[Campbell Biology P.568] According to Figure 24.16 and the accompanying text, what primary f... | Practice Question

According to Figure 24.16 and the accompanying text, what primary factor led to the breakdown of reproductive barriers and subsequent fusion in the Pundamilia cichlids of Lake Victoria?

  • A: Increased predation pressure on one of the species.
  • B: A new food source becoming available, reducing competition.
  • C: Increasingly cloudy (turbid) water, which interfered with the females' ability to distinguish mates by color.
  • D: A sudden decrease in population size, leading to random mating.

Explanation

The text states that 'Increasingly cloudy water in Lake Victoria over the past several decades may have weakened reproductive barriers between P. nyererei and P. pundamilia. In areas of cloudy water, the two species have hybridized extensively, causing their gene pools to fuse.' This directly links water turbidity to the breakdown of reproductive isolation via impaired mate choice.