We all descend from a single species: a skull that rewrites the man history
A hominid with characteristics previously never observed together in the fossils of one of our ancestor has been found in Georgia. The debate flares up among scholars: did the hominids of 1.8 million years ago all belong to the same species?
The human family tree could be revised, even rewritten, after the discovery of the remains of the hominid from Dmanisi, in Georgia, in which we recognise, as in a "collage", different characteristics never previously observed all together in the fossils of one of our ancestor.
As reported in an 2013 article (https://doi.org/10.1126/science.342.6156.297) published in the journal Science, David Lordkipanidze and his colleagues who study the human fossils of Dmanisi, Georgia, dating back to one million and 800,000 years ago, have put forward a proposal that would overturn the entire scheme of our evolution, at least for the last three million years.
If until now it was thought that after the divergence from the Australopithecines and the appearance of the genus Homo (about 2.5 million years ago), many different species had followed one another, all extinct except Homo sapiens, after this discovery we realize that this is not the case anymore.
Probably there would have been only one species in the early stages of man's evolutionary path. Although further studies are still needed to confirm the hypothesis what until now were considered different species would instead probably be groups with similar morphological characteristics.
Before the discovery of the Dmanisi hominid, it was thought that the oldest species of the Homo genus was Homo rudolfensis, which lived between 2.4 and 1.9 million years ago. The next species would have been Homo habilis from which Homo ergaster would have evolved, appearing about 1.8 million years ago.
Descended from Homo ergaster would have been Homo erectus, which soon also spread to Eurasia. Contemporary with the last phases of Homo erectus would have been (in Europe) Homo heidelbergensis, from which the Neanderthals would have descended, who lived between 300,000 and 30,000 thousand years ago in Europe, the Near and Middle East and Western Asia.
Anatomically modern man, i.e. Homo sapiens, appeared in Africa around 200,000 years ago and, around 40,000 years ago, entered Europe. But the 2013 discovery of the new hominid sweeps away this complex genealogical thicket.
In light of this discovery, it seems that all the morphological differences noted in the hominids would actually be evidence of normal biological variability within a single species, due to environmental adaptations or simple genetic variability.
Even if not all experts agree with this hypothesis, and there are those who even think that in the same site of Dmanisi there are fossils of different species, the discovery pushes us to change the way in which the "man evolved."
