A rare allele may become common in the gene pool of a small population after only a few generations by the process of________________.?
The process by which a rare allele may become common in a small population after only a few generations is known as genetic drift. Genetic drift is a random process that occurs due to the effects of chance on the inheritance of genes. Unlike natural selection, which operates based on the fitness of individuals, genetic drift occurs randomly, causing certain alleles to increase or decrease in frequency in a population over time.
To understand how genetic drift can lead to the increase in frequency of a rare allele, let's break down the process:
1. Start with a small population: Genetic drift is more likely to occur in small populations where chance events can have a greater impact on allele frequencies.
2. Allele frequency: In any population, there are multiple alleles for each gene. If a particular allele is present in very low numbers initially, it is considered rare.
3. Random mating: Individuals in the population mate randomly, meaning there is no preference for which alleles they pass on.
4. Random events: Due to chance, certain individuals may have more or fewer offspring than others. This randomness can cause the frequency of alleles to fluctuate from one generation to another.
5. Amplification of the rare allele: If, by chance, individuals carrying the rare allele have more offspring or survive more successfully than others, the frequency of that allele will increase in the next generation. This increase continues over subsequent generations, potentially leading to the rare allele becoming common in the gene pool.
It's important to note that genetic drift can have more significant effects on smaller populations since chance events are more likely to occur due to limited genetic diversity. Additionally, genetic drift is just one of the mechanisms that can shape the genetic makeup of a population, alongside natural selection, mutation, and migration.