The wide range of variety in domesticated dogs—from the petite Chihuahua to the monstrous mastiff—has powered a new view of what drives evolution.
NOBODY KNOWS. A new hypothesis might explain why purebred bull terrier snouts changed dramatically from (top to bottom) 1931 to 1950 to 1976. Fondon and M. Nussbaumer
Scientists have long known that the evolutionary changes that alter a species’ appearance or create new species frequently occur in rapid bursts.
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