News Animals

Classic sooty-moth tale bolstered by new results

Backyard experiment strengthens scenario for evolutionary changes due to pollution

By Susan Milius

- More than 2 years ago

A recently criticized textbook example of evolutionary forces in action, the dark forms of peppered moths that spread with industrialization in Britain, may be on its way back.

Results from a large experiment support the much-debated original hypothesis that industrialization favored a dark form (left) of the peppered moth over the lighter one (right) because hungry birds found light wings easy to spot against sooty backgrounds.