Evolution is sometimes very difficult to grasp despite the strongest belief in it. Some plants for example develop intricate relationships with insects that pray upon them for food. A family of orchids lures their victims into a Byzantine maze with a compulsory giftshop at the end that leaves the visitor with unwieldy yellow blobs that have no practical application and are usually left at the next nearest establishment of the kind.

I don't really know what social Darvinism is, but I do believe that the processes of evolution take place in the development of cultural and social structures. Just look at how music changes with time, always basing on previous achievements but all the time changing itself to match it's habitat, which is the human society. And as with the evolution of species, the new branch is not necessarily prettier than the one it sprang from.