Which addition to the pond likely contributed to the change between 1958 and 2008?
(A) A poisonous fish with a medium orange pigment
(B) Runoff from fields that makes the water dark and murky
(C) A light-orange water grass that grows in the pond
(D) Predatory birds that can easily see medium-orange pigment

A population of goldfish in a large, isolated pond were studied in 1958 and again in 2008. The fishes' pigment level varied from pale white-orange fish to dark brown orange fish. The color of each of the fish was recorded in the figure below.

Transcribed Image Text:

Number of Fish 1958 Goldfish Phenotype Distribution Light pigment Dark pigment