This is us: Earliest fossils of our species found in Morocco

  • This is us: Earliest fossils of our species found in Morocco

This is us: Earliest fossils of our species found in Morocco

Steele examined fossil bones and shells from the Jebel Irhoud archaeological site in Morocco where human ancestors lived 300,000 years ago.

Homo sapiens were hanging around and hunting gazelle in North Africa 100,000 years earlier than was previously believed-a new discovery that will dramatically change the story of the origin of the human species.

Bones found in a cave in Morocco add 100,000 years to the history of modern human fossils.

The bones are about 300,000 years old, and they were found in Morocco. This offers proof that early Homo sapiens were further spread out in Africa than had first been thought. That's why Hublin and his colleagues think the ancient denizens of Jebel Irhoud were an early evolutionary phase of Homo sapiens - somewhere on the developmental path between Homo heidelbergensisand us.

One of the few people who continued to ponder the Jebel Irhoud skull was French paleoanthropologist Jean-Jacques Hublin, who had begun his career in 1981 studying a jaw found at Jebel Irhoud. They show an early stage in the development of our species, when people had a face much like ours, but a brain shape that's more primitive. New dating techniques allowed scientists to establish a consistent chronology for recently discovered fossils as well as to to re-date prior findings.

A 2013 genomic study led by Teresa Rito of the University of Porto in Portugal suggested that "mitochondrial Eve" - the last common ancestor of the Khoe and San populations of southern Africa and the east African lineage that seeded the rest of modern humans around the globe - had lived around 180,000 years ago.

However, gaps in the fossil record and the uncertain chronological age of many specimens mean that the exact time and place that our species emerged from ancestral humans was uncertain. However, the interpretation of the Irhoud fossils has always been complicated by persistent uncertainties surrounding their geological age. Scientists dated the fossils to between 300,000 and 350,000 years old and the skulls found are nearly identical to those belonging to modern humans. Finds are rare and each one must be studied intensively to provide evidence about the many species of pre-humans and early modern humans that populated the world.

Though the new fossils have features that don't seem entirely human, such as a low skull, "I think we have a good instance of early Homo sapiens from Irhoud", says Rick Potts, head of the Smithsonian Institution's Human Origins Program, who was also not part of the study team.

Both McPherron and Hublin said they have categorized the fossils at the site as Homo sapiens, despite their differences from modern humans, because they show clear signs of being part of a line of evolutionary progress.

Sen. Susan Collins R-Maine left with Sen. Roy Blunt R-Mo. right questions Director of National Intelligence Dan Coats and other top national security chiefs as the Senate Select Committee on Intelligence discusses

The tools and fire evidence also point to this being a site linked with the Middle Stone Age.

Hublin says it's more likely Homo sapiens evolved gradually through mutation and intermingling between nomadic groups that roamed Africa during a wetter, greener era for the continent 300,000 years ago. But others in the field say this discovery will prompt others to look beyond East Africa, where so much research has been concentrated.

Hominid fossils unearthed at Jebel Irhoud in 1991 were dated to about 160,000 years ago and were initially thought to be Neanderthals. But, regardless of what we call these ancient relatives of ours, these new findings give us a better idea of how we became who we are today.

The Jebel Irhoud people had large braincases that lacked the globular shape of those today. In addition, new calculations of amounts of radioactive uranium in Jebel Irhoud sediment enabled dating the previously unearthed child's jaw from the site to between around 350,000 and 220,000 years ago.

Earlier finds from the same site in the 1960s had been dated to be 40,000 years old and ascribed to an African form of Neanderthal, a close evolutionary cousin of Homo sapiens.

"The really cool stuff with Irhoud", she said, is that "the traits that make them look more like humans are not primitive traits". "H. sapiens evolution happened on a continental scale", Gunz says.

One reason why understanding early human evolution has been so hard is that Homo sapiens do not appear to have buried their dead around this time.

"We do not know the actual age of the origin of modern humans, we have just pushed it back further in time", says Begun.