[Campbell Biology P.564] Considering the findings from the cichlid experiment, if Lake Victo... | Practice Question

Considering the findings from the cichlid experiment, if Lake Victoria became heavily polluted, causing its waters to become murky and reducing light penetration, what is the most likely long-term consequence for the Pundamilia pundamilia and Pundamilia nyererei populations?

  • A: Increased reproductive isolation and accelerated speciation due to environmental stress.
  • B: Enhanced distinctness in male breeding coloration as a compensatory mechanism.
  • C: Increased interbreeding between the two species, potentially leading to gene flow and a reduction in their genetic distinctness.
  • D: A shift in mate preference towards non-visual cues, maintaining reproductive isolation.

Explanation

The cichlid experiment demonstrated that when visual cues male coloration are obscured as by orange light or murky water , females lose their ability to distinguish between species, leading to indiscriminate mating and viable, fertile hybrids. This breakdown of the prezygotic barrier would result in increased gene flow between the two previously isolated species, reducing their genetic distinctness over time.