Cause Of Evolution Cindy Ruffin
Post University

Natural selection is the process that results in adaptive evolution, but it is not the cause of evolution. The cause of natural selection and, therefore, of adaptive evolution, is any environmental factor that results in differential fitness among phenotypes. Refocusing attention on the structure and consequences of ecological variation, a better characterization of selective agents would improve understanding of natural selection and evolution, including adaptive radiation, coevolution, the niche, the evolutionary ecology of the ranges of species and their response to environmental change (Campbell, Reece & Mitchell 1999).
Genotypic frequencies do change from one generation to the next. However, allele frequencies do not change. Nonrandom mating, by itself is not a cause of evolution, however, it does change the genetic composition of the population (Campbell, Reece & Mitchell 1999).
No Mutation can change allele frequencies for example; take about twenty five that are homozygous for a gene all twenty five are AA. If a mutation occurs in a gamete of one of these individuals and that gametes may be passed on to the next generation, then the genetic composition of the population has changed across the generation. Mutation is a cause of evolution however, it is a rare event and therefore does not fully affect allele frequencies (Freeman, & Herron 1998). However it is a cause of evolution there are no gene flow which is also a cause of evolution. Migration is the movement of alleles from one population to another. Alleles are moved from one population to another this happens when animals migrate to a new location also when pollen and seeds are blown by the wind, by the birds or moved by the water also by animals Example: If all the individuals on an island are homozygous for “a” (aa) while all the