Which of the following factors would be the most likely to contribute to allopatric speciation?
a. The separated population is large, and genetic drift occurs.
b. Selection pressures in the isolated population are similar to those in the ancestral population.
c. Gene flow between the two populations is extensive.
d. Different mutations begin to distinguish the gene pools of the separated populations.

Verified step by step guidance

1. Understand the concept of allopatric speciation: Allopatric speciation occurs when populations of the same species become geographically isolated, preventing gene flow between them. Over time, genetic differences accumulate, leading to the formation of new species.
2. Analyze the role of genetic drift: Genetic drift is more likely to have a significant impact in small populations rather than large ones. Therefore, option A is less likely to contribute to allopatric speciation in this scenario.
3. Evaluate the impact of selection pressures: If selection pressures in the isolated population are similar to those in the ancestral population, there is less likelihood of divergence. Thus, option B does not strongly support allopatric speciation.
4. Consider the effect of gene flow: Extensive gene flow between populations would counteract the genetic divergence necessary for speciation. Therefore, option C is unlikely to contribute to allopatric speciation.
5. Examine the role of mutations: Mutations introduce genetic variation, and if different mutations accumulate in the isolated populations, they can lead to divergence in the gene pools. This process is a key factor in allopatric speciation, making option D the most likely contributor.

Key Concepts

Allopatric Speciation

Allopatric speciation occurs when a population is geographically separated, leading to reproductive isolation. This separation can result from physical barriers like mountains or rivers, preventing gene flow between the groups. Over time, the isolated populations may evolve independently, potentially leading to the emergence of new species.

Genetic Drift

Genetic drift is a mechanism of evolution that involves random changes in allele frequencies within a population. It is particularly significant in small populations, where chance events can lead to the loss or fixation of alleles. This can contribute to divergence between separated populations, enhancing the likelihood of speciation.

Gene Flow

Gene flow refers to the transfer of genetic material between populations through migration and interbreeding. High levels of gene flow can counteract the effects of speciation by homogenizing genetic differences. In the context of allopatric speciation, reduced gene flow is crucial, as it allows populations to diverge genetically and adapt to their unique environments.