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In the paper, Kimura uses mathematical techniques to determine the probability of fixation of mutant genes in a population. He showed that the probability of fixation depends on the initial frequency of the allele and the mean and variance of the gene frequency change per generation. [4]
These random fluctuations within the allele frequencies can lead to the fixation or loss of certain alleles within a population. To the right is an image that shows through successive generations; the allele frequencies fluctuate randomly within a population. The smaller the population size, the faster fixation or loss of alleles will occur.
When two plants share the same incompatibility allele, they are unable to mate. Thus, a plant with a new (and therefore, rare) allele has more success at mating, and its allele spreads quickly through the population. [9] A similar example is the csd alleles of the honey bee. A larva that is homozygous at csd is inviable.
A selective sweep can occur when a rare or previously non-existing allele that increases the fitness of the carrier (relative to other members of the population) increases rapidly in frequency due to natural selection. As the prevalence of such a beneficial allele increases, genetic variants that happen to be present on the genomic background ...
Once an allele becomes fixed, genetic drift comes to a halt, and the allele frequency cannot change unless a new allele is introduced in the population via mutation or gene flow. Thus even while genetic drift is a random, directionless process, it acts to eliminate genetic variation over time.
Population structure (also called genetic structure and population stratification) is the presence of a systematic difference in allele frequencies between subpopulations. In a randomly mating (or panmictic) population, allele frequencies are expected to be roughly similar between groups. However, mating tends to be non-random to some degree ...
The allele frequency spectrum from a sample of chromosomes is calculated by counting the number of sites with derived allele frequencies . For example, consider a sample of = individuals with eight observed variable sites. In this table, a 1 indicates that the derived allele is observed at that site, while a 0 indicates the ancestral allele was ...
Gene conversion is the process by which one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion. [1] Gene conversion can be either allelic, meaning that one allele of the same gene replaces another allele, or ectopic, meaning that one paralogous DNA sequence converts another.