Question

In order for migration to alter allele frequencies in another population:

Answer 1

Migration can alter allele frequencies in a population if there is consistent immigration of individuals with a specific allele and the trait associated with that allele is favored due to selection pressures. Over time, this can lead to genetic drift and allopatric speciation, especially in geographically isolated populations.

Step-by-step explanation:

How Migration Alters Allele Frequencies

In biology, specifically genetics, gene flow takes place when individuals move into or out of a population. This movement can alter allele frequencies. If migration occurs at a high rate, significant changes can be seen within the genetic makeup of both the source and the destination populations. For a new trait to appear and then reach a high and steady frequency within a population, certain factors are essential:

• There must be a consistent source of immigrant individuals with the allele, introducing new genetic material into the population.
• The introduced trait must be favored by natural or sexual selection to reach a steady, high frequency.
• Environmental conditions may also play a role in whether the allele becomes more prevalent within the population.

For example, immigration of new individuals carrying a specific allele, such as a gene for white fur in rabbits, can lead to an increase of that allele in a population where it was previously rare. Alongside the environmental factors and selection pressures, genetic drift might also influence the changes in allele frequencies, particularly in smaller populations.

If separated populations remain isolated for a long period, allopatric speciation may occur, with evolving differences in allele frequencies as each population adapts to its specific environment and conditions. Divergent adaptations result from different mutation rates, environmental conditions, and genetic drift.

Answer 2

Gene flow refers to the transfer of alleles between populations by migration, influencing allele frequencies. For a new trait to become common, consistent immigration of individuals with that allele and selection favoring the trait are necessary.

Step-by-step explanation:

In biology, specifically in the context of population genetics, gene flow is the process of alleles moving between populations due to migration of individuals or gametes. Migration can alter the allele frequencies in another population significantly, especially if a consistent number of immigrants carry a particular allele. For a new trait to appear in a population and reach a steady, high frequency, several factors must be at play.

Firstly, new traits typically arise through gene mutations or genetic drift. However, for these traits to reach a high frequency in a population, there must also be a consistent influx of immigrant individuals with this allele. This presence of immigrants will introduce new genetic variations that can integrate into the gene pool of the population they enter.

Another critical aspect is whether the trait associated with the new allele is favored by natural or sexual selection. If the trait enhances the reproductive success of the individuals or improves their survival chances, it's more likely to increase in frequency. Conversely, if the trait has a neutral or negative impact on survival or reproduction, it is less likely to reach a high frequency.

Population structures also influence allele frequency. A geographically continuous population allows for more free-flow of alleles, leading to homogenized allele frequencies across the population range. In contrast, when populations become geographically discontinuous, the flow of alleles is restricted, which can result in different populations evolving along separate paths and possibly leading to allopatric speciation.

An example of this would be if a group of white rabbits, carrying the allele for white fur, migrate into a population of brown rabbits. The allele for white fur would become more frequent in the new population, given that immigration continues and the trait is beneficial in that environment.