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It is analogous to biological mutation. The classic example of a mutation operator of a binary coded genetic algorithm (GA) involves a probability that an arbitrary bit in a genetic sequence will be flipped from its original state. A common method of implementing the mutation operator involves generating a random variable for each bit in a ...
Recurrent mutation will maintain alleles in the population, even if there is strong selection against them. Migration genetically links two or more populations together. In general, allele frequencies will become more homogeneous among the populations. Some models for migration inherently include nonrandom mating (Wahlund effect, for example ...
Random mutations are the ultimate source of genetic variation. Mutations are likely to be rare, and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of ...
A disease that is caused by a loss-of-function mutation is Gitelman syndrome and cystic fibrosis. [54] Gain-of-function mutations also called activating mutations, change the gene product such that its effect gets stronger (enhanced activation) or even is superseded by a different and abnormal function.
Contemporary biologists accept that mutation and selection both play roles in evolution; the mainstream view is that while mutation supplies material for selection in the form of variation, all non-random outcomes are caused by natural selection. [59]
The resulting influx of deleterious mutations into a population over time is counteracted by negative selection, which acts to purge deleterious mutations. Setting aside other factors (e.g., balancing selection, and genetic drift), the equilibrium number of deleterious alleles is then determined by a balance between the deleterious mutation ...
Evolution is a change in the frequency of alleles in a population over time. Mutations occur at random and in the Darwinian evolution model natural selection acts on the genetic variation in a population that has arisen through this mutation. [2] These mutations can be beneficial or deleterious and are selected for or against based on that factor.
This process is often characterized by a description of the starting and ending states, or the kind of change that has happened at the level of DNA (e.g,. a T-to-C mutation, a 1-bp deletion), of genes or proteins (e.g., a null mutation, a loss-of-function mutation), or at a higher phenotypic level (e.g., red-eye mutation).