Cooperative Evolution
Michael Tomaselo article question why we have more white area then colour in the eye. Tomaselo points out the question should be, since they are 220 species of primates why humans are the only ones where the orientation of the eye can tell what humans are seeing, where for primates you can not follow the orientation of what they are seeing.
Tomaselo reason of this development due to social behaviour. Humans need the eyes to know intention, but but the evolution between the white and colour can be called that evolution cooperation.
Tomaselo inside impacts relationships from sport or poker, where a player try to hide the white part of the eye to hide his intentions.
Peter Kropoptkin in Mutual Aid give another line of thinking where cooperation is not just individual social interaction, but is specie interaction and some case the interaction with environment is necessary, like bees will need interaction with environment since pollen in such small they are need of more them and because the process collecting pollen is a group active. They are also symbiotic relationships which can be categorize as evolution of cooperation.

http://www.nytimes.com/2007/01/13/opinion/13tomasello.html