Jun 18, 2025 06:47 PM
https://www.eurekalert.org/news-releases/1087445
INTRO: Today, all non-Africans are known to have descended from a small group of people that ventured into Eurasia after around 50 thousand years ago. However, fossil evidence shows that there were numerous failed dispersals before this time that left no detectable traces in living people.
In a paper published in Nature this week, new evidence for the first time explains why those earlier migrations didn’t succeed. A consortium of scientists led by Prof. Eleanor Scerri of the Max Planck Institute of Geoanthropology in Germany, and Prof. Andrea Manica of the University of Cambridge has found that before expanding into Eurasia 50 thousand years ago, humans began to exploit different habitat types in Africa in ways not seen before.
“We assembled a dataset of archaeological sites and environmental information covering the last 120 thousand years in Africa. We used methods developed in ecology to understand changes in human environmental niches, the habitats humans can use and thrive in, during this time,” says Dr Emily Hallett of Loyola University Chicago, co-lead author of the study.
“Our results showed that the human niche began to expand significantly from 70 thousand years ago, and that this expansion was driven by humans increasing their use of diverse habitat types, from forests to arid deserts,” adds Dr Michela Leonardi of London’s Natural History Museum, the study’s other lead author.
“This is a key result.” explains Professor Manica, “Previous dispersals seem to have happened during particularly favourable windows of increased rainfall in the Saharo-Arabian desert belt, thus creating ‘green corridors’ for people to move into Eurasia. However, around 70,000-50,000 years ago, the easiest route out of Africa would have been more challenging than during previous periods, and yet this expansion was sizeable and ultimately successful.” (MORE - details, no ads)
INTRO: Today, all non-Africans are known to have descended from a small group of people that ventured into Eurasia after around 50 thousand years ago. However, fossil evidence shows that there were numerous failed dispersals before this time that left no detectable traces in living people.
In a paper published in Nature this week, new evidence for the first time explains why those earlier migrations didn’t succeed. A consortium of scientists led by Prof. Eleanor Scerri of the Max Planck Institute of Geoanthropology in Germany, and Prof. Andrea Manica of the University of Cambridge has found that before expanding into Eurasia 50 thousand years ago, humans began to exploit different habitat types in Africa in ways not seen before.
“We assembled a dataset of archaeological sites and environmental information covering the last 120 thousand years in Africa. We used methods developed in ecology to understand changes in human environmental niches, the habitats humans can use and thrive in, during this time,” says Dr Emily Hallett of Loyola University Chicago, co-lead author of the study.
“Our results showed that the human niche began to expand significantly from 70 thousand years ago, and that this expansion was driven by humans increasing their use of diverse habitat types, from forests to arid deserts,” adds Dr Michela Leonardi of London’s Natural History Museum, the study’s other lead author.
“This is a key result.” explains Professor Manica, “Previous dispersals seem to have happened during particularly favourable windows of increased rainfall in the Saharo-Arabian desert belt, thus creating ‘green corridors’ for people to move into Eurasia. However, around 70,000-50,000 years ago, the easiest route out of Africa would have been more challenging than during previous periods, and yet this expansion was sizeable and ultimately successful.” (MORE - details, no ads)