Human Evolution

Essay by antaik677College, UndergraduateB+, October 2007

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There is a theory that humans descended from an earlier, lower form of life. There is an assortment of evidence that shows that all living creatures on Earth descended from a common ancestry. Evolution doesn’t discriminate against humans. It is believed that we too are a product of an earlier predecessor. The similarities in all life are evident if you consider that every form of life builds from the same building blocks--20 essential amino acids, four nitrogen bases, and simple sugars. Each of Earth’s past and present forms of life are, or were composed of a combination of those building blocks called RNA or DNA. In the very beginning of life on Earth, the genetic structure was very simple, but as time has gone by, the best combinations in the genetic sequence were individuals that reproduced. Over the approximated 3.5 billion years that life has been in existence on Earth, there have been many mutations in the genetic codes of different forms of life.

Only very few of the genetic mutations are indeed beneficial to the function of the species. Negative mutations give the life form a disadvantage for survival, thus reducing its chances for reproduction, but a positive mutation gives the species an advantage to survive and produce offspring. The offspring have a copy of the positive mutation now in their genetics to eventually pass down to their young and so on. Now you can see how the positive mutations have a way of piling up into different piles, which is why our result is a widely diverse life, which exists on Earth today. This theory of how evolution came to be is known as natural selection. It states that a weaker individual has a lesser chance for survival and reproduction than that of a stronger. It’s nature’s way...