Sahara desert, once lush and green, was home to mysterious human lineage

According to DNA obtained from the remains of two individuals who lived about 7,000 years ago in what is now Libya, it was home to a mysterious lineage of people isolated from the outside world.

The Sahara Desert is one of Earth’s most arid and desolate places, stretching across a swathe of North Africa that spans parts of 11 countries and covers an area comparable to China or the United States. But it has not always been so inhospitable.