Table of Contents
Gene Pool Meaning
A gene is a portion of DNA or RNA that encodes for a specific molecular cell product. Physical characteristics and the genetic makeup of creatures belonging to the same species are determined by genes, which are typically passed down from generation to generation. Therefore, organisms belonging to the same species share comparable traits in terms of personality, structure, and function.
A population is a collection of individuals belonging to the same species. One or more populations with inter-breedable members may exist within a species. When members of the same species breed, genes are passed on to the progeny, resulting in variation. The gene pool affects how these genes are distributed among a population.
All the genes in a population are referred to as the gene pool. Within a gene pool, genes that are abundantly present are more prevalent in the subsequent generation. Some genes greatly influence the natural selection and evolution of individuals within a population. Organisms with advantageous genes or features can adapt and change when under environmental pressure. The gene pool of species going through evolution varies from generation to generation.
A population with a small gene pool and low genetic variety is more vulnerable to stress-induced fitness decline and is more likely to go extinct.
Natural selection, gene flow, and genetic drift all have the potential to alter the size of any gene pool over time. The size can change depending on whether a gene mutation occurs and persists as well as when alleles are eliminated, such as when a population experiences a bottleneck.
Hardy-Weinberg Principle
One can determine the frequency of occurrence of an allele of a gene or locus in a specific population. It is expected that this frequency will remain constant throughout many generations. According to the Hardy-Weinberg principle, allele frequencies in a population are consistent and stable across time. The gene pool, or the total number of genes and alleles in a population, does not change over time. This is termed genetic equilibrium.
Primary Gene Pool
Members of this gene pool can freely interbreed because they most likely belong to the same “species”. This gene pool is unique because it crosses easily, resulting in fertile hybrids with strong chromosome pairing, and proper gene segregation results in simple gene transfer.
Secondary Gene Pool
Members of this pool are most likely categorised as distinct species from the crop species under investigation (the primary gene pool). These species can, nevertheless, cross and create at least a few fertile hybrids because they are closely related.
Tertiary Gene Pool
The individuals in this gene pool are distantly connected to those in the primary gene pool. Gene transfer across the primary and tertiary gene pools is not conceivable without employing “rather extreme or radical procedures” like embryo culture or embryo rescue.
Examples
Humans
As a single species, humans can interbreed anywhere on Earth. Therefore, every allele of the roughly 19,000–20,000 human genes in our DNA contributes to the human gene pool.
Butterflies
At locus one, there are two alleles in a population of butterflies. Homozygous individuals (two copies of the same gene) for the recessive allele lack eyespots, but those with the dominant allele possess eyespots on their wings.
If an allele that produces eyespots mutates and is favoured by natural selection, eyespots may reappear in the population. Alternately, if members of the original butterfly population mate with members of another butterfly population that carries the trait for eyespots, eyespots can reappear through gene flow.
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