A new paper on ancient DNA (aDNA) posits that every person on the planet is descended from hunter-gatherers in Africa. The study was published last month in the journal Nature. In the paper, authors Elizabeth A. Sawchuk, Jessica C. Thompson, and more dive deep into their findings. According to ancient DNA, massive social changes 50,000 years ago helped shape the current state of people “living locally”.
Ancient DNA is shedding light on humanity’s past
In an article published on The Conversation, authors Elizabeth Sawchuk, Jessica Thomspon, and Mary Prendergast break down the study. The team of researchers included a total of 44 members. The researchers looked at ancient DNA from as far back as 18,000 years ago. This information, they say, has helped them understand more about how modern humans were moving and interacting with another in Africa long ago.
Africa is the cradle of human origins and ingenuity by man, including the creation of various ancient tools humans used. Between 80,000 and 60,000 years ago, though, Homo sapiens spread beyond Africa to other landmasses. This new study aimed to learn more about what happened after the spread, as well as why there hasn’t been more information about them before now.
By looking at ancient DNA discovered in Africa, the team was able to determine several things. First, people changed how they moved and interacted around the time of the Later Stone Age transition. Roughly 30,000 – 60,000 years ago, the Later Stone Age transition is a prominent feature of the archeological record in African studies. Many consider it the origin or dispersal of “modern humans.”
Based on the new aDNA they discovered, the researchers believe ancient people were descended from the same three populations. These populations are all related to present and ancient-day eastern, southern, and central Africans, the researchers say.
Something changed how humans interact 50,000 years ago
The connections the researchers found are intriguing. However, the researchers also discovered something else. They also found that something major happened around 50,000 years ago. This event changed how the people of Africa mixed and moved. Where the foragers had previously found partners away from their local areas, sometime around 20,000 years ago, most foragers in some regions were almost exclusively finding their partners in the local region. The researchers say this must have continued for some time, as the remains of ancient DNA didn’t appear to match with neighbors for several thousand years.
Despite learning more about the connection between all humans and those early African hunter-gatherers, the ancient DNA has only brought more questions. What happened to spur those foragers to start living more locally? The researchers aren’t sure just yet. What they do know, though, is that regionalization seems to have affected not only cultural traditions and stances but also the way that the genes flowed.
Unfortunately, finding these answers will take a lot of work. As the researchers note, Africa’s harsh, warm environment is a perfect killer for DNA. As such, finding new DNA records to study has been difficult. But the work doesn’t stop here. Luckily, researchers will continue to dig into ancient DNA to learn more about the past that helped shape modern-day humanity.