Question

In a bird population, 50 % of the individuals had white feathers, and 50% had colored feathers. Over time, it was observed that 98% of the population had colorful feathers. The rest had white feathers. How did the type of selection in this example affect the population’s biodiversity?
Directional selection did not increase the population’s biodiversity.
Stabilizing selection increased the population’s biodiversity.
Disruptive selection decreased the population’s biodiversity.
Ecosystem selection did not increase the population’s biodiversity.

Answer 1

Directional selection did not increase the population’s biodiversity.

Explanation: the population shifted from an even mix to almost all colorful individuals, indicating selection favored one phenotype (colorful). Directional selection moves the trait distribution toward one extreme and reduces variation in the population, so biodiversity (phenotypic/genetic variation) declined.