All humans today are members of the modern human species Homo sapiens — Latin for "knowing man." But we're far from the only humans who ever existed. Fossils are revealing more and more about early humans in the genus Homo — ancestors like Homo erectus (Latin for "upright man"), who lived in Africa, Asia and parts of Europe between 1.9 million and 110,000 years ago.
Scientists now recognize more than a dozen species in the Homo genus. So what, exactly, was the first human species? The answer, it turns out, is not crystal clear.
