Archaeological evidence indicates that the Sahara Desert was once a lush green savannah, home to a mysterious lineage of people who were isolated from the outside world. Researchers analyzed the genomes of individuals who lived in what is called the 'Green Sahara' and found that they were part of a distinct and previously unidentified human lineage. These individuals were pastoralists, herding domesticated animals, and their genetic legacy can still be seen in various North African groups today.