|White-bodied Pepper Moth|
The dark version of the pepper moth, called melanism, was first noticed in industrial Manchester England in 1848 and by 1895, 98% of the local pepper moths were dark. More evidence of natural selection appeared when clean air regulations cleared the air and the dark form frequency declined.
|Black-bodied Pepper Moth|
Some authors have challenged these studies based on their methodology. In the new study reviewed in sciencenews.org/, Michael Majerus carried out six years of rsearch in the relatively unpolluted area in Cambridge where he lived. Every spring and summer day he climbed a ladder and placed both varieties of pepper moth on his backyard trees and then watched as predatory birds grabbed them. He showed that the dark forms had only a 91% survival rate compared to the white forms.
While this doesn't necessarily indicate "evolution" with a capital "E" over 50 years, it does show how rapidly populations can change coloration in response to environmental change. From there it is only a short step in time to the development of a new species.