In Essentials of Biology, natural selection is categorized under ‘Evolution on a Small Scale’, but while natural selection is typically not a drastic, abrupt force that causes huge leaps and bounds in evolution in a short time, natural selection applies to all living things. Natural selection is a process which causes a population (interbred organisms in the same place at the same time) to adapt, meaning, to undergo a change in characteristics to be better suited to their environment. Natural selection is what allows members of a population, who are better suited to their environment, to live. There are various results of natural selection, such as an average phenotype becoming more prominent when nature favors less extreme variation (stabilizing …show more content…
Natural selection can result in a new species, even, and looking back at the bird beak example, this change is sometimes the case. The population starts out with birds of various beak sizes, and, over time, through natural selection, the bird population evolves into a population containing only birds with large beaks. Looking at this process on a large scale, it is still hard to believe that a simple mechanism like natural selection can cause the evolution that led single cell prokaryotes to evolve into every organism on this planet today, including humans. Now, with this in mind, natural selection is not the only mechanism of evolution; mutation and separation (allopatric speciation), for example, also drive evolution. Even with this in mind, natural selection can play a role in every other driving mechanism; it acts whenever there is inherited genetic variation within a population and the environment cannot support all of the population’s members. For example, even when prokaryotes were evolving into eukaryotes through environmental interactions and mutation, natural selection still allowed certain cells to survive, flourish, and reproduce because they were fit enough to survive in the environment (of prehistoric earth). Since this important idea has been established, it is now easy to understand why natural selection is so important: it is the driving mechanism that allows evolution to take place, eliminating those less fit for survival and resulting in all of the diverse organisms on earth