This paper briefly discusses several concepts pertaining to evolution, particularly the four forces of evolution. Although Charles Darwin and his Origin of the Species published in 1859 has been the most popularly known work about the theory of evolution, Russell Wallace and Carolus Linnaues had earlier discoveries that contributed to the development of the theory of evolution (Grolier, 159).
Evolution is “the process by which all living things have developed from primitive organisms through changes occurring over billions of years” (Grolier, 159). There are four forces responsible for evolution. According to Prins, Walrath, & McBride (27), these are gene flow, mutation, natural selection, and random genetic drift. The process of evolution that different living organisms go through distinguishes them from each other. This process is very slow and takes place over a long period of time. Although little changes occur, these slight variations are quite observable.
Mutation is considered the “ultimate source of evolutionary change” (Prins et al., 42). In this process, changes take place in the DNA of the living thing. That change affects all aspects of that living thing including the offsprings of that organism. The change therefore results in a new variation of the species. For example the evolution of man which has already reached the stage wherein he is able to walk on two legs, unlike the knuckle-walking demonstrated by his predecessors. These changes were a result of a “series of genetic mutations” (Prins et al., 42).
In natural selection, different environmental factors come into play to produce the best offspring; one species may thrive better in a certain environment making it able to sustain its number over the next generations. Evolution explained through natural selection was attributed to Charles Darwin who published his Origin of the Species in 1858, although another scientist Russell Wallace also made the discovery of the theory at almost the same time (Grollier, 159).
The process of natural selection has four components according to Futuyma (313) and these are variation, inheritance, high rate of population growth, and differential survival and reproduction. Variation pertains to differences in appearance and behavior, for example hair color or build of the body. Inheritance means traits that are passed on from parents to their children. For population growth rate, this means that there would be competition for available resources, thus individuals who adapt well and have stronger traits would be able to survive better.
The case of the genetic drift takes place when there are “chance fluctuations of allele frequencies in the gene pool” (Haviland et al., 42). This means that the changes that occurs in the population is a result of events that are not planned or those considered random or just by chance. “Over the course of a lifetime, a number of random events affect each individual’s survival” (Prins et al., 42). In turn, the gene flow process takes place when the genes migrate from one population going to another population.
Futuyma, D.J. Evolutionary Biology. 2nd ed. Sunderland, Massachusetts: Sinauer Associates, 1986.
Grolier Encyclopedia of Knowledge. “Natural Selection,” Grolier Encyclopedia of Knowledge. USA: Grolier Inc., 2002.
Haviland , William A., Prins , Harald E.L., Walrath, Dana, and Mcbride, Bunny. The Essence of Anthropology, Third Edition. USA:Cengage Learning, 2012.
Prins, Harald.EL., Walrath, Dana, and McBride, Bunny. Anthropology: The Human Challenge, 13th edition. USA: Wadsworth Cengage Learning, 2011.