Out of Africa earlier than expected: Modern man first arrived in Europe 130,000 years ago, researchers claim
First wave of migration out of Africa started 130,000 years ago, earlier than previously thought
Second dispersal to northern Eurasia followed about 50,000 years ago
By MARK PRIGG
PUBLISHED: 18:46 GMT, 22 April 2014 | UPDATED: 00:11 GMT, 23 April 2014

Modern man left Africa earlier than previously thought - and in multiple waves, new research has found.
Researchers say anatomically modern humans spread from Africa to Asia and Europe in several migratory movements, beginning 130,000 years ago.

They also found that there were several waves of migration, rather than the one previously believed to have occurred.


The team analysed the head shapes of skulls to work out how man migrated into Europe. The temporal bone (inset) has been shown to reflect modern human population history better than other parts of the cranium.


Man's move out of Africa: A first migration along the Indian Ocean rim occurred as early as 130 thousand years ago (green arrow) and was followed by a second, more recent migration wave into Eurasia (red arrow).

WHERE THEY WENT
Most scientists agree that all humans living today are descended from a common ancestor population which existed 100,000 to 200,000 years ago in Africa.

The first ancestors of today’s non-African peoples probably took a southern route through the Arabian Peninsula as early as 130,000 years ago, the researchers found.

They followed a coastal route through the Arabian Peninsula to Australia and the west Pacific region.

A team of researchers led by the University of Tübingen’s Professor Katerina Harvati analysed skull shapes to show that anatomically modern humans spread from Africa to Asia and Europe in several migratory movements.

The first ancestors of today’s non-African peoples probably took a southern route through the Arabian Peninsula as early as 130,000 years ago, the researchers found.

Scientists have previously suggested the exodus from Africa started between 40,000 and 70,000 years ago, although stone artifacts dating to at least 100,000 years ago that were recently uncovered in the Arabian Desert suggested that modern humans might have begun their march across the globe earlier than once suspected.

The latest study is published by Professor Katerina Harvati and her team from the Institute for Archaeological Sciences at the University of Tübingen and the Senckenberg Center for Human Evolution and Palaeoenvironment, in collaboration with colleagues from the University of Ferrara, Italy, and the National Museum of Natural History, France.

The study appears in the online Early Edition of the Proceedings of the National Academy of Sciences.

The scientists tested different hypothetical dispersal scenarios, taking into account the geography of potential migration routes, genetic data and cranial comparisons.

They found that the first wave of migration out of Africa started earlier than previously thought, taking place as early as the late Middle Pleistocene – with a second dispersal to northern Eurasia following about 50,000 years ago.

Most scientists agree that all humans living today are descended from a common ancestor population which existed 100,000 to 200,000 years ago in Africa.


The Out-of-Africa model that best fits both the genetic and cranial shape data, researchers say: The first migration along the Indian Ocean rim occurred as early as 130 thousand years ago (blue arrow) and was followed by a second, more recent migration wave into Eurasia (red arrow).

The decreasing genetic and phenotypic diversity observed in humans at increasing distances from Sub-Saharan Africa has often been interpreted as evidence of a single dispersal 50,000 to 75,000 years ago.
However, recent genetic, archaeological and palaeoanthropological studies challenge this scenario.

Professor Harvati’s team tested the competing out-of-Africa models of a single dispersal against multiple dispersals of anatomically modern humans.

The scientists compared modern human crania from different parts of the world, neutral genetic data, and geographical distances associated with different dispersal routes.

Likewise, they reconstructed population split times from both the genetic data and as predicted by each competing model.


Shown here is the mean temporal bone shape of all individuals in the study. The temporal bone was used in this study to infer migration patterns, in addition to genetic data.

Because each dispersal scenario is associated with specific geographic and temporal predictions, the researchers were able to test them against the observed neutral biological distances between groups, as revealed from both genetic and cranial data.

'Both lines of evidence – anatomical cranial comparisons as well as genetic data – support a multiple dispersal model,' says Katerina Harvati.

The first group of our ancestors left Africa about 130,000 years ago and followed a coastal route through the Arabian Peninsula to Australia and the west Pacific region.

'Australian aborigines, Papuans and Melanesians were relatively isolated after the early dispersal along the southern route,' says Hugo Reyes-Centeno, first author of the study and member of the Tübingen team.


The landmarks shown in one individual cranium, which show how researchers were able to track movement of modern man leaving Africa. In addition to genetic sequence data, information on cranial shape was used to infer modern human migration patterns.

He adds that other Asian populations appear to be descended from members of a later migratory movement from Africa to northern Eurasia about 50,000 years ago.

The researchers are confident that continued field work and advances in genetics will allow for fine-tuning of models of human expansion out of Africa.

So far we can only speculate whether, for example, severe droughts in East Africa occurring between 135,000 and 75,000 years ago prompted migration or had an impact on the local evolution of human populations. The southern route region is a vast geographical space that has been understudied by archaeologists and anthropologists, so future work in this area will help support their findings.

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