The discovery of five different skulls of hominins outside of the Afro-tropical region have helped paint a better picture of our ancestral history, says Professor of Biological Anthropology Colin Groves.
Professor Groves is delivering a public lecture at 4pm on Wednesday 15 January at the Molony Room in the ANU Emeritus Faculty on the recent discovery made in the country of Georgia.
He says the discovery dates back to 1.77 million years ago.
"They're not our direct ancestors but they are very similar to a population which existed before Homo ergaster which does seem to be our direct ancestor," he says.
Professor Groves says when a new species arises, very frequently there are new genetic characters arising in the centre of a species range where it's simply more numerous.
"This means that populations left around the periphery of this range of the species are primitive with respect to those in the centre."
The five specimens from Georgia show that there was a considerable sexual dimorphism in this population, he says.
"Looking at its closest if not slightly more advanced relative Homo ergaster in east Africa, it enables us to put some unallocated specimens into perspective, and it shows that Homo ergaster was also probably strongly sexually dimorphic."