14 DAY TRIAL // There is a vivid debate in the scientific community if modern humans and Neandethals interbred.
Genetic and fossil analyses come with pro and anti proofs.
New fossil evidence from Romania points that humans continued to evolve significantly long after they were established in Europe, and interbred with Neanderthals.
Archaeologists led by Professor Joao Zilhao of the University of Bristol and Professor Erik Trinkaus of Washington University found early modern human skulls, dated from Last Pleistocene (more than 35,000 years ago) in the Pestera cu Oase (the Cave with Bones) in southwestern Romania, in diggings between 2003-2005.
These new skulls presented many differences from human skulls the same age found in other places, suggesting complex population dynamics as modern humans spread into Europe.
The reconstructed cranium named Oase 2 ("oase" means "bones" in Romanian) was discovered in a bone bed rich in the remains of cave bears. Scientists believe Oase 2, due to its morphological resemblance to the 2002 find of Oase 1 human mandible, must have the same age with the last, of about 40,500 years ago.
In this case, these are the earliest modern human remains so far found in Europe, giving a precious clue about how modern humans who first dispersed into Europe looked like.
The researchers discovered that Oase 2 had the same proportions as modern human skulls and shared a number of modern human and/or non-Neanderthal features.
But they bore some archaic traits: frontal flattening, a large juxtamastoid eminence and exceptionally large upper molars with unusual size progression, typical for the Neanderthals. "Such differences raise important questions about the evolutionary history of modern humans. They could be the result of evolutionary reversal or reflect incomplete palaeontological sampling of Middle Paleolithic human diversity", said Zilhao.
"They could also reflect admixture with Neandertal populations as modern humans spread through western Eurasia. This mixture would have resulted in both archaic traits retained from the Neandertals and unique combinations of traits resulting from the blending of previously divergent gene pools."
"The ultimate resolution of these issues must await considerations of larger samples of European early modern humans and chronologically intervening specimens. But this fossil is a major addition to the growing body of fossil, genetic and archaeological evidence indicating significant levels of biological and cultural interaction between modern humans and the anatomically archaic populations (including the Neandertals) they met along the way as they spread from Africa into Eurasia."
Oase 2 skull points to a significant modern human morphological evolution since the early Upper Paleolithic.