Question

populations of individuals are geographically separated by landforms such as mountains, canyons, and rivers that prevent them from mating with one another

population bottleneck

geographic separation

evolution

frequency

variation

founder effect

natural selection

Explanation:

We analyze each option:

• "population bottleneck" refers to a sharp reduction in population size, not geographic separation.
• "geographic separation" matches the description of populations being separated by landforms preventing mating.
• "evolution" is a broad process of change over time, not this specific separation.
• "frequency" relates to occurrence rates, not separation.
• "variation" is about differences in traits, not separation.
• "founder effect" is about a new population from a small group, not geographic separation of existing populations.
• "natural selection" is about survival of fittest, not separation.

Answer:

B. geographic separation