U10a1 Life in the Universe Review Assignment - Coursework Example

Evolution is a natural phenomenon. Natural selection is the reason why evolution happens. In its most basic form, evolution is genetic change within a population - specifically changes in the allelic frequencies of said population. Genetic drift, natural selection, mutation, and migration these are the basic mechanisms of evolution. Evolutionary thought can be traced back to classic Greece, but it is most commonly associated with Charles Darwin. Darwin only described one of the mechanisms that now are known to guide evolution: Natural Selection.

He also put forward his idea that all the species have originated from a common ancestor and changed over time to the present situation. Natural Selection is the process by which favorable heritable traits become more common in successive generations of a population and unfavorable heritable traits become less common due to differential reproduction. That is: given a certain population, those individuals who are more fit to the selective pressure(s) by their habitat will leave more descendants than those less fit.

This means that for Natural Selection to act, a population must be composed by individuals that differ in their traits. Evolution is the explanation for the development, adaptation and diversity of life, as well as the morphological similarities between different kinds of life. Darwin's Theory of Evolution: Darwin's Theory of Evolution is the widely held notion that all life is related and has descended from a common ancestor: the birds and the bananas, the fishes and the flowers -- all related.

Darwin's general theory presumes the development of life from non-life and stresses a purely naturalistic "descent with modification". That is, complex creatures evolve from more simplistic ancestors naturally over time. In a nutshell, as random genetic mutations occur within an organism's genetic code, the beneficial mutations are preserved because they aid survival -- a process known as "natural selection." These beneficial mutations are passed on to the next generation. Over time, beneficial mutations accumulate and the result is an entirely different organism.

Darwin's Theory of Evolution - Natural Selection: Natural selection acts to preserve and accumulate minor advantageous genetic mutations. Suppose a member of a species developed a functional advantage, its offspring would inherit that advantage and pass it on to their offspring. The inferior members of the same species would gradually die out, leaving only the superior members of the species. Natural selection is the preservation of a functional advantage that enables a species to compete better in the wild.

Natural selection is the naturalistic equivalent to domestic breeding. Over the centuries, human breeders have produced dramatic changes in domestic animal populations by selecting individuals to breed. Breeders eliminate undesirable traits gradually over time. Similarly, natural selection eliminates inferior species gradually over time. With the proper tools, we can sample the DNA of a population to see how the abundance of a particular gene changes as the environment changes. For example, in the mangled example of antibiotic resistance in bacteria, one type of antibiotic targets the prokaryotic ribosomes.

A drug that binds bacterial ribosomes blocks the ability of the bacteria to synthesize proteins. One way that bacteria can evade this type of drug is to mutate the target site. If in the