I wouldn't want to lump egoism in there; Nature is below selfishness/greed. Selfishness/greed make sense; Promoting your germline/genes does not. Selfishness, at least, can lead to great things (someone may want to help others to boost his ego, or wants to live in a world where people are happy because that makes THEM happy. Both of those are selfish.
Not as much a defence of selfishness as pointing out that even human greed is a more "good" thing than primitivism. There is no such thing as the noble savage.