At what point is something different?
Relative (and blissful) ignorance helps the beholder see things as new and different all of the time, but to the well-educated, many of those differences are invisible.
For example, young artists spill their hearts out only to hear from critics that it's been done like that before. In this way critics help to push artist to find something different each generation.
Through trial and error, offense and defense, conviction and education, the best new artists create combinations of elements that feel unique to them and tirelessly push them forward through their critics internally and externally with the hope that what's left in the end is a complete enough collection to be worthy of being called a new species.
Like any species, fitness and its mortal partner Tenacity determine whether it lives or dies.