Question

Paleontologists 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?(1 point)

stabilizing; the curve would become taller in the middle and shorter on each side

directional; the curve would shift to the right

disruptive; the curve would break into two peaks with a dip in the middle

directional; the curve would shift to the left

Answer 1

directional; the curve would shift to the left

Explanation: as climate warms after an ice age, selection favors smaller bears, so the size distribution moves toward smaller values (leftward).