Essay on Evolution Applied to Human Health and Medicine

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Evolution is defined as a gradual process in which organisms become better adapted to their environment through gradual changes that occur from generation to generation. Throughout the history of life, the human species has changed to become better suited to the environment. All of the changes have ultimately resulted from mutations, which occur at the gene level. Pathogens such as bacteria or viruses that live inside of our cells have had a major influence upon our evolution (Parks, Panelli & Weinstein, 2003). Pathogens have affected our evolution in two major ways, which I will focus on: antibiotic resistance and virulence. Virulence has also changed in regards to ways of reproduction and establishing a higher rate of fitness. Other…show more content…
On the other hand, if a mutation increases the chances for survival, then it will be selected and will continue to be passed on through generations. Pathogens as well as their hosts can have mutations that increase their fitness. Pathogens are also in the presence of selection pressures: temperature, pH, and medicines such as antibiotics (Fitch, Leiter, Li & Palese, 1991) and will, therefore, also evolve. As the human species experiences illnesses, doctors will prescribe medicine, usually an antibiotic, which will kill many of the pathogenic bacteria. In regard to pathogens, if a virus is attacking the body, an antibiotic will destroy the bacteria and leave the virus alone. Viruses or bacteria that survive medication will develop resistance to that medicine (Parkes, Panelli & Weinstein, 2003). As a resistance is developed, they can also reproduce and pass the resistance trait to their offspring, increasing the level of fitness. There has been documentation of evolution resistance in bacterial populations and within individual large-scale human populations. Experimentally, there have been studies where the use of antibiotics was lessened and so was resistance in bacteria (Bull & Wichman, 2001). This shows the correlation that as antibiotics are being used, bacteria and viruses are able to withstand the effects of medicine and can develop a resistance to
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