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TheEvolutionary Process According To Darwin`s Theory of Evolution
Anoverview of the evolution Process
CharlesDarwin’s theory of evolution is among the significant revolutionsin the history of human being. The theory changed individuals’opinion of the world. During his time, the majority of scientists hadthe opinion that every organism and adaptations was the creatorswork. According to Darwin, evolutionary change takes place graduallyand slowly (Gould 12). The assertion was backed by the lengthyperiods of slow change in living beings as evidenced in the fossilrecord (Gould 14). This, together with the lack of evidenceindicating sudden appearance of novel species, has made biologists todocument a wide range of gradual evolutionary modifications indifferent lineages.
Darwinalso demonstrated that species modify over space and time. Specieswhich live in the present-day are different from those that existedsome years back. Besides, such populations differ depending with thegeographical area. The species differ in behavior and form. Theevolution theory also puts forth that all organisms have commonancestors (Ridley 21). It asserts that with time, species divide intodiverse species, sharing a similar ancestral population. It isevidenced by the claim that humans had a similar predecessor withchimpanzees approximately 8 million years back. The resemblance ofsuch organisms evidences the common ancestry. Darwin explained thenatural selection mechanism, which is the fundamental method throughwhich change takes place gradually. The mechanism results Imodifications in traits within an ancestry from one generation to theother.
TheProcess of Natural Selection
Darwinexplained the process of natural selection as the aspect of “strugglefor existence” indicating how species struggle for the availablelimited resources for survival (Gould 22).This only favors somespecies with various traits, thus changing the frequency ofcharacteristics within such populations. The characteristics thatgive advantage to such species are known as adaptations (Ridley 16).Natural selection can only work on certain characteristics if theyhave heritable variation and give an advantage to enable speciescompete for resources. Darwin defined natural selection as theprocedure through which organisms modify with time due tomodifications in heritable behavioral or physical characteristics.Such modifications enable organisms to adapt in the best way possibleto their environment, allowing them to survive and produce more.Through natural selection, population can modify their size and colorover numerous generations.
Naturalselection is made probable by mutations. They are behavioral andphysical modifications that take place at the level of genes and DNA(Gould 32). Mutations result from various factors includinginaccuracies in DNA imitation and damage in radiation. Besides, it ispossible to intentionally induce mutations in order to allow anorganism adapt in a modifying environment. Mutations can be neutralor detrimental but in some exceptional cases, they prove useful toorganisms. The evolutionary process is guided by natural selection.The process preserves and adds up useful mutations while rebuffingthe harmful ones.
Thecomponents of the natural selection process encompass variation,inheritance, increased population growth and disparity in survival aswell as reproduction. Increased growth in population means that somepopulations bring forth more offspring every year making it difficultfor the environment to support them. The result is struggle for thelimited resources and only the fittest survive. As a result, everygeneration endure considerable mortality. Adaptation is shaped bynatural selection that also makes a distinction among thereproductive successes of members of a population. The genetic makeup of an individual determines its capability to have offspring. Ifindividuals are best suited to a certain environment as a result oftheir inherited traits, then they have an increased ability toreproduce, implying increase in population size.
Theevolutionary process has been evidenced to cause various concerns tothe environment. For instance, the natural selection process resultsin competition for resources (Ridley 28). It is an interactionbetween species wherein or the fittest survive. Considering thatresources such as water and food are limited, competition isguaranteed. The community structure is affected greatly bycompetition, which is considered as being among the interactingabiotic and biotic aspect (Gould 42). Interspecific competition takesplace between populations of dissimilar species, while intraspecificcompetition takes place amongst populations of a similar species(Ridley 6). The competitive exclusion doctrine argues that members ofa population that are not well-matched to struggle for the limitedresources must adapt to the environment or die out. The evolutionarytheory points out the usefulness of such competition in naturalselection.
Adaptationand natural selection are the two elements that operate jointly toshape genes in a specific population. According to Darwin
Species possess possible fertility which results in increased population size if the population continues to reproduce
There are limited resources in the environment that result in increased competition between species
Members of a certain population differ broadly in their traits, affecting their capability to survive in their surrounding as well as reproduce
The variation is generally genetic in nature thus, heritable (Ridley 16).
Somebiologists have argued that the evolutionary process is the cause ofthe current pressing health issues including cancer, diabetes,autoimmune illnesses, as well as cardiovascular illnesses amongothers. This is in spite of the fact that the evolutionary approacheshave not been incorporated by medical schools. Biomedical researchhas focused on the exploration of microbial illnesses and theirdynamics in human bodies. This can only be explained with regard tothe evolutionary process. Microbes cause various infectious diseasessuch as Ebola and others such as malaria. Such microbes change andadapt to their new environments making them harmful and extremelyhard to treat. The intrinsic variability among such microbes permitsthem to search for novel ways that helps them evade and defeat theimmune system of individuals (Ridley42).Through natural selection process, them become drug resistance andevolve. Bacteria that are resistance to antibiotics also demonstratethe natural selection process. Those which survive can be termed asbeing the fittest, explaining the aspect of survival for the fittest.They also reproduce in the human body and their followers inherittheir traits.
Virusesare also explained in terms of the evolutionary process. It has beenevidenced that some of them evolve gradually and others suddenly. Forinstance, virus causing HIV evolves quickly considering that itsreplicating technique entails an amplified level of mutation. Due tothe mutation, such viruses are able to acquire novel forms, meaningthat they modify themselves quickly. During treatment, the virusmodifies itself but this varies from one person to the other.Isolation, different environments, as well as struggle for survivalmake the HIV virus to develop autonomously. This is similar to theDarwin’s microscopic case of Galapagos.
Gould,Stephen Jay. TheStructure of Evolutionary Theory.Harvard: Harvard University Press, 2002. Print.
Ridley,Mark. Evolution.New York: Wiley Blackwell: 2003. Print.