Estimating Genetic Mutation Rates

ABSTRACT

Spontaneous mutation causes both valuable genetic novelty and harmful genetic disorders. Scientists and medical professionals in fields from microbiology to epidemiology to taxonomy benefit from accurate understanding of mutation, especially the measurement and predication of mutation rates. Three distinct methods of estimating this rate are profiled in this study, each suited to a particular type of organism and research question. All techniques are literature grounded and used by biologists in actual applications.

The first technique measures differences in DNA within pseudogenes of related species and then leverages chronological knowledge of when the species diverged to estimate the mutation rate. The critical assumption here is that evolutionary forces do not act on these pseudogenes (aka junk DNA) and that the accumulation of mutations is the result of random chance, which allows accurate measurement of unbiased mutation rates.

The second observes that many genetic disorders (e.g. hemophilia) can arise from both heredity and mutation. Scientists can compare estimates for the likelihood that an affected individual will pass on the disease to children to census data of actual populations over time to approximate the number of mutation-induced cases of the disease occur over time.

In the final method, an organism and its descendants can be sequenced and the mutation rate can be measured directly. This requires meticulous analysis of many generations of organisms in a laboratory setting, but provides probably the most accurate method for diagnosing mutation rates.

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Mike Hughes,
Jan 13, 2009, 12:18 PM
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Mike Hughes,
Jan 13, 2009, 12:18 PM
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