Study sheds new light on ancestral human movement patterns leading to colonization of the Mediterranean region
By Summit Voice
FRISCO — Scientists have long speculated that humans migrated across the Sahara region of Africa to populate the Mediterranean region, but the exact movement corridor has remained a mystery.
A new study, led by researchers with the University of Hull, shows there may have been three ancient river systems that created a viable route about 100,000 years ago.
By simulating paleoclimates in the region, the researchers found quantitative evidence for the river systems that likely existed in North Africa 130,000-100,000 years ago, but are now largely buried by dune systems in the desert. When flowing, these rivers would have provided fertile habitats for animals and vegetation, creating green corridors across the region.
“It’s exciting to think that 100, 000 years ago there were three huge rivers forcing their way across a 1000 kilometers of the Sahara desert to the Mediterranean … and that our ancestors could have walked alongside them” said University of Hull geographer Tom Coulthard.
At least one river system is estimated to have been 100 kilometers wide and largely perennial. The Irharhar river, westernmost of the three identified, may represent a likely route of human migration across the region. In addition to rivers, the researchers’ simulations suggest massive lagoons and wetlands in northeast Libya, some of which may have spanned more than 70,000 square kilometers.
Previous studies have shown that people traveled across the Saharan mountains toward more fertile Mediterranean regions, but when, where and how they did so is a subject of debate. Existing evidence supports the possibilities of a single trans-Saharan migration, many migrations along one route, or multiple migrations along several different routes.
The existence of ‘green corridors’ that provided water and food resources were likely critical to these events, but their location and the amount of water they carried is not known. The simulations provided in this study aim to quantify the probability that these routes may have been viable for human migration across the region.
The findings were published September 11 in the open access journal PLOS ONE.