Humans Migrated From Africa 'Recently'

Jan. 12, 2007 — New research backs the theory that modern humans spread out of Africa relatively recently, around 50,000 years ago, on the first step of our species' conquest of the planet.

The "Out of Africa" scenario is well known but only a few hominid fossils or artifacts have emerged to explain when the great trek began and how humans dispersed.

A find in Russia, though, and a fresh look at a skull discovered in South Africa more than half a century ago, offer new clues, scientists say.

An international research team, delving into a site of ancient volcanic ash on the River Don around 250 miles (400 kilometers) south of Moscow, found teeth, stone and ivory tools that suggest Homo sapiens moved there some 45,000 to 42,000 years ago.

The finds at Kostenki include perforated shell ornaments that can be traced to the Black Sea more than 300 miles (500 km) away, and a carved piece of mammoth ivory that appears to represent a small human figurine.

If so, it could represent the earliest piece of figurative art in the world.

The stones used to make these artifacts were imported from sites between 60 to 100 miles (100 to 180 km) away.

"The big surprise here is the very early presence of modern humans in one of the coldest, driest places in Europe," co-researcher John Hoffecker of the University of Colorado at Boulder, told the journal Science, where the paper was published.

"It is one of the last places we would have expected people from Africa to occupy first."

Another paper, also appearing in Science, recounts how scientists used high-tech optical scanning and uranium dating methods to reassess a skull found in 1952 near Hofmeyr, South Africa.

The fossil is calculated to be 36,000 years old, plus or minus 3,300 years, making its original owner a near-contemporary of the Kostenki people.

Some of the skulls features are "archaic", meaning that they are consistent with the craniums of Eurasians from the Upper Palaeolithic era rather than of humans today.

The Upper Palaeolithic, also called the Old Stone Age, ran from around 40,000 years ago to 10,000 years ago. It is considered a key period in the human odyssey, coinciding with the emergence of new stone tools, weapons and cave paintings.

Anatomically modern humans are thought to have appeared in sub-Saharan Africa around 200,000 years ago.

East Africa's Rift Valley, where H. sapiens remains dating back 160,000 years have been found, is widely considered the place where it all began.

So if the Hofmeyr dating is right, it means our forebears headed south out of the Rift Valley as well as north, migrating to southern Africa as well as to the Middle East and Eurasia.

Another option would be that the cradle of H. sapiens is southern Africa, and that the migration was all northbound — although there is no fossil evidence to back this.

Apart from some early sites in the Middle East, until now the oldest evidence of modern humans out of Africa has been in Australia, from around 50,000 years ago, according to Hoffecker.