Serbian cave produces oldest human ancestor in this part of Europe

A fragment of lower jaw recovered from a Serbian cave has now been dated as the oldest hominin ancestor found in this part of Europe. The fossil was dated to between 397,000 and 525,000 years old, a time when distinctly Neanderthal traits began to appear in Europe. The evolution of these traits was strongly influenced by periodic isolation of groups of individuals, caused by glacial episodes.

According to research published in February 2012 in the open access journal PLoS ONE, the individual probably evolved under different conditions than populations who inhabited more western parts of the continent during the same time frame.

Geographic isolation

Humans in southeastern Europe were never geographically isolated from Asia and Africa by glaciers, and according to the authors, this resulted in different evolutionary forces acting on early human populations in this region. Roksandic explains that their study confirms the importance of southeast Europe as a ‘gate to the continent’ and one of the three main areas where humans, plants and animals sought refuge during glaciations in prehistoric times. She adds, “We have very few fossils of hominins in general from this time, a period that was critical for shaping the appearance and evolution of uniquely human morphology and behaviours.”
In 2000, Dr. Mirjana Roksandic, a paleoanthropologist with the University of Winnepeg and a leading research team member began excavating a cave in Balanica, Serbia, along with her colleagues. While they were away, looters secretly dug a deeper pit within the cave. On discovering this, the scientific team then decided, as the site had already been disturbed to a deeper layer, that they should excavate further.
In June 2008, a possible Homo erectus jaw was excavated from this lower stratum; The morphology of the mandible differs significantly from Homo heidelbergensis; and there is a complete lack of derived Neanderthal features.
The jaw represents one of an increasing number of specimens from the southeast of Europe demonstrating plesiomorphic ‘erectus-like’ traits coupled with synapomorphic traits common to Middle Pleistocene hominins.

New dates for the fossil

Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 . This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene.

“In the past, anthropologists assumed that Neanderthals were widespread throughout Europe, basing that assumption on Neanderthal fossils almost exclusively found in Western Europe“, Roksandic told Live Science.
The new findings suggest that Neanderthals may not have evolved in this region of Southeastern Europe, instead, several ice ages cut off Western Europe from the rest of the continent, and this isolation contributed to the evolution of Neanderthals’ distinctive features from the more primitive Homo erectus.
Ancient humans in Southeastern Europe, by contrast, were never cut off due to rising glaciers. “So there is no pressure on them to develop into something different,” she said.
But not everyone is convinced of this interpretation and the specimen may come from “an unusual individual in a population of which some others might be more Neanderthal-like,” according to Fred Smith, a paleoanthropologist at Illinois State University, who was not involved in the study.
What is certain is the date – and this in itself pushes forward the study of hominin dispersal around half a million years ago.

 http://www.pasthorizonspr.com/index.php/archives/02/2013/serbian-cave-produces-oldest-human-ancestor-in-this-part-of-europe

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