The Sahara Desert was once a lush, green landscape known as the Green Sahara, home to early human populations. Recent genomic analysis of ancient remains reveals insights into their origins and connections to other regions, challenging previous hypotheses about migration and genetic exchange.
Picture the Sahara: endless sand dunes, the sun beating down, and no ice-cold beverages in sight. However, it wasn’t always this way. Thousands of years ago, the Sahara was lush, green, and almost unrecognizable. This paradise was home to human populations, but studying them has proven challenging. Researchers have long pondered who these people were, where they came from, and how they connected to other human societies of their time. Surprisingly, the key to unraveling these mysteries was hidden in a cave, buried within the DNA of just two individuals.
It may sound odd to hear that the Sahara was once unrecognizable, especially since it is the most iconic desert in the world, covering nearly all of Northern Africa. Yet, between 11,000 and 5,000 years ago, it was characterized by trees, lakes, and significant rainfall. This period is referred to as the Green Sahara, which is part of the African Humid Period—a larger cycle of wet and dry phases in the region that has persisted for over 5 million years.
The climatic changes that led to the Green Sahara are related to the Earth’s tilt and orbit, which shift slowly over long periods. These minor shifts triggered feedback loops between climate and vegetation. At the onset of a wet period, the Earth’s tilt allows the Northern Hemisphere to receive more sunlight, increasing surface temperatures and evaporation. This leads to heavier monsoons, resulting in more water and vegetation. The vegetation, in turn, absorbs more solar radiation, raising surface temperatures and further increasing evaporation, perpetuating the cycle.
Evidence from pollen and leaf wax molecules indicates that this cycle ended around 5,000 years ago, marking the transition to the Sahara Desert we know today. Before this transformation, the region was filled with lush grasslands, shade, and permanent water sources—ideal conditions for human settlement.
Humans began settling in Egypt over 10,000 years ago and continued to inhabit the Sahara until the rains ceased around 5,500 years ago. Archaeological evidence suggests that the earliest societies in this region were composed of hunter-gatherers who may have domesticated some animals and created Africa’s earliest ceramics. Over the following millennia, these populations began to live alongside sheep, goats, and cows, with domesticated animals likely introduced from Asia via migrations from Sinai and the Red Sea.
The prevailing hypothesis has been that populations from Northern Africa migrated into the Saharan region as it became green, later mixing with groups from the Mediterranean and sub-Saharan Africa. However, testing this hypothesis has been challenging due to the scarcity of genomic data, as the dry, sandy conditions of the modern Sahara are not conducive to DNA preservation. Consequently, when human remains are discovered, they often cannot be genetically profiled.
To bridge this gap, archaeologists sought individuals with well-preserved DNA. Remarkably, they found two such individuals.
In 2003, archaeologists uncovered a rock shelter in southwestern Libya known as Takarkori. This site contained traces of settlements dating back between 4,000 and 10,000 years, providing valuable insights into the people who lived in the Green Sahara. Among the findings were pottery shards with traces of milk fat, representing the oldest clear evidence of dairy production in Africa.
At the back of the cave, researchers discovered human remains from 15 burials, dating from 8,900 to 4,800 years ago. Two of these remains belonged to women in their 40s, who died approximately 7,000 years ago during the Green Sahara period. As the Sahara dried out, their remains became natural mummies, preserving their DNA.
In 2025, researchers published the results of a genomic analysis revealing the identities of these women and, by extension, the inhabitants of the Green Sahara. Contrary to previous hypotheses, the analysis indicated that these women shared the most genetic similarities with a group from what is now Morocco, dating back 15,000 years. This connection suggests that the same lineage of people inhabited the region long before it transformed into a lush grassland.
Interestingly, the Takarkori individuals exhibited minimal genetic material from sub-Saharan Africa, indicating that the Sahara Desert acted as a barrier to human migration even when crossing it was less perilous.
The Takarkori women had significantly less Neanderthal DNA compared to populations outside Africa, suggesting a more isolated genetic history. The Moroccan population had about half as much Neanderthal DNA as those found around the Mediterranean, while the Takarkori individuals had only one-tenth of that amount. This indicates that the residents of the Green Sahara were genetically distinct from Mediterranean populations, raising questions about their livestock domestication practices.
Despite evidence of cultural exchange, the genetic analysis revealed limited genetic mixing between populations. The Takarkori pottery resembled that found elsewhere in Northern Africa, suggesting that while there was interaction and exchange of ideas, there was little in terms of genetic exchange.
The DNA analysis of these two individuals has provided crucial insights into trade, agriculture, migration patterns, and the economies of people living 7,000 years ago in the Green Sahara. This research highlights the importance of understanding our past, as it can reshape our knowledge of human history and migration. Even if one feels insignificant in life, the impact of ancient individuals can resonate through time, revealing the complexities of human existence and adaptation in changing environments.
