What if Homo erectus (H. erectus), the direct ancestor of modern humans, arrived in China much earlier than we thought? New research published in Science Advances on February 18, may rewrite our understanding of early human dispersal in that area.
A study by a team of geoscientists and anthropologists, including corresponding author Christopher J. Bae from the University of Hawaiʻi at Mānoa's Department of Anthropology in the College of Social Sciences , confirms that H. erectus appeared in Yunxian, China 1.7 million years ago, about 600,000 years earlier than previous studies indicated.
Prior to this study, which was funded by the National Natural Science Foundation of China and the U.S. National Science Foundation, the oldest Yunxian H. erectus fossils were reported to be about 1.1 million years old. The revised timeline reshapes one of the earliest chapters of human history, suggesting our ancestors spread across continents earlier—and possibly more successfully—than scientists once believed.
"While Homo erectus, our distant ancestor, is widely recognized to have originated in Africa before dispersing into Eurasia, the precise timeline of its arrival in eastern Asia was unknown," said Bae. "Using the combination of the Yunxian H. erectus fossils and burial dating data, we have now been able to recreate a fairly robust dating reconstruction of when these hominins appeared in eastern Asia."
Calculating burial data
The researchers used Aluminum-26 (Al-26) and Beryllium-10 (Be-10) burial dating to determine the age of the Yunxian fossils. Hua Tu, lead author, describes the method as using aluminum and beryllium isotopes in sediment from the same stratigraphic level as the fossils to determine when it was first buried and shielded from cosmic radiation.
"Al-26 and Be-10 isotopes are produced when cosmic rays hit quartz minerals. Once buried deeply underground, isotope production stops and radioactive decay takes over. By using aluminum's and beryllium's known decay rates, and comparing the ratio of the two types of atoms left in sediment samples surrounding a fossil, researchers can calculate how long a fossil has been buried. This is key as traditional Carbon-14 dating is limited to the last 50,000 years while the Al-26/Be-10 method allows researchers to accurately date materials as far back as 5 million years ago," said Tu, from the Institute of Marine Sciences, Shantou University and College of Geographical Sciences, Nanjing Normal University.
Related story: Possible new ancient human species uncovered by UH scientist , November 2024
Bae added, "These findings challenge long-held assumptions regarding when the earliest hominins are thought to have moved out of Africa and into Asia. While these results are significant, the mystery of exactly when H. erectus first appeared and last appeared in the region remains. If H. erectus was not the earliest occupant to reach Asia, alternative species must be considered. The updated chronology for Yunxian is a critical step toward resolving these debates."
In addition to Bae and Tu, other team members include:
- Xiaobo Feng: School of History and Culture, Shanxi University
- Lan Luo: Department of Physics and Astronomy, Purdue Rare Isotope Measurement Laboratory, Purdue University
- Zhongping Lai: Institute of Marine Sciences, Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University and Alpine Paleoecology and Human Adaptation Group (ALPHA), State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences
- Darryl Granger: Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
- Guanjun Shen: College of Geographical Sciences, Nanjing Normal University and Institute of Marine Sciences, Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University
The post Early human ancestor's journey to Asia happened sooner than believed first appeared on University of Hawaiʻi System News .
