Key that controls coat color in mice evolved nine times,
research shows
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.
Now Harvard researchers are using their example to answer
one of the fundamental questions about evolution. Is it a process marked by
large leaps — single mutations that result in dramatic changes in an organism —
or is it the result of many smaller changes that accumulate over time?