If homo sapiens weren't around, then Neanderthals perhaps would have been first to civilization. They would have spread south and started trading and socializing more, as trade was one of the biggest boost to sapiens because one didn't have to find all the "good stuff" on the same land anymore. Those with extra top-notch stones but short food could trade. "Comparative advantage" long before Adam Smith's time. The instinct to war with competitors would be diminished as those good at trade could prosper without risking war dead.