Latest news with #UniversityofCopenhagen
Yahoo
3 days ago
- General
- Yahoo
2.2 million-year-old teeth reveal secrets of human relatives found in a South African cave
When you buy through links on our articles, Future and its syndication partners may earn a commission. Small pieces of tooth enamel from deep in a South African cave have begun to reveal secrets held for 2 million years by a distant human relative, a new study finds.. Archaeologists recovered teeth from four members of the species Paranthropus robustus, a two-legged human relative who lived between 1.8 million and 1.2 million years ago, from Swartkrans, a fossil-bearing cave in Africa's Cradle of Humankind World Heritage site. Using cutting-edge techniques that can analyze fossils' amino acid sequences, the researchers were able to determine the sex of the individuals and discovered surprising genetic variation that could point to the existence of a previously unknown species. These techniques are part of the field of proteomics, or studying sets of preserved proteins — a relatively new area of science that is shedding much-needed light on the evolution of early hominins, a group that includes humans and our closest relatives. "Figuring out the human family tree using proteins is the goal," Claire Koenig, a postdoctoral researcher at the University of Copenhagen and co-author of a study published Thursday (May 29) in the journal Science, told Live Science in an email co-written with lead author Palesa Madupe and co-author Ioannis Patramanis. But currently "our ability to distinguish between different species is limited by the small number of different proteins present in enamel." Although DNA has been recovered from ancient skeletons in Africa, so far that technique has only successfully worked on hominin material dating to no more than 20,000 years ago — well within the lifetime of our own species, Homo sapiens — because DNA degrades quickly in that environment. To get at the roughly 6 million-year history of hominin evolution, analysis of the harder and more stable tissue of dental enamel is needed. In the new study, an international team of researchers led by Madupe employed paleoproteomic analysis to move beyond the limits of ancient DNA and understand the genes of four hominins who lived around 2 million years ago. "Proteomics is inherently a destructive technique, but we take great care to minimize impact, especially when working with rare or precious specimens," Koenig said. Related: In a 1st, ancient proteins reveal sex of human relative from 3.5 million years ago The researchers focused their proteomic analysis on four P. robustus individuals who likely all died around the same time. They were able to identify AMELY-specific peptides, which are found in the tooth enamel of males, in two individuals. The other two individuals had a high AMELX intensity, meaning they were likely female. Correctly determining the sex of a fossil is important in paleoanthropology because most hominins are sexually dimorphic, with males being, on average, larger than females. Experts therefore expect that any species will have some larger and some smaller individuals. But Madupe and colleagues discovered a surprising result: one P. robustus individual who was thought to be female, based on tooth size and shape, was actually male, based on proteomic data. "Our results thus indicate that measurements of dental size are not necessarily accurate for correct sex estimation," the researchers wrote in the study. Since sex alone could not explain the differences in the appearance of P. robustus, the team investigated whether the diversity they were seeing could be the result of different groups or species they didn't know about, or the result of interbreeding, as P. robustus overlapped in time with australopithecines and early members of the Homo genus. The researchers found a couple amino acid sequence positions that varied among the P. robustus specimens they examined, and that were different from the amino acid sequences seen in present-day humans, Neanderthals and Denisovans. This analysis revealed that one of the individuals — SK-835, whose molecular sex and morphological sex did not match up — was more distantly related to the other three individuals than they were to each other. "It would be premature to classify SK-835 as a member of the newly proposed Paranthropus [capensis] taxa," Koenig said, but it remains a possibility that the amino acid difference reflects its position in a different species than the rest. It could also be explained, however, by microevolution at different sites, study co-author Rebecca Ackermann, a biological anthropologist at the University of Cape Town, told Live Science in an email. "We need to analyse more Paranthropus material from different sites to get a better handle on the variation within southern African Paranthropus," she said. RELATED STORIES —Smallest human relative ever found may have been devoured by a leopard 2 million years ago —What's the oldest known case of cancer in humans? —World's oldest human DNA found in 800,000-year-old tooth of a cannibal Because the enamel proteome is so much smaller — and provides less information — than a full genome, reconstructions of fossil human relatives need to be cautiously interpreted, Ackermann said. Koenig expects that further methodological developments will be beneficial, including less invasive methods such as acid etching to remove an extremely thin layer of dental enamel, and the development of faster and more sensitive protein-sequencing instruments. "It remains to be seen, for example, whether or not we can molecularly tell apart a Paranthropus robustus from an Australopithecus africanus," Koenig said, "because these species are closely related and therefore their proteins are going to look very similar."
Daily Maverick
3 days ago
- Science
- Daily Maverick
Ancient protein from pre-human teeth reveals genetic secrets of human evolutionary tree
Researchers have extracted 2 million-year-old protein remains from ancient pre-human teeth to reveal biological sex and genetic variability. Researchers have extracted 2 million-year-old protein remains from ancient pre-human teeth to reveal biological sex and genetic variability. The teeth are from Paranthropus robustus, an extinct hominin genus that emerged and evolved in Africa between 2.8 and 1.2 Ma. It is considered to be a side branch of our evolutionary tree. It walked on two legs and co-existed with early species of Homo in Africa, possibly interacting. The work, published in the journal Science, marks a significant breakthrough in human evolution studies. It provides some of the oldest human genetic data from Africa and reveals previously undetected genetic variability. 'Because we can sample multiple African Pleistocene hominin individuals classified within the same group, we're now able to observe not just biological sex but, for the first time, genetic differences that might have existed among them,' says the study's co-lead Palesa Madupe. Madupe is a postdoctoral research Fellow at the Globe Institute at the University of Copenhagen and research associate at the Human Evolution Research Institute (HERI) at the University of Cape Town. The researchers used a technique called palaeoproteomics to retrieve ancient protein sequences from the teeth of four Paranthropus robustus fossils recovered from the cave site Swartkrans. Solving the riddle Using state-of-the-art mass spectrometry techniques, they partially reconstructed the ancient enamel protein sequences from the teeth. They found that two of the fossils are male and two are female. But how was this done? Madupe explains: Among the proteins found in tooth enamel, there's one called amelogenin. This protein is unique because its genetic instructions are located on the sex chromosomes: biological females have a version called amelogenin X, while biological males have both amelogenin X and amelogenin Y. 'We used mass spectrometry to detect which protein fragments are present in the fossilised teeth we are analysing. The precise detection of amelogenin Y protein fragments allows us to confidently identify that specimen as belonging to a male individual. 'The challenge comes when we only detect amelogenin X protein fragments, as this could indicate either a female or a male individual whose amelogenin Y is not measured. 'To solve this, we developed a quantitative method for increasing certainty that the lack of amelogenin Y detection proves that those individuals are females.' Eventually, two were identified as male and two as female, just by tiny ancient proteins. Ancient diversity A single genetic variant in another protein, enamelin, was also identified that differentiated the four specimens from one another. Two specimens carried one version of the protein, a third carried another and a fourth specimen appeared to carry both. Their methodology allows for the partial recovery of the amino acid sequences of specific proteins from dental enamel. 'You can imagine this 'amino acid sequence' as a sequence of letters, with each letter corresponding to a specific amino acid [and with 20 possible letters to choose from for each position of the sequence]. An amino acid sequence is usually characteristic of a species; members of the same species will have the same sequence of letters for a protein. 'When we recovered and looked at the enamelin sequence of the four specimens, we saw that the sequences differed at one letter; they had 'a single genetic variant'.' Ioannis Patramanis and Claire Koenig, co-leads from the University of Copenhagen, explained that there are a number of reasons this difference could have occurred. For example, it could be that Paranthropus robustus has a high genetic diversity, or that the four samples belong to different populations or subspecies of Paranthropus, or that we sampled the same species but at different time points in its evolution. 'When studying proteins, specific mutations are thought to be characteristic of a species and, as such, used to identify it. We were thus quite surprised to discover that what we initially thought was a mutation uniquely describing Paranthropus robustus, was actually variable within that group; some individuals had it while others did not,' says Patramanis. The future and DNA HERI co-director Rebecca Ackermann was a senior author on the study, with contributions from co-director Robyn Pickering and several HERI research associates. 'Being able to accurately determine the sex of ancient fossils is a big breakthrough as it allows us to determine whether the variation we see in a sample is due to sexual dimorphism or other factors such as taxonomic diversity,' says Ackermann. 'This has the potential to help us understand sex-related differences in morphology and behaviour. It also provides some control for determining how many species are being sampled. It also may provide direct evidence for understanding the hominin family tree, though this is based on a very small amount of genetic information, so we need to be very cautious in these interpretations. 'Palaeoproteomics does give us insight into genetics, as DNA encodes proteins, so we can work backwards to reconstruct DNA sequences. 'But it's important to remember that the enamel proteome is very small, so this is just a tiny bit of genetic information. At this point, ancient proteins are our only genetic information for deep-time African fossils. 'DNA preservation is poor in African environments, and so far our time depth for understanding human evolution from ancient DNA in Africa is only about 20 thousand years. Only time will tell whether this can be pushed back further!' says Ackerman. DM
Yahoo
5 days ago
- Business
- Yahoo
You'll Spit Take When You Hear How Little Time Workers Are Saving With AI, According to This Huge New Study
The use of AI chatbots has exploded in the workplace. White-collar workers have adopted the tech in huge numbers. Executives are looking for every opportunity to shoehorn AI into every aspect of their businesses. Companies continue to pour tens of billions of dollars into building out enormous data centers to support increasingly power-hungry AI models. But is any of this actually leading to higher efficiency at work and increased pay? According to a recently-released working paper by a pair of economists at the University of Chicago and the University of Copenhagen that was spotted by Fortune, it's not looking great. After analyzing data about 25,000 workers across 7,000 workspaces, users of AI only saved on average three percent of time. And only a meager three to seven percent of those productivity gains translated into bigger paychecks, they found. Put simply, AI isn't even close to coming for everybody's jobs, a frequently cited fear — and it's not exactly making workers more productive, either, despite the industry's many reassurances. "While adoption has been rapid, with firms now heavily invested in unlocking the technological potential, the economic impacts remain small," the two economists wrote in their paper. "Our findings challenge narratives of imminent labor market transformation due to generative AI." As The Economist points out, while many pundits point to growing unemployment and blame AI, existing macroeconomic data suggests there are plenty of other reasons to blame. To the contrary, the magazine found that employment in white-collar work has actually risen in the past year. "Software, writing code, writing marketing tasks, writing job posts for HR professionals — these are the tasks the AI can speed up," coauthor Anders Humlum, at UChicago, told Fortune. "But in a broader occupational survey, where AI can still be helpful, we see much smaller savings." "I might save time drafting an email using a large language model, so I save some time there, but the important question is, what do I use that time savings for?' he added. "Is the marginal task I'm shifting my work toward a productive task?" What workers actually do with the tiny amounts of extra free time, courtesy of AI, isn't exactly comforting, either. More than 80 percent of workers in the study said they used saved time for more work. Less than ten percent said they took the time off. The findings "suggest that workers are not exactly knocking on the boss's door asking for more work," Humlum told Fortune. Signs that the impact of AI on the labor market has been overblown are certainly there. Earlier this year, Klarna CEO Sebastian Siemiatkowski admitted that his all-in approach to replacing human customer service agents with AI was not working. The company revealed last week that it's facing net losses of $99 million for the first quarter of this year, more than double compared to the same period last year. Last week, Duolingo CEO Luis von Ahn walked back his earlier promises to replace all contract workers with AI following an immense wave of customer blowback. Earlier this month, an IBM survey found that only a fraction of AI initiatives are delivering a return on investment after surveying 2,000 CEOs. These latest findings are an intriguing reality check for the notion that AI is coming for all of our jobs. Perhaps the tech is both making us efficient, but also failing to make us redundant. The conclusion highlights growing concerns that generative AI tech may be a dead end after all, as some experts have warned. Perhaps our jobs may be safe — other societal factors, like historic levels of economic uncertainty, notwithstanding. More on AI job automation: AI Is Replacing Women's Jobs Specifically
The Star
17-05-2025
- Health
- The Star
Scientists exploring how to beat heat for better sleep
Cool showers and less coffee or alcohol: sleep quality is being harmed by hotter temperatures caused by climate change, and scientists say we need to learn how to adapt. The human brain is very sensitive to heat, with higher temperatures raising the body's central thermostat and activating stress systems. Scientists are increasingly exploring mechanisms that can help the body adapt to rising temperatures affecting our sleep and leading to health complications. "Rising temperatures induced by climate change and urbanisation pose a planetary threat to human sleep, and therefore health, performance, and wellbeing," according to a 2024 review of scientific literature published in the journal Sleep Medicine. Humans lost an average of 44 hours of sleep a year during the first two decades of the 21st century compared to earlier periods, according to a 2022 study published in the journal One Earth, which linked the data to rising temperatures. The intensification of global warming could lead to an annual loss of 50 to 58 hours of sleep per person by 2099, according to research led by Kelton Minor, from the University of Copenhagen, based on data gathered from more than 47,000 individuals in 68 countries. "Interventional studies and field experiments are now urgently needed to foster adaptation and safeguard the essential restorative role of sleep in a hotter world," Minor and other authors of the paper said. Neurons regulating temperature and sleep in the brain are highly interconnected, and lowering the body's internal thermostat is key to improving sleep quality. Adapting to heat comes at a cost to the body, according to Fabien Sauvet, a researcher at Paris Cite University. "We sweat more and faster, for example, but it requires additional hydration. And it has limits, so during heatwaves, the most important thing is to adapt our behaviour," such as activities, schedules and clothing, Sauvet said. But humans could "tolerate higher temperatures than commonly thought", he added, pointing to several studies showing that good sleep quality can be achieved with a room temperature of up to 28 degrees Celsius (82.4 degrees Fahrenheit). Challenging "the false belief that the bedroom must be at 18-20C", he said that sleeping in light clothing such as a t-shirt and shorts, and with a simple sheet as well as good ventilation, could help dealing with a few more degrees. "If we always sleep with air conditioning, we will never acclimatise," he said. Fight 'sleep enemies' Armelle Rancillac, a neuroscientist at the Centre for Interdisciplinary Research in Biology, said anything beyond 28C "becomes much more complicated". An excessive lack of sleep is known to disrupt the body's recovery. In the short term, this can lead to drowsiness, fatigue and a higher risk of accidents at the workplace or on the road. In the long run, it can create a harmful sleep "debt", impacting our metabolism and increasing the risk of weight gain, diabetes, cardiovascular diseases and even neurodegenerative diseases like Alzheimer's, Rancillac said. A sleep deficit can also reduce stress resistance and have a negative impact on mental health. To sleep better in a hotter environment, Rancillac stressed that there is a need to "eliminate or at least pay attention to sleep enemies". Before bedtime, it is recommended to take a cool shower – but not an icy one – reduce stimulants like coffee, and limit alcohol, which facilitates falling asleep but slightly raises the internal body temperature. Avoid hot tubs after a workout, opting instead for outdoor temperatures or a cold bath, said Sauvet. Napping during the hottest hours of the day have also been proven to mitigate the impacts of a sleep deficit. Short naps – "30 to 40 minutes, and before 2:00 pm" – are ideal, so as not to interfere with a good night's sleep, according to the researcher. — AFP
The Star
16-05-2025
- Science
- The Star
Shaggy surprise on medieval books
MEDIEVAL scribes filled volumes called bestiaries with illustrations and descriptions of fantastic creatures. The manuscripts containing representations of these animals also depended on a menagerie of beasts: the covers of these and other volumes were fashioned from the skins of calves, goats, sheep, deer, pigs and – in some macabre instances – humans. Most of these hides were shorn before they were turned into book bindings. But one set of medieval manuscripts from northeastern France has a peculiar finish: its weathered covers are covered in clumps of hair. A manuscript created during the 12th or 13th century in the scriptorium of Clairvaux Abbey in France, found to be bound in sealskin. 'These books are too rough and far too hairy to be calfskin,' said Matthew Collins, a bioarchaeologist at the University of Copenhagen and Cambridge University and an author of the new study. But identifying the source of the shaggy leather has proved difficult. While these furry tomes would seem at home in a Hogwarts library, they were originally made in the scriptorium of Clairvaux Abbey, a hub for an order of Catholic monks, the Cistercians. The abbey, founded in 1115 in the Champagne-Ardenne region of France, was home to one of the largest monastic libraries in medieval Europe. Some 1,450 volumes of the abbey's extensive corpus survive. Roughly half of these manuscripts remain in their fragile, original bindings. Many were bound during the 12th and 13th centuries in the Romanesque style, which placed the parchment between wooden boards fastened with thread and cord. At Clairvaux Abbey, these Romanesque books were often housed inside a secondary cover that was bristled with fur. Traditionally, this unshorn leather was thought to be made from boar or deer. However, the hair follicles on some of the manuscripts do not match the fur of either mammal. Collins and his colleagues examined the hairy covers of 16 manuscripts that were once housed at Clairvaux Abbey. The researchers rubbed the flesh side of the leather with erasers to carefully remove crumb-size samples. They then utilised a range of techniques to analyse protein sequences and bits of ancient DNA from the leather. Their findings, published on April 2 in the journal Royal Society Open Science, reveal that the books are bound not in the hides of local land mammals, but in sealskin. Several of the books were bound in harbour seal skin, and at least one came from a harp seal. Comparing them with contemporary DNA suggests an origin of the seals in Scandinavia and Scotland, or potentially as far away as Iceland or Greenland. These disparate areas were once connected by a complex medieval trading network. In the Middle Ages, Norse traders harvested walrus ivory and pelts from Greenland and sent them to mainland Europe. While Clairvaux and its monks were far inland from these coastal outposts, the abbey was near a well-trafficked trading route. According to Mary Wellesley, a fellow at the Institute of Historical Research in London who specialises in medieval manuscripts and was not involved in the new paper, its findings shed light on medieval society. 'The small details of manuscripts can tell you so much about the world that created them,' Wellesley said. 'It's a popular assumption that people didn't move around, but these monastic institutions are part of this amazing network of goods, books and ideas.' A microscopic view of the hair fibres on one of the book covers from a French abbey, found to be bound in sealskin. — Matthew Collins and Elodie Leveque/The New York Times Seals were a valuable commodity because of their meat, blubber and waterproof skin, which could be fashioned into boots and gloves. Some records even claim that sealskin was used to pay church taxes. Coastal communities in Scandinavia and Ireland used sealskin to bind books, but the practice was much rarer in mainland Europe. Cistercian monks, though, appear to have had a fondness for sealskin books. Examples of these fur-covered manuscripts have been found in other abbeys that descended from Clairvaux. These monks even used the material to bind their most important documents, such as historical information about St Bernard, a major Cistercian figure. According to Collins, the colour of seal fur may explain the monks' penchant for using the animals' skins. While the manuscripts' covers are now yellowish-grey or splotchy brown, they were once encased in the white fur of seal pups. This shade matched the monks' undyed vestments. 'In medieval Europe, you don't really have anything that's pure white,' Collins said. 'It must have been quite magical.' The seals themselves likely seemed akin to magical entities to the monks: in medieval bestiaries, seals were labelled 'sea calves' and resemble dogs with fish tails, rather than pudgy pinnipeds. — ©2025 The New York Times Company This article originally appeared in The New York Times
