Ancient DNA recovery is rare
Experts have studied the skeletons and artifacts unearthed at the site over the years, but attempts to recover DNA from the remains proved elusive.
In 2019, scientists were able to recover mitochondrial DNA, which traces the maternal line, but obtaining this DNA didn’t paint the full picture, Ringbauer said.
“A couple of years ago, the samples made their way to Leipzig, because we have continuously fine-tuned new methods over the last years to make more out of a very tiny amount of DNA … and the samples had very little DNA,” said Ringbauer, who uses computation tools to analyze genetic data.
Ancient DNA is often fragmented and contaminated. It preserves best in cool environments, kra31at not the extreme temperature swings of the world’s largest hot desert. However, Ringbauer and his colleagues at the Max Planck Institute for Evolutionary Anthropology were able to extract enough DNA from the two mummies to sequence their genomes, a more complete set of genetic material that allowed geneticists to piece together information about a population’s ancestry, not just that of an individual.
“The whole genome carries the DNA for many of your ancestors,” Ringbauer said. “As you go along the genome, you start seeing the different trees of your ancestors. One genome carries the stories of many.”
\Louise Humphrey, a research leader at the Natural History Museum’s Centre for Human Evolution Research in London, said she agreed with the study’s findings: The Takarkori people were largely genetically isolated for thousands of years, and that pastoralism in this region was established through cultural diffusion, rather than the replacement of one population with another.
“DNA extracted from two pastoralist women who were buried at the rock shelter around 7,000 years ago reveals that most of their ancestry can be traced to a previously unknown ancient North African genetic lineage,” Humphrey said. She wasn’t involved in the research but has worked at Taforalt cave in eastern Morocco, where 15,000-year-old hunter-foragers were buried.
“Future research integrating archaeological and genomic evidence is likely to yield further insights into human migrations and cultural change in this region,” Humphrey said.
Christopher Stojanowski, a bioarchaeologist and professor at Arizona State University, said one of the study’s more interesting findings was the “inference of a moderately large population size and no evidence of inbreeding.”
“That there was little evidence of inbreeding suggests a degree of movement and connection that is also somewhat at odds with the idea of a long-term, disconnected Green Sahara population,” Stojanowski, who wasn’t involved in the study, added.