Your professor isn't trying to be a mutualist or any of that bullshit. The humans that organized and formed a means of communication and exchange are the ones that survived, while the aggressive and 'individualistic' humans died out. That doesn't mean that any of them were altruistic, though.
Captialism in this sense is not the same, because it's a very 'cooperative' system, humans are together, exchanging and organizing themselves in a manner that involves all of them, no matter how odd we deem that organization is.
Humans are not naturally cooperative and altruistic people. Humans are all motivate by self-interest, however, we realize that the only way that all of us bastards can feel satisfied is if we organize ourselves and adjust ourselves to a system that is more efficient than Capitalism.
[FONT="Courier New"] “We stand for organized terror - this should be frankly admitted. Terror is an absolute necessity during times of revolution. Our aim is to fight against the enemies of the Revolution and of the new order of life. ”
― Felix Dzerzhinsky [/FONT]
لا شيء يمكن وقف محاكم التفتيش للثورة