Question

question 6 of 25
scale color in a population of lizards ranges from tan through brown. a prolonged drought kills much of the vegetation in the area where the lizards live, exposing light - colored sandstone. on sandstone, brown lizards are more visible to predators than tan lizards. within a few generations, the percentage of tan lizards has increased. conversely, the percentage of brown lizards has decreased.
what form of selection has taken place in this population?
○ frequency - dependent selection
○ directional selection
○ disruptive or diversifying selection
○ stabilizing selection

Explanation:

Directional selection favors one extreme phenotype (tan lizards here) over others, leading to a shift in the population's trait distribution. The drought-exposed light sandstone made tan lizards less visible to predators, so their frequency increased while brown lizards (the other extreme) decreased—this matches directional selection.

Answer:

B. directional selection