by Xinhua writers Hu Tao, Zhang Wenjing
LANZHOU, April 19 (Xinhua) -- Chinese archaeologists are using the latest technology to understand the lives of an ancient ancestor of human beings, based on a jawbone fossil found on the Qinghai-Tibet Plateau.
By studying the fossil and sediments from the Baishiya Karst Cave in which the fossil was discovered, researchers have identified the jawbone as belonging to an extinct species of archaic human named Denisovan hominins that had previously only been found in Siberia.
In addition to extending the known range of the Denisovans, the discovery provides evidence of pre-historic human activity on the Qinghai-Tibet Plateau at least 160,000 years ago, much earlier than the previous date of 40,000 years ago.
The research has also highlighted the valuable role of modern technology in resolving archaeological riddles that were previously beyond the scope of science.
In 2018, archaeologists from Lanzhou University started excavations at the Baishiya Karst Cave, with an altitude of more than 3,200 meters, in the northeastern portion of the Qinghai-Tibet Plateau.
Much of their research focused on a jawbone with human-like characteristics that hinted at pre-historic human activity in the area.
Collaborating with multiple institutions around the world, the Lanzhou University team employed a range of technologies, including analysis of proteins from one of the teeth and uranium-thorium decay dating of the carbonate crust on the fossil. They also analyzed mitochondrial DNA found in sedimentary materials excavated from the cave.
The findings confirmed a long-term occupation of the Denisovans on the Qinghai-Tibet Plateau, and confirmed their close relationship with the late Denisovans found in Siberia, while shedding light on the physical characteristics and way of life of these ancient humans.
"New technologies are now helping us to establish a complete and reliable age framework for this extinct human group," said Zhang Dongju, an archaeologist from the College of Earth and Environmental Sciences of Lanzhou University who led the research.
"Beyond that, they help us understand the Denisovans' stone-tool production technology, plant and animal utilization strategies, as well as their living environment and strategies for adapting," said Zhang.
The analysis of mitochondrial DNA in sediments has been particularly useful, according to Zhang, since it could provide reliable information of ancient humans who has occupied the archaeological sites where human fossils are hard or barely found.
The results of the study were published in the journal Science in October 2020, pulling together the joint efforts by institutions in China, Germany, Australia and the United States.
The research demonstrates the increasing role of new scientific tools and methods in Chinese archaeology, allowing researchers to reconstruct the lives and social scenes of the ancient human groups. By pulling together fragmented pieces of scientific data, researchers can now understand their life-span, physical morphological characteristics, gene sequences and diet etc.
"Our work is similar to that of criminal investigators," said Gao Xing, a researcher of the Institute of Vertebrate Paleontology and Paleoanthropology under the Chinese Academy of Sciences. "We use scientific and technological methods to obtain more and richer ancient information through fragmented materials and information."
By analyzing stable isotopes, for example, researchers can determine what humans ate and how they lived hundreds of thousands of years ago, according to Gao.
"The increasing intervention of science and technology in archaeology is effectively linking the past with today and the future, restructuring a more real and vivid human history," said Zhang.