Two populations of deer, one of them large and living in a mainland forest and the other small and inhabiting a forest on an island, regularly exchange members that migrate across a land bridge that connects the island to the mainland. If you compared the allele frequencies in the two populations, what would you expect to find?

Verified step by step guidance

1. Understand the concept of gene flow: Gene flow refers to the transfer of alleles or genes from one population to another. In this case, migration across the land bridge facilitates gene flow between the mainland and island deer populations.
2. Consider the size of the populations: The mainland population is large, while the island population is small. This difference in population size affects the impact of gene flow. Allele frequencies in the smaller island population are more likely to be influenced by incoming migrants from the mainland.
3. Analyze the effect of migration: Migration tends to homogenize allele frequencies between populations. Over time, the allele frequencies in the island and mainland populations will become more similar due to the regular exchange of individuals.
4. Account for genetic drift: In the smaller island population, genetic drift (random changes in allele frequencies) may have a stronger effect compared to the larger mainland population. However, gene flow from the mainland can counteract these random changes, stabilizing allele frequencies.
5. Predict the outcome: Given regular migration, you would expect the allele frequencies in the two populations to converge over time, becoming more similar. However, the rate of convergence depends on the migration rate and the relative sizes of the populations.

Key Concepts

Allele Frequency

Allele frequency refers to how often a particular allele appears in a population compared to other alleles for the same gene. It is a key measure in population genetics, indicating genetic diversity and the potential for evolution. Changes in allele frequencies over time can signal evolutionary processes such as natural selection, genetic drift, or gene flow.

Gene Flow

Gene flow is the transfer of genetic material between populations through migration and interbreeding. In the context of the deer populations, the exchange of members across the land bridge allows for gene flow, which can alter allele frequencies by introducing new alleles or changing the proportions of existing ones. This process can reduce genetic differences between populations and increase genetic diversity.

Population Structure

Population structure refers to the composition of a population in terms of genetic variation and how it is distributed among subpopulations. In this scenario, the mainland and island deer populations may exhibit different allele frequencies due to their distinct environments and sizes. However, regular migration can lead to homogenization of allele frequencies, making the populations more genetically similar over time.