Music and Evolution

I keep not posting cause i don't have extended things to say , sometime only a line of two.
please forgive. But people talk about all musical innovation as being evolutionary,yet if we are basing this on nature, possibly we might be stricter and point out in nature there are all types of variations produced that don't always result in a forward progression of the species.
Many of these are sterile, so what really constitutes what is evolutionary is the ability of something to produce fertile offspring as opposed to sterile hybrids. Let history define where musical evolution is or what might be like the parallel to Monsanto. What good is it to go somewhere if once you get there there is no where to go but the way one comes in. Perhaps there are more Cul-de-Sacs than ever before, but perhaps history knows them as the commonest of lots.