Latest news with #radiocarbondating
Yahoo
14 hours ago
- Science
- Yahoo
Evidence is building that people were in the Americas 23,000 years ago
When you buy through links on our articles, Future and its syndication partners may earn a commission. The age of "rarely preserved" ancient human footprints dotting the landscape at White Sands National Park in New Mexico has been hotly debated for years. Now, a new study has found that these footprints really are around 23,000 years old — but the date isn't accepted by everyone. If the 23,000-year-old age is accurate, it would mean that humans were in North America around the peak of the Last Glacial Maximum, the coldest part of the last ice age — far earlier than archaeologists had previously thought. In the new study, the researchers radiocarbon-dated organic sediment in core samples from the site, which provided dates for the footprints as well as for the entire paleolake and river system that once existed there. The analysis was done in labs unaffiliated with earlier studies. "Our data supports the original data" that dated the site to 23,000 years ago, study first author Vance Holliday, a professor emeritus of anthropology and geosciences at the University of Arizona, told Live Science. "Plus, we now have an idea of what the landscape was like when people were out there." The saga of dating the roughly 60 footprints goes back to 2021, when a study reported the discovery of the footprints and dated them to between 21,000 and 23,000 years old. However, a 2022 rebuttal took issue with using the seeds of ditch grass (Ruppia cirrhosa), a water plant, for radiocarbon dating. Water plants get their carbon from underwater, which can be much older than carbon from the atmosphere. This can skew the levels of carbon 14, a radioactive version of the atom, in the samples, making the plants appear older than they really are. So, in 2023, researchers redated the site with optically stimulated luminescence (OSL) dating, which revealed when quartz or feldspar grains in the tracks were last exposed to sunlight, and radiocarbon dating of ancient conifer pollen from the footprint layer — which proved to be another way to use carbon 14 without relying on water plants. Related: The 1st Americans were not who we thought they were Again, the scientists found that the footprints were 21,000 to 23,000 years old. While some scientists called the results "very convincing," others, including those who wrote the 2022 rebuttal, were still wary of the results, saying the samples weren't taken from the right layer. Now, the new study offers more evidence that the footprints date to the Last Glacial Maximum, when the area was a vast wetland inhabited by ice age animals. The footprints likely came from hunter-gatherers who arrived in the Americas after traveling along the Bering Land Bridge, which connected Siberia and Alaska when sea levels were lower, research suggests. For decades, researchers thought the earliest Americans were the Clovis, who lived in North America around 13,000 years ago. But the footprint discovery and others are slowly revealing that Indigenous people reached the Americas much earlier than thought. Holliday has been working at White Sands since 2012, and some of his data was used in the original 2021 study, making him a co-author, he noted. This time, Holliday and his colleagues radiocarbon-dated mud cores from the site. They found that the trackways date to between 20,700 and 22,400 years ago, which closely matches the original dates. When added together, there are now a total of 55 radiocarbon-dated samples of mud, seeds and pollen from the footprint layer that support the 21,000- to 23,000-year-old dates, Holliday said. Ancient human footprints are "so rarely preserved," he said. And now, scientists have "dates on three different materials that all coincide" on a time for these tracks. "You get to the point where it's really hard to explain all this away," he said in a statement. "As I say in the paper, it would be serendipity in the extreme to have all these dates giving you a consistent picture that's in error." However, more work is needed to securely date the footprints at White Sands, said Michael Waters, director of the Center for the Study of the First Americans at Texas A&M University, who was not involved with the study. "Even with these new data, I remain concerned about the radiocarbon ages generated to date the footprints at White Sands," Waters told Live Science in an email. He reiterated the known Ruppia issue, saying the radiocarbon dates "are likely too old" because the plant got its carbon from the water. In fact, the same underwater carbon issues could have also affected the sediments dated in the new study, he said. "The new ages on bulk organic sediments presented in this paper are interesting, but it is unclear about the origin of the carbon being dated," Waters said. RELATED STORIES —13 of the oldest archaeological sites in the Americas —Ice age children frolicked in 'giant sloth puddles' 11,000 years ago, footprints reveal —How did humans first reach the Americas? Furthermore, Holliday and his colleagues acknowledge that their study doesn't address another hot-button issue: Where are the artifacts or settlements from these ice age people at White Sands? That question remains to be answered, Holliday said. But it's unlikely that hunter-gatherers would have left behind valuable items in the short time it took them to trek around the wetland. "These people live by their artifacts, and they were far away from where they can get replacement material," Holliday said in the statement. "They're not just randomly dropping artifacts. It's not logical to me that you're going to see a debris field."
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The Independent
05-06-2025
- Science
- The Independent
Dead Sea Scrolls mystery deepens as AI finds manuscripts to be much older than thought
Many of the manuscripts known as the Dead Sea Scrolls may be much older than previously thought, according to a new study that could transform our understanding of their Jewish and Christian origins. The mysterious scrolls are a collection of ancient Jewish texts mainly written in Hebrew that were found in 1947 by nomadic Arab shepherds looking for a lost sheep. They are the oldest Bible texts ever found, containing passages of the Old Testament from over 1,800 to 2,000 years ago. Until now, a study of ancient handwriting suggests most of the scrolls are from the third century BC to the second century AD. Some date-bearing manuscripts written in Aramaic/Hebrew have been estimated to be from the fifth or fourth centuries BC, and the late first and early second century AD. But since most of the scrolls do not have any other date-bearing manuscripts for reference, the ages of the individual manuscripts haven't been precisely estimated. Archaeologists have yet to accurately date over a thousand manuscripts and fragments from the Dead Sea Scrolls collection. Now, researchers have combined radiocarbon dating and an AI prediction model to arrive at a more accurate estimate of the age of individual manuscripts. Scientists found that two biblical scroll fragments of the scrolls come from the same time as their presumed biblical authors. These fragments have been objectively dated to between the fourth century BC and the second century AD, according to the latest study published in the journal PLOS One. In the study, scientists trained their AI date-prediction model to analyse handwritten ink-trace patterns and digitised manuscripts. The model was trained to analyse intricate geometries of the ink trace, looking into the curvature of each character's shape, helping it probe the texts beyond what traditional palaeography offered. Researchers cross-verified the AI model with texts that have already been convincingly dated. They found that it could predict the age of manuscripts just from the writing style with an uncertainty of some 30 years. Scientists then used the AI to date roughly one thousand Dead Sea manuscripts. They first made the model analyse the digitised images of 135 scrolls and let professional palaeographers evaluate the AI's predictions. It then confirmed that many Dead Sea Scrolls are much older than previously thought, transforming our understanding of the development of two ancient Jewish scripts called "Hasmonaean" and "Herodian." Scroll fragments written in these scripts could belong to the late second century BC instead of the current prevailing view of the mid-first century BC. Manuscripts in the Hasmonaean-type script could be older than their current estimate of 150 BC to 50 BC, researchers found. It still remains a mystery who exactly wrote the manuscripts. Researchers suspect it was an anonymous author from the Hellenistic period of the third century BC. The latest findings impact our understanding of political and intellectual developments in the eastern Mediterranean during the Hellenistic and early Roman periods, scientists say.
The Guardian
04-06-2025
- General
- The Guardian
Many of Dead Sea scrolls may be older than thought, experts say
Many of the Dead Sea scrolls could be older than previously thought, with some biblical texts dating from the time of their original authors, researchers say. The first of the ancient scrolls were discovered in the caves of Qumran in the Judean desert by Bedouin shepherds in the mid-20th century. The manuscripts range from legal documents to parts of the Hebrew Bible, and are thought to date from around the third century BCE to the second century CE. Now researchers have used artificial intelligence to glean fresh insights into the dates of individual scrolls – findings experts suggest could challenge ideas about when, where and by whom they were produced. 'It's like a time machine. So we can shake hands with these people from 2,000 years ago, and we can put them in time much better now, said Prof Mladen Popović, first author of the research from the University of Groningen in the Netherlands. While some scrolls were radiocarbon dated in the 1990s, Popović said scholars did not tackle the problem of castor oil contamination – a substance applied in the 1950s to help experts read the manuscripts, but which could skew results. In addition, many of the scrolls had only been dated by handwriting analysis. Writing in the journal Plos One, the team report how they attempted radiocarbon dating of 30 samples from different manuscripts found at four sites and thought to span five centuries. Crucially, the team first cleaned the samples to remove the castor oil contamination. The researchers successfully radiocarbon-dated 27 samples, finding that while two were younger than handwriting analysis had suggested, many were older. Among other findings, the researchers discovered two different writing styles, known as Hasmonean and Herodian scripts, coexisted for a much longer period than previously thought, while a sample from a manuscript called 4Q114 – which contains verses from the book of Daniel – was older than traditional palaeography had suggested. 'It was previously dated to the late second century BCE, a generation after the author of the Book of Daniel. Now, with our study we move back in time contemporary to that author,' said Popović. The team then used a type of AI known as machine learning to build a model they called Enoch – a nod to a biblical figure associated with scientific knowledge. The team trained Enoch by feeding it 62 digital images of ink traces from 24 of the radiocarbon dated manuscripts, together with the carbon-14 dates. They then verified the model by showing Enoch a further 13 images from the same manuscripts. In 85% of cases the model produced ages that tallied with the radiocarbon dates, and in many cases produced a smaller range of probable dates than obtained from radiocarbon dating alone. 'What we have created is a very robust tool that is empirically based – based on physics and on geometry,' said Popović. When Enoch was presented with images from 135 undated manuscripts it had not previously seen, it realistically dated 79% of them – as judged by expert palaeographers. Popović added those deemed unrealistic might have had problematic data, such as poor quality images. The system has already produced new insights including that a copy of the biblical book Ecclesiastes dates from the time of the book's presumed author. Popović said Enoch meant the age of further scrolls could now be uncovered without radiocarbon dating – a process that requires the destruction of small samples. 'There are more than 1,000 Dead Sea scrolls manuscripts so our study is a first but significant step, opening a door unto history with new possibilities for research,' he said. Prof emerita Joan Taylor of King's College London, said the results would have a major impact on Qumran studies. 'These results mean that most of the manuscripts found in the caves near Qumran would not have been written at the site of Qumran, which was not occupied until later,' she said. However, Dr Matthew Collins of the University of Chester cautioned that radiocarbon dating only shed light on the age of the parchment, not when it was written on, while there were also questions about how stylistically representative the small number of training samples were for different periods in time. 'Overall, this is an important and welcome study, and one which may provide us with a significant new tool in our armoury for dating these texts,' he said. 'Nevertheless, it's one that we should adopt with caution, and in careful conjunction with other evidence.'
