I notice some well qualified people on this forum, I am no scientist but I have a nagging, maybe stupid, question to ask regarding Evolution. I know more or less the workings of Evolution and can understand how abnormalities in the offspring of a creature can make it fitter for survival and how change can therefore be propagated through natural selection. This is all understandable as long we are talking about small changes that could bring immediate benefit to the creature (Like color change for example). I cannot see this functioning when we are talking about the development of something complex (like wings for example) that does not give the creature any advantage in the survival game while it is busy developing (over millions of years). I can only see that partly developed wings could be to the detriment of the animal. So the question: What is it that drives the development of a complex feature (like wings) over a period of millions of years?