How were birds wings invented?

Bird wings evolved from the forelimbs of theropod dinosaurs through a gradual process of adaptation. Initially, these limbs were used for balance and grasping, but over time, modifications such as elongated feathers and changes in bone structure allowed for gliding and eventually powered flight. Natural selection favored individuals with these advantageous traits, leading to the diverse wing structures seen in modern birds. Thus, bird wings represent a complex evolutionary transition rather than a singular invention.