Question

What are the five factors that act to change allele frequencies?

Answer 1

Factors leading to frequency change:

1. When the frequency of alleles changes in a population, it means the population has evolved.
2. Genetic equilibrium and population heterogeneity are influenced by five factors.These elements are referred to as evolutionary agents.
3. These are the following: mutations, genetic recombination, gene flow or gene migration, genetic drift, natural selection.

Mutations:

1. These are massive, rapid alterations in the genetic material that are passed down down the generations.
2. Mutations are random.
3. The vast majority of mutations are either harmful or harmless.
4. The rate of mutation is quite low.
5. Mutations add new genes and alleles to a gene pool, as well as generating and maintaining population variations.
6. The accumulation of mutations over a lengthy period of time can lead to speciation.

Recombination of genes:

1. Sexually reproducing organisms and those with gametogenesis followed by fertilisation have more opportunities for recombination.
2. Despite the fact that only existing characters are reshuffled and no new genes are produced, recombination causes redistribution of distinguishing traits across individuals in a population.
3. In many organisms, different combinations result in genetic and phenotypic variation. As a result, recombination acts as an evolutionary catalyst.
   

Genetic drift:

It is the occurrence of chance variations in the frequency of alleles, resulting in a random change in allele frequency.

Gene migration (gene flow):

1. A modest quantity of immigration can result in substantial changes in allele frequencies if two populations are genetically quite dissimilar.
2. If migrating individuals contact with members of the local population, a process known as hybridization, many novel alleles may be introduced into the host population's gene pool.
3. This is known as gene migration, and gene flow refers to the addition or removal of alleles as people arrive or leave a group from another location.
4. When gene flow is allowed, the differences across gene pools are reduced, and the distinctiveness of populations is reduced.

Natural selection:

Natural selection is the process through which nature favours substantially more fitted individuals from a heterogeneous population over the less adapted individuals.