Question

which best describes biogeographic isolation?
○ it always leads to the formation of new species.
○ it cannot lead to evolution.
○ it is a mechanism for evolution.
○ it occurs only through geographic forces.

Explanation:

• Analyze each option:
• Option 1: Biogeographic isolation doesn't always form new species (e.g., populations might adapt without speciation), so incorrect.
• Option 2: Biogeographic isolation can drive evolution (e.g., by creating different selection pressures), so "cannot lead to evolution" is wrong.
• Option 3: Biogeographic isolation (geographic separation) is a mechanism for evolution as it can cause genetic divergence via natural selection, genetic drift, etc., making this correct.
• Option 4: It's not only geographic forces (e.g., ecological factors can also isolate populations), so incorrect.

Answer:

C. It is a mechanism for evolution.