Natural Selection

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Natural Selection

The theory of natural selection by Charles Darwin is understood as a process of differential survival whereby the reproduction of individuals or species is because of differences in their respective phenotype. It is considered a critical part of the mechanism of evolution. Natural selection is considered as one of the key mechanism of evolution of organisms together with others such as migration, genetic drifty and mutation. The theory of natural selection is founded on key components namely the presence of variations in traits, differential reproduction, and heredity which results in natural selection as the primary outcome.

In essence, the process of natural selection is understood as a process through which species or organisms adapt to possible changes within their respective environments (Dare 38). The process of natural selection usually leads to evolutionary changes when organisms that possesses specific traits, which provide them with enhanced possibility of survival and reproduction than other organisms in the population, pass these traits to their offspring. This affirms the understanding that natural selection is a relatively consistent variation in reproduction and survival capabilities across different genotypes or genes.

The reasons provided by scholars such as Charles Darwin and Alfred Russel Wallace provide an explanation of the relevance of natural selection in nature. Darwin’s works provided in On the Origin of Species by Means of Natural Selection gained critical acclaim due to the new perspectives provided on the incidence of natural selection (Freedman 29). Subsequent research affirmed that natural selection and evolution are valid claims, which explain the emergence of stronger breeds because of adaptation to shifts in environmental conditions. It is important to note that the basic tenet of natural selection is the presence of genetic variations, which enable evolution of species or organisms.

Furthermore, recombination of genetic phenotypes and mutation usually plays a role in the generation of new genotypes known as alleles. These processes play a critical role in inducing genetic variation. Natural selection through mutation, recombination, and adaptation may give rise to new species. Natural selection is the only process of evolution or adaptation that takes place within species (Dare 41). In some instances, natural selection may play an important role in the emergence of new species.

It is important to note that during his voyages as a naturalist, Darwin was able to note the presence of differences amongst tortoises from different islands as he toured the Galapagos Islands. His findings brought about three primary inferences.

1. Species or populations of organisms breeding amongst themselves, evolve over time and space. The representatives of each of the species within the population differ significantly from those that lived in the past. In addition, the populations of organisms in varied geographical locations differ in terms of behavior and form.
2. All organisms share a common origin with other organism. Over time, the populations of these organisms are divided into varied species because of adaptation and variations in genetic makeup.

• Evolutionary changes are usually slow and gradual according to Charles Darwin. His claim was affirmed the overly lengthy process of change in organisms evident in the fossil records. From this inference, paleontologists and biologists have been able to document the changes of species as they evolve to adapt to environmental shifts.

The findings provided by Darwin illustrate that the primary means of change over a period is only through natural selection (Darwin, Desmond, and Moore 43). Darwin notes that the process of natural selection is undertaken through four primary stages namely variation, inheritance, population growth and subsequent differential survival and reproduction.

1. Variation

This is whereby the organisms within a given set of population usually exhibit individually varied traits in terms of behavior and form or appearance. Such variations provide the organisms with the necessary skills and capabilities for survival in a competitive environment.

1. Inheritance

Some traits exhibited by organisms are inherited as they are passed from parent to offspring. These traits are heritable whereas others are influenced and emergent because of the prevailing environmental conditions.

• High Population Growth

In a majority of populations, the organisms usually have offspring in excess of what the environment and existing resources can sustain leading to incidences of high competition for the declining resources.

1. Differentiated Survival and Reproduction

Individuals with the distinctive traits are usually suited to thrive in the struggle for the meager resources and contribute significantly towards growth in populations and emergence of new species or organisms with varied genomes, which enable them to survive in prevailing environmental conditions.

The struggle for existing resources from one generation to another, in what Darwin refers to as the “struggle for existence,” favors the individuals or organisms that have suitable variations than others (Darwin and Beer 36). Thus, this brings about frequency of change in terms of traits amongst the members of the population as a means of achieving survival in competitive environments. This is what Darwin refers to as natural selection. The traits that provide an advantage to a number of organisms or species within a population set to bring about new offspring are referred to as adaptations. Thus for natural selection to focus primarily on traits, it is imperative that such traits be heritable and variable and provide the individual with an advantage in the competition for available resources over other members of the population.

Works Cited

Darwin, Charles, Adrian J. Desmond, and James R. Moore. The Descent of Man, and Selection in Relation to Sex. London: Penguin, 2004. Print.

Darwin, Charles, and Gillian Beer. The Origin of Species. Oxford: Oxford University Press, 1996.  Print.

Dare, Bill. Natural Selection. London: Piatkus, 2004. Print.

Freedman, Dave. Natural Selection. New York: Hyperion, 2006. Print.