Evolution is a scientific theory utilized by the biologists to explain the changes in residing things over a long time and how they come to be. Changes caused through the environmental conditions are speculated to cause the evolution of both terrestrial vegetation and animals. The modifications in the environment may attribute to the extinction of international species than other factors causing evolution. As a end result of the human activities, the ongoing environmental changes include nitrogen levels in the soil, carbon dioxide, PH, and phosphorus levels. Extinction of the plant and animal species is attributed to environmental constraints witnessed in physiologic and morphologic changes. The modifications somehow favor the new species outdoing others in the competition main to overall domination by the new species.
On the contrary, evolution is also said to be caused by natural selection as one of its basic mechanisms along with genetic drifts and mutations. The theory of Natural selection was proposed by Charles Darwin where he documented that organisms evolved in a manner that they became suited to the environment as time goes. According to the theory, the concept of Charles Darwin was based on key observations such as the trait of the species.
The reason for the importance of natural selection
is that it explains the design of nature that is responsible for the evolution process due to the adaptation of the living organism to the environment (Ker, 1). The theory of natural selection caused quite a stir in explaining how the adaptive evolution of living organisms takes place. According to natural evolution, changes can occur without formation of the new species, and many examples of the theory are evident. In some instances, natural selection contributes to the origin of new species simply by splitting the species into two lineages. The lineage is divided from the ancestral origin so that the results can be two different species. The process of ancestral origin splitting is caused by natural selection but not always. Natural selection is a process of evolution that goes against chances and predictable (Douglas, 1). It establishes that the outcome of evolution is predictable since it states the environmental contexts in which the genotypic changes are expected to occur. While after the changes, one genotype proves to be better than another in reproduction or survival due to some reasons regarding the characteristics of the environment, thus it’s sometimes predictable and consistent. Despite Darwin’s theory being regarded as dangerous, it shows a simple mechanism for explaining the appearance of living things. Before the discovery of the method, all the changes in living organisms were attributed to the omnipotent being among other arguments for the causes of the changes. Darwin, therefore, made his case from an accomplished design of biology in what other scientists had accomplished in physics. Natural selection provides a purely biological explanation for the appearance of living things (Douglas, 2). While agreeing with the topic, the environmental as undergone climatic change due to human actions. As a result of human activities, rates of the nutrients are greatly affected due to the constraints in the sustainability of the ecosystem. Diversity in the composition of the ecosystem is also affected due to the alteration in the rates o the nutrients. Due to human acts, the rates of nutrients such as nitrogen and phosphorus are doubled to increase the atmospheric concentrations of carbon dioxide. Additionally, the nutrient levels in the soil are reduced through acidic leaching. Due to farming activities, humans have altered the fire frequency that plays a major role in modelling communities and ecosystems (Stephen, 2). Humans now have full control of terrestrial productions while leaving behind the ecosystems with inadequacy of herbivores; as a result, there is lack of top to down constraints. The outcome of the environment affects the living species composition and functioning of the ecosystem. The models of environmental constraints try to explain the challenges faced by the living organisms. The ecological limitations caused by the human actions can predict if the large species can persist for a given period. The tool can also be used in explaining the multi-coexistence of different species. Through the method, it is possible to predict persistence of various species towards the environmental constraints. Due to human activities that alter morphologic and physiologic life history of the living things, which constrains its survival only in a range of environmental conditions (Douglas, 3). For a single species, the competition is at its best when the niche is a narrower range of the environmental conditions. The characteristics of the environment thus limit other species if they cannot adequately compete for the available resources. Often, the resources are in shortage due to activities of human nature. Additionally, the environmental constraints are responsible for creating vacant niches that signify the environmental condition where no species is well adapted. Moreover, the growth rates of plants are temperature dependent. Temperature is the is the likely cause of geographic separation of species. All in all, the evolution of various species is contributed by both natural selection and anthropogenic activities. The ability to understand the impact of human actions can greatly contribute to the conservation of the living things from extinction.
Works Cited
David Tilman. Human-Caused environmental change: Impacts on plant diversity
and evolution. PNAS, 2017. http://m.pnas.org/content/98/10/5433.full Accessed 29 Oct, 2017.
Douglas Fatuyma. Natural Selection: How Evolution Works. actionbioscience,
2017. http://www.actionbioscience.org/evolution/futuyma.html Accessed 29 Oct, 2017.
Ker Than. Darwin’s Natural Selection Still at Work in Humans. LIVESCIENCE, Nov.
2005. https://www.livescience.com/445-darwin-natural-selection-work-humans.html Accessed 29 Oct, 2017.
Stephen R. Palumbi. Human’s as the World’s Greatest Evolutionary Force. Sep.
2017. http://palumbi.stanford.edu/manuscripts/evolution.pdf Accessed 29 Oct, 2017.
