Period 6 Biomedical Research

The capacity for quick change among disease-causing microbes is what makes them so dangerous to large numbers of people and so difficult and expensive to treat. they leap from wildlife or domestic animals into humans, adapting to new circumstances as they go. Their inherent variability allows them to find new ways of evading and defeating human immune systems.

By natural selection these microbes acquire resistance to drugs that should kill them. They evolve. There's no better or more immediate evidence supporting the Darwinian theory than this process of forced transformation among our inimical germs.

Other harmful infections and diseases are caused by the same problem. HIV's method of replicating itself involves a high rate of mutation. and those mutations allow the virus to assume new forms. After just a few years of infection and drug treatment, each HIV patient carries a unique version of the virus

The disease microbe called Staphylococcus aurus, causes infections usually with patients in hospitals going through surgery. Penicillin was, in 1943, found useful in preventing or curing the infection. Through evolution, strands of the disease became resistant to another cure, methicillin.

DDT, an herbicide/insecticide, had resistance effects. It was successful in fighting the flies, but through evolution (natural selection), house flies became resistant within a decade.[http://www.nature.com/nature/journal/v180/n4595/abs/1801132a0.html]

Specification, when a lineage splits into two species, is the other major phase of evolutionary change. This makes the divergence between lineages, that Darwin wrote about, possible. Many individual mutations have to accumulate before individual populations seperate.

A biologist named Stephen Palumbi has calculated that it would take thirty billion dollars a year for the treating of penicillin - resistant and methicillin- resistant staph infections just in the United States.

Insects and weeds become resistant to our insecticides and herbicides because they evolve. Natural selection transforms them into a new population that is resistant to the insecticide fo herbicide so it is less vulnerable to that paticular poison.

Peter and Rosemary Grant, who are two British born researchers, spent decades researching evolution with thier long term sudies of beak size among the Galapagos finches. William R.Rice and George W. Salt witnessed evolution through studies of 35 generations of fruit flies

The supreme potency of penicillin didn't last long. The first resistant strain of staphylococcus aureus were reported in 1947. A newer staph-killing drug, methicillin, came into use during the 1960s, but methicillin-resistant strains appeared soon, and by the 1980s those strains were widespread.

With the evolvement of Staph infections (strains that are resistant to prescription drugs) made a very practical problem by adding expense, as well as misery and danger, to the challenge of coping with staph. With new strains forming, humans have to keep coming up with new Staph killing prescriptions that will defeat the bacterial infection for the time being.

"A greater problem is that many staph infections no longer respond to common antibiotics. Though most staph infections can still be successfully treated, it may only be a matter of time before the bacteria become resistant to all currently available medications". http://www.mayoclinic.com/health/staph-infections/DS00973

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