Variations of a single gene drive diverse pigeon feather patterns

Biologists have discovered that different versions of a single gene, called NDP (Norrie Disease Protein), have unexpected links between color patterns in pigeons, and vision defects in humans. These gene variations were likely bred into pigeons by humans from a different pigeon species and are now evolutionarily advantageous in wild populations of feral pigeons living in urban environments.
Source: Science Daily