Intriguingly, the genetic data suggest that male Denisovans interbred with modern human
females, indicating the potential nature of the interactions as small numbers of modern humans
first crossed Wallace's Line and entered Denisovan territory," the study authors said.
More analyses of additional early modern humans
across Eurasia will further refine our understanding of when and how modern humans
spread across Europe and Asia," Svante Pbo added.
Cooper said questions have now been raised about how modern humans
met and interacted in Denisovans 50,000 years ago on their way to New Guinea and Australia, noting that modern humans
also crossed paths with the Denisovans on their way west.
Although modern humans
are the only surviving members of the human lineage, others once roamed the Earth, including the Neanderthals.
in eastern Africa may have initially evolved some archaic-looking traits on their own, suggests anthropologist Katerina Harvati of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
According to Yates, Neanderthals had deeper voices than modern humans
This fossil find indicates that the migration out of Africa and into East and Southeast Asia occurred at a relatively rapid rate, and that, once there, modern humans
weren't limited to environments that they had previously experienced," said Kira Westaway, of Macquarie University in Australia said.
The authors of both studies suspect that modern humans
advanced speedily out of Africa in various directions, out competing and hastening the demise of Neandertals and others.
Some Neanderthal DNA 'survives' in modern humans
, though it's unclear if this is the result of interbreeding or just relics from a common ancestor.
Researchers from the University of Washington, Seattle, arrived at this conclusion by comparing the whole genome sequences of modern humans
against our Denisovan ancestors.
Scientists say that an ancient upper jawbone and associated stone tools could also mean that Homo sapiens -- modern humans
-- arose in Africa far earlier than fossils now show.
The analysis also proposes that modern humans
interbred with Denisovans about 100 generations after their trysts with Neanderthals.