Which process leads to different selection pressures in geographically isolated populations?

The correct answer is genetic drift. This process occurs in small populations that are isolated from one another, leading to random changes in allele frequencies over generations. As certain alleles may become more or less common purely by chance, genetic drift can contribute to the development of distinct genetic traits in these isolated populations. Consequently, these differences may lead to varying selection pressures as each population adapts to its unique environment or ecological niche.

In contrast, ecological isolation refers to populations that may live in the same geographical area but occupy different habitats, leading to limited interaction. This does not necessarily involve geographical isolation that creates distinct selection pressures.

Behavioural isolation occurs when populations develop different mating behaviors or rituals, preventing interbreeding. While this can contribute to speciation, it does not directly relate to the geographical isolation that leads to different selection pressures.

Temporal isolation deals with populations that breed at different times, such as different seasons or times of day. While it can lead to reproductive isolation, it does not inherently create the geographical separation needed to establish varied selection pressures on isolated populations.

Understanding genetic drift and its impact helps clarify how isolated populations can evolve independently, leading to speciation influenced by distinct environmental factors.