[Campbell Biology P.560] The text describes that female mosquitofish prefer to mate with mal... | Practice Question

The text describes that female mosquitofish prefer to mate with males whose body shape is similar to their own. Given the different selective pressures in ponds with and without predators, how does this mating preference contribute to reproductive isolation?

  • A: It promotes gene flow between mosquitofish populations from different pond types, leading to hybridization.
  • B: It acts as a behavioral barrier, preventing interbreeding between populations adapted to different predatory environments.
  • C: It causes the mosquitofish to develop identical body shapes regardless of their environment.
  • D: It directly alters the genetic code of mosquitofish to prevent fertilization between different body types.

Explanation

The preference of female mosquitofish to mate with males of a similar body shape acts as a pre-zygotic, behavioral reproductive barrier. This means that even if individuals from different pond types with different body shapes due to distinct selective pressures meet, they are less likely to interbreed, thereby reducing gene flow and reinforcing the genetic divergence between the populations. This behavioral isolation prevents the formation of hybrids and contributes to the ongoing speciation process.