Researchers plotted a distribution curve for leg length in a population of birds, with length from short to long on the x-axis. The curve shifts to the right after a disturbance. Which statement is correct about natural selection in this population of birds?

Question

a. birds with short legs were selected for
b. birds with long legs were selected for
c. birds with medium-length legs were selected for
d. birds with long legs and birds with short legs were selected for

Answer 1

b. birds with long legs were selected for.

A shift to the right in a distribution curve for a trait indicates that individuals with that trait are becoming more common in the population. In this case, after the disturbance, birds with longer legs were more successful in survival and reproduction compared to birds with shorter legs. This indicates that natural selection favored birds with longer legs, leading to a shift in the distribution curve towards longer leg lengths.