May Random Mutation Ever be in your Favor

            Natural selection is one of many concepts for Evolution. Evolution is change over time. In order for natural selection to happen, over population, variation, and competition has to occur. After all these conditions have been met, Charles Darwin suggests that the fittest will survive. Fittest doesn’t necessary mean the strongest. Organism with variation that will benefit them in survival over the others will triumph, and will survive and reproduce.

            The snails in the article are an excellent example of natural selection. Cepaea nemoralis is the snails that are being studied for evolution. These snails are highly variable as their shells can be yellow, pink or brown. Their shells can also be banded, which are genetically inherited. This variability is spread out over many regions as their color allows them to survive in different environment. Snails are able to possess different colors of shell because shell color is controlled by a single gene with three alternative alleles. On the other hand, the band in the snail’s shell is controlled by a single gene with two alleles. Researches have shown that darker shells, which are brown or pink, will be able to absorb more solar radiation than yellow shells. Therefore they can adapt to cooler climates, as they can keep themselves warm. Snails that inherited the yellow shell will prefer the warmer climate as they can bathe in sunshine without dying of heat. Their environment also plays a role. If the snails lived in a open grassland, where grasses are yellow, the snails with yellow shells will be able to camouflage among the grasses while the snails with darker shells get eaten by predators. The environment and the climate supports the snails that are best adapted to it, while killing off the rest. The ones that survive grow up and eventually pass on their advantageous gene by reproducing. This is natural selection.     

            Another case of natural selection, which is rapidly becoming a problem today, is the evolution of antibiotic resistance in bacteria. Due to random mutation, a few bacteria will become resistant to the antibiotic. Once a few bacteria are able to resist the antibiotic, it can pass on its gene to other bacteria by plasmid exchange. Antibiotic was first introduced by the usage of penicillin, which was first discovered by Alexander Fleming in 1928. Since then, bacteria have mutated due to over-prescription of antibiotics by the physician, or patient’s incompetence to follow the antibiotic prescription instructions. Antibiotics kill off bacteria which isn’t able to resist it, giving the bacteria’s environment pressure. As a result, only the bacteria with the antibiotic resistant gene are able to survive. With their competition eliminated, they can divide freely, and their population will rise. They can then reproduce and pass on their traits to their offspring. This natural selection of the bacteria eventually produces bacteria that have several antibiotic resistant genes called superbug. This is becoming a major problem as places that are sanitary like hospitals are slowly generating superbug.

http://www.sciencedaily.com/articles/a/antibiotic_resistance.htm

http://www.answersingenesis.org/articles/am/v2/n3/antibiotic-resistance-of-bacteria

            There is a relationship between evolution, ecology and genetics. Ecology is the interaction between biotic factors, and their interaction between abiotic factors. When living organisms interact with each other, competition occurs due to the population of the organism exceeding the carrying capacity of the ecosystem. The ecology therefore creates an environmental pressure for the organism to adapt, and evolve. Organisms that gain an advantage due to random mutation of the genes will be more likely to pass on their genes to their offspring. In the end, the organism that has this genetic advantage will accumulate over time due to natural selection, and evolve to adapt to its ecosystem.