In a distribution curve for a trait affected by directional selection, the curve will shift in the direction of the favored trait. This means that individuals with the favored trait will become more common in the population, while individuals with the unfavored trait will become less common. This can result in a skewed distribution curve, with the peak of the curve shifting towards the favored trait. Additionally, the variance of the trait may decrease as individuals with the favored trait are selected for and individuals with the unfavored trait are selected against.
In a population of birds, brightly colored males and very dull males survive best. Which type of selection is this, and what is most likely true about the proportion of males of intermediate coloring?
