Yes, but it's somewhat tautological. All animal traits evolve as a means of surviving longer than other animals. The other animals in this case would be humans in the same population which didn't posess the gene whose phenotype is the emotion in question. I don't mean to be trite, but that's just the way evolution works.

"Human" emotions are observable in other primates, as happiness, affection, anger, grief, frustration, friendship, and anxiety. They all seem to be part and parcel of dealing with each other in a highly social setting, and it can be argued that many such tendencies are found across the animal kingdom. I strongly recommend books by Frans De Waal, a primate ethologist working at the Yerkes Institute, for work on the primate origins of human emotional and political tendencies. It is likely that we *elaborated on* emotions as intelligence increased, possibly more as a side effect of increasing intelligence than as an adaptive trait in itself. Frans De Waal's books include many available at Amazon: http://www.amazon.com/exec/obidos/search-handle-form/002-0349561-5746426 Edit: true, this did not directly answer the question. The answer would most likely be, "sort-of"; emotions have been around a lot longer than humans, and while some (like fear) are very directly survival-oriented, with some it is simply that we have a much wider and more subtle feedback system on what is good and what is bad for the individual in question -- and humans simply succeeded in making it a lot more complicated.