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?
Answer:
Feather color loses importance in sexual selection and becomes disadvantageous for males. There is a decrease in red color variation among males.
Step-by-step explanation:
In cardinal species, females choose males to mate according to their vibrant red color. The redder the male is, the better genetic charge it has, and the better choice for mating it becomes.
Red feather color is a trait that reflects the genetic quality of males. So individuals with the most vibrant red color express better capabilities of finding food, competing for resources, competing for males, among others, are the best option to mate and to ensure successful offspring.
The brightest or most vibrant males are in red, the better chances they have to mate and pass their genes to the following generations. So the organism spends energy and resources to produce more vibrant colors to enhance mating chances.
However, if females begin using different criteria than feather color when they choose mates, color production stops making sense. What is even more, it becomes more disadvantageous for males because females do not use color for their choices, males spend energy when producing it, and the redder the males are, the more chances to be predated they have. So basically, males´ feather color loses importance. The selection pressure in males turns to the evolution of another trait. The shade variation of red feathers will decrease over time.