A change in DNA that is useful for one property to start with, can become useful later for a different function. Explain.
Answer:
A change/feature/property of an organism that may have helped it to adopt to an environmental condition can also become useful for a completely different function in the future. For example: feathers in birds, a character developed and selected during natural selection because it provided insulation in cold weather have become useful in later stages for flight.
Some dinosaurs had feathers, but they could not fly. Birds later adapted the feathers to fly.