Paleontologist observed changes in the sizes of black bears as their environment changed during warmer periods between ice ages. Most black bears were small during ice ages most black bears were large which type of selection is this and how would a graph of the distribution curve of black bear size change, as earth moved out of an ice age Two peaks with a dip in the middle or Stabilizing the curve would become taller in the middle and shorter on each side or directional. The curve would shift to the left or directional the curb would ship to the right.
This type of selection is called directional selection. It is characterized by a shift in a population towards one extreme trait value due to a selective pressure.
In this case, as the environment changed during warmer periods between ice ages, black bears adapted to the new conditions. Most black bears were small during ice ages because smaller body size helped them navigate and survive in a cold climate with limited resources. However, during the warmer periods, larger body size became advantageous for various reasons, such as improved hunting ability or competitive advantages in acquiring resources. As a result, most black bears were large during these warmer periods.
If we were to graph the distribution curve of black bear size as the earth moved out of an ice age, it would shift to the right. This means that the curve would move towards larger body sizes, as the population adapted to the changing environment.