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)

Question

Responses

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

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

directional; the curve would shift to the right
directional; the curve would shift to the right

directional; the curve would shift to the left
directional; the curve would shift to the left
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Answer 1

Directional; the curve would shift to the right

During ice ages, most black bears were large, indicating directional selection for larger size. As Earth moved out of an ice age and the environment changed, the selection pressure for larger size would decrease, causing the distribution curve of black bear size to shift to the right as smaller bears become more common.