Two members of the same animal species might have very different looks.
• Is this difference just chance or is there a purpose to
it.
• Why just chance?
• What purpose might it serve?
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Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.