This is also the rationale behind the arrival of variations in the species of organisms through time. The genius of evolution lies in the fact that although organisms have obviously changed through time, a lot of their features remain strikingly comparable to something from a different age. (The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California, 2008)
Simply put, evolution is one of the major factors that cause different life forms to continue to exist in the universe. Evolution is a complex process that makes use of several mechanisms or sub-processes. These evolutionary mechanisms are responsible for affecting change in population.. (The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California, 2008)
The basic mechanisms of evolution that affect change include natural selection, genetic drift, migration or gene flow and mutation. (The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California, 2008)
Natural selection is the course of action by which inherited characteristics that are pertinent to continued existence and reproduction become more prominent. In natural selection, the traits that are detrimental to one's survival become less prominent in the next generations. (DOBZHANSKY, 1955)
According to the 'Understanding Evolution' website, genet...
Genetic drift can be likened to a lottery where a "winner" is determined by sheer luck or in this case, chance. Genetic drift affects the process of evolution in three ways. First, genetic drift causes a reduction in variations. This causes a population to be responsive to only a certain set of forces. Next, genetic drift takes effect faster than the other mechanisms when applied to smaller populations. Third, genetic drift is one of the major the evolutionary mechanisms responsible for the creation of a new species. (The University of California Museum of Paleontology, Berkeley, and the Regents of the University of California, 2008)
Migration is described as the relocation of individuals or organisms into new locations with the intention of settling. From a socio-economic standpoint, migration has become a trend embraced by certain individuals in order to make their lives better by earning their keep in foreign soil. Genetically speaking, migration becomes an instrument of evolution when a sufficient amount of alleles from a migrant species are successfully mixed together with that of the resident species by intermarriage in humans and mating in animals, plants and other organisms. An example of this would be an offspring of a Chinese man and an American woman who may be born with dark hair reminiscent of his Asian ancestry and wide blue eyes reminiscent of his American ancestry. (DOBZHANSKY, 1955)
The "Learn Genetics" website defines mutation as a " permanent change in the DNA sequence of a gene". Mutations bring about "major changes in the amino acid sequence of a protein" chain that is inherent in the gene. Mutations are such that the structure of a gene is either changed or damaged.