Causes of Variation and Its Importance to Living Organisms

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Causes of Variation and its Importance to Living Organisms Variation between living organisms is almost certainly one of the most important features of all life on planet earth as a whole. Without both interspecific and intraspecific variation, Life as we know it would not exist. Variation between members of the same species, known as intraspecific variation, is one of the driving forces behind evolution through natural selection. Minute variations in organisms, brought about through mutations in their DNA can cause certain members of a community to be better adapted to their environment than others, making them more likely to breed successfully and pass on their superior genes. Alternatively, differences in DNA may provide immunity to a disease which affects most members of a species. Although, if widespread disease can wipe out large amounts of a species, it will create a genetic bottleneck, where the size of a species gene pool is dramatically reduced and only the individuals with the mutated genes survive. This leads to a founder effect, where there is very little diversity in the species. A good example of this can be seen in the cheetah population. They suffer from many genetic problems caused by inbreeding, after hunting severely reduced their population. Theoretically, a species of organism may survive in the same body form in an unchanging environment for millions of years. However, most environments change over time. Under this circumstance, variation generated by sexual reproduction ensures that the individuals within the population survive under the changing environment. If all individuals are genetically identical to one another, when one is not adapted by an environmental change, then all individuals are affected and the population will be perished. Therefore, increasing genetic variation is essential. Because of the differences, some may be slightly

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