The first members of our species, Homo Sapiens, evolved at least 300,000 years ago, the fossil remains of five individuals seem to suggest.
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.
An worldwide team of scientists unearthed teeth, bones and skulls belonging to three Homo sapiens adults, a teenager and a child among animal bones and stone tools.
Jean-Jacques Hublin, a Professor at the Max Planck Institute for Evolutionary Anthropology in Leipzig who reported the discovery, said that while these fossils come from a very young stage in the species' development, he believes there existed an even earlier stage that has yet to be discovered. At Jebel Irhoud, for example, the 300,000-year-old braincases-the part of the skull that houses the brain-are elongated in shape and accommodate a larger cerebellum, the part of the brain that plays an important role in maintaining balance, coordinating voluntary movements, and fine-tuning motor skills.
Early Homo sapiens roamed Africa 300,000 years ago, sporting modern-looking faces that would not stand out in a crowd today, according to research published Wednesday that pushes back our origins by a hundred millennia.
Before the discovery at the site called Jebel Irhoud, located between Marrakech and Morocco's Atlantic coast, the oldest Homo sapiens fossils were known from an Ethiopian site called Omo Kibish, dated to 195,000 years ago. Additional findings reveal that this ancient population didn't expand out of Africa for another 125,000 years.
Researchers say that they have found the oldest Homo sapiens remains on record in an improbable place: Morocco.
The findings may also re-organize the human evolutionary tree and eliminate certain extinct Homo relatives as potential human ancestors.
Homo sapiens is now the only human species, but 300,000 years ago it would have shared the planet with several now-extinct cousins in Eurasia - Neanderthals in the west and Denisovans in the east - and others in Africa.
With few fossil remains to work with, the evolutionary history of modern humans is full of holes and relies heavily on conjecture.
Scientists have learned these ancient humans had an elongated brain shape, according to the AP. Many were collected during the 1960s but had been imprecisely dated to 40,000 years ago. "We realized this site was much older than anyone could imagine".
These could be dated with a special technique called thermoluminescence, which measures exposure to radiation generated by heat.
This mix of archaic and modern features supports the theory that Homo sapiens didn't burst onto the African scene fully formed.
The tools and fire evidence also point to this being a site linked with the Middle Stone Age. Although they tried to extract DNA from them, it wasn't there, Hublin said.
The researchers hope to return to Jebel Irhoud because there is still more to be excavated. But this discovery widens the "cradle of life" from East Africa to the whole continent, Hublin said, and suggests that these evolutionary changes were happening across the continent at the same time. The new date for the fossils suggests some elements of Homo sapiens anatomy developed a more modern appearance much earlier than thought, says Adam Van Arsdale of Wellesley College, who was not involved with the study.