Latest news with #Denisovans
The Independent
4 days ago
- General
- The Independent
Archaeologists finally crack origin mystery of Tibet's ‘ghost ancestors'
Archaeologists have discovered that the ancestors of the Tibetan people, including a mysterious group known as the 'ghost' population, came from China 's Yunnan province more than 7,100 years ago. Researchers say the discovery helps solve an important mystery about how humans spread across East Asia. Scientists studying ancient DNA from East and Southeast Asia know that humans started spreading across the continent at least 19,000 years ago and that they split into northern and southern branches early on. But there are significant gaps in our understanding of the genetic origin of modern populations such as the Tibetans. Tibetan people carry genes from northern East Asians but also from an unknown group – the 'ghost' population – which some archaeologists think may be linked to ancient humans such as the Denisovans or an early group of modern humans from Asia. Denisovans are 'an extinct group of archaic humans previously known mainly from remains discovered in Siberia and Tibet ', according to the European Research Council. Previous research has pointed to China 's Yunnan region as the key to understanding the origins of Tibetan as well as Austroasiatic populations, referring to ethnic communities in Southeast Asia who speak Austroasiatic languages like Vietnamese, Khmer, and Mon. Studies indicate that about 80 per cent of the genetic makeup of Tibetan people comes from northern Chinese populations who lived between 9,500 and 4,000 years ago. The ancestry of the remaining 20 per cent remains unclear and is referred to as Tibet 's 'ghost' population. In a new study, scientists sequenced DNA from over 125 individuals who lived in Yunnan between 7,100 and 1,500 years ago. They compared the ancient genomes to the DNA of modern Tibetans and found that one person who might belong to the 'ghost' group carried genes of both ancient and modern Tibetans. This 7,100-year-old individual from Yunnan was discovered to be as genetically distinct from most modern East Asians as a 40,000-year-old person from the area now known as Beijing, indicating a previously unknown Asian ancestry. Scientists say this individual is the first known potential representative of Tibet 's previously uncharacterised 'ghost' lineage. Researchers suspect this lineage likely diverged from other early Asian people over 40,000 years ago and managed to survive in southern regions due to more stable climates during the Ice Age. They discovered that a unique 'central Yunnan' ancestry, different from the known northern and southern East Asian groups, appeared some 5,500 years ago and helped shape the genes of people speaking Austroasiatic languages today. This ancestry seems to have emerged before the widespread adoption of agriculture in the region, suggesting demographic expansions likely preceded the spread of farming. The findings show that Yunnan was for long an important crossroads where different groups of people met and mixed. 'This study not only fills a critical gap in the genetic data of prehistoric populations in East and Southeast Asia but also identifies one of the Tibetan Plateau's 'ghost ancestors' for the first time from a genetic perspective,' researchers said.
Yahoo
26-05-2025
- Science
- Yahoo
Underwater Fossils Surface to Reveal a Lost World of Archaic Humans
An artificial island of sand dredged from Indonesia's seafloor has accidentally revealed evidence of a long-lost sunken world, inhabited by early humans. Scattered across the newly created island, scientists have uncovered more than 6,700 fossils of fish, reptiles, and mammals dredged from the deep, including the remains of two hominin skulls. This is the first discovery of ancient human fossils between the islands of Indonesia. The bones belong to Homo erectus – the longest surviving of all our human relatives. Until now, the only evidence of H. erectus in the region was confined to the island of Java. But as it turns out, this population was not so isolated after all. More than 130,000 years ago, when sea levels were 100 meters (328 feet) lower than today, it seems that H. erectus left the island of Java and lived among the valleys and plains of sunken 'Sundaland'. Sunda is the name for the largest drowned shelf in the world, and while it is now a shallow sea, in the past, it was occasionally a land bridge between the Asian mainland and the islands of Borneo, Sumatra, and Java. This means that H. erectus may have even come into contact with other human species living in Asia at the time, like Neanderthals or Denisovans. "Homo erectus could disperse from the Asian mainland to Java," says lead author and archaeologist Harry Berghuis from Leiden University in the Netherlands. "This makes our discoveries truly unique. The fossils come from a drowned river valley, which filled up over time with river sand. We have been able to date the material to approximately 140,000 years ago." At that time, experts suspect Sundaland resembled the African savannah. The fossils found on the artificial island included hippos, crocodiles, elephants, Komodo dragons, rhinos, big cats, and hoofed, ruminant animals, similar to bison or buffalo. Most are now extinct. Given the dry habitat of this prehistoric ecosystem, it is likely that H. erectus stuck to the rivers in Sundaland, which would have provided a perennial source of drinking water and fish. Experts suspect the hominin may have also taken advantage of large game that visited the waters. "Among our new finds are cut marks on the bones of water turtles and large numbers of broken bovid bones, which point to hunting and consumption of bone marrow," says Berghuis. "We didn't find this in the earlier Homo erectus population on Java, but do know it from more modern human species of the Asian mainland. Homo erectus may have copied this practice from these populations. This suggests there may have been contact between these hominin groups, or even genetic exchange." That's an interesting hypothesis, but further evidence is necessary. Past fossil finds on Java have led scientists to believe this island was the last stronghold for H. erectus – a hominin that journeyed out of Africa and across Asia in a decidedly impressive two-million-year run. By 400,000 years ago, however, H. erectus had gone extinct in Asia and Africa. Yet the species persisted on Java until around 108,000 years ago. It's a big win pulling the remains of H. erectus from the seabed off the coast of Java, but the fossils were found between a small and narrow strait separating two islands. How much further afield H. erectus travelled from Java is a mystery. "The answers may very well be at the bottom of the sea," write the authors. The research was published in four installments in Quaternary Environments and Humans here, here, here, and here. Scientists Discovered a Hidden Clue Why Men Are Taller Than Women Being Bored Could Actually Be Good For Your Brain, Scientists Reveal Couples Who Cuddle at Bedtime Have Lower Stress And Feel More Secure
Mint
25-05-2025
- Health
- Mint
A search for new antibiotics in ancient DNA
Buried in the DNA of the long extinct woolly mammoth is a compound that scientists hope will one day yield a lifesaving antibiotic. In experiments, mammuthusin, as the compound is called, has eradicated superbugs—bacteria that are resistant to today's antibiotics and cause infections that are hard to treat—says César de la Fuente, the bioengineer who helped discover the molecule. De la Fuente, a professor at the University of Pennsylvania, is among a group of scientists probing ancient and unlikely places—from genetic remnants of Neanderthals and extinct animals to unassuming backyard dirt—to find new antibiotics. He says the search is desperate: 'Antibiotic resistance is one of the greatest challenges we face as a society." Infections caused by superbugs contribute to the deaths of more than five million people globally each year, and that toll is growing. Antibiotics are increasingly losing potency against even common infections. Without new drugs, antibiotic resistance could kill some 39 million people by 2050, a study last year predicted. Now, fresh approaches to research are coming to an industry that has been slow to make new drugs and has been stymied by bacteria's ability to rapidly evolve defenses against those that exist. Most of the antibiotics we use today, and that have saved hundreds of millions of lives, were found in nature—many of them decades ago and several by accident. Alexander Fleming discovered penicillin in 1928 after returning from vacation and finding that mold on a petri dish had prevented harmful bacteria from growing. To help combat superbugs, doctors say we need new antibiotics with novel chemical structures or mechanisms of action. But only a handful of such drugs has entered the market over the past several decades. De la Fuente is banking on artificial intelligence to help end this dry spell. He and his collaborators have built deep-learning algorithms to comb through enormous genetic databases to find peptides, or protein fragments, that have antibacterial properties. They have used this method to analyze animal venoms, the human microbiome and archaea, an underexplored group of microorganisms. They have also mined the genetic codes from fossils of long-extinct animals and humans, including Neanderthals and Denisovans. 'This deep-learning model has opened a window into the past," de la Fuente says. Most antibiotics used today are small-molecule drugs, mostly derived from bacteria and fungi. Small molecules can usually penetrate cell membranes with ease and are commonly administered as pills. Peptides, made up of short chains of amino acids, are larger and more complex. They tend to be more unstable in the body and can't easily be made into pills. But advances have been made in recent years to improve the ability of peptide drugs—which include some IV antibiotics, GLP-1s and insulin—to be absorbed and used by the body. Antibacterial peptides are also plentiful in nature, as they are a part of the immune system in most organisms. 'Peptides are the next big thing in medicine," says de la Fuente, who launched a startup in January to further explore the antibiotic potential of mammuthusin and other peptides. When the algorithms identify a new peptide with antibiotic potential, de la Fuente and his team use robots to manufacture the compound in their lab and then test it in mice infected with bacteria. So far, a few hundred peptides made in de la Fuente's lab have safely and effectively cured sick mice. One of them was mammuthusin, identified in the genetic code of Mammuthus primigenius, a species of mammoth that last roamed the Earth about 4,000 years ago. The researchers discovered the peptide after mining a National Center for Biotechnology Information database of DNA sequencing data obtained from the fossils of extinct animals. In experiments, mammuthusin was as potent as polymyxin B, an antibiotic often used as a last resort for serious infections, according to a paper published in the journal Nature in June. The mammoth peptide effectively eradicated a type of bacterium that the World Health Organization has designated a critical pathogen because of its resistance to many common antibiotics. The work with extinct species is 'expanding the chemical space that we could explore," says James Collins, a bioengineer at the Massachusetts Institute of Technology. 'These are molecules that evolved in a different time and a different setting." Collins's lab has built its own algorithms to trawl chemical databases, such as those of existing pharmaceutical drugs, for potential antibacterial compounds. His lab is also experimenting with using generative AI to design completely new molecules that could kill bacteria. Collins and colleagues said in a 2024 paper that they had identified structurally unique antibiotics after analyzing more than 12 million chemical compounds. Modern scientific techniques could uncover new opportunities in old hunting grounds, says Gerry Wright, a biochemist at McMaster University in Canada. 'The way people found antibiotics in the past was they would go out and get something in the dirt," he says, referring to the fungi and bacteria that most antibiotics are derived from. Microbes have been waging war against one another for eons and have developed excellent defenses against one another. 'There haven't been any compounds better than those made in nature," Wright says. By the 1990s, however, scientists who were probing natural environments for antibiotics hit a wall: They kept finding the same antibiotic compounds again and again. 'People got frustrated," Wright says. 'It led to the misunderstanding that there was nothing more to find in these organisms." But by using genetic sequencing and chromatography, a technique to separate mixtures, researchers in Wright's lab have been able to analyze known microbes and find less-obvious antibacterial molecules that were previously missed. Patience has also proved fruitful. A researcher in Wright's lab took soil from a backyard in Ontario and extracted liquid from it that she kept in a petri dish under her bench for an entire year. Instead of adding nutrients to the dish and checking for organisms that grew quickly—long typical for antibiotic-hunting—she starved them and waited for rarer organisms to appear. One of these slow-growing species was found to pump out a common antibiotic—but more detailed analysis showed that it also produced a previously unknown antibacterial peptide. That peptide, which would be considered a structurally novel antibiotic, eradicated drug-resistant bacteria in mice, according to a March paper published in Nature. 'We are going back with different eyes and different techniques and discovering that there's still a lot of wealth to be found," Wright says. Write to Dominique Mosbergen at
The Irish Sun
06-05-2025
- Science
- The Irish Sun
Jaw of lost human cousin that's NOT Neanderthal found at bottom of sea with teeth intact & may only be 10,000 years old
THE mystery of a robust ancient jawbone with large teeth and what species it belongs to has baffled scientists since it was dredged up in the 2000s. But in a new study, scientists say the bone may belong to one of the most elusive of human ancestors - Denisovans. Advertisement 4 The bone, known scientifically as Penghu 1, was netted by a fisherman off the coast of Taiwan Credit: Yousuke Kaifu 4 Denisovans are a long-extinct human relative who lived at the same time as Neanderthals and Homo sapiens Credit: Yousuke Kaifu Paleoanthropologists have long debated whether the bone came from a Homo erectus, an archaic The bone, known scientifically as Penghu 1, was netted by a fisherman from the floor of the Penghu Channel, about 15.5 miles off the west coast of Taiwan. A technique that analyses the amino acids and proteins in bones found that the individual it belonged to was male, and most similar to Denisovans. "The same technique can and is being used to study other hominin fossils to determine whether they too are Denisovans, Neanderthals or other hominin populations," study co-author Frido Welker, a molecular anthropologist at the University of Copenhagen, told Advertisement READ MORE ON ARCHAEOLOGY Denisovans are a long-extinct human relative who lived at the same time as Neanderthals and Homo sapiens. The species roamed "It is now clear that two contrasting hominin groups – small-toothed Neanderthals with tall but gracile mandibles and large-toothed Denisovans with low but robust mandibles coexisted during the late Middle to early Late Pleistocene of Eurasia," the researchers wrote in the study published in Denisovan fossils remain elusive, so the entire species is shrouded in mystery. Advertisement Most read in Science Unlike Neanderthals, whose bones have been found throughout Europe and western Asia for more than a century, Denisovans are mostly known from DNA. Face of oldest direct human ancestor, which lived 3.8million years ago, revealed by scientists Only a handful of fossils have ever been found, most of which come from Denisova Cave in Siberia. Experts have struggled to identify new Denisovan skeletons without a large collection of fossils to compare to. Little is known, therefore, about where Denisovans lived and how they are related to humans. Advertisement Animal bones found alongside the Penghu 1 suggest it may also be the youngest fragment of a Denisovan ever discovered - trumping the current title holder by 30,000 years. Researchers were unable to use traditional methods such as carbon-14 or uranium dating on the bones because it was waterlogged for so long. DNA extraction attempts also failed. However, Welker explained that animal bones found with the jawbone suggest two age ranges - either 10,000 to 70,000 years ago or 130,000 to 190,000 years ago. Advertisement "If the specimen falls into the younger age range, it could potentially be the youngest Denisovan found to date," he said. Currently, the youngest Denisovan fossil, found on the Tibetan Plateau, is 40,000 years old. 4 A rough composite of a young girl who lived at Denisova Cave in Siberia in Russia 75,000 years ago Credit: MAAYAN HAREL 4 Denisovan fossils remain elusive, so the entire species is shrouded in mystery Credit: Cheng-Han Sun Advertisement
Scottish Sun
06-05-2025
- Science
- Scottish Sun
Jaw of lost human cousin that's NOT Neanderthal found at bottom of sea with teeth intact & may only be 10,000 years old
Denisovan fossils remain elusive, so the entire species is shrouded in mystery LOST AT SEA Jaw of lost human cousin that's NOT Neanderthal found at bottom of sea with teeth intact & may only be 10,000 years old Click to share on X/Twitter (Opens in new window) Click to share on Facebook (Opens in new window) THE mystery of a robust ancient jawbone with large teeth and what species it belongs to has baffled scientists since it was dredged up in the 2000s. But in a new study, scientists say the bone may belong to one of the most elusive of human ancestors - Denisovans. Sign up for Scottish Sun newsletter Sign up 4 The bone, known scientifically as Penghu 1, was netted by a fisherman off the coast of Taiwan Credit: Yousuke Kaifu 4 Denisovans are a long-extinct human relative who lived at the same time as Neanderthals and Homo sapiens Credit: Yousuke Kaifu Paleoanthropologists have long debated whether the bone came from a Homo erectus, an archaic Homo sapiens, or a Denisovan. The bone, known scientifically as Penghu 1, was netted by a fisherman from the floor of the Penghu Channel, about 15.5 miles off the west coast of Taiwan. A technique that analyses the amino acids and proteins in bones found that the individual it belonged to was male, and most similar to Denisovans. "The same technique can and is being used to study other hominin fossils to determine whether they too are Denisovans, Neanderthals or other hominin populations," study co-author Frido Welker, a molecular anthropologist at the University of Copenhagen, told Live Science. Denisovans are a long-extinct human relative who lived at the same time as Neanderthals and Homo sapiens. The species roamed Asia, from the chilly corners of Siberia to humid areas like Taiwan, during the Pleistocene era - between 2.6 million to 11,700 years ago. "It is now clear that two contrasting hominin groups – small-toothed Neanderthals with tall but gracile mandibles and large-toothed Denisovans with low but robust mandibles coexisted during the late Middle to early Late Pleistocene of Eurasia," the researchers wrote in the study published in Science. Denisovan fossils remain elusive, so the entire species is shrouded in mystery. Unlike Neanderthals, whose bones have been found throughout Europe and western Asia for more than a century, Denisovans are mostly known from DNA. Face of oldest direct human ancestor, which lived 3.8million years ago, revealed by scientists Only a handful of fossils have ever been found, most of which come from Denisova Cave in Siberia. Experts have struggled to identify new Denisovan skeletons without a large collection of fossils to compare to. Little is known, therefore, about where Denisovans lived and how they are related to humans. Animal bones found alongside the Penghu 1 suggest it may also be the youngest fragment of a Denisovan ever discovered - trumping the current title holder by 30,000 years. Researchers were unable to use traditional methods such as carbon-14 or uranium dating on the bones because it was waterlogged for so long. DNA extraction attempts also failed. However, Welker explained that animal bones found with the jawbone suggest two age ranges - either 10,000 to 70,000 years ago or 130,000 to 190,000 years ago. "If the specimen falls into the younger age range, it could potentially be the youngest Denisovan found to date," he said. Currently, the youngest Denisovan fossil, found on the Tibetan Plateau, is 40,000 years old. 4 A rough composite of a young girl who lived at Denisova Cave in Siberia in Russia 75,000 years ago Credit: MAAYAN HAREL
