In the sense humans are "better" or "greater" or something? Well, consider the global biomass of bacteria compared to humans - they seem to be doing okay. Or that there's more bacterial cells in you than human cells. Single-celled yeast evolved from mushrooms, barnacles evolved from something like shrimp or crabs, and there are eukaryotes that lost eukaryotic features like mitochondria because they didn't need them to survive. Buuut that's besides the point. I'm not sure how to make it more clear, but I meant subtractive as in selection is just about who dies. Random mutation is what adds features and new species.