Isn't all work a derivative of some sort? Is anything we do completely original? Aren't we all copycats to some degree?
If we paint without aid on a blank canvas, it is seen as original work...something authentic which we alone created. But, where did the idea of painting come from? How about the brush, the paint, the canvas, the idea this sort of creation would be appreciated? Perhaps the originality of our work has more to do with our mark on it instead of the work itself.
This photo of early morning runners has surely been captured in some form by someone else. But, not exactly like this one. Beyond the physical variations (light, subjects, angles, exposure, etc.), there's also the mind's eye, the inspiration and the hope that it would evoke a certain feeling for the viewer. But, it might still be considered a copy, the inspiration gained from seeing another similar photo which came before it.
It's becoming harder and harder to separate original from modified. The lines are blurred more now than ever before because producing and sharing work is so much easier and hence more abundant. Should it matter? In the end, we need and deserve better, which requires learning from others and improving what came before. Innovation, invention, art and the creative act itself are bold moves. But, rarely original.
"Good artists copy. Great Artist's steal", who really knows.
Perhaps we should worry less about being original and more about making our mark...to make it better.