Question

A male cardinal’s red color is an example of a trait affected by natural selection. The females of the species choose mates based on the vibrant colors of the males’ feathers. If females begin using different criteria than feather color when they choose mates, what would most likely happen to the color of the male cardinals over time?
increased variation in the shades of red because there is no advantage in one specific color
increased variation in the shades of red because the cardinals try different ways to impress the females
decreased variation in the shades of red over time because no form of the trait is advantageous
decreased variation in the shades of red after a single generation

Answer 1

Answer: increased variation in the shades of red because there is no advantage in one specific color.

Explanation: If females stop selecting by feather color, that sexual selection pressure is removed. Without selection favoring a particular shade, different alleles for color are effectively neutral and over generations mutation and genetic drift will tend to increase (or at least fail to reduce) variation. Options 2–4 are incorrect because animals don't “try” new traits deliberately, and decreased variation would require selection favoring one form.