The Four Forms Of Evolution And Natural Selection

Over time species have evolved due to four forms of evolution: mutation, genetic drift, gene flow, and natural selection. Mutation is the evolutionary force that causes a completely new allele to be produced from one generation to the next. It is the only form of evolution that has the ability to create new alleles. This can be seen through different genotypes and even phenotypes found in a species. Plainly put, a mutation is a genetic error, it was not supposed to occur. Genetic drift is a change in the frequency of alleles found in a population over time. As a population grows the chances that an allele is lost is very slim because there is a higher chance of that allele being passed on. On the other hand with small populations the chance that genetic drift occurs and an allele becomes lost or just less frequent increases because their is a smaller population to reproduce that allele.

Gene flow has become much more common in humans in the past few centuries due advances in transportation which can bridge the gap between two populations. However, for primitive species, gene flow is not as common because species can be easily separated by things such as bodies of water and mountain ranges. Natural selection is the ability of a species to adapt to its environment in an attempt to increase its fitness. Fitness, in relation to evolution, is the ability of a species to survive and reproduce. Natural selection is the selection of species that have the highest fitness. If an animal develops a phenotype that gives it an advantage over the rest of the species, then it will pass on that trait because it can survive and from then on the trait keeps getting passed