One Gene, Many Mutations: Key That Controls Coat Color in Mice Evolved Nine Times, Harvard University Study

For deer mice living in the Nebraska Sandhills, color can be the difference between life and death. When the dark-coated mice first colonized the region, they stood out starkly against the light-colored, sandy soil, making them easy prey for predators. Over the next 8,000 years, however, the mice evolved a system of camouflage, with lighter coats, changes in the stripe on their tails, and changes in body pigment that allowed them to blend into their habitat.

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