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Scientists are finally digging deep into African history and making discoveries

rock overhang.jpg
Jacob Davis, CC BY-ND
People took shelter in natural rock overhangs, leaving behind an archaeological record of their daily activities – and sometimes their graves. By digging carefully, archaeologists can connect information from aDNA to information about their social lives.

Historians know a lot more about ancient societies in Europe and Asia than they do about Africa, where human origin is traced. Part of the problem is DNA doesn't stand up to heat, but also, scientists say people haven't invested in learning about Africa.

One researcher invested in African research is Yale University Anthropologist Jessica Thompson. She is coauthor on a study on migration patterns. It's based on newly discovered DNA.

Ancient DNA Illuminates Early Social Connections in Africa

She and others found small fragments in the southeastern African country of Malawi. In one case, a single finger bone from an infant.

“I started working in a different part of Malawi in 2016, where I knew that there were rock shelters," says Thompson. "Those are overhangs of rocks where people would take refuge. Then underneath there, there’s like a little pocket of protection from the elements and you have much better preservation in these areas.”

Geneticists analyzed the DNA from these six new discoveries and 34 others who lived an estimated 500 to 20,000 years ago. Combined, she says, this is the largest genetic data set so far when studying hunters and gathers in Africa.

The sample bone powder containing DNA shows Africans traveled all over the continent initially but then became largely regional.

Jessica Thompson
Yale University Anthropologist Jessica Thompson on an excavation site in Malawi.

“This is a very, very, long story of widespread movement and then, ultimately, people are starting to spend more time closer to home,” says Thompson. "At the very least, what the genetic data tells us is they were choosing their mating partners closer to home.”

She continues, “Archaeologically, we see they are making artifacts that are much more regional in their design style. And who knows — we may be looking at the development of ethnolinguistic identities in this area.”

Thompson points to jewelry made out of ostrich eggs which were similar in southern and eastern Africa. About 30,000 years ago the styles of the beads changed. The hypothesis is there was a barrier to movement at that time. Possibly changing environments made it more economical to forage closer to home. Or maybe there were complex trade networks reducing the need to travel. This new research is based on discoveries from 44 scientists in 12 countries.

Jennifer Miller, CC BY-ND
Beads made from ostrich eggshells were hot trade items and can show the extent of ancient social networks.

For the research to expand, Thompson says more funding and collaboration is needed in Malawi. She looks forward to getting back there after a COVID hiatus.

With more than 30 years of journalism experience in the Greater Cincinnati market, Ann Thompson brings a wealth of knowledge and expertise to her reporting. She has reported for WKRC, WCKY, WHIO-TV, Metro Networks and CBS/ABC Radio. Her work has been recognized by the Associated Press and the Society of Professional Journalists. In 2019 and 2011 A-P named her “Best Reporter” for large market radio in Ohio. She has won awards from the Association of Women in Communications and the Alliance for Women in Media. Ann reports regularly on science and technology in Focus on Technology.