Researchers have uncovered 300,000-year-old fossil bones of Homo sapiens-the oldest reliably dated fossil evidence of our species.
The understanding of human origins has been turned on its head with the announcement of the discovery of fossils unearthed on a Moroccan hillside that are about 100,000 years older than any other known remains of our species, Homo sapiens.
The discovery, which also included stone tools and animal bones, took place at Jebel Irhoud, Morocco-the site of multiple hominid fossil discoveries dating back to the early 1990s. "In light of this new date - at 300,000 years old - it convinced us that this material that we present is the very root of our species".
The fossils reveal a complex evolutionary history of humankind that likely involved the entire African continent, notes the team, which professor Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and Abdelouahed Ben-Ncer of the National Institute for Archaeology and Heritage in Rabat, Morocco, led.
"The story of our species in the last 300,000 years is mostly the evolution of our brain and in this time period, a number of mutations occurred affecting brain connectivity", Hublin said. "The oldest Homo sapiens ever found in Africa".
Prior to this discovery, the oldest known Homo sapiens fossils were 195,000-year-old remains found at Omo Kibish in Ethiopia. Before this discovery, it was believed that the early modern humans we evolved from were in Africa 200,000 years ago and looked very similar to modern humans.
A composite reconstruction of the fossils from Jebel Irhoud show these early Homo sapiens already have a modern-looking face that falls within the variation of humans living today.
Modern humans might not be as modern we thought.
The site has been long-known as a source of human fossils, but the age of earlier discoveries at the site has been unclear.More news: Watch Common Freestyle to Halle Berry in New Video
The study also indicated these ancient humans may have employed stone tools and used fire. But based on the brain case they discovered, these Homo sapiens did have a larger cerebellum than Neanderthals.
Fossils of early members of Homo sapiens found in Morocco (left) display a more elongated skull shape than do modern humans (right).
The fossils were initially dated to about 40,000 ago, and later to about 160,000 years.
"Thanks to improvements in dating techniques, particularly in luminescence dating, this layer, from which all the specimens had been excavated, is now revealed to be approximately twice as old as previously thought", Chris Stringer and Julia Galway-Witham of Britain's Natural History Museum, who were not involved in the research, wrote in a commentary. "We realized this site was much older than anyone could imagine".
This is a common argument in anthropology - where does a newly discovered fossil, especially one with a mix of ancient and more modern features, fit in the bushy family tree of human ancestry?
"It really seemed like people were fond of hunting", she said.
"It means they were no slouches intellectually", Professor Groves said. "The faces of these people would have been short, flat, and retracted", says Hublin.
Human remains, including a skull, were first discovered at the Jebel Irhoud site by miners in the 1960s.
"Our results challenge the preconceived notion of early modern humans in East Africa in many ways regarding the date of emergence of our species, the geographical conditions of this emergence and the conditions of the evolution of the early forms of Homo sapiens", Hublin said.