Term Paper on Evolution

Evolution
Term Paper: Ask and Answer Paper

I. In my paper I decided to concentrate my attention on one of the most interesting and fundamental questions – “How does natural selection works?” I believe that the answer to this question is essential to understanding the evolution as a whole.

II. First of all, let me start with defining the process of natural selection: “Natural selection is the process by which species adapt to their environment.” (ActionBioscience.org, 2004, answer 1)

Now I’ll enlarge on the mechanism of this evolutionary process. In the most general words, “natural selection, the principal known mechanism of evolution, harnesses nonrandom change by preserving ‘desirable’ (adaptive) features and eliminating ‘undesirable’ (nonadaptive) ones.” (Rennie, 2002, pt.8)

The species have to adapt to the environmental conditions they live in. Some species are considerably more successful in it. Such species are noted for the higher survival and reproductive rate. Therefore, a concept of reproductive success was introduced. It refers to the successful passing of the beneficial features to their offspring. The beneficial features are those able to serve the survival and reproduction.

Simultaneously, those species that appear to be unsuccessful in adaptation to their environment gradually become extinct – there’s a possibility that they may die before producing offspring, or become less prolific. If the natural selection is believed to be the principal mechanism of the design in nature, it’s often labeled as the adaptive evolution. The adaptation happens during the course of the so-called struggle for existence.

Now lat me list the main facts that should be remembered about the natural selection. First of all, natural selection isn’t the only mechanism of evolution, the other include, for instance, genetic variation. Secondly, natural selection doesn’t always but only sometimes leads to the origin of new species. Thirdly, the natural selection doesn’t mean the survival of the fittest – it is used to characterize reproductive success in the first place.

We should keep in mind that “an animal’s success in the gene pool is measured by the number of offspring it successfully raises to pass on its DNA.” (Pickrell, 2003, “Against Darwin?”)

Moreover, some species may be equally fit occupying different facets of the environment. The natural selection is divided into ecological selection and sexual selection. If the species loses its ecological niche, then survival is the matter of ecological conditions in the first place. Sexual selection refers to competition among male representatives of the species. Darwin considered sexual selection to be secondary, but the majority of the contemporary scientists perceive ecological and sexual selection as a complex. In reality, the theory of natural selection is much more sophisticated and scientifically backed. But to cut the long story short, Darwin himself summarizes his theory (1995, p.154) by stating that “new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct.”

Making a conclusion, I can say that the process of natural selection works as follows: a numbers of variations in heritable characteristics are present within every species of living beings. Some features help a representative of the species to gain an advantage over others, when the matter concerns surviving and reproducing. Therefore, the offspring are more have better chances for surviving and reproducing. This process results in the survival of the living beings that are best suited for the particular environmental conditions.

III. As for my personal opinion about the natural selection matter, I find Darwin’s argument and evidence quite persuasive. Still, natural selection is not only evolutionary mechanism. I strongly deem that the rest of evolutionary mechanisms don’t receive adequate attention from the scientific community.

Natural selection is the key assumption of the evolutionary theory. Darwin’s theory has many blanks and misconceptions, but no other theory explaining the origins of life (e.g. creationism) is acceptable for me.

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