Four Mechanisms Of Evolution

Evolution is a change in populations over time. It is the population that evolves, rather than an individual. There are four mechanisms of evolution: mutation, gene flow, genetic drift, and natural selection. There were multiple contributors to the ideas of evolution, including Charles Darwin and Alfred Wallace. To begin with, mutations cause genetic variation. Genetic variations are the differences in DNA sequences. The differences in DNA sequences caused by mutations are known as alleles. Inherited mutations result in a population evolving because of new alleles being added to the gene pool. Mutations occur randomly and for various reasons, such as: errors in DNA replication, collisions with molecules, heat or chemical agents. Secondly, …show more content…
Genetic drift is a random process in which allelic frequencies change because of differences in survival and reproduction from generation to generation. Genetic drift is more likely to differ the gene pool of small population. In contrast, genetic drift is less likely to alter the gene pool of larger population. For example, an endangered species with a small population can be impacted greatly by genetic drift because of a loss of genetic variation. The last mechanism of evolution is natural selection. Natural selection is an evolutionary process that occurs when a population adapts to its environment. Natural selection improves an organism’s rate of survival and reproduction in its environment. Individuals within a population may have traits that enhance survival and reproduction rates. Traits that allow an individual to function better become more prevalent over time. Traits that are not advantageous to an individual’s survival …show more content…
Adaptability is evident when a population improves its ability to function, survive, and reproduce with the population’s habitat. An example of adaptation is mice that need a specific coat color to survive against predators. On a lighter colored surface, mice with a lighter coat color are more likely to survive and reproduce. In contrast, mice with a darker coat color are less likely to survive and reproduce. In this example, the lighter colored mice are more likely to survive and reproduce, and the darker colored mice are more likely to survive and become prey. Over time, the traits of the lighter colored mice will become more prevalent and better suited for its habitat by adaptation. There are three types of natural selection: directional selection, stabilizing selection, and disruptive selection. Directional selection occurs when individuals have one specific extreme of an inherited trait that gives an advantage over the rest of the population. The example of mice with a lighter coat color surviving predators is an example of directional