The Great London [Search results for Spain

  • Human Evolution: DNA from Neanderthal relative may shake up human family tree

    Human Evolution: DNA from Neanderthal relative may shake up human family tree

    In a remarkable technical feat, researchers have sequenced DNA from fossils in Spain that are about 300,000 to 400,000 years old and have found an ancestor—or close relative—of Neanderthals. The nuclear DNA, which is the oldest ever sequenced from a member of the human family, may push back the date for the origins of the distinct ancestors of Neanderthals and modern humans, according to a presentation here yesterday at the fifth annual meeting of the European Society for the study of human evolution.

    DNA from Neanderthal relative may shake up human family tree
    DNA from these fossilized bones and teeth in a Spanish cave are providing
     clues about the origins of Neanderthals and modern humans 
    [Credit: J.-J. Hublin; Royal Museum For Central Africa,
     Tervuren, Belgium]

    Ever since researchers first discovered thousands of bones and teeth from 28 individuals in the mid-1990s from Sima de los Huesos (“pit of bones”), a cave in the Atapuerca Mountains of Spain, they had noted that the fossils looked a lot like primitive Neanderthals. The Sima people, who lived before Neanderthals, were thought to have emerged in Europe. Yet their teeth, jaws, and large nasal cavities were among the traits that closely resembled those of Neanderthals, according to a team led by paleontologist Juan-Luis Arsuaga of the Complutense University of Madrid. As a result, his team classified the fossils as members of Homo heidelbergensis, a species that lived about 600,000 to 250,000 years ago in Europe, Africa, and Asia. Many researchers have thought H. heidelbergensis gave rise to Neanderthals and perhaps also to our species, H. sapiens, in the past 400,000 years or so.

    But in 2013, the Sima fossils’ identity suddenly became complicated when a study of the maternally inherited mitochondrial DNA (mtDNA) from one of the bones revealed that it did not resemble that of a Neanderthal. Instead, it more closely matched the mtDNA of a Denisovan, an elusive type of extinct human discovered when its DNA was sequenced from a finger bone from Denisova Cave in Siberia. That finding was puzzling, prompting researchers to speculate that perhaps the Sima fossils had interbred with very early Denisovans or that the “Denisovan” mtDNA was the signature of an even more ancient hominin lineage, such as H. erectus. At the time, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who had obtained the mtDNA announced that they would try to sequence the nuclear DNA of the fossils to solve the mystery.

    After 2 years of intense effort, paleogeneticist Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology has finally sequenced enough nuclear DNA from fossils of a tooth and a leg bone from the pit to solve the mystery. The task was especially challenging because the ancient DNA was degraded to short fragments, made up of as few as 25 to 40 single nucleotides. (Nucleotides—also known as base pairs—are the building blocks of DNA.) Although he and his colleagues did not sequence the entire genomes of the fossils, Meyer reported at the meeting that they did get 1 million to 2 million base pairs of ancient nuclear DNA.

    DNA from Neanderthal relative may shake up human family tree
    Researchers have spent decades studying the remains found in the 'Pit of Bones', 
    reconstructing the skull shown above, which revealed it had suffered a 
    heavy blow to the head before death [Credit: msf]

    They scanned this DNA for unique markers found only in Neanderthals or Denisovans or modern humans, and found that the two Sima fossils shared far more alleles—different nucleotides at the same address in the genome—with Neanderthals than Denisovans or modern humans. “Indeed, the Sima de los Huesos specimens are early Neanderthals or related to early Neanderthals,” suggesting that the split of Denisovans and Neanderthals should be moved back in time, Meyer reported at the meeting.

    Researchers at the meeting were impressed by this new breakthrough in ancient DNA research. “This has been the next frontier with ancient DNA,” says evolutionary biologist Greger Larson of the University of Oxford in the United Kingdom.

    The close affinity with Neanderthals, but not with Denisovans or modern humans, suggests that the lineage leading to Neanderthals was separate from other archaic humans earlier than most researchers have thought. That means that the ancestors of modern humans also had to split earlier than expected from the population that gave rise to Neanderthals and Denisovans, who were more closely related to each other than they were to modern humans. (Although all three groups interbred at low levels after their evolutionary paths diverged—and such interbreeding may have been the source of the Denisovan mtDNA in the first Sima fossil whose DNA was sequenced.) Indeed, Meyer suggested in his talk that the ancestors of H. sapiens may have diverged from the branch leading to Neanderthals and Denisovans as early as 550,000 to 765,000 years ago, although those results depend on different mutation rates in humans and are still unpublished.

    That would mean that the ancestors of humans were already wandering down a solitary path apart from the other kinds of archaic humans on the planet 100,000 to 400,000 years earlier than expected. “It resolves one controversy—that they’re in the Neanderthal clade,” says paleoanthropologist Chris Stringer of the Natural History Museum in London. “But it’s not all good news: From my point of view, it pushes back the origin of H. sapiens from the Neanderthals and Denisovans.” The possibility that humans were a distinct group so early shakes up the human family tree, promising to lead to new debate about when and where the branches belong.

    Author: Ann Gibbons | Source: ScienceMag/AAAS [September 11, 2015]

  • Great Legacy: Egypt receives ancient stolen limestone relief from UK

    Great Legacy: Egypt receives ancient stolen limestone relief from UK

    Egypt's embassy in London received a limestone relief that had been stolen from Queen Hatshepsut's temple in Luxor, the Ministry of Antiquities said.

    Egypt receives ancient stolen limestone relief from UK
    The recovered relief [Credit: Egypt Ministry of Antiquities]

    Shaaban Abdel Gawad, general supervisor of the ministry's antiquities repatriation department, in a statement said that the ministry repatriated the relief in collaboration with the Ministry of Foreign Affairs and the British Museum after proving its possession. The recovery of the relief is "very important" especially since it will help in restoration work currently being carried out by a Polish archaeological mission, he said.

    The relief, which is carved in limestone and engraved with hieroglyphic symbols, was stolen from the temple in 1975 and smuggled out of the country, he said. It was put on show in an auction hall in Spain and a British antiquities dealer bought it, the statement said.

    Last year, U.S. officials returned dozens of illegally smuggled artifacts to Egypt, including a Graeco-Roman style Egyptian sarcophagus.

    Source: The Associated Press [December 20, 2016]

  • Environment: Wildfire on warming planet requires adaptive capacity at local, national, international scales

    Environment: Wildfire on warming planet requires adaptive capacity at local, national, international scales

    Industrialized nations that view wildfire as the enemy have much to learn from people in some parts of the world who have learned to live compatibly with wildfire, says a team of fire research scientists.

    Wildfire on warming planet requires adaptive capacity at local, national, international scales
    A locale in the French Western Pyrenees, where communities practice fire management to maintain seasonally flammable 
    grassland, shrub and woodland patches for forage and grazing animals [Credit: Michael Coughlan]

    The interdisciplinary team say there is much to be learned from these "fire-adaptive communities" and they are calling on policy makers to tap that knowledge, particularly in the wake of global warming.

    Such a move is critical as climate change makes some landscapes where fire isn't the norm even more prone to fire, say the scientists in a new report published in a special issue of the >Philosophical Transactions of the Royal Society B.

    "We tend to treat modern fire problems as unique, and new to our planet," said fire anthropologist Christopher Roos, Southern Methodist University, Dallas, lead author of the report. "As a result, we have missed the opportunity to recognize the successful properties of communities that have a high capacity to adapt to living in flammable landscapes—in some cases for centuries or millennia."

    One such society is the ethnically Basque communities in the French Western Pyrenees, who practice fire management to maintain seasonally flammable grassland, shrub and woodland patches for forage and grazing animals. But the practice is slowly being lost as young people leave farming.

    Additionally, Aboriginal people in the grasslands of Western Australia use fire as part of their traditional hunting practices. Children begin burning at a very young age, and the everyday practice is passed down. These fires improve hunting successes but also reduce the impact of drought on the size and ecological severity of lightning fires.

    Social institutions support individual benefits, preserve common good

    Fire-adaptive communities have social institutions in place that support individual benefits from fire-maintained landscapes while preserving the common good, said Roos, whose fire research includes long-term archaeological and ecological partnerships with the Pueblo of Jemez in New Mexico.

    "These institutions have been shaped by long-histories with wildfire, appropriate fire-use, and the development of social mechanisms to adjudicate conflicts of interest," said Roos, an associate professor in the SMU Department of Anthropology. "There is a wealth of tried and tested information that should be considered in designing local fire management."

    The authors note that globally, a large number of people use fire as a tool to sustain livelihoods in ways that have been handed down across many generations. These include indigenous Australians and North Americans, South Asian forest dwellers, European farmers, and also hunters, farmers and herders in tropical savannahs.

    Global Warming will likely bring new fire problems, more flammable landscapes

    Global Warming will likely bring new fire problems, such as making some landscapes more flammable, Roos said. More effort will be required to balance conflicting fire management practices between adjacent cultures. Currently most fire-related research tends to be undertaken by physical or biological scientists from Europe, the United States and Australia. Often the research treats fire challenges as exclusively contemporary phenomena for which history is either absent or irrelevant.

    "We need national policy that recognizes these dynamic challenges and that will support local solutions and traditional fire knowledge, while providing ways to disseminate scientific information about fire," Roos said.

    The authors point out that one of the greatest policy challenges of fire on a warming planet are the international consequences of smoke plumes and potential positive feedbacks on climate through carbon emissions. Most infamously, wildfire smoke plumes have had extraordinary health impacts during Southeast Asian "haze" events, which result in increased hospitalization and mortality in the region.

    Not all fire is a disaster; we must learn to live with and manage fire

    Carbon emissions from wildfires can be as much as 40 percent of fossil fuel emissions in any given year over the last decade. Although only deforestation fires and land conversion are a net carbon source to the atmosphere, the contribution of wildfires to global carbon emissions is non-trivial and should be a formal component of international climate dialogs.

    "It is important to emphasize that not all fire is a disaster and we must learn how to both live with as well as manage fire," said co-author Andrew Scott, earth sciences professor at Royal Holloway University of London.

    The report, "Living on a flammable planet: interdisciplinary, cross-scalar and varied cultural lessons, prospects and challenges," was published May 23, 2016 by The Royal Society, the U.K.'s independent scientific academy.

    Authors call for holistic study of fire on Earth

    The authors are from the United States, Great Britain, Canada, Australia, South Africa and Spain. The synthesis emerged from four days of international meetings sponsored by the Royal Society - the first of its kind for fire sciences.

    The authors advocate for greater collaboration among researchers studying all aspects of fire.

    Pyrogeography—the holistic study of fire on Earth, "may be one way to provide unity to the varied fire research programs across the globe," the authors write.

    "Fire researchers across disciplines from engineering, the natural sciences, social sciences and the humanities need to develop a common language to create a holistic wildfire science," said Roos. "The magnitude of the wildfire challenges we face on a warming planet will demand greater collaboration and integration across disciplines, but our job won't be done unless we are also able to translate our research for policymakers, land managers, and the general public."

    Source: Southern Methodist University [June 01, 2016]

  • Breaking News: Complex genetic ancestry of Americans uncovered

    Breaking News: Complex genetic ancestry of Americans uncovered

    By comparing the genes of current-day North and South Americans with African and European populations, an Oxford University study has found the genetic fingerprints of the slave trade and colonization that shaped migrations to the Americas hundreds of years ago.

    Complex genetic ancestry of Americans uncovered
    A 1770 painting showing Spanish, Peruvian and mixed-race people
    [Credit: WikiCommons]

    The study published in Nature Communications found that:

    • While Spaniards provide the majority of European ancestry in continental American Hispanic/Latino populations, the most common European genetic source in African-Americans and Barbadians comes from Great Britain.
    • The Basques, a distinct ethnic group spread across current-day Spain and France, provided a small but distinct genetic contribution to current-day Continental South American populations, including the Maya in Mexico.
    • The Caribbean Islands of Puerto Rico and the Dominican Republic are genetically similar to each other and distinct from the other populations, probably reflecting a different migration pattern between the Caribbean and mainland America.
    • Compared to South Americans, people from Caribbean countries (such as the Barbados) had a larger genetic contribution from Africa.
    • The ancestors of current-day Yoruba people from West Africa (one of the largest African ethnic groups) provided the largest contribution of genes from Africa to all current-day American populations.
    • The proportion of African ancestry varied across the continent, from virtually zero (in the Maya people from Mexico) to 87% in current-day Barbados.
    • South Italy and Sicily also provided a significant European genetic contribution to Colombia and Puerto Rico, in line with the known history of Italian emigrants to the Americas in the late 19th and early 20th century.
    • One of the African-American groups from the USA had French ancestry, in agreement with historical French immigration into the colonial Southern United States.
    • The proportion of genes from European versus African sources varied greatly from individual to individual within recipient populations.

    The team, which also included researchers from UCL (University College London) and the Universita' del Sacro Cuore of Rome, analysed more than 4,000 previously collected DNA samples from 64 different populations, covering multiple locations in Europe, Africa and the Americas. Since migration has generally flowed from Africa and Europe to the Americas over the last few hundred years, the team compared the 'donor' African and European populations with 'recipient' American populations to track where the ancestors of current-day North and South Americans came from.

    'We found that the genetic profile of Americans is much more complex than previously thought,' said study leader Professor Cristian Capelli from the Department of Zoology.

    The research team analysed DNA samples collected from people in Barbados, Columbia, the Dominican Republic, Ecuador, Mexico, Puerto Rico and African-Americans in the USA.

    They used a technique called haplotype-based analysis to compare the pattern of genes in these 'recipient populations' to 'donor populations' in areas where migrants to America came from.

    'We firstly grouped subsets of people in Africa and Europe who were genetically similar and used this fine scale resolution to find which combinations of these clusters resulted in the sort of mixtures that we now see in people across the Americas', said the study's first author, Dr Francesco Montinaro from the Department of Zoology.

    'We can see the huge genetic impact that the slave trade had on American populations and our data match historical records', said study author Dr Garrett Hellenthal from the UCL Genetics Institute, 'The majority of African Americans have ancestry similar to the Yoruba people in West Africa, confirming that most African slaves came from this region. In areas of the Americas historically under Spanish rule, populations also have ancestry related to what is now Senegal and Gambia. Records show that around a third of the slaves sent to Spanish America in the 17th Century came from this region, and we can see the genetic evidence of this in modern Americans really clearly.'

    These genetic findings also uncover previously unknown migration. ‘We found a clear genetic contribution from the Basques in modern-day Maya in Mexico’, said Professor Capelli. ‘This suggests that the Basque also took part in the colonisation of the Americas, coming over either with the Spanish conquistadores or in later waves of migration’.

    'The differences in European ancestry between the Caribbean islands and mainland American population that we found were also previously unknown. It is likely that these differences reflect different patterns of migration between the Caribbean and mainland America.'

    'These results show just how powerful a genetic approach can be when it comes to uncovering hidden patterns of ancestry. We hope to use the same approach to look at other populations with diverse genetic contributions, such as Brazilians,' said Professor Capelli.

    Source: University of Oxford [March 24, 2015]

  • UK: Roman fresco unearthed in London

    UK: Roman fresco unearthed in London

    An ornate fresco that once adorned the residence of a wealthy Roman citizen has been discovered by a team of archaeologists at 21 Lime Street, in London.

    Roman fresco unearthed in London
    A section of a decorative fresco, dating to the 1st-century AD 
    Roman Britain [Credit: (c) MOLA]

    Archaeologists from the Museum of London Archaeology (MOLA) uncovered the fresco six metres below street level, whilst undertaking archaeological fieldwork for a new office development. Dating to the late 1st century AD, and the first decades of London, it is one of the earliest surviving frescos from Roman Britain.

    Thanks to a huge Roman construction project, the fate of this rare wall painting was literally sealed in the ground. In AD 100, construction of the 2nd Forum Basilica, the main civic centre for the city and the largest Roman building ever built north of the Alps, began. In advance of construction of the Forum the area was flattened. The painted wall was deliberately toppled and the Forum immediately built over it, incredibly preserving the fresco for nearly 2000 years.

    Roman fresco unearthed in London
    The Roman fresco is more than 2m wide and 1.5 metres high 
    [Credit: (c) MOLA]

    Discovered face down, the fresco was identified from the distinctive markings of the keyed daub onto which the plaster was attached. The fragile remains, surviving to a width of nearly 2.5 metres and a height of over 1.5 metres, were carefully removed from the site by archaeological conservators, who lifted the fresco in 16 sections.

    Each section was supported, undercut and block lifted so that soil encased and protected the plaster. Back in the lab the conservators worked quickly to micro-excavate the soil whilst it was still damp, to expose the millimetre-thin painted surface beneath.

    Roman fresco unearthed in London
    Conservators from MOLA removing a section of the 1st century 
    upturned Roman wall plaster [Credit: (c) MOLA]

    The painting is likely to have decorated a reception room where guests were greeted and entertained. Building materials specialists will study the elaborate fresco further to learn more about the fashions and interiors favoured by London’s first wealthy citizens.

    The central section, on a background of green and black vertical panels, depicts deer nibbling trees, alongside birds, fruit and a vine woven around a candelabrum. Red panels, bordered with cream lines, surround the main decorative scheme.

    Roman fresco unearthed in London
    Tiles that sat below the London's Roman Forum 
    in the 2nd-century [Credit: (c) MOLA]

    The fresco was hand-painted by a skilled artist in natural earth pigments, except one area of red on the twisting vine stem which is picked out in cinnabar, an expensive mercuric sulphide pigment that had to be mined in Spain.

    Fascinatingly, a slight error in the design reveals that the craftsman who painted the fresco made a mistake. It suggests that there was more than one person painting the wall and that they may have been working to a pre-prepared template. The mistake could only have been corrected by repainting the whole middle panel.  

    Roman fresco unearthed in London
    MOLA archaeological conservator, Luisa Duarte, a section 
    of decorated Roman wall [Credit: (c) MOLA]

    Although small fragments of Roman wall plaster have been found in London, complete collapsed wall paintings are extremely rare and the 21 Lime Street example is one of the earliest known from Britain. This design scheme has not previously been seen in Roman Britain; the closest example comes from a Roman villa in Cologne, Germany.

    Specialists from MOLA continue to study the fresco and archaeological records from the dig and hope to build a picture of what the area looked like in the Roman period and how it developed over almost 2,000 years of London’s history.

    Source: MOLA [February 03, 2016]

  • Breaking News: New dwarf galaxies discovered in orbit around the Milky Way

    Breaking News: New dwarf galaxies discovered in orbit around the Milky Way

    Astronomers have discovered a 'treasure trove' of rare dwarf satellite galaxies orbiting our own Milky Way. The discoveries could hold the key to understanding dark matter, the mysterious substance which holds our galaxy together.

    New dwarf galaxies discovered in orbit around the Milky Way
    The Magellanic Clouds and the Auxiliary Telescopes at the Paranal Observatory in the 
    Atacama Desert in Chile. Only 6 of the 9 newly discovered satellites are present in
     this image. The other three are just outside the field of view. The insets show images
     of the three most visible objects (Eridanus 1, Horologium 1 and Pictoris 1) and
     are 13x13 arcminutes on the sky (or 3000x3000 DECam pixels) 
    [Credit: V. Belokurov, S. Koposov (IoA, Cambridge)/
    Photo: Y. Beletsky (Carnegie Observatories)]

    A team of astronomers from the University of Cambridge have identified nine new dwarf satellites orbiting the Milky Way, the largest number ever discovered at once. The findings, from newly-released imaging data taken from the Dark Energy Survey, may help unravel the mysteries behind dark matter, the invisible substance holding galaxies together.

    The new results also mark the first discovery of dwarf galaxies -- small celestial objects that orbit larger galaxies -- in a decade, after dozens were found in 2005 and 2006 in the skies above the northern hemisphere. The new satellites were found in the southern hemisphere near the Large and Small Magellanic Cloud, the largest and most well-known dwarf galaxies in the Milky Way's orbit.

    The Cambridge findings are being jointly released today with the results of a separate survey by astronomers with the Dark Energy Survey, headquartered at the US Department of Energy's Fermi National Accelerator Laboratory. Both teams used the publicly available data taken during the first year of the Dark Energy Survey to carry out their analysis.

    The newly discovered objects are a billion times dimmer than the Milky Way, and a million times less massive. The closest is about 95,000 light years away, while the most distant is more than a million light years away.

    According to the Cambridge team, three of the discovered objects are definite dwarf galaxies, while others could be either dwarf galaxies or globular clusters -- objects with similar visible properties to dwarf galaxies, but not held together with dark matter.

    New dwarf galaxies discovered in orbit around the Milky Way
    The Magellanic Clouds and the stream of neutral hydrogen. The insets show the image
     of the largest satellite discovered (Eridanus 2) as well as the smallest one (Indus 1).
     The insets are 13x13 arcminutes on the sky (or 3000x3000 DECam pixels) for
     Eridanus 2 and 6.5x6.5 arcminutes (or 1500x1500 DECam pixels) for Indus 1 
    [Credit: V. Belokurov, S. Koposov (IoA, Cambridge)/
    HI image: M. Putman (Columbia)]

    "The discovery of so many satellites in such a small area of the sky was completely unexpected," said Dr Sergey Koposov of Cambridge's Institute of Astronomy, the study's lead author. "I could not believe my eyes."

    Dwarf galaxies are the smallest galaxy structures observed, the faintest of which contain just 5000 stars -- the Milky Way, in contrast, contains hundreds of billions of stars. Standard cosmological models of the universe predict the existence of hundreds of dwarf galaxies in orbit around the Milky Way, but their dimness and small size makes them incredibly difficult to find, even in our own 'backyard'.

    "The large dark matter content of Milky Way satellite galaxies makes this a significant result for both astronomy and physics," said Alex Drlica-Wagner of Fermilab, one of the leaders of the Dark Energy Survey analysis.

    Since they contain up to 99 percent dark matter and just one percent observable matter, dwarf galaxies are ideal for testing whether existing dark matter models are correct. Dark matter -- which makes up 25 percent of all matter and energy in our universe -- is invisible, and only makes its presence known through its gravitational pull.

    "Dwarf satellites are the final frontier for testing our theories of dark matter," said Dr Vasily Belokurov of the Institute of Astronomy, one of the study's co-authors. "We need to find them to determine whether our cosmological picture makes sense. Finding such a large group of satellites near the Magellanic Clouds was surprising, though, as earlier surveys of the southern sky found very little, so we were not expecting to stumble on such treasure."

    New dwarf galaxies discovered in orbit around the Milky Way
    Distribution of the Galactic satellites on the sky. The underlying background
     image is the Infrared Map produced by the 2MASS survey 
    [Credit: S. Koposov, V. Belokurov (IoA, Cambridge)/
    Background: 2MASS]

    The closest of these pieces of 'treasure' is 97,000 light years away, about halfway to the Magellanic Clouds, and is located in the constellation of Reticulum, or the Reticle. Due to the massive tidal forces of the Milky Way, it is in the process of being torn apart.

    The most distant and most luminous of these objects is 1.2 million light years away in the constellation of Eridanus, or the River. It is right on the fringes of the Milky Way, and is about to get pulled in. According to the Cambridge team, it looks to have a small globular cluster of stars, which would make it the faintest galaxy to possess one.

    "These results are very puzzling," said co-author Wyn Evans, also of the Institute of Astronomy. "Perhaps they were once satellites that orbited the Magellanic Clouds and have been thrown out by the interaction of the Small and Large Magellanic Cloud. Perhaps they were once part of a gigantic group of galaxies that -- along with the Magellanic Clouds -- are falling into our Milky Way galaxy."

    The Dark Energy Survey is a five-year effort to photograph a large portion of the southern sky in unprecedented detail. Its primary tool is the Dark Energy Camera, which -- at 570 megapixels -- is the most powerful digital camera in the world, able to see galaxies up to eight billion light years from Earth. Built and tested at Fermilab, the camera is now mounted on the four-metre Victor M Blanco telescope at the Cerro Tololo Inter-American Observatory in the Andes Mountains in Chile. The camera includes five precisely shaped lenses, the largest nearly a yard across, designed and fabricated at University College London (UCL) and funded by the UK Science and Technology Facilities Council (STFC).

    The Dark Energy Survey is supported by funding from the STFC, the US Department of Energy Office of Science; the National Science Foundation; funding agencies in Spain, Brazil, Germany and Switzerland; and the participating institutions.

    The Cambridge research, funded by the European Research Council, will be published in The Astrophysical Journal.

    Source: University of Cambridge [March 10, 2015]

  • Geology: Signs of ancient mega-tsunami could portend modern hazard

    Geology: Signs of ancient mega-tsunami could portend modern hazard

    Scientists working off west Africa in the Cape Verde Islands have found evidence that the sudden collapse of a volcano there tens of thousands of years ago generated an ocean tsunami that dwarfed anything ever seen by humans. The researchers say an 800-foot wave engulfed an island more than 30 miles away. The study could revive a simmering controversy over whether sudden giant collapses present a realistic hazard today around volcanic islands, or even along more distant continental coasts. The study appears today in the journal Science Advances.

    Signs of ancient mega-tsunami could portend modern hazard
    Geologists think that the eastern slope of Fogo volcano crashed into the sea some 
    65,000 to 124,000 years ago, leaving a giant scar where a new volcano can be
     seen growing in this satellite image [Credit: NASA]

    "Our point is that flank collapses can happen extremely fast and catastrophically, and therefore are capable of triggering giant tsunamis," said lead author Ricardo Ramalho, who did the research as a postdoctoral associate at Columbia University's Lamont-Doherty Earth Observatory, where he is now an adjunct scientist. "They probably don't happen very often. But we need to take this into account when we think about the hazard potential of these kinds of volcanic features."

    The apparent collapse occurred some 73,000 years ago at the Fogo volcano, one of the world's largest and most active island volcanoes. Nowadays, it towers 2,829 meters (9,300 feet) above sea level, and erupts about every 20 years, most recently last fall. Santiago Island, where the wave apparently hit, is now home to some 250,000 people.

    There is no dispute that volcanic flanks present a hazard; at least eight smaller collapses have occurred in Alaska, Japan and elsewhere in the last several hundred years, and some have generated deadly tsunamis. But many scientists doubt whether big volcanoes can collapse with the suddenness that the new study suggests. Rather, they envision landslides coming in gradual stages, generating multiple, smaller tsunamis. A 2011 French study also looked at the Fogo collapse, suggesting that it took place somewhere between 124,000-65,000 years ago; but that study says it involved more than one landslide. The French researchers estimate that the resulting multiple waves would have reached only 45 feet--even at that, enough to do plenty of harm today.

    A handful of previous other studies have proposed much larger prehistoric collapses and resulting megatsunamis, in the Hawaiian islands, at Italy's Mt. Etna, and the Indian Ocean's Reunion Island. But critics have said these examples are too few and the evidence too thin. The new study adds a new possible example; it says the estimated 160 cubic kilometers (40 cubic miles) of rock that Fogo lost during the collapse was dropped all at once, resulting in the 800-foot wave. By comparison, the biggest known recent tsunamis, which devastated the Indian Ocean's coasts in 2004 and eastern Japan in 2011, reached only about 100 feet. (Like most other well documented tsunamis, these were generated by movements of undersea earthquake faults--not volcanic collapses.)

    Signs of ancient mega-tsunami could portend modern hazard
    On a clear day, from these cliffs in northern Santiago island, it is 
    possible to see a silhouette of Fogo, nearly 40 miles away. The geologists 
    on this ridge believe that a tsunami generated by Fogo's sudden collapse 
    generated a wave that swept the spot where they are standing 
    [Credit: Kim Martineau/Lamont-Doherty Earth Observatory]

    Santiago Island lies 55 kilometers (34 miles) from Fogo. Several years ago, Ramalho and colleagues were working on Santiago when they spotted unusual boulders lying as far as 2,000 feet inland and nearly 650 feet above sea level. Some are as big as delivery vans, and they are utterly unlike the young volcanic terrain on which they lie. Rather, they match marine-type rocks that ring the island's shoreline: limestones, conglomerates and submarine basalts. Some weigh up to 770 tons. The only realistic explanation the scientists could come up with: A gigantic wave must have ripped them from the shoreline and lofted them up. They derived the size of the wave by calculating the energy it would have taken to accomplish this feat.

    To date the event, in the lab Ramalho and Lamont-Doherty geochemist Gisela Winckler measured isotopes of the element helium embedded near the boulders' surfaces. Such isotopes change depending on how long a rock has been lying in the open, exposed to cosmic rays. The analyses centered around 73,000 years--well within the earlier French estimate of a smaller event. The analysis "provides the link between the collapse and impact, which you can make only if you have both dates," said Winckler.

    Tsunami expert Bill McGuire, a professor emeritus at University College London who was not involved in the research, said the study "provides robust evidence of megatsunami formation [and] confirms that when volcanoes collapse, they can do so extremely rapidly." Based on his own work, McGuire s says that such megatsunamis probably come only once every 10,000 years. "Nonetheless," he said, "the scale of such events, as the Fogo study testifies, and their potentially devastating impact, makes them a clear and serious hazard in ocean basins that host active volcanoes."

    Ramalho cautions that the study should not be taken as a red flag that another big collapse is imminent here or elsewhere. "It doesn't mean every collapse happens catastrophically," he said. "But it's maybe not as rare as we thought."

    Signs of ancient mega-tsunami could portend modern hazard
    The tsunami generated by Fogo's collapse apparently swept boulders like this one 
    from the shoreline up into the highlands of Santiago island. Here, a researcher
     chisels out a sample [Credit: Ricardo Ramalho]

    In the early 2000s, other researchers started publishing evidence that the Cape Verdes could generate large tsunamis. Others have argued that Spain's Canary Islands have already done so. Simon Day, a senior researcher at University College London has sparked repeated controversy by warning that any future eruption of the Canary Islands' active Cumbre Vieja volcano could set off a flank collapse that might form an initial wave 3,000 feet high. This, he says, could erase more than nearby islands. Such a wave might still be 300 feet high when it reached west Africa an hour or so later he says, and would still be 150 feet high along the coasts of North and South America. So far, such studies have raised mainly tsunamis of publicity, and vigorous objections from other scientists that such events are improbable. A 2013 study of deep-sea sediments by the United Kingdom's National Oceanography Centre suggests that the Canaries have probably mostly seen gradual collapses.

    Part of the controversy hangs not only on the physics of the collapses themselves, but on how efficiently resulting waves could travel. In 1792, part of Japan's Mount Unzen collapsed, hitting a series of nearby bays with waves as high as 300 feet, and killing some 15,000 people. On July 9, 1958, an earthquake shook 90 million tons of rock into Alaska's isolated Lituya Bay; this created an astounding 1,724-foot-high wave, the largest ever recorded. Two fishermen who happened to be in their boat that day were carried clear over a nearby forest; miraculously, they survived.

    These events, however, occurred in confined spaces. In the open ocean, waves created by landslides are generally thought to lose energy quickly, and thus to pose mainly a regional hazard. However, this is based largely on modeling, not real-world experience, so no one really knows how fast a killer wave might decay into a harmless ripple. In any case, most scientists are more concerned with tsunamis generated by undersea earthquakes, which are more common. When seabed faults slip, as they did in 2004 and 2011, they shove massive amounts of water upward. In deep water, this shows up as a mere swell at the surface; but when the swell reaches shallower coastal areas, its energy concentrates into in a smaller volume of water, and it rears up dramatically. The 2004 Indian Ocean earthquake and tsunami killed 230,000 people in 14 countries; the 2011 Tohoku event killed nearly 20,000 in Japan, and has caused a long-term nuclear disaster.

    James Hunt, a tsunami expert at the United Kingdom's National Oceanography Centre who was not involved in the study, said the research makes it clear that "even modest landslides could produce high-amplitude anomalous tsunami waves on opposing island coastlines." The question, he said, "is whether these translate into hazardous events in the far field, which is debatable."

    When Fogo erupted last year, Ramalho and other geologists rushed in to observe. Lava flows (since calmed down) displaced some 1,200 people, and destroyed buildings including a new volcano visitors' center. "Right now, people in Cape Verde have a lot more to worry about, like rebuilding their livelihoods after the last eruption," said Ramalho. "But Fogo may collapse again one day, so we need to be vigilant."

    Source: The Earth Institute at Columbia University [October 02, 2015]

  • Forensics: Single strain of plague bacteria sparked multiple historical and modern pandemics

    Forensics: Single strain of plague bacteria sparked multiple historical and modern pandemics

    A single entry of the plague bacterium into Europe was responsible for the Black Plague of the mid-14th century. This same strain sparked recurrent outbreaks on the continent over the following four centuries before spreading to China, where it triggered the third plague pandemic in the late 19th century. The wave of plague that traveled to Asia later became the source population for modern-day epidemics around the globe. The bacterium's routes over time were revealed by genome analyses published in >Cell Host & Microbe.

    Single strain of plague bacteria sparked multiple historical and modern pandemics
    This is a photo of a mass burial site in Ellwangen, Germany 
    [Credit: Rainer Weiss]

    "Our study is the first to provide genetic support for plague's travel from Europe into Asia after the Black Death, and it establishes a link between the Black Death in the mid-14th century and modern plague," says first author Maria Spyrou of the Max Planck Institute for the Science of Human History.

    The plague bacterium, Yersinia pestis, is one of the deadliest pathogens in human history, sparking three major pandemics: the Plague of Justinian, which struck the Roman Empire during the 6th and 8th centuries; the second plague pandemic, which first erupted in Europe in the mid-14th-century Black Death and continued to strike the continent in recurrent outbreaks until the mid-18th century; and the third plague pandemic, which emerged in China during the late 19th century.

    Evidence based on ancient DNA samples and historical climate patterns has suggested that the recurrent outbreaks of the second pandemic were caused by multiple reintroductions of Yersinia pestis into Europe, most likely from Asia. Moreover, some scientists have recently suggested that the plague bacterium migrated from Europe to Asia after the Black Death, later giving rise to the third pandemic. But until now, genomic evidence to support this model was missing.

    To shed light on the origin and path of the second pandemic, Spyrou and co-senior study authors Alexander Herbig, Kirsten Bos, and Johannes Krause of the Max Planck Institute for the Science of Human History collected samples from plague-infected individuals buried in mass grave sites in Barcelona, Spain, and Ellwangen, Germany, as well as a single grave in Bolgar City, Russia.

    "The mass burials where our samples come from often represent events where hundreds of people died of plague during a single outbreak," Herbig says. "This gives us an impression about how significant the impact of this disease was during medieval times."

    The Bolgar City site was dated to the second half of the 14th century using coin artifacts known to have been minted after 1362. Radiocarbon dates from bone fragments and tooth roots were estimated at 1300-1420 for Barcelona, 1298-1388 for Bolgar City, and 1486-1627 for Ellwangen.

    Single strain of plague bacteria sparked multiple historical and modern pandemics
    This visual abstract depicts the findings of Spyrou et al., who sequenced historical Yersinia pestisgenomes 
    from victims of the Black Death and subsequent outbreaks in Europe. Their data suggest a connection between 
    the Black Death and the modern-day plague pandemic as well as the persistence of plague in Europe 
    between the 14th and 18th centuries [Credit: Spyrou et al./Cell Host & Microbe 2016]

    After analyzing DNA extracts from the teeth of 178 individuals, the researchers identified Y. pestis DNA in extracts from 32 individuals. Three individuals from Barcelona, Bolgar City, and Ellwangen had sufficient Y. pestis DNA for genome-level analysis. The researchers sequenced the genomes of these three ancient Y. pestis strains and compared them to 148 previously sequenced ancient and modern strains to reconstruct the Y. pestis phylogenetic tree.

    The phylogenetic analysis revealed no differences between their Black Death strain from Barcelona and previously genotyped strains from mid-14th-century London. The simultaneous presence of the same strain in both southern and northern Europe suggests that Y. pestis entered the continent in a single wave rather than through multiple pulses during the Black Death.

    These Black Death strains from London and Barcelona gave rise to a branch containing the Ellwangen strain and previously sequenced 18th-century strains from the Great Plague of Marseille in France. Moreover, all three newly reconstructed genomes and previously sequenced genomes from the second plague grouped together in the same branch on the phylogenetic tree. Taken together, these findings suggest that a single Y. pestis lineage was responsible for the Black Death and subsequent second pandemic outbreaks throughout Europe.

    Meanwhile, the Bolgar City strain shared similarities with the Black Death London strain as well as all modern strains. This finding supports the idea that one Y. pestis lineage traveled from Europe to Asia after the Black Death, later sparking the third pandemic and modern-day epidemics worldwide.

    "Our most significant finding revealed a link between the Black Death and modern plague," Krause says. "Though several plague lineages exist in China today, only the lineage that caused the Black Death several centuries earlier left Southeast Asia in the late 19th century pandemic and rapidly achieved a near worldwide distribution."

    In future studies, the researchers plan to gain additional insights into the entry and end points of the Black Death in Europe. They hope to expand their sample range and explore these regions further to better understand the route traveled by the disease, the evolutionary changes it acquired at different stages, and the toll it had on the human population.

    "We hope that our findings will highlight the importance for more extensive sampling and sequencing of both ancient and modern plague isolates around the world, and open up new research themes regarding the role played by Europe and West Asia in plague's evolution and ecology," Bos says.

    Source: Cell Press [June 09, 2016]

  • Fossils: Elbows of extinct marsupial lion suggest unique hunting style

    Fossils: Elbows of extinct marsupial lion suggest unique hunting style

    Scientists from the Universities of Bristol and Málaga have proposed that the long extinct marsupial lion hunted in a very unique way -- by using its teeth to hold prey before dispatching them with its huge claws.

    Elbows of extinct marsupial lion suggest unique hunting style
    Reconstruction of Thylacoleo [Credit: Mauricio Antón]

    The marsupial lion, or Thylacoleo carnifex, was a predator in the Pleistocene era of Australia and was about the same size as a large jaguar.

    It was known to have existed from around two-and-a-half-million years ago until as recently as a few tens of thousands of years ago.

    The animal is depicted on native Australian cave art and some speculate it still survives as the "Queensland Tiger."

    As its name suggests, the marsupial lion has long been presumed to be a cat-like predator, despite lacking large canine teeth -- instead it had large, protruding incisors that have been suggested to be canine substitutes.

    Thylacoleo was a powerful beast but, as other researchers have noted, it had limbs of different proportions to a lion, suggesting it was not a fast.

    It also sported a very large claw on its hand, similar to the dew claw of cats but of a much bigger size, with a bony sheath foisted on a mobile first digit (thumb).

    Elbows of extinct marsupial lion suggest unique hunting style
    Author Christine Janis holding a cast of the skull of Thylacoleo carnifex in the Natural History Museum, London 
    [Credit: Elsa Panciroli]

    The new study, >published in Paleobiology by Christine Janis, a Marie Curie Research Fellow at the University of Bristol (currently on a leave of absence from a professorship at Brown University, USA) with colleagues Borja Figueirido and Alberto Martín-Serra from the University of Málaga, Spain looked at the elbow joints of a large number of living mammals.

    This showed a strong association between the anatomy of the humerus (upper arm bone) where it articulates with the forelimb and the locomotor behaviour of mammals.

    Animals more specialized for running (like a dog) have a joint indicating movement limited for back and forwards, stabilising their bodies on the ground, while animals more specialised for climbing (like a monkey) have a joint that allows for rotation of the hand around the elbow. Modern cats, which (unlike dogs) use their forelimbs to grapple with their prey, have an elbow joint of intermediate shape.

    Christine Janis said: "If Thylacoleo had hunted like a lion using its forelimbs to manipulate its prey, then its elbow joint should have been lion-like."

    Elbows of extinct marsupial lion suggest unique hunting style
    Thylacoleo hand, containing giant claw 
    [Credit: Borja Figueirido]

    "But, surprisingly, it a unique elbow-joint among living predatory mammals -- one that suggested a great deal of rotational capacity of the hand, like an arboreal mammal, but also features not seen in living climbers, that would have stabilized the limb on the ground (suggesting that it was not simply a climber)."

    Christine Janis and colleagues proposed that this unique elbow joint, in combination with the huge "dew claw" on a mobile thumb, would have allowed the marsupial lion to use that claw to kill its prey.

    In contrast the large incisors were blunt. While Thylacoleo had massive shearing teeth in the back of its jaw, the incisors appear to have functioned better for gripping than for piercing flesh in a killing bite.

    They concluded that, unlike a real lion, which holds its prey with its claws, and kills it with its teeth, the marsupial lion -- unlike any living predator -- used its teeth to hold its prey, while it despatched it with its huge claws.

    Source: University of Bristol [August 16, 2016]

  • North America: Site with clues to fate of fabled Lost Colony may be saved

    North America: Site with clues to fate of fabled Lost Colony may be saved

    Clues to what became of North Carolina's fabled Lost Colony could lie in a waterfront tract where developers once wanted to build thousands of condos - and now, one of those would-be developers is seeking millions of dollars to preserve the property.

    Site with clues to fate of fabled Lost Colony may be saved
    Archaeologists excavate an area in rural Bertie County, N.C. 
    [Credit: First Colony Foundation via AP]

    The effort to save the 1,000 acres in rural Bertie County is in an early stage. Even the environmental group that developer Michael Flannelly hopes will help hasn't seen the property yet. But Flannelly said he's optimistic that his vision will eventually become a reality.

    "I want to see the site preserved," said Flannelly, who lives on a boat that's usually docked in Norfolk, Virginia, or near his land in Bertie County. "I think it would make a fantastic place for people to come."

    The mystery of the Lost Colony - England's first settlement in North America - has intrigued historians and the popular imagination for centuries.

    In 1587, 116 English settlers landed on Roanoke Island, led by explorer John White. He left them there when he sailed back to England that same year for more supplies. Delayed by war between England and Spain, he didn't return until 1590 - and when he did, he discovered the entire colony had simply vanished.

    White knew the majority had planned to move "50 miles into the maine," as he wrote, referring to the mainland. The only clues he found about the fate of the other two dozen were the word "CROATOAN" carved into a post and "CRO" lettered on a tree trunk, leading historians to believe they moved south to live with American Indians on what's now Hatteras Island.

    But some archaeologists now suspect that at least some of the Roanoke colonists found their way to the inland site south of the Chowan River bridge, roughly 50 miles from Roanoke. It first came to light in 2012, when researchers at the British Museum in London announced they had found a drawing of a fort that had been obscured under a patch on a map of Virginia and North Carolina drawn by White in the 1580s.

    The drawing placed the fort in an area of Bertie County where archaeologists had found colonial-era English pottery and signs of a Native American village several years earlier during a dig that the state required before Flannelly and his partners could get permits for the subdivision that was never built. Archaeologists have since found further evidence on the tract, dubbed Site X, including bale seals used to verify cloth quality and 16th-century nails.

    Before the site can be preserved, Flannelly must buy out his former development partners.

    Flannelly estimates it will take $4 million to $5 million, along with a conservation group willing to help raise the money and preserve the land. To any cynics who suspect Flannelly is doing this only for the money, he says he would get 8 percent of any sale, plus a tax credit. And the proposed buyout is far less than the $10 million Flannelly says the developers paid for the property.

    A spokesman for the company, Forest City, said in an email that officials know about the archaeological finds but have no other updates about the status of the property. Forest City no longer works in land development, spokesman Jeff Linton said.

    Flannelly said that when archaeologists uncovered the property's historical significance, he insisted that those areas be cordoned off as green space and not developed.

    Flannelly personally owns 15 acres that include the possible Lost Colony site, but said he didn't know about the artifacts when he chose that land for his own home. "They felt the same I did," he said of the settlers. "That's the best piece of property on the whole tract."

    He has turned to North Carolina's Coastal Land Trust, a nonprofit that has preserved more than 65,000 undeveloped acres in 31 counties since 1992. Lee Leidy, attorney and northeast regional director for the trust, said officials there hope to view the property later this month.

    "It's fascinating," she said. "It's one that we're very excited to take a look at and learn more about."

    But raising funds to preserve the land presents a challenge, since limited conservation dollars must cover many projects, she said.

    "If it's done properly, I think it could be tremendous," said Arwin Smallwood, who wrote "Bertie County: An Eastern North Carolina History" and chairs the history department at N.C. A&T State University in Greensboro. "Right now in Bertie County, you can have a true sense of history and what the landscape was like."

    Tourists travel by the thousands to Dare County, home of the outdoor performance of "The Lost Colony" at an outdoor amphitheater on Roanoke Island. Now Bertie County residents have adopted the settlers as their own as well. More than 300 people attended the town of Windsor's first Lost Colony Festival in April, said Billy Smithwick, the town fire chief and tourism manager. In addition, the county is acquiring 137 acres for a nearby park.

    "I think it would be quite a tourist attraction," said Smithwick. "The Lost Colony is the greatest mystery in history that there is."

    Author: Martha Waggoner | Source: Associated Press [July 22, 2016]

  • Astrophysics: Accelerating research into dark energy

    Astrophysics: Accelerating research into dark energy

    A quick method for making accurate, virtual universes to help understand the effects of dark matter and dark energy has been developed by UCL and CEFCA scientists. Making up 95% of our universe, these substances have profound effects on the birth and lives of galaxies and stars and yet almost nothing is known about their physical nature.

    Accelerating research into dark energy
    This false-coloor image of the large-scale structure in a computerized Universe reveals the process behind the new 
    technique. On the left, a regular virtual universe has the locations of galaxies highlighted in blue, showing how they 
    cluster together. In the early Universe (center) the relationship between these blue regions and the orange regions
     that expand into empty voids was symmetric. This allows a reverse version of the cosmos to be built (right) where
     the galaxies now inhabit the very regions that used to be empty voids. The latest results show how combining 
    results from the original and reverse virtual Universe is a quick way to make accurate predictions
     for the real cosmos [Credit: Andrew Pontzen UCL]

    The new approach, published today in >Monthly Notices of the Royal Astronomical Society and funded by the Royal Society, is twenty-five times faster than current methods but is just as accurate, allowing scientists more computer power to focus on understanding why the universe is accelerating and galaxies are positioned where they are.

    "To uncover the nature of dark energy and the origin of our 14 billion year old accelerating universe, we have to compare the results from big studies to computational models of the universe," explained Dr Andrew Pontzen, UCL Physics & Astronomy.

    "Exciting new ventures, including the Large Synoptic Survey Telescope and the Javalambre Physics of the Accelerating Universe survey, are on the horizon, and we want to be ready to do the best possible job of understanding them", added joint author Dr Raul Angulo, CEFCA, Spain.

    Dr Pontzen continued: "But every computer simulation we run gives a slightly different answer. We end up needing to take an average over hundreds of simulations to get a 'gold standard' prediction. We've shown it's possible to achieve the same model accuracy by using only two carefully-constructed virtual universes, so a process that would take weeks on a superfast computer, can now be done in a day."

    The scientists say their method will speed up research into the unseen forces in the universe by allowing many model universes to be rapidly developed to test alternate versions of dark energy and dark matter.

    "Our method allows cosmologists to run more creative experiments which weren't feasible before due to the large amount of computer time needed. For example, scientists can now generate lots of different models of dark energy to find the one which best explains real-world survey data. We could also use this approach to see how individual galaxies look and fit inside the overall structure of the universe by spending the freed-up time on computing the virtual universes in much greater detail," said Dr Pontzen.

    The new method removes the biggest uncertainties in the model universe by comparing its properties with an 'inverted' version. In the inverted model universe, galaxies are replaced by empty voids, and the empty voids of space with galaxies. The scientists tried this approach after noticing a mathematical symmetry linking the two seemingly different pictures.

    When they compared the output of the paired universes to that of the gold standard method - which averages 300 virtual universes to remove uncertainties - they found the results to be very similar. The new approach showed less than 1% deviation from the gold standard, suggesting the new approach makes predictions that are accurate enough to use in forthcoming experiments.

    "In addition to the reversal process, we also adjust the ripples of the early universe to carefully-chosen values, to further eliminate inaccuracies" added Dr Angulo.

    The team now plan on using the new method to investigate how different forms of dark energy affect the distribution of galaxies through the universe. "Because we can get a more accurate prediction in a single shot, we don't need to spend so much computer time on existing ideas and can instead investigate a much wider range of possibilities for what this weird dark energy might really be made from," said Dr Pontzen.

    Source: University College London [July 06, 2016]

  1. The Lapita: Oceanic Ancestors exhibition at the Quai Branly Museum in Paris
  2. Bulgaria to unveil 10,000 unique archaeology treasures
  3. Public to see limestone box that may have been casket for Jesus’ brother
  4. 'Rhodes: A Greek Island and Gateway to the East' at the Louvre
  5. Ancient tablets reveal mathematical achievements of ancient Babylonian culture