Birds evolved from feathered dinosaurs. Feathers allowed for flight but also facilitated disease spread. Certain diseases like influenza and West Nile virus can survive in birds and spread from them to other animals. Understanding feather evolution may help prevent disease spread. As feathers evolved over time they became more specialized for functions like insulation, flight assistance, and mate attraction depending on the bird species. Future feather adaptations could include increased water resistance or variations in color and size.