Another Revolution in our Knowledge of Evolutionnew paper explains:
Until recently, evolutionary hypotheses envisioned their [feathers] origin through elongation of broad, flat scales driven by selection for aerial locomotion such as gliding or flapping flight. Over the course of the past two decades, fossil discoveries, especially from northeast China, have revealed that the early precursors of feathers were filament-like rather than expanded scales and that branched pinnate feathers of modern aspect predate the origin of active flight. The revolution in our understanding of feather evolution continues, driven by rapid fossil discoveries and by new information from the study of extant birds.
So in other words, feathers evolved, and as luck would have it they were a great solution for flight. So with feathers already available, flying later evolved. Evolution got lucky again. And here all along we thought feathers evolved so creatures could fly.
It’s another giant leap forward in our knowledge of how the world came to be. It is literally a revolution in our knowledge of evolution. But how, on the one hand, can our knowledge be so flawed while, on the other hand, we can know for certain that evolution is a fact?