The wolf was bred selectively over thousands of years to produce a wide variety of domesticated dog breeds.
The bone structure of the pentadactyl limb of a human, whale, bird, frog, and alligator; they all have the same basic layout despite having evolved for different functions
The Hawaiian honeycreepers show continuous variation across their geographical range, suggesting that they diverged gradually from a common ancestor
In areas with higher levels of air pollution the frequency of melanistic moths increases
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