POST NEWS NETWORK
Pathbreaking recent research has disturbed the evolutionary applecart by suggesting that the first human ancestor can be traced back to Europe – rather than East Africa – 7.2 million years ago
The first hominin species, a line that eventually leads to humans, may have emerged in Europe 7.2 million years ago and not Africa — the most widely accepted starting point for our ancestors.
An international team of scientists has presented two studies that suggest the divergence point between chimpanzees and humans took place in the Eastern Mediterranean rather than East Africa 200,000 years ago. The findings, published in the journal PLOS ONE, are based on two fossils of the species Graecopithecus freybergi or “El Graeco”, which were discovered in Greece and Bulgaria and have now been dated to between 7.2 and 7.1 million years ago.
Researchers have assumed up to now (before the new findings) that the lineages diverged five to seven million years ago and that the first pre-humans developed in Africa. According to the 1994 theory of French palaeoanthropologist Yves Coppens, climate change in Eastern Africa could have played a crucial role. The two studies of the research team from Germany, Bulgaria, Greece, Canada, France and Australia now outline a new scenario for the beginning of human history.
Credit: Wolfgang Gerber, University of Tübingen
The team analysed the two known specimens of the fossil hominid Graecopithecus freybergi: a lower jaw from Greece and an upper premolar from Bulgaria. Using computer tomography, they visualised the internal structures of the fossils and demonstrated that the roots of premolars are widely fused.
Environmental changes drove divergence
As with the out-of-East Africa theory, the evolution of pre-humans may have been driven by dramatic environmental changes. The team led by Böhme demonstrated that the North African Sahara desert originated more than seven million years ago. The team concluded this based on geological analyses of the sediments in which the two fossils were found. Although geographically distant from the Sahara, the red-coloured silts are very fine-grained and could be classified as desert dust. An analysis of uranium, thorium, and lead isotopes in individual dust particles yields an age between 0.6 and 3 billion years and infers an origin in Northern Africa.
Credit: Wolfgang Gerber, University of Tübingen
Fire, grass, and water stress
The researchers further showed that, contemporary to the development of the Sahara in North Africa, a savannah biome formed in Europe. Using a combination of new methodologies, they studied microscopic fragments of charcoal and plant silicate particles, called phytoliths. Many of the phytoliths identified derive from grasses and particularly from those that use the metabolic pathway of C4-photosynthesis, which is common in today’s tropical grasslands and savannahs. The global spread of C4-grasses began eight million years ago on the Indian subcontinent — their presence in Europe was previously unknown.
