Charles Darwins Evolution Theory - Essay Example

Theory of Natural Selection affiliation The evolution theory Charles Darwin’s evolution theory by naturalselection stands out as one of the memorable scientific research that has marveled many scholars up to date (Maynard-smith, 2003). Many scientific fields offer credit to Darwin’s natural selection some of which include genetic, geology and developmental biology. Darwin was not the first one to come up with theories of origin, other theories exist but evolution by natural selection stands out to be the best of all explaining precisely in depth the course of origin of life and survival, closely supported by evidence gathered during Darwin’s journey around the globe. The approach with which Darwin digs up information supported by tangible evidence stands undisputed and only attracts keen interest to study further having this antiquity as the foundation on which to build more knowledge. According to Charles Darwin, several factors influenced the existence and survival of certain species of organism. For an organism to have grown and attained maturity to reproduce several environmental and genetic factors play an essential role. In trying to elaborate on how certain species of organisms survived up to date while others got extinct Darwin presented a number of stages that determined the existence of living organism (Pagel, 2009). An organism was to appropriately fit into these stages in order to reach maturity and reproduce as well as survive in the stiff ecological competition and changes. All species have unique traits encoded in their genetic make-up, the population must reproduce in greater numbers in each generation to survive and reproduce. The individuals who survive in the population possess certain advantageous traits over others then after successfully passing through the first three stages the organism in the population. It is the combination of these factors that animals are found to change with time owing to heritable behavioural and physical characterizes. Natural selection greatly determines how certain species significantly change in colour, size and survival traits through a number of generations. Genetic variation is responsible for various physiological and outward characterizes on organisms (Fay & Wittkopp, 2008). For instance the size and colour of an organism is determined by the gene coding that is already prewired before birth. Due to genetic differences there existed brown and green battles. This color difference plays a significant role in determining survival of these beetles depending on their immediate environment. In this case colour difference in beetle species is a heritable variation. According to Charles Darwin, for any animal population to continue existing, they must reproduce in large numbers to overcome all uncertainties of environmental factors that can make them extinct. In the environment those animals with suitable characteristic grow in numbers through reproduction making them less vulnerable to extinction. Comparing the beetle population with different colours, those with green colour were often preyed on by bird since the environment in which they were made them more conspicuous than the brown beetle. As a result their number reduced drastically such that only a few grew to maturity to reproduce and finally were eliminated from the environment. On the other hand brown beetle coumflaged to the environment making them less preyed on by birds, this made most of them grow to maturity and reproduce in larger numbers making them survive long in the environment. Brown color being a survival trait is passed on from one generation of beetles to another through genetic inheritance. A lot more brown beetles are reproduced each generation making them resistant to extinction. As the number grows better survival traits are acquired through crossbreeding and mixing of genes. This trend is vital to the survival of organism since acquisition of new traits helps them conform to the environmental changes and food chain competition than the ancestral organism. The generation of beetles that has the best traits for survival and reproduction are fit in the natural system of selection. This implies that the population of a certain population of organism has the ability to effectively adapt to environmental changes and is able to brave environmental threats against their existence. Referring back to the beetle population, brown ones have the advantageous character over the green ones since they are favoured by the environment. Focusing on several future generation of the beetle population it is likely that the brown beetles will form the entire population because the green ones get extinct since their colour does not guarantee their survival. Darwin also brings in evolutionary fitness of living things as the main theme of natural selection. He argues that the ability to reproduce and consistently survive is the true determines of fitness since they are vital in influencing the population of organisms in the environment. There is a clear difference between fitness and the total number of certain animal species in the environment, fitness is more of the ability of the organisms to pass on favourable and survival traits from one generation to another through genetic inheritance. In finding further meaning of fitness, an organism that has good reproduction and survival characteristic may not qualify the definition of fitness if these traits are not carried on to the offspring as well as if the offspring were delicate and fewer in numbers to survive. As compared to other theories of origin and evolution, the theory of evolution by natural selection identifies that individual organism survive in the environment because of inherited functional dissimilarities which are transferred to a new generation. Natural selection has various facets that shape up the survival and reproduction of an organism in the environment, they come as directional,indirect,stabilizers and disruptive all affecting different organisms at varied strength. Moreover, there is a rich source of evidence availed as fossils and typical examples of living things that have cruised through all these stages of natural selection. This simply isolates Darwin’s theory as the most advanced and prolific in advancing scientific research on the exodus of survival in organisms. Driving forces for evolutionary change Evolution has been fuelled by a number of interrelated factors that are internal and external to an organism. Genetic drift which is a randomized process pivotal in determining the alleles that survives. This implies that a significant change in allele frequency takes progressing from one generation to another, allele tend to grow stronger or weaker depending on the external selective factors. This therefore explains how some traits get extinct over years while others grow prominent (Stephens, 2004). Another driving force is mutation that entails noticeable alterations of DNA in organism. These basic changes also influence somatic characteristics and physiological adaptability of an organism either by favouring its existence or working against survival. Organisms that attain favourable chemical DNA changes such as acquiring resistance to certain environmental factors such as diseases are able to survive long enough to attain maturity and reproduce. Ecological interaction of different organisms also formed a special driving force in the path of evolution. Most species were in a constant struggle for survival depending on the position they occupied in the food chain, organisms evolved to secure better chance of obtaining food and avoiding being a meal for another. Animals had to shape up and adapt to the changing ecological factors that influenced their interaction. The whole essence of species interaction is to create genetically different organism that survive better in the environment than their ancestors. All these factors equally exhibit the same characteristics that modify evolution that are also postulated by Darwin in his evolution theory of natural selection. The common denominator here is that at the driving forces refines an organism to survive long in the environment by facilitating acquisition of favourable genetic and somatic traits. Finally, Darwin’s evolution of natural selection succinctly explains how environmental factors shape supper survival traits out of primitive forms of life. Heredity, reproduction, passing of suitable traits to a new generation and adaptation play an important role in determining the survival or extinction of an organism (Frank, 2009). Closely related are factors that fuel evolution and the need to acquire better survival traits, genetic mutation, gene drift and environmental interaction necessitate acquisition of new physiological and genetic traits. Though there have been other evolution theories by other scientists, Darwin’s natural selection is conspicuously isolated as a better scientific explanation of observed changes in animal traits as it is supported by vast sources of scientific evidence. References Fay, J. C., & Wittkopp, P. J. (2008). Evaluating the role of natural selection in the evolution of gene regulation. Heredity, 100, 191–199. doi:10.1038/sj.hdy.6801000 Frank, S. A. (2009). Natural selection maximizes Fisher information. Journal of Evolutionary Biology. doi:10.1111/j.1420-9101.2008.01647.x Maynard-smith, J. (2003). Evolution by natural selection : more evidence than ever before. Commentary, 76, 699–716. doi:10.4067/S0716-078X2003000400012 Pagel, M. (2009). Natural selection 150 years on. Nature, 457, 808–811. doi:10.1038/nature07889 Stephens, C. (2004). Selection, Drift, and the “Forces” of Evolution*. Philosophy of Science. doi:10.1086/423751  Read More