On the Galápagos Islands, natural selection pressures maintain the boundaries between three species even though there is substantial gene flow between them. This example provides evidence that
A) neither the biological nor the ecological species concept applies to all situations.
B) multiple genes influence beak size.
C) these three species should be classified as a single species.
D) the medium ground finch (Geospiza fortis) has the optimal beak size.

Question

Quizplus · Accepted Answer

The fact that natural selection pressures maintain boundaries between species despite gene flow suggests that the traditional biological and ecological species concepts, which emphasize reproductive isolation and ecological niche respectively, may not apply to all situations. This highlights the need for a more nuanced and flexible approach to species classification.

On the Galápagos Islands, Natural Selection Pressures Maintain the Boundaries