Which of the following scenarios is likely to promote local adaptation?

Local adaptation occurs when a population develops traits that enhance its fitness in a specific environment. Strong selection pressures favor individuals with advantageous traits, while low gene flow allows for these traits to become established in a particular population without being diluted by individuals from different environments.

The scenario of low gene flow paired with strong selection is optimal for promoting local adaptation. This is because strong selection acts on traits that confer a survival or reproductive advantage within a particular environment, thereby allowing those traits to be favored and become more common. Additionally, low gene flow means that individuals from different populations are less likely to migrate and introduce potentially less advantageous traits, which supports the establishment of adaptations specific to the local conditions.

In contrast, scenarios with high gene flow, whether paired with weak or strong selection, tend to homogenize traits across populations. When high gene flow occurs, advantageous traits from one population can be diluted by the influx of traits from another population, making it more challenging for local adaptations to become fixed. Similarly, if gene flow is low but selection is non-existent, there are no adaptive pressures to drive changes in the population, resulting in stagnation rather than adaptation. Therefore, the combination of low gene flow and strong selection creates the ideal environment for local adaptation to occur.