Final answer:
Gene flow in fish populations involves the transfer of genes across populations due to migration. It can increase genetic diversity and help fish species adapt to changing environments.
Step-by-step explanation:
Gene flow refers to the transfer of genes across fish populations due to the migration of individuals or gametes. This flow of alleles in and out of a population can have a significant impact on the genetic diversity and allele frequencies within fish populations.
For example, if a fish population experiences high gene flow, individuals from other populations may introduce new genetic variations to the population. This can help increase the overall genetic diversity of the population, which can be beneficial for the survival and adaptation of fish species.
On the other hand, if a fish population is isolated and experiences low gene flow, there may be limited genetic variation within the population. This can make the population more susceptible to genetic diseases and reduce its ability to adapt to changes in the environment.