Essay About Reproductive Success And Charles Darwins Theory

Evolution
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Charles Darwin had two great themes in “On the Origin of Species” which accounted for the similarities and adaptations
characteristic of living organisms. To account for the adaptations of organisms and those innumerable features that equip
them for survival and reproduction, Darwin (and Wallace) independently came up with the central theory of evolutionary
process: natural selection. Natural selection gives insight in to why organisms are the way that they are. Adaptations are
phenotypic variants that result in the highest fitness among a specified set of variants in a given environment. In reference
to humans, there are many traits that have been selected and adapted for throughout their evolutionary history giving them
the characteristics that they have today. In this paper I will discuss some parts of the human body, which have been found
to be selected for by the evolutionary mechanisms of natural selection, adaptation and mutation.
Natural selection, adaptation, and mutations are three components of the evolutionary process, each one having either
positive or negative effects on the other. What exactly is natural selection? There are many variations of the definition but
most agree that it must include the following concepts: some attribute or trait must vary among biological entities, and there
must be a consistent relationship, within a defined context, between the trait and one or more components of reproductive
success, where “reproductive success” includes both survival and the reproductive processes themselves (Futuyma, 1998).
Charles Darwins theory of natural selection states “if variations useful to any organic being ever occur, assuredly
individuals thus characterized will have the best chance of being preserved in the struggle for life; and from the strong
principle of inheritance, these will tend to produce offspring similarly characterized.” Regardless of how it is defined,
natural selection and its action can have tremendous effects on the members of a population. It is natural selection that
causes adaptation, and these adaptations evolve to ensure the survival of a species.
Evolution, in a very broad sense, is defined as descent with modification and often with diversification (Futuyma, 1998).
Darwins idea of evolution was that it occurred by descent with modification, from common ancestors. Some mechanisms
involved in evolution are mutation, recombination, gene flow, isolation, random genetic drift, and natural selection. These
ideas together constitute our idea of the evolutionary theory. When you factor in all of these elements of evolution you can
view evolution as a “progressive development through time from simple to gradually more complex and more diverse
organisms” (Ayala, 1997).
Darwin devoted one single sentence in “The Origin of Species” to the controversial topic of human evolution: “Light
will be thrown on the origin of man and his history”(Futuyma, 1998). Although his evasion did not work, human evolution
is still a controversial topic today. Since this area is so controversial there have been many studies conducted in the area
of human evolution. These evolutionary studies have provided us with abundant, well-documented evidence on the
relationship of humans to other species, on the steps by which some human characteristics evolved, and on genetic
variation within and among human populations.
Some theorists believe that natural