We can't argue that it is indeed natural to defend our personal space/ hunting grounds and females. This is a trait that has been passed along for millions of generations. But that doesn't mean it's the optimal solution. For example, my instincts may tell me that I must father all of the next generation. Then if another male grazes my territory, eyeing my women, I must defend them. But, why not share? Why maintain this egotistical nature our instincts have forced upon us?
What we know about genetics tells us that genes with the most diversity yeilds the healthiest spawn. It's a way to avoid unhealthy genes and throw some fresh ones into the mix, instead of ending up with double sets of unhealthy ones. Would it really be so strange if our instincts weren't the most optimal solution? Selfishness is about to ruin our world! Obviously it's not a good trait, it was simply what we needed to get this far. I think the next step is to break away from our instincts. Start thinking about the repercussions on the world, before personal gain. How do you feel about our future? Could our problems be solved with good old instincts?