an organisms make up. Geographical changes especially would affect organisms. This gave Darwin more proof that organisms…