More Essay Examples on Evolution Rubric
Microevolution is nothing but the small change that occurs in plants or animals because of genetic inconsistency present in the gene pool of the inhabitants. Microevolution could be the main cause for the origin of a new species. The changes in allele (alternate terms of a gene) frequency, which could be a result of mutation, natural selection, genetic drifting and gene pool. Microevolution could occur due to some destructive changes caused by environmental pollution or degeneration or due to changes in mutation and failure of proper genetic information, which could lead to the formation of a new species.
Some of the examples of microevolution that could be discussed are, due to changes in the genes, and the separation of a small part of the gene pool, people might be born with certain handicaps like short stature of the body, an extra sixth finger, fingers that are very short and other blood diseases. Specific examples that can be mentioned are circular overlaps (gulls), exclusive Hawaii flies, the finches and tortoises in the islands of Galapagos, the sparrows in the United States, dog breeding through artificial means, Madeira rabbits and people with distinct skin color, mongoloid eyes, the stout Eskimos and the tall and thin Africans.
All the above examples of microevolution were caused by natural selection. This is evident in the case of the “circular overlaps”, the two types of the European gulls —the herring gull and the smaller black-backed gull, which breed with a chain of other subspecies that expand throughout the world, they do not interbreed with each other. In these circular overlaps a series of many forms of species, which interbreed with each other throughout the chain, broadens for a lengthy geological distance, other than where the main links in the series extend beyond; the final two species are different species, because they do not interbreed with one another. The Finches can also be taken as an example of such variation change. Other examples that could be described are birds and other insects like the fruit-flies. Sexual selection, the evolution that is entirely based on greater reproduction and an example of this is the male peacock’s feathers. Sickle-cell anemia is an example of balancing selection. Descriptive and hand waving, could be used as an example of kin selection, because similar genes are inherited from the ancestors to their immediate relatives, any gene which controls a person to assist its relations can consequently develop the endurance of the other replica of the same gene which is carried by the relatives.
Certain bacteria’s developing resistance to certain antibiotics and viruses that manage to transform their formation so that they can avoid resistance are all examples of microevolution through mutation. An incredible amount of difference and alteration can happen due to the genetic diversity. Most of the genetic diversity like different alleles and amalgamation of genes are caused by mutation. Microevolution by means of genetic variation is a practical fact. There is no evidence of the formation of fresh genes with exclusively new groups of gene arrangement and function.
MICROEVOLUTION, Evolution in Action?, Retrieved 24 September 2007, http://mywebpages.comcast.net/mkent595/Microevolution.html
R. Totten, Evolution is partly true, World View Test Site, Retrieved 24 September 2007, http://www.geocities.com/worldview_3/parttrueevol.html