New Genetic Studies Refine Timeline of Early Human Population Splits
Similar Articles
Australopithecus and Early Homo Shared Landscape 2.6 Million Years Ago
Ancient DNA Reveals Homo Erectus Interbred with Denisovans
Ancient Malaria Risk Influenced Human Settlement and Genetic Exchange
Ancient DNA Reveals Neanderthal Group Lived in Central-Eastern Europe 100,000 Years Ago
Ancient DNA Reveals Plague and Population Shift in Neolithic French Tomb
A 2023 study analyzing modern and ancient genomes suggests the earliest detectable population split among living humans occurred between 120,000 and 135,000 years ago. The research indicates that before this split, early human populations were loosely connected and exchanged genes for hundreds of thousands of years. A subsequent 2024 study found 9,000 years of genetic continuity in southernmost Africa, while ancient DNA reveals genetic variation not seen in people today.
Facts First
- The earliest detectable population split among living humans occurred 120,000–135,000 years ago, according to a 2023 model.
- Before this split, early human populations formed a 'weakly structured stem' with ongoing gene flow for hundreds of thousands of years.
- Only 1–4% of modern genetic differentiation traces back to variation between these ancestral stem populations.
- A 2024 study found 9,000 years of genetic continuity in southernmost Africa, based on ancient genomes.
- Ancient southern Africans carried genetic variation outside the range seen in living people, including Homo sapiens-specific variants.
What Happened
A 2023 study published in the journal Nature analyzed genome data from modern populations across southern, eastern, and western Africa. The research team utilized 44 newly sequenced genomes from modern Nama individuals, an Indigenous population in southern Africa with high genetic diversity, collected via saliva samples between 2012 and 2015. The best-fitting model from this study suggests the earliest population split detectable in living people occurred approximately 120,000 to 135,000 years ago. The study indicates that before this split, two or more weakly differentiated Homo populations exchanged genes for hundreds of thousands of years in a structure the researchers describe as a 'weakly structured stem.'
A subsequent 2024 study published in Nature Ecology & Evolution reported 9,000 years of genetic continuity in southernmost Africa. Another Nature study analyzed genomes from 28 ancient southern African individuals dated between 10,200 and 150 years before the present. This study found that ancient southern Africans carried genetic variation outside the range seen in living people and identified Homo sapiens-specific variants.
Why this Matters to You
This research refines the scientific understanding of human origins, which may influence how you see humanity's shared history and deep connections. The finding that only 1% to 4% of modern genetic differences trace back to these very ancient populations underscores the profound genetic unity of all people living today. This knowledge could gradually reshape public narratives about race and ancestry, potentially fostering a greater sense of shared heritage.
What's Next
Further genetic studies of diverse modern and ancient populations are likely to continue refining this model of early human history. The discovery of genetic variation in ancient individuals that is not present today suggests there is more ancestral diversity to uncover, which could lead to new insights into human adaptation and migration. Researchers may focus next on integrating this genetic data with archaeological and climatic records to build a more complete picture of our species' early development.