Natural selection is one of the driving forces behind evolution, but it is not the only force influencing the evolution of species. Mutation, migration, and genetic drift also play crucial roles. Darwin’s theory of natural selection can be confusing and it is often misunderstood, especially by creationists. Many creationists believe that natural selection is a God-ordained process that allows species to survive post-flood. It is true that natural selection can help organisms with certain heritable traits to survive and reproduce more successfully than species who lack certain traits. However, the term natural selection should not be confused with evolution because they are not the same thing. In order for natural selection to occur, certain criteria must be met. For example, there must be genetic variation among traits, selection pressures causing there to be differences in reproductive success among species with different traits, and the ability of traits to be passed on from generation to generation. One of the arguments in this article is that natural selection cannot lead to evolution because it is nondirectional when selection pressures are removed. While this idea is true, when there are no selection pressures the traits that get passed onto the next generation are random, it is important to remember that natural selection does not always lead to the evolution of new species. Therefore, natural selection does not have to be unidirectional to help drive evolution. Another argument is that speciation has never been observed to form an organism of a different kind, such as a dog species producing a cat. However, evolution does not work this way. Instead, evolution is the gradual change in a species genetic makeup that leads to the evolution of new species. An organism like a dog would not suddenly evolve into a cat. Instead, genetic mutations accumulating over many generations would gradually lead to changes in species and the evolution of new species. Many of these species being links, or common ancestors, in a phylogenetic tree.
Posted by: Katie Kossack