Just read a great article:
http://www.economicpopulist.org/content/human-nature-needs-be-back-business?google_editors_picks=true
In it, there is a nice quote from Darwin. This side of Darwin's thinking was ignored by his robber-baron lauding "social Darwinist" contemporaries:
An advancement in the standard of morality will certainly give an immense advantage to one tribe over another. A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection.
This perspective was not ignored by Kropotkin:
http://en.wikipedia.org/wiki/Peter_Kropotkin#Cooperation_and_competition
Kropotkin was misunderstood and belittled by his western contemporaries, as Gould describes in this great article:
http://www.marxists.org/subject/science/essays/kropotkin.htm