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?
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Gizmodo
2 days ago
- Gizmodo
Astronomers Discover Most Energetic Cosmic Explosions Ever Observed
Astronomers in Hawaii have discovered a new kind of explosion, and they're the most energetic stellar explosions ever recorded. Meet 'extreme nuclear transients' (ENTs): when supermassive black holes tear apart stars at least three times heavier than the Sun, triggering an immense release of energy. An international team of researchers describes the discovery of this newly observed phenomenon in a study published Wednesday in the journal Science Advances, shedding light on events that will help astronomers study the distant universe. 'We've observed stars getting ripped apart as tidal disruption events for over a decade, but these ENTs are different beasts, reaching brightnesses nearly ten times more than what we typically see,' Jason Hinkle, lead author of the study and PhD student at the Institute for Astronomy at the University of Hawaii, said in a W. M. Keck Observatory statement. Tidal disruptions consist of supermassive black holes tearing apart any star that wanders too close, so ENTs are a kind of tidal disruption. 'Not only are ENTs far brighter than normal tidal disruption events, but they remain luminous for years, far surpassing the energy output of even the brightest known supernova explosions,' he added. Their discovery took place almost by accident. While searching for enduring flares projecting from the center of galaxies in data from the European Space Agency's Gaia mission, Hinkle came across two strange signals from 2016 and 2018, which started a multi-year investigation. At the same time, two separate teams found a comparable flare from 2020 in an astronomical survey called the Zwicky Transient Facility (ZTF). More data from the W. M. Keck Observatory in Hawaii confirmed the 2020 event's similarity to the two Gaia events. Given that these events unleashed more energy than any supernova known to science, Hinkle and his colleagues concluded that they weren't your average stellar explosions. The enormous energy release and the shape of the event's light curves indicated the presence of a supermassive black hole actively absorbing material, a process called accretion. Unlike regular black hole accretion, however—which sees nearby matter heat up and project irregular light—the astronomers discovered that these astrophysical events clearly involve a supermassive black hole systematically shredding and eating a giant star. ENTs represent the most energetic known explosions in the universe. Gaia18cdj, the team's strongest documented ENT, released 25 times more energy than the most energetic supernovae known to science. More broadly, each ENT releases as much energy as 100 Suns would emit over their entire 10-billion-year lifespans. For comparison, a regular supernova usually unleashes similar amounts of energy to a single Sun. 'These ENTs don't just mark the dramatic end of a massive star's life,' Hinkle explained. 'They illuminate the processes responsible for growing the largest black holes in the universe.' ENTs are also at least 10 million times rarer than supernovae. Nevertheless, their massive energy outputs will prove to be extremely useful for astronomers studying far-away massive black holes. 'Because they're so bright, we can see them across vast cosmic distances—and in astronomy, looking far away means looking back in time,' said Benjamin Shappee, study co-author and Associate Professor at the University of Hawaii's Institute for Astronomy. 'By observing these prolonged flares, we gain insights into black hole growth during a key era known as cosmic noon, when the universe was half its current age when galaxies were happening places—forming stars and feeding their supermassive black holes 10 times more vigorously than they do today.' From theories of black holes leading to white holes to the suggestion that the universe might exist in a black hole and that supermassive black holes could replace particle colliders, the recent study joins a host of research shedding light on one of the most mysterious components of our universe.
Forbes
2 days ago
- Forbes
‘Biggest Booms Since The Big Bang' Found As Black Holes Shred Stars
Caption: Artist's concept of the formation of Extreme Nuclear Transients (ENTs). Astronomers have captured the most energetic explosions ever recorded in the universe since the big bang as massive stars get ripped apart by supermassive black holes. These Extreme Nuclear Transients, as they've been named, are a new class of rare and powerful cosmic explosions so bright they appear to release more energy than 100 supernovae (exploding stars). Black holes are such strong gravity that nothing can escape from them, not even photons of light. Supermassive black holes are the most massive type and reside at the centers of galaxies. While some of these black holes continuously consume gas and dust and glow for millions of years, others lie dormant — only revealing themselves when an unlucky star drifts too close. ENTs may be a glimpse into these otherwise unseen objects. 'We've observed stars getting ripped apart as tidal disruption events for over a decade, but these ENTs are different beasts, reaching brightnesses nearly ten times more than what we typically see,' said Jason Hinkle, a doctoral graduate of the University of Hawaii's Institute for Astronomy, who led the study published this week in Science Advances. These powerful events don't just flare and fade quickly. It can take over 100 days for an ENT to reach peak brightness and more than 150 days to dim to half its maximum. A tidal disruption event is when a star gets 'spaghettified' by a supermassive black hole, causing a brilliant flare, but an ENT is even more powerful. 'Not only are ENTs far brighter than normal tidal disruption events, but they remain luminous for years, far surpassing the energy output of even the brightest known supernova explosions," said Hinkle. These flares occur in the centers of galaxies and radiate more energy than any previously known event. At least 10 million times less frequent than supernovae, ENTs occur when massive stars — at least three times more massive than our sun — come too close to a supermassive black hole. A tidal disruption follows, tearing the stars apart and releasing more energy than 100 supernovae. What's different about them is their speed — ENTs allow astronomers to watch as a massive star is 'digested' over time by a supermassive black hole. 'These ENTs don't just mark the dramatic end of a massive star's life,' said Hinkle. 'They illuminate the processes responsible for growing the largest black holes in the universe.' Artist's concept of the formation of Extreme Nuclear Transients (ENTs). The research included data on the most energetic event yet recorded, an ENT named Gaia18cdj. A typical supernova emits about as much energy as the sun ever will over 10 billion years. Gaia18cdj emitted 25 times more energy than the most powerful supernova ever observed. The discovery came from scientists analyzing data from the European Space Agency's Gaia mission, which made three trillion observations of two billion stars while orbiting the sun between 2014 and 2025 when it ran out of fuel. It recorded unexplained flares in 2016 and 2018, with scientists discovering another — called ZTF20abrbeie and nicknamed 'Barbie' — in 2020, using data from the Zwicky Transient Facility survey telescope in California. Follow-ups were then made using data from other telescopes, including the Keck Observatory in Hawaii and NASA's Neil Gehrels Swift Observatory and WISE spacecraft. Artist's concept of the formation of Extreme Nuclear Transients (ENTs). Although all astronomy is looking back in time (even the sun's light is eight minutes old), the brightness of ENTs allows them to be seen over vast distances. That opens up the possibility of seeing them in a time called the 'cosmic noon,' when the universe was half its current age. This was "when galaxies were happening places — forming stars and feeding their supermassive black holes 10 times more vigorously than they do today,' said Benjamin Shappee, Associate Professor at IfA and co-author of the study. 'ENTs provide a valuable new tool for studying massive black holes in distant galaxies.' NASA's Nancy Grace Roman Space Telescope, launching as early as 2026, will use its infrared vision to catch these rare flashes from over 12 billion years ago — when the universe was just 10% of its current age — and help astronomers trace how black holes shaped galaxies over cosmic time. Wishing you clear skies and wide eyes.
Yahoo
2 days ago
- Yahoo
Experts sound alarm over hidden health risks at major sportswear factories: 'A consequence of low wages and poor working conditions'
An investigation has uncovered a disturbing pattern of fainting at Nike factories in Cambodia, even after decades of efforts to improve labor monitoring and working conditions. ProPublica broke down the dangerous working conditions faced by garment workers in Cambodia, including in factories like Y&W Garment that make or once made apparel for Nike. A medical worker at one factory told the nonprofit journalism organization that up to 10 people are too weak to work each month because of stifling conditions — with more than a dozen people affected monthly from May to June, when temperatures begin to ramp up. Around 57,000 people produce Nike goods in the Southeast Asian country. ProPublica cited news reports detailing mass fainting events — defined as either losing consciousness or becoming too weak or dizzy to perform duties — occurring in 2012, 2014, 2017, 2018, and 2019 at factories manufacturing products for the world's largest athletic apparel brand. Cambodian officials have attributed the fainting episodes to a combination of factors, including heat (the top weather-related killer), pesticide spraying, chemicals used in manufacturing, inadequate ventilation, and poor nutrition. Nike, Wing Luen Knitting Factory Ltd., and Haddad Brands — which workers at Y&W said manufactured Nike clothes — didn't respond to ProPublica's request for comment. Nike went to Cambodia to look into the situation in 2012 and asked international labor officials to intervene, as ProPublica noted. At the time, the company told the Guardian it considered the situation a "serious" matter and said it could indicate "issues within a factory that may require corrective action." However, workers at Y&W Garment, whose parent company is Wing Luen Knitting Factory Ltd., said fainting episodes continued during the two years their factory made Nike products, according to ProPublica. Jill Tucker, who headed the oversight group Better Factories Cambodia from 2011 to 2014, said the reports were not shocking. Tucker said it was "a consequence of low wages and poor working conditions that continue, even after decades of work on this issue," noting: "People work very hard for very little pay." Unfortunately, the problem is widespread, particularly in the fast-fashion industry, which rapidly produces apparel on the cheap and relies on consumers buying in mass quantities to keep up with ever-changing trends. What should the government do about the fast fashion industry? Set strict regulations Incentivize sustainable options Use both regulations and incentives Nothing Click your choice to see results and speak your mind. The industry doesn't only have a questionable human rights record — which is concerning enough on its own. It has also fueled an eye-popping volume of textile waste that mars otherwise stunning scenic areas and destroys ecosystems. Action to protect Cambodian garment workers began in 1999, as ProPublica noted, after President Bill Clinton signed a trade deal to boost the Southeast Asian nation's economy as it built back following the Cambodian genocide carried out in the 1970s by the communist political group Khmer Rouge. The idea was that the United States would increase its import quotas and American companies would feel comfortable operating in Cambodia if workers had better working conditions. However, those efforts seem to have fallen short, even though Nike, for its part, has withdrawn from Cambodia at times after reported violations, including when the BBC discovered children working for one of its suppliers. Nike has also relied on Better Factories Cambodia for oversight. Yet ProPublica also described Better Factories Cambodia's record as "mixed," reporting the group has raised the alarm about Cambodian factories' failures to adhere to labor laws, yet also given perfect marks for compliance when workers reported issues such as union busting. One of the best ways to hold brands accountable is to use your purchasing power to show that you support sustainable and ethical working conditions. Ditching fast fashion and building your wardrobe through thrifting and shopping ethical brands are options to consider. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
