19th Century

• Industrial melanism as a result of more melanin production was observed in more than 70 species of moths in England during the Industrial Revolution, when soot darkened tree trunks and the moths' habitat. Researchers observed that dark-colored peppered moths, which were rare before 1800, became common between 1819 and 1886.
  
  

Non-Industrial Areas

• In contrast, it was observed that light-colored moths remained more common than dark moths in non-industrial woods, where dark moths were more easily visible, according to the university.
  
  

Confirmation

• Observations of bird predation and collection of moths in the 1950s by biologist H.B.D. Kettlewell confirmed that the visibility of moths in these different environments affected bird predation, according to the university.