Philippa Kaur

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    Ancient humans may have cooked and eaten snails 170,000 years ago

    A shell from a snail in the family Achatinidae, similar to those thought to have been cooked at Border Cave in South AfricaMarine Wojcieszak
    Broken bits of shells found in a cave in South Africa have given researchers the earliest evidence for prehistoric people roasting and eating snails.
    Other studies have pointed to snail consumption at sites in Europe around 30,000 years ago and in Africa around 40,000 years ago. “There is a huge gap from that to our findings,” says Marine Wojcieszak, who did the new work while … More

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    Hunter-gatherer genes gave European farmers an immunity boost

    Stone Age hunter-gatherers had children with farmers in EuropeAlamy Stock Photo
    The offspring of Stone Age farmers that settled in Europe inherited an unusually high share of immunity genes from local hunter-gatherers, suggesting that the development of farming wasn’t the sole reason early humans became more resistant to pathogens.
    It has long been thought that ancient farmers would have had improved immune systems over hunter-gatherers, due to living in more densely populated conditions and having closer contact with animals, increasing exposure to pathogens. As these farming populations expanded, their immunity genes would be best adapted and passed to their offspring.
    But the story is more complex than that. “These early farming groups came into Europe, bringing their lifestyle and technology, but there [were] also hunter-gatherers in Europe,” says Pontus Skoglund at the Francis Crick Institute in London, and the two populations mixed.Advertisement
    To learn more, Skoglund and his colleagues analysed the genomes of 677 ancient individuals from across western Eurasia, spanning from approximately 12,000 to 5000 years ago.
    The team divided the genomes into three groups: early farmers who had moved west from the region now occupied by Turkey and the Balkans, European hunter-gatherers and later individuals with mixed inheritance. “Fast forward a few millennia, and the remaining farming groups now have about 20 per cent of their ancestry that can be traced back to hunter-gatherers,” says Skoglund.
    But in a specific genome region, called the major histocompatibility complex (MHC), this split was closer to 50:50, suggesting that hunter-gatherer genes here were more favoured by selection processes. The MHC contains many genes for adaptive immunity, which is how the body targets specific pathogens, but exactly why the hunter-gatherer genes were selected for is unclear, says Skoglund.
    The simplest explanation is that hunter-gatherers may have been better adapted to pathogens in western Europe, so their genes provided an advantage once the farmers had settled there.
    But there is an alternative, thanks to a quirk of evolution that means groups that generally pass on a minority of their genes, like the hunter-gatherers, can provide more genes for functions where diversity is important, such as immunity – where the most successful offspring will be those that can survive a range of diseases.

    The MHC plays a large role in determining whether we can survive a particular infection, says Mark Thomas at University College London, who wasn’t involved in the work. “So, from an evolutionary point of view, it makes sense that we’re very diverse for MHC. It means we can fight off more pathogens,” he says.

    Topics:genetics/farming More

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    Why preserving your lemons in salt will make them even tastier

    The Picture Pantry/Alamy
    IS THERE any fruit more useful than a lemon? The citric acid in its juice can provide a touch of sharpness that improves a vast range of dishes. The fragrant oil concentrated in the peel of lemons has an aroma so appealing that we add it to cleaning products. It is also a good source of vitamin C: once its power to prevent scurvy was discovered in the 1750s, it led to a boom in demand for lemons.
    The family history of citrus fruits is complex and uncertain, but genomic studies suggest that lemons are a hybrid of a … More

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    in Space & Astronomy

    The mystery of Christiaan Huygens’ flawed telescopes may have been solved

    17th century scientist Christiaan Huygens set his sights on faraway Saturn, but he may have been nearsighted.

    Huygens is known, in part, for discovering Saturn’s largest moon, Titan, and deducing the shape of the planet’s rings. But by some accounts, the Dutch scientist’s telescopes produced fuzzier views than others of the time despite having well-crafted lenses.

    That may be because Huygens needed glasses, astronomer Alexander Pietrow proposes March 1 in Notes and Records: the Royal Society Journal of the History of Science.

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    To make his telescopes, Huygens combined two lenses, an objective and an eyepiece, positioned at either end of the telescope. Huygens experimented with different lenses to find combinations that, to his eye, created a sharp image, eventually creating a table to keep track of which combinations to use to obtain a given magnification. But when compared with modern-day knowledge of optics, Huygens’ calculations were a bit off, says Pietrow, of the Leibniz Institute for Astrophysics Potsdam in Germany.

    One possible explanation: Huygens selected lenses based on his flawed vision. Historical records indicate that Huygens’ father was nearsighted, so it wouldn’t be surprising if Christiaan Huygens also suffered from the often-hereditary affliction.

    Assuming that’s the reason for the mismatch, Pietrow calculates that Huygens had 20/70 vision: What someone with normal vision could read from 70 feet away, Huygens could read only from 20 feet. If so, that could be why Huygens’ telescopes never quite reached their potential. More

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    Cave paintings of mutilated hands could be a Stone Age sign language

    Hand stencils with missing digits at Cosquer cave in Marseille, FrancePatrick Aventurier/getty images
    DEEP inside Gargas cave in the Pyrenees mountains of southern France is something that has puzzled every visitor who has made the journey into its dark inner chambers. Among prehistoric paintings and engravings of horses, bison and mammoths are hundreds of stencils made tens of thousands of years ago by people spitting red and black paint over their outstretched hands. Such motifs are found at ancient sites around the world, from Australia to the Americas and from Indonesia to Europe. For years, archaeologists have wondered at their meaning. But those in Gargas are especially mysterious because around half of the hands appear to be injured.
    “It’s very obvious that some of the fingers are missing,” says Aritz Irurtzun at the National Centre for Scientific Research (CNRS) in Bayonne, France. So-called mutilated hands can be seen at many other prehistoric rock art sites, but Gargas cave is the most striking example of this phenomenon.
    It has been suggested that these missing fingers are the result of accidents, frostbite or ritual mutilation. Another possibility is that their creators deliberately folded away their fingers to produce specific patterns. Irurtzun and Ricardo Etxepare, also at CNRS, have now found a way to test this idea. What they have discovered convinces them that Gargas’s hand stencils reflect a Stone Age sign language. If so, these patterns add to a growing body of evidence suggesting that Palaeolithic cave paintings may contain a variety of hidden codes. The Gargas stencils could even represent the oldest … More

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    in Space & Astronomy

    A runaway black hole has been spotted fleeing a distant galaxy

    A streak of light stretching away from a remote galaxy might be the first sure sign of a gargantuan black hole on the run, a new study reports. The putative black hole, fleeing its host galaxy, appears to be leaving a trail of newborn stars and shocked gas in its wake. If confirmed, the intergalactic escape could help astronomers learn more about what happens to black holes when galaxies collide.

    “It’s a very cool, serendipitous discovery,” says astronomer Charlotte Angus of the University of Copenhagen, who was not involved in the new work. “The possibility that this might be due to a supermassive black hole that’s been ejected from its galaxy is very exciting. These events have been predicted by theory, but up until now, there’s been little evidence for them.”

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    While looking for colliding dwarf galaxies with the Hubble Space Telescope, astronomer Pieter van Dokkum and colleagues spotted something peculiar: a long, straight line that seemed to extend away from a distant galaxy, growing narrower and brighter as it went (SN: 5/18/22).

    “Whatever it is, we haven’t seen it before,” says van Dokkum, of Yale University. “Most astronomical objects are shaped like a spiral or a blob. There are not many objects that are just a line in the sky.” When astronomers do see lines, they’re usually from something moving, like a satellite crossing the telescope’s field of view (SN: 3/3/23).

    To figure out what it was, van Dokkum and colleagues took follow-up observations with the Keck Observatory in Hawaii. Those observations showed that the streak was associated with a galaxy whose light took about 8 billion years — more than half the age of the universe — to get to Earth, the team reports in a paper submitted February 9 to arXiv.org. The distance measurement let the team calculate the length of the line: roughly 200,000 light-years.

    That certainly ruled out a satellite.

    “We considered a lot of explanations, and the one that fit the best is what we’re witnessing is a massive object, like a black hole, moving very rapidly away from the galaxy,” van Dokkum says.

    The runaway black hole showed up as a straight line in a Hubble image (shown). The origin galaxy is at the top right of the streak. The galaxy is so far away that the line stretches for 200,000 light-years.P. van Dokkum et al/arXiv.org 2023

    Black holes on their own are invisible. But “if a black hole leaves a galaxy, it doesn’t leave by itself,” van Dokkum says. Some of the stars and gas that were gravitationally bound to the black hole leave with it. That gas will emit strong radiation that telescopes can detect. The black hole’s path through the gas and dust in the galaxy’s outer regions can compress some of that gas into new stars, too, which would also be visible (SN: 7/12/18).

    Another possibility is that the line is a jet of radiation launched by the galaxy’s central supermassive black hole. But that scenario would probably lead to a beam that is narrow when it is close to the galaxy and broadens as it gets farther away. This streak does the opposite.

    If it’s a black hole, it could have been ejected from the galaxy’s center by interacting with one or two other black holes nearby. Almost every galaxy has a supermassive black hole at its center. When galaxies merge, their central black holes also eventually merge (SN: 3/5/21). If the conditions are right, that merger can give the resulting black hole a “kick,” sending it flying away at high speed (SN: 4/25/22).

    Alternatively, the black hole could have been spat out of a smashup among three galaxies. When a third galaxy joins an ongoing merger, three supermassive black holes jockey for position. One black hole can be tossed out of the galactic smashup, while the other two take off more slowly in the other direction.

    That’s what van Dokkum thinks happened in this case. There are signs of a shorter, dimmer streak heading in the opposite direction from the bright, straight line.

    More observations of this system, perhaps with the James Webb Space Telescope, are needed to confirm that it really is an ejected supermassive black hole, Angus says. More theoretical calculations of what a runaway supermassive black hole should look like would help too.

    The finding motivates Angus to search through archived data for more potential black hole streaks. “I wonder if there are more of these features out there, sitting in someone’s data that might have just been missed,” she says.

    Van Dokkum does too. “Now that we know what to look for, these very thin streaks, it makes sense to go back to Hubble data. We have 25 years of Hubble images that have not been searched with this purpose,” he says. “If there are more to be found, I think we can do it.” More

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    Relics illuminate the wreck of HMS Gloucester, a 17th-century warship

    A 3D representation of the wreck site is shown in this photogrammetry image from the Maritime Archaeology Trust.Norfolk Historic Shipwrecks Ltd
    THIS intriguing selection of images documents a catastrophic shipwreck that, after more than 300 years, has had some of its relics brought to the surface. They will be showcased in a new exhibition, The Last Voyage of the Gloucester, by the University of East Anglia and Norwich Castle Museum and Art Gallery, both in the UK.
    1682 painting of the wreck by Johan Danckerts.Royal Museums Greenwich/Wikimedia Commons
    In 1682, the warship HMS Gloucester set sail for Edinburgh carrying the future King James II of England and Ireland, who was also King James VII of Scotland. Not long into its journey, the ship struck a sandbank off the Norfolk coast and sank. James survived, but some 250 people on board died.Advertisment

    It wasn’t until 2007 that the miraculously well-preserved shipwreck was discovered by brothers Julian and Lincoln Barnwell, who had spent years scuba diving in search of the vessel. However, the pair were unable to reveal their find until last year so it could be protected.
    The ship’s lifting tools on the seabed
    A 3D representation of the wreck site is shown in the main picture in a photogrammetry image from the Maritime Archaeology Trust.

    Pictured above: a pair of glasses in their case; and below two salt-glazed jugs, known as Bellarmine bottles; and a “Sun in Splendour” bottle. All were found at the site.
    Two salt-glazed jugs, known as Bellarmine bottles, left; and a “Sun in Splendour” rightNorfolk Historic Shipwrecks
    Pictured below the 65-kilogram bronze bell of HMS Gloucester.

    The exhibition is at Norwich Castle Museum and Art Gallery until 10 September.

    Topics:archaeology/ships More

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    Anaximander review: Did Anaximander create science, asks Carlo Rovelli

    Most of the ideas of Anaximander (second from right) have come to us through the writing of AristotleElla_Ca/shutterstock
    Anaximander and the Nature of ScienceCarlo Rovelli (translated by Marion Lignana Rosenberg)(Allen Lane)
    ASTRONOMY was conducted at Chinese government institutions for more than 20 centuries before Jesuit missionaries turned up and, somewhat bemused, pointed out that Earth is round. Why, after so much close observation and meticulous record-keeping, did 17th-century Chinese astronomers still think Earth was flat?
    Theoretical physicist Carlo Rovelli addresses this in Anaximander and the Nature of Science, … More