Free Evolution and Biogeography Essay Sample
This report discusses evolution, biogeography and factors affecting the evolution. Evolution is a study of how simple organisms descended to complex organisms. Charles Darwin through his work called “On the Origin of Species by Means of Natural Selection” of 1859 accounts for the evolution process. Darwin’s theory is a widely held concept, which states that all forms of life are associated and descended from a common ancestor. Darwin's theory assumes that nature was in control of the development of living organisms from non-life substances and stress. This implies that complex organisms evolved from highly simple organisms over time (Sax, Stachowicz, & Gaines, 2005). Additionally, the theory also suggests that genetic, structural and functional modifications occur from generation to generation. The concept of natural selection claims that organisms accumulate minor, beneficial genetic mutations to adapt to the ecosystem. The complex organisms stated in Darwin’s are the result of natural selection. The acquired mutations result in variations, which are fundamental for survival of species (Sax, Stachowicz, & Gaines, 2005). Through survival, organisms are able to reproduce facilitating the continuation of the ancestry. Complexity of organisms increases with changes in the environment and organisms that are unable to adapt face extinction. Darwin referred to this line of thinking as survival of the fittest.
Biogeography refers to the study of dispersion of a living organism in a given geographical area (Sax, Stachowicz, & Gaines, 2005). It provides both substantial presumptions evidences for evolution and testable predictions, which are prone to criticism by creationists. The geographical distribution of organisms helps in the understanding of the evolution process. This concept claims that global distribution of organism depends on their genetic associations to each other, though few exceptional cases explicable by the continental drift theory exist. The existence of marsupials in Australia acts as an evidence for the global distribution of organisms. According to continental drift theory, South America, Antarctica and Australia were part of a single continent (Sax, Stachowicz, & Gaines, 2005). The birds of these continents show some similarity, and they are likely to move to from the continents, which is evolutionary evidence.
Various factors such as predation and isolation affect the evolution of species. In predation, one organism, the predator feeds on another organism referred to as the prey (Sax, Stachowicz, & Gaines, 2005). Overfeeding causes extinction of the prey resulting to no species to evolve. Isolation mode involves the separation of organization, which hinders reproduction.
In conclusion, Darwin’s theory states that all forms of life descend from and are connected to a common ancestor. The geographical distribution of organisms helps in the understanding of the evolution process. Predation and isolation of species affects evolution.