Palaeo-anthropologists agree that modern humans evolved in Africa about 200,000 years ago, yet fossil evidence for the earliest examples is scarce. One problem is the difficulty in recognising true modern humans in the fossil record: At this time, many thought to be early members of our species possess a mix of modern and primitive traits. For some, this means our species once had a greater range of physical variation than today - for others, that more than one species of Homo may have lived in Africa at this time.
     Despite these challenges, there are several candidates for the earliest known members of our species.
     Omo I and II (195,000 years ago): In 1967, a team led by Richard Leakey discovered possible Homo sapiens fossils in the Kibish Formation near the Omo River in southern Ethiopia. Re-analysis in 2005 revealed they are 195,000 years old - the oldest fossils assigned to Homo sapiens. Researchers largely agree Omo I was a modern human; flat face, fully formed chin, high forehead and globular brain case. They are less certain about Omo II, with its thicker cranial bones and sloping forehead.
     Herto (160,000 years ago): Tim White of the University of California at Berkeley and colleagues unearthed three largely complete skulls in the Middle Awash region of Ethiopia in 1997. They appear quite modern, but because certain traits are outside the range of modern variation, they were placed in their own subspecies.
     Qafzeh and Skhul (~100,000 years ago): In the 1930s, researchers working in these caves in northern Israel found the remains of at least 30 individuals, a few purposefully buried. Some suggest they represent an early migration out of Africa, but like Omo II some are difficult to classify. The primitive traits in this population might have resulted from interbreeding with Neanderthals, who also lived in the region at this time.

Edited from Smithsonian.com (11 January 2012)