Question

a male cardinals red color is an example of a trait affected by natural selection. the females of the species choose males based on the vibrant colors of the males feathers. if females begin using different criteria than feather color when they choose males, 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

Explanation:

Natural selection acts on traits that confer an advantage. If feather color is no longer a criterion for female choice, there is no selective pressure favoring a specific shade of red. Without this pressure, different shades of red (variation) would not be selected against or for in a consistent way. Option B is incorrect as it implies a conscious "trying" which is not how natural selection works. Options C and D suggest a decrease in variation. But without the advantage of a specific color (due to change in female - choice criteria), there's no reason for a decrease in variation. Variation is more likely to increase or remain stable as no single color has an edge.

Answer:

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