Feathers as insulation existed long before they were used for flight. The discovery of feathers as far back as the Early Triassic period highlights a recurring theme: evolution repurposes existing features for new adaptive abilities over time.
New research, led by the University of Bristol, suggests that feathers arose 100 million years before birds — changing how we look at dinosaurs, birds, and pterosaurs, the flying reptiles. …
“What surprised people was that this was a dinosaur that was as far from birds in the evolutionary tree as could be imagined,” said Maria McNamara, researcher at the University College Cork. “Perhaps feathers were present in the very first dinosaurs.”
… “We saw that many of their whiskers were branched,” Benton said. “We expected single strands — monofilaments — but what we saw were tufts and down feathers. Pterosaurs had feathers.”
The succession of revelations recently regarding the origin of feathers suggest they emerged during the Early Triassic, in the wake of a devastating mass extinction event. …
Feathers then probably arose to aid this speeding up of physiology and ecology, purely for insulation. The other functions of feathers, for display and of course for flight, came much later.”
We can apply this evolutionary idea to many things as a key to unlock certain mysteries. Writing, for example, could be seen as having roots in primordial chemical signaling between cells. Is this useful? It can be. From the cell signaling roots point of view all writing is simply attracting what we want and repelling what we don’t want.