Monday, August 12, 2019

Species Divergence Essay Example | Topics and Well Written Essays - 1000 words

Species Divergence - Essay Example physiology, the mode of interaction with its environment, nutrition regime, etc. While evolutionist ideas may be discerned in several pre-modern scholars’ ruminations, it was only with the advent of the 18th century Enlightenment that modern evolutionary theories formed, with that of Charles Darwin soon taking the pre-eminent place among them. The formation of currently mainstream version of evolutionary biology was immensely helped by the respective advances in the fields of genetics and molecular biology, which helped define the organic basis for evolutionary processes. From a biological organization point of view, evolution proceeds on a species level, as individuals comprising a species do not themselves evolve over the course of their lifespan. However, the results of their interaction with the environment enable the accumulation of new heritable responses within their genotype structures, giving rise to a process of natural selection. The latter, in its turn, conditions the changes in the species’ phenotype (i.e. the complex of biological features). Natural selection may be properly defined as a gradual process of genetic variation whereby the individuals with most favorable gene combinations are more frequently able to transplant their genes to subsequent generations of a species, so that their descendants will define the face of their species. While natural selection process is individual, being transmitted across a species only indirectly, it is genotype of a species as a whole that it impacts on, so that heritable changes in those individuals’ genotypes that are favored by natural selection are spread to the subsequent generations of a species as a whole. The mechanisms of natural selection are varied; however, some of them may be assigned more prominent roles in its perpetration. Of those, ecological selection, with an emphasis on fitting with one’s biological environment, and sexual selection, with an individual’s fecundity and ability to find prospective sexual partners as a key factor, may be considered the primary ones. In turn, these mechanisms may be sub-divided into more specific methods of selection, with, e.g., ecological selection encompassing the mechanisms of intraspecies competition, kin selection, etc., and sexual selection including those of intrasexual selection, intersexual selection (sexual dimorphism), etc. b. Evidence for biological evolution is manifold and comprises the number of data from different scientific disciplines. Within the context of this essay, five types of this evidence will be examined. Plate tectonics. The discovery of the movements of plates in the 20th century laid to rest the notion of unchangeable nature of Earth’s tectonics, contributing to an idea of nature’s propensity for change. On a more specific level, Charles Lyell’s studies on the impact of climatological and geological changes on the distribution of species, with specific emphasis on extinct flora, led the researchers to conclude that movements of large land masses lead to conversion of climates, which meant that animal and plant species had to be dynamic entities, the spatial distribution whereof changes in accordance with the changes of topography brought about by geological agents. Consequently, the changes in floras and faunas were decisively connected with the corresponding shifts of land masses, contributing to the development of an idea of ecological selection. Biogeography. The research in the connection between plate tectonics and changes in life on Earth that was referred to above has been directly connected with the research in the field of biogeography. Such scientists as Edward Forbes, Wallace and Willer Matthew conducted an extensive research in the

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