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An international research team is formalizing plans to drill nearly 5,000 feet below the seabed to take core samples from the crater of the asteroid that wiped out the dinosaurs.

The group met last week in Merida, Mexico, a city within the nearly 125-mile-wide impact site, to explain the research plans and put out a call for scientists to join the expedition planned for spring 2016. The roughly $10 million in funding for the expedition has been approved and scheduled by the European Consortium for Ocean Research Drilling (ECORD) — part of the International Ocean Discovery Program (IODP) — and the International Continental Scientific Drilling Program (ICDP).

Dinosaurs and other reptiles ruled the planet for 135 million years. That all changed 65.5 million years ago when a 9-mile-wide asteroid slammed into the Earth, triggering a series of apocalyptic events that killed most large animals and plants, and wiped out the dinosaurs and large marine reptiles. The event set the stage for mammals — and eventually humans — to take over. Yet, we have few geologic samples of the now buried impact crater.

Sean Gulick, a researcher at The University of Texas at Austin Institute for Geophysics (UTIG), and a team of scientists from the U.K. and Mexico are working to change that. The team is planning to take the first offshore core samples from near the center of the impact crater, which is called Chicxulub after the seaside village on the Yucatán Peninsula near the crater’s center.

The team, led by Gulick and Joanna Morgan of Imperial College London, will be sampling the crater’s “peak ring” — an enigmatic ring of topographically elevated rocks that surrounds the crater’s center, rises above its floor and has been buried during the past 65.5 million years by sediments.

A peak ring is a feature that is present in all craters caused by large impacts on rocky planetoids. By sampling the Chicxulub peak ring and analyzing its key features, researchers hope to uncover the impact details that set in motion one of the planet’s most profound extinctions, while also shedding light on the mechanisms of large impacts on Earth and on other rocky planets.

“What are the peaks made of? And what can they tell us about the fundamental processes of impacts, which is this dominant planetary resurfacing phenomena?” said Gulick, who is also a research associate professor at the UT Jackson School of Geosciences. UTIG is a research unit of the Jackson School.

The researchers are also interested in examining traces of life that may have lived inside the peak ring’s rocks. Density readings of the rocks indicate that they probably are heavily broken and porous — features that may have served as protected microenvironments for exotic life that could have thrived in the hot, chemically enriched environment of the crater site after impact. Additionally, the earliest recovery of marine life should be recorded within the sediments that filled in the crater in the millions of years after the impact.

“The sediments that filled in the [crater] should have the record for organisms living on the sea floor and in the water that were there for the first recovery after the mass extinction event,” Gulick said. “The hope is we can watch life come back.”

The expedition will last for two months and involve penetrating nearly 5,000 feet beneath the seabed from an offshore platform. The core will be the first complete sample of the rock layers from near the crater’s center.

Once extracted, the core will be shipped to Germany and split in two. Half will be immediately analyzed by an international team of scientists from the U.S., U.K., Mexico and other nations, and half will be saved at a core repository at Texas A&M University for future research needs by the international community.

The team also includes researchers from the National Autonomous University of Mexico (UNAM) and Centro de Investigación Científica de Yucatán (CICY). Scientists interested in joining the mission must apply by May 8, 2015. For more information on the mission and the application process, see the European Consortium for Ocean Research Drilling’s call for applications.

Source: University of Texas at Austin [April 06, 2015]

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.

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.

'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]

Scientists studying the Chicxulub crater have shown how large asteroid impacts deform rocks in a way that may produce habitats for early life.

Around 65 million years ago a massive asteroid crashed into the Gulf of Mexico causing an impact so huge that the blast and subsequent knock-on effects wiped out around 75 per cent of all life on Earth, including most of the dinosaurs. This is known as the Chicxulub impact.

In April and May 2016, an international team of scientists undertook an offshore expedition and drilled into part of the Chicxulub impact crater. Their mission was to retrieve samples from the rocky inner ridges of the crater -- known as the 'peak ring' -- drilling 506 to 1335 metres below the modern day sea floor to understand more about the ancient cataclysmic event.

Now, the researchers have carried out the first analysis of the core samples. They found that the impact millions of years ago deformed the peak ring rocks in such a way that it made them more porous, and less dense, than any models had previously predicted.

Porous rocks provide niches for simple organisms to take hold, and there would also be nutrients available in the pores, from circulating water that would have been heated inside the Earth's crust. Early Earth was constantly bombarded by asteroids, and the team have inferred that this bombardment must have also created other rocks with similar physical properties. This may partly explain how life took hold on Earth.

The study, which is published today in the >journal Science, also confirmed a model for how peak rings were formed in the Chicxulub crater, and how peak rings may be formed in craters on other planetary bodies.

The team's new work has confirmed that the asteroid, which created the Chicxulub crater, hit the Earth's surface with such a force that it pushed rocks, which at that time were ten kilometres beneath the surface, farther downwards and then outwards. These rocks then moved inwards again towards the impact zone and then up to the surface, before collapsing downwards and outwards again to form the peak ring. In total they moved an approximate total distance of 30 kilometres in a matter of a few minutes.

Professor Joanna Morgan, lead author of the study from the Department of Earth Science and Engineering, said: "It is hard to believe that the same forces that destroyed the dinosaurs may have also played a part, much earlier on in Earth's history, in providing the first refuges for early life on the planet. We are hoping that further analyses of the core samples will provide more insights into how life can exist in these subterranean environments."

The next steps will see the team acquiring a suite of detailed measurements from the recovered core samples to refine their numerical simulations. Ultimately, the team are looking for evidence of modern and ancient life in the peak-ring rocks. They also want to learn more about the first sediments that were deposited on top of the peak ring, which could tell the researchers if they were deposited by a giant tsunami, and provide them with insights into how life recovered, and when life actually returned to this sterilised zone after the impact.

Source: Imperial College London [November 17, 2016]

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.

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]

Genes that drive the shape of human noses have been identified by a UCL-led study. The four genes mainly affect the width and 'pointiness' of noses which vary greatly between different populations. The new information adds to our understanding of how the human face evolved and may help contribute to forensic DNA technologies that build visual profiles based on an individual's genetic makeup.

The study, published today in >Nature Communications, analysed a population of over 6,000 people with varied ancestry across Latin America to study the differences in normal facial features and identify the genes which control the shape of the nose and chin.

The researchers identified five genes which play a role in controlling the shape of specific facial features. DCHS2, RUNX2, GLI3 and PAX1 affect the width and pointiness of the nose and another gene -- EDAR -- affects chin protrusion.

"Few studies have looked at how normal facial features develop and those that have only looked at European populations, which show less diversity than the group we studied. What we've found are specific genes which influence the shape and size of individual features, which hasn't been seen before.

"Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans. It brings us closer to understanding how genes influence the way we look, which is important for forensics applications," said the first author of the report, Dr Kaustubh Adhikari, UCL Cell & Developmental Biology.

People have different shaped facial features based on their genetic heritage and this is partly due to how the environment influenced the evolution of the human genome. The nose, for example, is important for regulating the temperature and humidity of the air we breathe in so developed different shapes in warmer and cooler climates.

"It has long been speculated that the shape of the nose reflects the environment in which humans evolved. For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate. Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species. It may also help us understand what goes wrong in genetic disorders involving facial abnormalities," explained Professor Andrés Ruiz-Linares UCL Biosciences, who led the study.

The team collected and analysed DNA samples from 6,630 volunteers from the CANDELA cohort recruited in Brazil, Colombia, Chile, Mexico and Peru. After an initial screen, a sample size of 5,958 was used. This group included individuals of mixed European (50%), Native American (45%) and African (5%) ancestry, resulting in a large variation in facial features.

Both men and women were assessed for 14 different facial features and whole genome analysis identified the genes driving differences in appearance.

A subgroup of 3,000 individuals had their features assessed using a 3D reconstruction of the face in order to obtain exact measurements of facial features and the results identified the same genes.

The study identified genes that are involved in bone and cartilage growth and the development of the face. GLI3, DCHS2 and PAX1 are all genes known to drive cartilage growth -- GLI3 gave the strongest signal for controlling the breadth of nostrils, DCHS2 was found to control nose 'pointiness' and PAX1 also influences nostril breadth. RUNX2 which drives bone growth was seen to control nose bridge width.

The genes GLI3, DCHS2 and RUNX2 are known to show strong signals of recent selection in modern humans compared to archaic humans such as Neanderthals and Denisovans; GLI3 in particular undergoing rapid evolution.

Source: University College London [May 19, 2016]

Beneath the Aurora Borealis an oil tanker glides through the night past the Coast Guard ice breaker Amundsen and vanishes into the maze of shoals and straits of the Northwest Passage, navigating waters that for millennia were frozen over this time of year.

Warming has forced a retreat of the polar ice cap, opening up a sea route through the Canadian Arctic Archipelago and connecting the Atlantic and Pacific Oceans for several months of the year.

Commander Alain Lacerte is at the helm as the vessel navigates the Queen Maud Gulf, poring over charts that date from the 1950s and making course corrections with the help of GPS.

"Where it's white (on the chart), it means the area hasn't been surveyed," he explains -- leaning over a map that is mostly white. "Most of the far north hasn't been surveyed, so our maps are unreliable."

The crew constantly take radar and multi-beam sonar measurements and check their position.

"We don't want any shoals named after us," says the old sea dog from behind his spectacles.

Almost the size of the European Union, the Canadian Arctic seabed remains largely uncharted. The waters are also shallow and navigating unknown parts can be deadly -- even when the north is ice-free.

Today, taking this route cuts 7,000 kilometers (4,350 miles) off a trip from London to Tokyo, saving time and fuel.

'Never imagined this'

Since the 15th century there have been a dozen expeditions seeking a faster shipping route from Europe to Asia through the north.

The Norwegian explorer Roald Amundsen was the first to cross the Northwest Passage, on board the Gjoa, in an expedition that took three years, finishing in 1906.

Afterward interest in the waterway waned. An average of one ship per year attempted to make the crossing over the past century.

But thawing of the polar ice promises Arctic nations new opportunities to open ocean trade routes and offshore oil fields.

In the summer months the Amundsen is used by Canadian government scientists -- among them Roger Provost, a Canadian Ice Service meteorologist -- as well as a network of scientists led by the ArcticNet organization.

Provost looked with amazement from the wheelhouse at the lack of any ice cover around the coast guard ship.

"Anyone who still denies climate change is real has their head in the ground, they're blind," he said.

In 37 years of Arctic exploration, he said he "never imagined ever seeing this," pointing to satellite images showing a clear path through the Queen Maud Gulf and the M'Clintock Channel, where the Amundsen is headed.

Almost 112 years ago to the day, the explorer Amundsen got stuck in the pack ice here. And in 1979, Provost recalls, another Canadian Coast Guard ice-breaker had to cut short its inaugural journey, unable to push beyond this point through thick ice.

Over the past five years the number of cargo and cruise ships, tankers and others crossing the Passage climbed to 117.

In 2010, Canada imposed shipping regulations on seafarers going through the Passage, but the United States and the European Union do not recognize Canada's ownership of the waterway, considering it international waters.

'Completely disappear'

The ice cover has steadily retreated over the past decade, with this year set to be the hottest on record, according to the US National Oceanic and Atmospheric Administration.

The previous year saw average global temperatures rise one degree Celsius -- but by three degrees in the Arctic.

What most worries Provost is the loss of "multi-year ice," formed over centuries. "In a few years it will completely disappear," he forecast.

"It's a tragedy for all humanity what is happening."

Glaciologist Lauren Candlish said: "We're now in the transition phase, from having multi-year ice through the entire summer, to a seasonally ice free Arctic."

Poring over data on her computer in a nook of the ship the University of Manitoba researcher says: "It's a different Arctic now. Less predictable, with more fluctuations."

The last such melting occurred "before the last ice age," from AD 100,000 to AD 10,000, she noted.

Most aboard the ship doubt we are headed for an Arctic shipping boom predicted by many, as the weather remains unpredictable and harsh. But there is sure to be an increase, which raises concerns for the environment.

"When it was covered in ice, this ecosystem was not threatened," says Provost. The Arctic is a unique and diverse ecosystem that is home to whales, seals, polar bears, walruses and several bird species.

"A massive oil spill like the one in the Gulf of Mexico in 2010 must never happen in the Arctic," he said. "The consequences would be much more serious."

Author: Clement Sabourin | Source: AFP [October 20, 2015]

An 800-year-old Mexican skull decorated with turquoise mosaic, for decades believed to have been a masterpiece of Mixtec indigenous art is a forgery, a Dutch museum and media said Saturday.

>The National Museum of Ethnology in the western university city of Leiden made the shock discovery after an intensive four-year study on the skull, one of only around 20 in existence world-wide.

"Radiometric dating showed the skull and the turquoise are from the correct time period and origin and are authentic," the museum said on its website.

"But alas: further investigation showed a 20th-century glue was used (to mount the mosaic)," the museum said.

The teeth are also false "as it was too well preserved for a skull that lay underground for centuries," Dutch daily Trouw reported.

The museum bought the piece in 1963 for the equivalent of around $20,000 (19,000 euros) and was seen as a striking example of ancient Mesoamerican art.

An investigation into possible skull-duggery was launched after the museum's conservator Martin Berger received a telephone call back in 2010 from a French colleague in Marseille, Trouw said.

The colleague told Berger they received a similar skull from a private collection and that person who donated the art had doubts about its authenticity.

Berger and his colleagues travelled to a Paris-based laboratory where the Dutch-owned skull was analysed and where "we realised that ours was also a bit more 'modern' than we thought".

Berger told the paper he suspected the fake was mounted by a Mexican dentist back in the 1940s or 1950s, when Mexican archeological sites were subjected to large-scale plunder and dealing in artworks like those of the Mixtecs was a lucrative business.

Asked whether he was disappointed by the revelation, Berger told the newspaper: "No. In actual fact it's given us a bizarre story and that's exactly what museums want to do, to tell stories. It remains as one of our masterpieces -- except, we've changed the information on the sign board."

In any case, said Berger, the skull is only a "partial forgery".

"The skull as well as the turquoise are unique archaeological material. Only, the Mixtecs themselves didn't do the glueing," he said.

Similar Central American crystal skulls housed in museums in Paris, London and Washington, D.C. believed to have been pre-Colombian, were revealed to be fake in a scientific study published in 2008.

Source: AFP [November 26, 2016]