Watch the skull of our oldest ancestor, 1.8 million years old

Georgia: A 1.8 million year old skull has been found in in Dmanisi, Georgia, in Eastern Europe. The skull is of a homo sapiens. Scientists say the Dmanisi population was most likely an early part of our primary ancestral species, Homo erectus.This is the fifth such skull from the region spanning a period of a few centuries. It is known at present only as “Skull 5”. The lower jaw of the skull was found in 2000, and the matching brain case turned up in 2005.Scientists say, the skull provides a vivid picture of early evolution and indicates the human family tree may have fewer branches than some believe.Anthropologists have found much older hominin fossils dating back several million years, but entire skulls comprising the brain case, the face and the lower jaw are rare. Researchers say that it is the most complete skull of an adult from this date. Earlier the oldest discovered hominin remains in comparable condition were the famous Turkana Boy skeleton, which is 1.5 million years old.The skull and other remains offer a glimpse of a population of pre-humans of various sizes living at the same time - something that scientists had not seen before for such an ancient era.This diversity bolsters one of two competing theories about the way our early ancestors evolved, spreading out more like a tree than a bush.Nearly all of the previous pre-human discoveries have been fragmented bones, scattered over time and locations.The findings at Dmanisi are more complete, weaving more of a short story. Before the site was found, the movement from Africa was put at about one million years ago.When examined with the earlier Georgian finds, the skull shows that this special immigration out of Africa happened much earlier than previously thought, said study lead author David Lordkipanidze, director of the Georgia National Museum.Even bush-favouring scientists say these findings show one single species nearly two million years ago at the former Soviet republic site.But they disagree that the same conclusion can be said for bones found elsewhere, such as Africa.However, Lordkipanidze and colleagues point out that the skulls found in Georgia are different sizes but are considered to be the same species.So, they reason, it's likely the various skulls found in different places and times in Africa may not be different species, but variations in one species.