Natural selection has favored the dark form of the peppered…
Natural selection has favored the dark form of the peppered moth in areas subject to severe air pollution, perhaps because on darkened trees, moth-eating birds see them less easily. As pollution abated, the light forms increased in the population because
Read DetailsA virgin pine forest covers a valley, and one of the inhabit…
A virgin pine forest covers a valley, and one of the inhabitants is a red squirrel species. A large volcanic eruption occurs and separates the valley with a huge lava flow, thus producing two populations of squirrels. What must occur for the two populations of squirrels to be considered separate species?
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