Sahara desert, once lush and green, was home to mysterious human lineage, study says
Researchers from Germany's Max Planck Institute for Evolutionary Anthropology detailed in a
study published
in Nature this week their findings from the DNA of two 7,000-year-old naturally mummified individuals excavated from the Takarkori rock shelter in southwestern Libya.
The humans lived during the "African Humid Period," when the Sahara desert was green and dotted with lakes and streams. Humans lived in the area, and pastoralism — or flock tending — was prevalent, researchers said.
Aridification, when a region becomes gradually and increasingly drier, turned the once lush oasis into the Sahara desert known today.
Using genomic analysis, the researchers found that the North African lineage diverged from sub-Saharan African populations at about the same time as the modern human lineages that spread outside of Africa around 50,000 years ago.
The Takarkori mummies had their own unique and isolated lineage.
The mummies shared close genetic ties with 15,000-year-old foragers that lived during the Ice Age in Taforalt Cave, Morocco. Researchers also traced the mummies' Neandertal ancestry and found they have tenfold less Neandertal DNA than people outside Africa, but more than contemporary sub-Saharan Africans.
"Our findings suggest that while early North African populations were largely isolated, they received traces of Neandertal DNA due to gene flow from outside Africa," senior author Johannes Krause, director at the Max Planck Institute for Evolutionary Anthropology,
said
in a statement.
The findings also revealed that the "Green Sahara" wasn't as widely used for migration as previously thought, researchers said. That meant instead of different populations intermixing during large movements, groups more than likely interacted infrequently, and did so through cultural interchange.
"Our research challenges previous assumptions about North African population history and highlights the existence of a deeply rooted and long-isolated genetic lineage,"
said
Nada Salem, a first author and researcher from the Max Planck Institute for Evolutionary Anthropology. "This discovery reveals how pastoralism spread across the Green Sahara, likely through cultural exchange rather than large-scale migration."
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