Notable differences characterized the encounter in Africa. In particular, the archaic populations there were genetically closer related to fully modern humans. The closer relationship between archaic and fully modern humans in Africa had consequences for how their encounters played in the long period from 70,000 to 12,500 BCE. In some areas separate archaic and fully modern human populations appear to have persisted for thousands of years after 48,000 BCE, utilizing different but nearby environments, or making different use of the same environments. In other regions the makers of Middle Stone Age cultures remained the predominant populations down nearly to the end of the last ice age. In some cases late-persisting Middle Stone Age populations may have sought to compete by imitating and adding features of Later Stone Age tool making to their existing toolkits. Possessing syntactic language allowed humans to think about, and to talk with each other about, the surrounding conditions of their lives.