Final answer:
Yes, barriers can isolate a species' gene pool through mechanisms such as prezygotic and postzygotic barriers, resulting in the evolution of two separate gene pools.
Step-by-step explanation:
Yes, barriers can isolate a species' gene pool. Prezygotic and postzygotic barriers can prevent interbreeding of species, leading to a lack of gene flow between them. When populations become geographically discontinuous, it hinders the free movement of alleles and results in the evolution of two separate gene pools.
For example, if a river forms a new branch or a group of organisms travels to a new location without the ability to return, it can isolate populations and lead to allopatric speciation. Speciation occurs when populations evolve along different trajectories due to environmental differences, causing their allele frequencies to gradually become increasingly different.
Isolation of populations can also lead to negative effects from genetic drift and the rise of maladaptive gene variants. Therefore, gene pools of species can indeed be influenced and isolated by barriers.