Two 7,000 -year -old old mummies belong to a previously unknown human line which has remained isolated in North Africa for thousands of years, according to a new study.
Mummies are the remains of women who once lived in the “green Sahara”, also known as the African wet period. Between 14,500 and 5,000 years old, the now hospital Sahara was a humid and green savannah, which housed humans who hunted and ultimately developed animals alongside lakes and rivers.
The DNA of the two mummies revealed that the North African line never seen was distinct and isolated from the populations living in sub-Saharan Africa at the same time. The results, reported on April 2 in the newspaper NatureSuggest that there was little genetic exchange through the green Sahara during this period, although certain cultural practices spread in the region.
Between 2003 and 2006, archaeologists uncovered the remains of 15 individuals in the Rock Takarkori refuge, located near the middle of the Sahara in what is now the southwest of Libya. The site included evidence of human occupation and pastoralism, or breeding, dating back more than 8,000 years. Of the 15 individuals, most of whom were women and children, two had naturally mummified, which helped preserve their DNA.
“We were lucky to have samples preserved at this level”, co-author of the study Nada SalemA paleogeniticist at the Max Planck Institute for evolutionary anthropology in Germany, said Scientific magazine. High temperatures in the region can quickly decompose DNA in human remains, leaving some examples of old DNA in the region.
A 2019 study examined the mitochondrial DNA of the same remains. However, mitochondrial DNA, which is inherited only from the mother, does not provide as much information on the dynamics of the population as DNA Chromosomes, which is inherited from both parents. To obtain this data at the genome scale, the researchers extracted the preserved DNA from mummified remains and compared it to the DNA of around 800 current individuals from Africa, the Near East and the South of Europe, as well as 117 ancient genomes from the same regions.
In relation: Could the Sahara be green again?
Takarkori individuals had distinct genetic markers from populations in sub -Saharan Africa, noted that the team suggesting that they came from a prior and relatively isolated line which diverged populations from sub -Saharan Africa about 50,000 years ago. But the individuals had ancestors of the Levant, an extent of land bordering the eastern Mediterranean Sea. Takarkori DNA has also shown traces of Neanderthal Ancestry that could only have been acquired outside Africa, because the Neanderthals lived in Eurasia. But the genomes of mummies contained 10 times less Neanderthal DNA than those of people living outside Africa today.
The results suggest that the green Sahara did not act as a migration corridor between sub -Saharan Africa and North Africa. However, archaeological evidence suggests that the cultural exchange between the regions has occurred.
“We now know that they were isolated in terms of genetics, but not in cultural terms”, co-author of the study Savino di lerniaAn archaeologist at the University of Sapienza in Rome, said Cnn. “There are a lot of networks that we know from several parts of the continent, because we have pottery from sub -Saharan Africa. We have pottery from the Nile valley and others.”
The rise of pastoralism in the Sahara was also born out of interactions with other groups that raised domestic animals at the time, rather than by large -scale migrations, researchers suspected.
This isolated line no longer exists in its original form today, but at some point, people in this line have mixed with foreigners, which is why some people living in North Africa have today inherited this genetic heritage, according to researchers.
“By highlighting the deep past of the Sahara, we aim to increase our knowledge of human migration, adaptations and cultural evolution in this key region,” said Di Lernia in a statement.