The interpretation of the Dmanisi finds has kicked up a scientific controversy and whichever way it is resolved (or proves to be unresolvable), we will know a little more, and also know the limits to our knowledge a little better.
The five Dmanisi skulls
The five skulls found in one place at one geological time (they are from about 1.8 million years ago) might have been classified as different species had they been found separately. The principle of parsimony requires us to postulate they are the same species. The range of variation is similar to the range of variation found in modern chimpanzees and humans. This opens the question of whether the finds around the globe are at best regional variations of one species?
