Coexistence for 99% of our past? Underlying our hopelessness is the story we commonly tell ourselves and our children about our past. People have been warring with each other since the beginning of time. Scratch the veneer of civilization and you will get a Kosovo or Rwanda.
For the last ten thousand years - during the last one percent of human evolution - there exists clear and often abundant evidence of organized violence and warfare. It takes the form of bones with spearheads or arrowheads embedded in them, mass graves, remains of fortifications, settlements destroyed violently, and ancient art depicting scenes of war and carnage. Much of the evidence of violence antedates "civilization" - defined as the building of cities, the invention of writing, and the birth of the state. There can be little doubt that violence and war leave clear traces in the archaeological record.
What is surprising, therefore is that convincing evidence of organized violence becomes so sparse before ten thousand years ago. In the period from ten to fourteen thousand years ago, there are two credible if controversial sets of evidence of small group violence, a cemetery in Jebel Sahaba, Sudan, and rock paintings in Arnhem Land, Australia; both instances seem to have occurred in the wake of catastrophic ecological change. Beyond that, there is evidence, in at least nine skeletons, pointing to scattered individual killings stretching back across time, but little or no evidence of war itself.
This doesn't mean that our ancestors never killed one another. They almost certainly did. But they appear to have coexisted much more than they fought. And we're not talking about an insignificant period of time, but 99% of our time on earth.