Fossil changes everything we knew about spread of humans out of Africa


If the species originated in sub-Saharan Africa around 200,000 years ago as was thought, the bone-dry Sahara Desert could have been a formidable barrier to migration out of the motherland.

The oldest human fossils outside Africa, a partial upper jaw bone and several teeth, were found in Misliya Cave in Israel and may be nearly 200,000 years old.

There's not much left of this person who lived and died in a cave on the slopes of Israel's Mt. Carmel between 177,000 and 194,000 years ago.

"We now have clear fossil evidence that modern humans moved out of Africa earlier than we previously believed", Rolf Quam, study coauthor and anthropology professor at Binghamton University, said in an email.

The scientists detailed their findings in the January 26 issue of the journal Science.

An global team that includes Tel Aviv University, Binghamton University and the University of NY has announced the discovery of the earliest modern human fossil to be found outside of Africa dating from 50,000 years ago.

Moreover, researchers studying DNA recovered from fossils have shown that as H. sapiens entered new lands it did in fact interbreed with archaic human species it encountered, including the Neandertals and the mysterious Denisovans. The find adds to evidence that our species was overlapping with human relatives such as Neanderthals in the crossroads of the Levant for longer than previously realized.

"Our species", Hershkovitz added, "is a genetic mishmash of several hominins". The remains were found in the Misliya Cave in 2002 but only after intensive research over the past 15 years, the scientists were able to say the fossil is 200,000 years old. Previous research suggested the exodus from Africa started between 70,000 and 40,000 years ago.

But the new discovery provides further evidence to support the theory that Homo sapiens first trekked out of Africa through a northern route along the Nile river and not through a mid-continental route across the Bab al-Mandeb strait into the southern coast of Saudi Arabia, India and then Asia. Although this ancient person may have shared some anatomical characteristics with present-day people, this "modern human" would have probably looked much different from anyone living in the world today.

"It is well-known from numerous studies that these were used mostly for the hunting of animals and processing their meat and skin (leather), as well as cutting plants", says Daniella Bar-Yosef, a researcher at Tel Aviv University and an associate at Harvard's Peabody Museum of Archaeology and Ethnology who is one of the co-authors of the paper. The site was believed to have been a rock shelter occupied by prehistoric humans, but no one was aware of exactly how long ago human occupancy actually began in the region. With 1-4% of modern Europeans carrying the genetic DNA of Neanderthal man, these findings appear to confirm a meeting of minds and bodies far earlier than we had previously surmised.

It is possible that descendants of the early Homo sapiens populations who out of Africa were seeking prey and additional resources. Accompanying the oldest human fossils were burnt flints and other tools, which reinforces the idea that the remains are human rather than ape.

Besides the fossil itself, archaeologists have excavated stones nearby shaped by humans in a sophisticated way known as the Levallois technique. The jawbone represents an interim step in the migration from Africa to Asia and fits in a more expansive timeline of human evolution that scientists are starting to adopt as the true historical record.

Of all the human species that have ever lived, only one, Homo sapiens, conquered the entire planet.