Latest news with #TianyiWang
Yahoo
5 days ago
- General
- Yahoo
Scientists Studied DNA From 7,100-Year-Old Remains—and Found a Mysterious Ghost Lineage
Here's what you'll learn when you read this story: Ancient DNA—from the bones of an individual found at an archaeological site in southern China—reveals the presence of a 'ghost lineage' connected to the peoples of Tibet. This ghost lineage remained uncharacterized until now, and after further analysis, it was determined to be unrelated to other lineages from the region. More sampling from ancient and modern people living in the region where this skeleton was found could reveal more about its origins and the origins of Tibetan groups in general. The Xingyi archaeological site in Central Yunnan, China, was the final resting place for many deceased, but paleoanthropologist Tianyi Wang was haunted by the skeletal remains of one Early Neolithic individual in particular. The remains, which once belonged to a woman who had been buried with her knees to her chin, had a secret—her 7,100-year-old bones deepened the mystery of a ghost lineage in Tibet's past. Ancient DNA is usually fragmented, with parts having degraded over hundreds (and often thousands) of years. But there was enough information in the genes of this particular individual to identify a lineage that had previously gone uncharacterized. When exactly this lineage diverged from other East Asian lineages is unknown, but it diverged deeply, and is ancestral to Tibet. Yunnan is located at the crossroads of southern China, southeast Asia, and the Tibetan plateau, making it an ideal place to research the genetic diversity of ancient peoples that now only live on in the ancestry of modern humans. Many questions have gone unanswered about the origins of existing East Asian populations—which include groups from the Tibetan Plateau and speakers of Austroasiatic languages predominantly spoken in Southeast Asian countries, such as Vietnam and Cambodia. The phantom lineage in Tibetan DNA is unrelated to any other. 'Some have suggested an archaic origin due to high frequencies of a Denisovan [lineage] in Tibetan populations and the physical presence of Denisovans on the plateau,' Wang and her team said in a study recently published in Science Advances. 'Others have proposed a modern origin related to Paleolithic Eurasians, including an early Asian lineage.' So far, no source population of the ghost lineage has been found, which makes it difficult to figure out from whom Tibetans originated. Ancient DNA from the Tibetan Plateau and the Himalayan arc between Tibet and the north of India was previously found to have East Asian ancestry from both the Yellow River Valley in lowland East Asia and the Amur River Valley in inner Mongolia. However, this ancestry are unrelated to the ghost lineage. It is unclear how populations in East and Southeast Asia shifted as hunting and foraging made way for the rise of agriculture. In mainland Southeast Asia, the ancestors of Australasian speakers are linked to agriculture and rice farming, since rice paddies thrive in the humid, tropical climate. The descendants of these ancient people now live in Southeast Asia, southern China, and India. Not enough genetic sampling has been done on the ancient populations of southern China, which may be part of the reason why the origins of the ghost lineage are so elusive. Radiocarbon dating on the bones of the Xingyi individual told researchers that she had lived 1,500 years earlier than others buried at the site. Genomic sequencing and DNA analysis revealed more about where, and who, she came from. Her ancestry was compared to many ancient human groups, and unsurprisingly, she has the closest links to both ancient and modern East and Southeast Asian populations. Her DNA was significantly different from ancient individuals from northern and southern China, who are related to modern East and Southeast Asians. Wang and her team think the ghost lineage she carries diverged from other populations in Asia some 40,000 years ago. During the Pleistocene epoch, when much of Earth froze over, people with this lineage must have survived in southern regions with a more stable climate. The Xiaodong rock shelter in Yunnan has a 43,500-year history of human occupation that they think could be linked with Asian ancestries that diverged deeply—possibly including the Tibetan ghost lineage. '[The Xingyi specimen] shows the existence of a second deeply diverged Asian population that lived in southern latitudes during the mid-Holocene and reveals […] ancestry that affected ancient and present-day Tibetan populations,' the team said. The ghost lineage took its secrets to the grave, and for now—even after the excavations—it seems to be keeping them there. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Miami Herald
02-06-2025
- Science
- Miami Herald
7,100-year-old skeleton reveals origins of ‘ghost' lineage in Tibetan Plateau
For tens of thousands of years, the people and cultures of southeast Asia have intertwined, moved around and diversified through time. The region, primarily encompassing modern-day China, is brought together today by shared language and culture, reflected now in their genetic makeup. But one group remains genetically isolated, separated geographically and culturally. The people of the Tibetan Plateau, an area also known as the Xizang Autonomous Region by the Chinese government and under the control of China, have what archaeologists have called a 'ghost ancestry,' researchers said in a study published May 29 in the peer-reviewed journal Science. Their genetic code varies 'significantly from modern East Asians,' researchers said in a May 29 news release from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences. Where and how this divergence occurred was a mystery, until the remains of a person from 7,100 years ago were found in Yunnan, China, according to the study. 'Nestled between the Tibetan Plateau, Southeast Asia, and southern China, the region known today as the Chinese province of Yunnan is home to the highest ethnic and linguistic diversity in China today. Ancient humans that lived in this region may be key to addressing several remaining questions on the prehistoric populations of East and Southeast Asia,' researchers said. The remains of a woman were found at the Xingyi archaeological site in central Yunnan, a site that dates to between 7,158 and 6,888 years ago, according to the study. The 7,100-year-old remains were included in an analysis of genomes from 127 ancient bodies found in the region, researchers said, but were distinct among the findings. The woman was found below all other layers of other burials, researchers said, and was dated to about 1,500 years older than the other remains. 'Although the individual genetically differed significantly from modern East Asians, the researchers noted that the individual's ancestry shared qualities similar to those of populations indigenous to the Qinghai-Tibet Plateau,' researchers said. 'This aligns with previous observations that these plateau populations have certain genetic characteristics that make them distinct from other present-day human groups.' Researchers called the finding a 'large piece of the puzzle,' because it explained that after an early Asian population separated in southwestern China around 40,000 years ago, it persisted in the region. Then, when humans migrated westward and north, the lineage went on to start the native Tibetan populations, according to the release. The lineage was named the 'Basal Asian Xingyi ancestry,' according to the study, and will help researchers learn more about the history of the Tibetan Plateau. Tibet is an autonomous region controlled by China, which is on Tibet's northern border. Yunnan Province in south-central China. The research team includes Tianyi Wang, Melinda A. Yang, Zhonghua Zhu, Minmin Ma, Han Shi, Leo Speidel, Rui Min, Haibing Yuan, Zhilong Jiang, Changcheng Hu, Xiaorui Li, Dongyue Zhao, Fan Bai, Peng Cao, Feng Liu, Qingyan Dai, Xiaotian Feng, Ruowei Yang, Xiaohong Wu, Xu Liu, Ming Zhang, Wanjing Ping, Yichen Liu, Yang Wan, Fan Yang, Ranchao Zhou, Lihong Kang, Guanghui Dong, Mark Stoneking and Qiaomei Fu.
