Both natural selection and genetic drift lead to evolution process by varying the gene frequency of a population over time. Both these processes are involved in evolution and are not mutually exclusive. However, natural selection is the only process, which selects the best adaptive organism to the environment, and genetic drift reduces the genetic variation.
Natural selection (aka survival of the fittest) is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time.
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection.
In the second of the nineteenth century a fierce debate broke in the scientific community about Darwin's theory of evolution. However, by the twentieth century the debate was over.
Tipped off by an article on economics on the survival of the fittest in the free market economy, the English biologist Charles Darwin initiated a study on the fish population. Little did he know that he was about to cause a dramatic change in thinking in natural sciences.
Virtually all live-born babies grow up to have their own babies. Does this mean human natural selection, hence the evolution of humans, is coming to an end?
World Health Organisation estimates worldwide there are 1 billion cases of influenza annually. We catch the flu, recover from it, but we are not off the hook, we can catch the flu again.
Little did the English economist Thomas Malthus know, with the publication of his book in 1789 he was rolling a snowball that would soon turn into an avalanche.
Evolution is a fact. It is not just a theory that may be falsified in the future. Even if it were, evolution would still be a fact. Theories change, facts don't.