Evolution simply means change occurring over time, especially a gradual change. You can, for example, speak of an evolution in architectural styles, or in music.The evolution that biologists talk about is organic evolution.Natural selection is the name of the process suggested by Alfred Russell Wallace and Charles Darwin in the mid-nineteenth century to explain how organisms might have evolved. The process involves some individuals in a population surviving, and others not.If the survivors possess one or more qualities that make them more likely to survive, and that are hereditary (encoded in DNA), then the genes that produce these qualities will become more abundant over time in the population.Evolution is a process of slow change in a group of organisms, natural selection is the means by