The earliest humans have been traced to?

The Tigris Valley also known as The Fertile Crescent. It is located in Iraq. While human civilization can be traced to Mesopotamia, the earliest evidence for modern humans as a species can be traced back over 100,000 years to Africa and Asia Minor. Our ancestry can be traced back still further to the australopithecines, ape-like hominids from Africa that can be found as early as 4 million years ago, and perhaps even farther. See the Smithsonian Institution Human Origins Program webpage for more information: http://anthropology.si.edu/humanorigins/