The theory of evolution is one of the great intellectual revolutions of human history, drastically changing our perception of the world and of our place in it. Charles Darwin put forth a logical theory of evolution and amassed a great body of evidence in support of this theory. In Darwin's time, most scientists fully believed that each organism and each adaptation was the work of the creator such as God. This theory was proved wrong by Charles Darwin. In other words all the similarities and dissimilarities among groups of organisms, that are a direct result from the branching process. This process is shown by the great tree of life. 

Natural selection is the process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms, and unfavorable traits that are heritable become less common

·        This unbounded population growth resembles a simple geometric series (2-4-8-16-32-64..) and quickly reaches infinity.

·        As a consequence, there is a "struggle" (metaphorically) to survive and reproduce, in which only a few individuals succeed in leaving children.

·        Offspring tend to resemble parents, including in characters that influence success in the struggle to survive and reproduce.

·        Parents possessing certain traits that enable them to survive and reproduce will contribute disproportionately to the offspring that make up the next generation.
To the extent that offspring resemble their parents, the population in the next generation will consist of a higher proportion of individuals that possess whatever adaptation enabled their parents to survive and reproduce.

Natural selection - Wikipedia, the free encyclopedia