While it is now generally accepted that the ancestors of early Americans made their way across the Bering Strait, few scientists would accept the idea that human origins lie in Siberia.
Yet that is the claim made by a established Russian archaeologist, Yuri Machonov, who led expedition members on a tour of his dig.
Known as Diring, the site is located near the banks of the Lena River, south of Yakutsk. Machonov has worked it for almost15 years using hundreds of laborers and the support of the government. In that time he has transformed a mountaintop into what looks like a series of open-pit mines - enormous holes cut straight through yellow-sandy soil, all of it forming the most immense archaeological dig experienced expedition members had ever seen.
''Notice how these stones lie in a kind of formation, and the one in the center is upright,'' the scientist says, standing in the middle of an enormous open pit. ''It would be very difficult for these to be placed in such a way without a human presence. We estimate the age to be over a million years, perhaps even two.''
The rocks did look well-worn; they did appear to be placed in some kind of ordered fashion. They were even lying in a hard red-clay layer, which members of the expedition say could date back over 1 million years.
Yet unlike in Tanzania's Olduvai Gorge, for example, here there is no ''smoking gun'': Machonov has found no bones or other clear evidence of human habitition.
Over many years Machonov developed an international reputation for numerous other Siberian excavations; his wife, Svetlana, is also an experienced archaeologist. Yet his claim to have discovered one of the earliest sites known has sparked considerable debate in scientific circles, particularly because he has long been hesitant to allow independent verification of the evidence. The expedition's brief glimpse was a start; perhaps a thorough look by impartial archaeologists could help resolve the debate.