Good dog? Bad dog? Their personalities can change

Girl and her dog, an Alaskan malamute.

When dog-parents spend extra time scratching their dogs' bellies, take their dogs out for long walks and games of fetch, or even when they feel constant frustration over their dogs' naughty chewing habits, they are gradually shaping their dogs' personalities. Dogs, like people, have moods and personality traits that shape how they react in certain situations. New findings from Michigan State University went where few researchers have gone before to reveal that, also like humans, dogs' personalities likely change over time.

"When humans go through big changes in life, their personality traits can change. We found that this also happens with dogs -- and to a surprisingly large degree," said William Chopik, professor of psychology and lead author. "We expected the dogs' personalities to be fairly stable because they don't have wild lifestyle changes humans do, but they actually change a lot. We uncovered similarities to their owners, the optimal time for training and even a time in their lives that they can get more aggressive toward other animals."

Additionally, Chopik found that dogs' personalities can predict many important life outcomes. For example, canines' personalities will influence how close they feel to their owners, biting behavior and even chronic illness.

The research, published in Journal of Research in Personality, is one of the first -- and is the largest -- studies of its kind to examine changes in dogs' personalities. Chopik surveyed owners of more than 1,600 dogs, including 50 different breeds. Dogs ranged from just a few weeks old to 15 years, and were split closely between male and female. The extensive survey had owners evaluate their dog's personalities and answered questions about the dog's behavioral history. The owners also answered a survey about their own personalities.

"We found correlations in three main areas: age and personality, in human-to-dog personality similarities and in the influence a dog's personality has on the quality of its relationship with its owner," Chopik said. "Older dogs are much harder to train; we found that the 'sweet spot' for teaching a dog obedience is around the age of six, when it outgrows its excitable puppy stage but before its too set in its ways."

One trait that rarely changes in age with dogs, Chopik said, was fear and anxiety.

Honing in on the saying, "dogs resemble their owners," Chopik's research showed dogs and owners share specific personality traits. Extroverted humans rated their dogs as more excitable and active, while owners high in negative emotions rated their dogs as more fearful, active and less responsive to training. Owners who rated themselves as agreeable rated their dogs as less fearful and less aggressive to people and animals.

The owners who felt happiest about their relationships with their dogs reported active and excitable dogs, as well as dogs who were most responsive to training. Aggression and anxiety didn't matter as much in having a happy relationship, Chopik said.

"There are a lot of things we can do with dogs -- like obedience classes and training -- that we can't do with people," he said. "Exposure to obedience classes was associated with more positive personality traits across the dog's lifespan. This gives us exciting opportunities to examine why personality changes in all sorts of animals."

Chopik's findings prove how much power humans have over influencing a dog's personality. He explained that many of the reasons a dog's personality changes are a result of the "nature versus nurture" theory associated with humans' personalities.

Next, Chopik's will research will examine how the environment owners provide their dogs might change the dogs' behavior.

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Honeybees' waggle dance no longer useful in some cultivated landscapes

A honeybee performing a waggle dance.

For bees and other social insects, being able to exchange information is vital for the success of their colony. One way honeybees do this is through their waggle dance, which is a unique pattern of behavior, which probably evolved more than 20 million years ago. A bee's waggle dance tells its sisters in the colony where to find a high-quality source of food. However, in recent years people have begun to study the actual benefits of this dance language. Biologists at the University of Lausanne in Switzerland and at Johannes Gutenberg University Mainz (JGU) in Germany have now shed some new light on the benefits and disadvantages of the bee dance. "To our surprise, we found that bee colonies are more successful at collecting food if they are deprived of their dance language," reported Dr. Christoph Grüter, a behavioral ecologist at Mainz University. One possible reason may be human-induced habitat change. Together with his colleagues in Lausanne, Grüter conducted experiments over several years to examine what effect the dance language has on a colony's success.

There are about ten different species of honeybees communicating through waggle dancing. However, the vast majority of bees, i.e., more than 500 species of highly social stingless insects, have no dance language. Thus, Grüter was interested in the benefits the waggle dance brings to colonies, not least because, as a communication strategy, it is relatively time-consuming. Some waggle dances can last only a few seconds, while others may take up to five minutes.

In the experiments, the scientists manipulated the conditions influencing some of the bee colonies to confuse and, as a result, disorientate the dancing bees. Performed under such conditions, the waggle dance no longer made sense to its bee audience. To create these conditions, light was prevented from falling on the honeycombs, and they were also turned into a horizontal position, preventing the bees from using gravity to orientate themselves. Another particularly important aspect was to take into account their ability to memorize the location of food. "Bees foraging for food have an excellent memory and can recall a rich feeding spot for several days," explained Grüter. Thus, the research team had to prevent foragers performing the waggle dance for 18 days to ensure they could not use their memory to tell other bees where to fly to find the excellent sources of food. Foraging bees are older than other colony members. In their final phase of life, they no longer work in the hive, but go out to collect nectar and pollen. Typically, they are in the last 18 days of their life.

Honeybees with no information from the waggle dance are more effective in challenging conditions

The team of biologists was surprised by their result that beehives without the dance information were more active and produced more honey than beehives that used dance language. "We were expecting to confirm that dance language was important, but our results were the exact opposite," said Dr. Robbie I'Anson Price, lead author of the study. "I suspect that the bees probably lose interest when confronted with a disoriented dance, and they go out to search for food on their own initiative," added Price. The differences are significant: Bees in colonies with no dance language went on foraging flights that were eight minutes longer and yielded 29 percent more honey over the entire 18-day period than bees using the waggle dance.

The conclusion is that some bees, such as the Buckfast bee in this study, a 100-year-old cross-bred western honeybee, may do better without social communication. Grüter believes that the environment and the availability of food play an important role. If there is a large apple tree in full bloom nearby, then waiting for information on its location is probably a good strategy. If, on the other hand, there is only a sparse scattering of flowering plants on balconies or roadsides, it may be better to leave the hive sooner and forage independently. "In our opinion, the behavior we observed can be primarily explained in terms of how much time the bees save," said Grüter.

Bees might be able to learn how to assess the value of waggle dance information

By observing the bees, the scientists made the extraordinary discovery that the bees were apparently able to judge the relevance of the information content of a dance and hence would lose interest in disoriented dancing. "It looks as if after a while they become aware that something is wrong," postulated Grüter. "Our results raise the possibility that humans have created environments to which the waggle dance language is not well adapted," write the authors in their study, recently published in the journal Science Advances.

The idea that bees may be capable of evaluating the quality of information in a dance is one that Grüter wants to investigate more closely in the future. He is also planning to repeat the experiments in the Mainz area under different conditions -- in urban and rural areas and at different times of the year.

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Signals on the scales: How the brain processes images

Retinal ganglion cells (RGCs, green) imaged by two-photon microscopy. Their axonal fibers (upper right) project to the visual thalamus via the optic nerve. Blood vessels are stained in red.

How are the images cast on the retina reassembled in the brain? Researchers in Munich and Tuebingen find that processing of visual stimuli occurs at the earliest waystation on the way to the visual cortex -- but not all are treated equally.

In humans, the visual system collects up to 80% of all the sensory data received from the environment. In order to make sense of this deluge of optical information, the visual inputs that are picked up and converted into electrochemical signals by the approximately 130 million light-sensitive cells in the retina are fed into, and processed by a complex network of nerve cells in the brain. How the brain manages to accomplish this task is still not fully understood. A more detailed picture of the steps involved is, however, essential for the further development of artificial visual systems. Now a team led by Ludwig-Maximilians-Universitaet (LMU) in Munich neurobiologist Laura Busse, in cooperation with Thomas Euler and Philipp Berens (University) has succeeded in shedding new light on a longstanding and controversial issue in this field. In an article that appears in the leading journal Neuron, the researchers demonstrate that incoming signals from the retina are subjected to selective processing and weighting at the first neuronal waystation in the functional pathway that connects the retina to the visual cortex.

In the mouse, the visual image that impinges on the retina is received by more than 30 specialized and functionally distinct types of ganglion cells. These different cell types respond in different ways to the input from the photoreceptors. For example, some react selectively to dark contrasts, while others are sensitive to particular spatial patterns. The streams of information that emanate from this retinal processing step are then conveyed in several parallel channels to the brain. "Primates appear to possess a similarly diverse set of retinal ganglion cells, and this most probably holds true for humans as well," says Busse. "Using the mouse as a model system, we have asked which types of ganglion cells project into the visual thalamus, and whether the information that arrives there is simply passed on, or is subjected to processing and transformation." The visual thalamus is the first waystation on the way to the cerebral cortex, and this processing pathway is, among other things, responsible for the perception and analysis of form and for object recognition. Both of the questions posed by Busse and her colleagues have been the focus of controversial debates. On the one hand, functional studies appeared to argue against the processing of ganglion input in the thalamus. However, recent anatomical studies have shown that individual cells in the thalamus may receive input from more than 90 retinal ganglion cells, which strongly suggests that these thalamic cells have a selective and/or an integrative processing role.

Working closely together, the teams in Munich and have now investigated what happens to the incoming signals in the visual thalamus of the mouse. They used an array of controlled visual stimuli designed to evoke a range of responses -- such as switching from dark to bright or vice versa, and alterations in contrast or changes in the period of a flickering signal -- and analyzed the reactions of both retinal and thalamic cells. They found that most types of retinal ganglion cells indeed transmit information to the visual thalamus. They then used the results of their electrophysiological measurements to construct a computer model that allowed them to deduce which, and how many, of these cells contribute to the response of the thalamus. "The model indicated that the response of an individual thalamus cell depends on no more than five different types of retinal ganglion cells," says Busse. That cell essentially combines the signals received from these five cell types, but not all are given equal weight. Instead, the information received from two types of input cell dominates the output signal emitted by any given thalamus cell. The signals contributed by the other three have little influence on the form of the output, such that the latter often shows a strong resemblance to the input provided by one of the retinal ganglion cells.

According to the authors, however, the weak signals conveyed by the non-dominant cell types may nevertheless help to make the visual system more 'robust' to computational errors -- by for example enhancing the functional connections between the cells in the network, in cases where a single retinal ganglion projects to many different cells in the thalamus. It is also possible that the relative weightings of the signals can be varied, to allow different combinations of input to be dynamically processed during learning processes, for instance. "At all events, the thalamus is not simply a passive relay station between the retina and the brain. It also serves as a signal processing site, and plays an important role in the relative weighting of incoming signals."

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High IQs won't be enough to prevent ecological disasters

High IQs aren't going to be enough to stop an ecological disaster. It's going to take social intelligence, too.

That's the conclusion of a new study co-authored by a University of Central Florida researcher and published Wednesday in the journal Nature Communications.

The findings could help identify why some groups better manage shared resources, such as water or fisheries, than others. And as Earth's population is growing at a rate that is putting a strain on resources, finding ways to better manage them is critical.

"Especially in the case of common property, there is often an inbuilt tension between what is good for the individual and what is good for the group," says Jacopo Baggio, an assistant professor in UCF's Department of Political Science and lead author of the study.

"Individuals often have different cognitive abilities," Baggio says. "For example, individuals with high general intelligence will be more able to discern patterns and dynamics of resources, and individuals with high social intelligence communicate more effectively and understand the mental state of others."

Using a digital game to simulate a virtual ecosystem, the researchers found that when teams of people with high general intelligence, but low social intelligence faced a situation where resources became scarce, those teams depleted resources faster, harvested less potential resources and pushed the ecosystem to its limits.

But when both general and social intelligence were high, teams harvested a greater percentage of potential resources and kept the ecosystem from collapsing.

"It's a way to really start to understand how individuals and groups interact and what type of individuals are more prone or less prone to favor group benefits over individual costs," Baggio says.

General intelligence helped people figure out the rules of the game and how the resources, in this case digital tokens, regenerated, while social intelligence helped people cooperate to optimize performance, says Thomas Coyle, co-author of the study and professor of psychology at the University of Texas at San Antonio.

"In theory, people with higher levels of social intelligence are more effective in reducing conflict among group members and in getting people to work toward common goals," Coyle says. "Such 'people' skills are important for managing shared resources."

The work points to a need for education in diverse types of intelligence, says Jacob Freeman, an assistant professor of anthropology at Utah State University and study co-author.

"It suggests that our education systems should focus on cultivating both general and social intelligence to better equip groups to deal with complex, social-ecological challenges," Freeman says.

Coyle says researchers are still exploring ways to improve social intelligence.

For the study, the researchers used a digital game where people collected virtual tokens in exchange for actual money. Participants were 216 undergraduates from two large universities in the Western United States. They were randomly placed into one of two experimental conditions: either a game where the conditions began improving and tokens continued to be replenished, or one where conditions began deteriorating and tokens did not regenerate fast enough.

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Captured carbon dioxide converts into oxalic acid to process rare earth elements

Carbon dioxide scrubbers remove emissions from power plant systems.

Until now, carbon dioxide has been dumped in oceans or buried underground. Industry has been reluctant to implement carbon dioxide scrubbers in facilities due to cost and footprint.

What if we could not only capture carbon dioxide, but convert it into something useful? S. Komar Kawatra and his students have tackled that challenge, and they're having some success.

A team lead by Kawatra, a professor of chemical engineering at Michigan Technological University, his PhD students, Sriram Valluri and Victor Claremboux, and undergraduate Sam Root, have designed a carbon dioxide scrubber. They are working on converting the carbon dioxide that they capture into oxalic acid, a naturally occurring chemical in many foods.

Root and Valluri have been invited to present their research at the Society of Mining, Metallurgy and Exploration's annual meeting in Denver in February.

Oxalic acid is used by industry to leach rare earth elements from ore bodies. The rare earths are used in electronics such as cell phones. Rare earths are not presently produced in the United States; China produces 90 percent or more of the rare earths in the world. By producing oxalic acid domestically, it may be possible to profitably extract rare earth elements in the U.S., which is important for national security, Kawatra said.

How a Carbon Dioxide Scrubber Works

The group installed their carbon dioxide scrubber at the Michigan Tech steam plant, where they are testing with real flue gas at pilot plant scale.

The steam plant produces flue gas that contains eight percent carbon dioxide. The chemical engineers' scrubber brought the emissions down to four percent and their goal is to reduce it below two percent.

"Below two percent, we are happy," Kawatra said. "Below one percent, we will be very happy."

It's a real possibility. "We've already got it down to zero percent in the laboratory," Valluri noted.

In the steam plant, they tap a sample stream of flue gas from the boiler's main exhaust line. The flue gas comes out of the burner at 300-350 degrees Fahrenheit. The sample is compressed through a filter that removes particles, then passes through a cooling unit before it enters the bottom of the scrubbing column.

Soda Ash Captures Carbon Dioxide

A sodium carbonate solution is pumped into the top of the 11-foot-tall scrubbing column. The flue gas is bubbled up through the column. As it moves toward the top, the sodium carbonate or soda ash removes much of the carbon dioxide from the gas. Kawatra and his students monitor the amount of carbon dioxide constantly.

"The biggest challenge is a fluctuating ratio of gases in the flue gas," Valluri said. Team member Root elaborates, "You need a cascade control system that measures the carbon dioxide and manipulates the amount of scrubbing solution accordingly."

"Our next challenges are, how much can we scale the scrubber up and what can we use the carbon dioxide for," Valluri says. This ties into Valluri's and Claremboux's other research project, the conversion of carbon dioxide to useful products. They have been able to produce oxalic acid from carbon dioxide at laboratory scale.

Tech Alumnus Supports Research

John Simmons, a Michigan Tech alumnus in the Chemical Engineering Academy at Tech and chairman of Carbontec Energy in Bismarck, North Dakota, is supporting Kawatra's research. He says the savings to industry of this kind of carbon dioxide scrubber is enormous.

The usual method of removing carbon dioxide from emissions uses amines, nitrogen-based chemical compounds that bind the carbon dioxide. But amines cost $20,000 a ton, Simmons said. Carbonates like the soda ash that Kawatra's team is using cost $200 a ton.

Simmons is excited about the potential for producing a commercial product from the captured carbon dioxide. "I don't think sequestering it in the ground is a good idea," he says. "We have to find a way to utilize it commercially."

The technology, trade-named the "Clearite VI Carbon Dioxide Capture/ Utilization Process," was patented (Patent No. US7,919,064B2 ) by the inventors, S. Komar Kawatra, Tim Eisele and John Simmons, and assigned to Michigan Tech. Carbontec Energy Corporation, the technology sponsor, is the exclusive world-wide licensee and plans to commercialize the technology through joint ventures and sub-licenses.

Read more at Science Daily

Do volcanoes or an asteroid deserve blame for dinosaur extinction?

Layered lava flows within the Wai Subgroup from near Ambenali Ghat, Western Ghats.

Based on new data published today in the journal Science, it seems increasingly likely that an asteroid or comet impact 66 million years ago reignited massive volcanic eruptions in India, half a world away from the impact site in the Caribbean Sea.

But it leaves unclear to what degree the two catastrophes contributed to the near-simultaneous mass extinction that killed off the dinosaurs and many other forms of life.

The research sheds light on huge lava flows that have erupted periodically over Earth's history, and how they have affected the atmosphere and altered the course of life on the planet.

In the study, University of California, Berkeley, scientists report the most precise and accurate dates yet for the intense volcanic eruptions in India that coincided with the worldwide extinction at the end of the Cretaceous Period, the so-called K-Pg boundary. The million-year sequence of eruptions spewed lava flows for distances of at least 500 kilometers across the Indian continent, creating the so-called Deccan Traps flood basalts that in some places are nearly 2 kilometers thick.

"Now that we have dated Deccan Traps lava flows in more and different locations, we see that the transition seems to be the same everywhere. I would say, with pretty high confidence, that the eruptions occurred within 50,000 years, and maybe 30,000 years, of the impact, which means they were synchronous within the margin of error," said Paul Renne, a professor-in-residence of earth and planetary science at UC Berkeley, director of the Berkeley Geochronology Center and senior author of the study, which will appear online Feb. 21. "That is an important validation of the hypothesis that the impact renewed lava flows."

The new dates also confirm earlier estimates that the lava flows continued for about a million years, but contain a surprise: three-quarters of the lava erupted after the impact. Previous studies suggested that about 80 percent of the lava erupted before the impact.

If most of the Deccan Traps lava had erupted before the impact, then gases emitted during the eruptions could have been the cause of global warming within the last 400,000 years of the Cretaceous Period, during which temperatures increased, on average, about 8 degrees Celsius (14.4 degrees Fahrenheit). During this period of warming, species would have evolved suited to hothouse conditions, only to be confronted by global cooling from the dust or by climate cooling gases caused by either the impact or the volcanos.

The cold would have been a shock from which most creatures would never have recovered, disappearing entirely from the fossil record: literally, a mass extinction.

But if most of the Deccan Traps lava emerged after the impact, this scenario needs rethinking.

"This changes our perspective on the role of the Deccan Traps in the K-Pg extinction," said first author Courtney Sprain, a former UC Berkeley doctoral student who is now a postdoc at the University of Liverpool in the United Kingdom. "Either the Deccan eruptions did not play a role -- which we think unlikely -- or a lot of climate-modifying gases were erupted during the lowest volume pulse of the eruptions."

The hypothesis that climate-altering volcanic gases leak out of underground magma chambers frequently, and not just during eruptions, is supported by evidence from present-day volcanos, such as those of the gas-spewing Mt. Etna in Italy and Popocatepetl in Mexico, the researchers said. Magma stewing below the surface is known to transmit gases to the atmosphere, even without eruptions.

"We are suggesting that it is very likely that a lot of the gases that come from magma systems precede eruptions; they don't necessarily correlate with eruptions," Renne said. In the case of the K-Pg extinction, the symptoms of significant climate change occurred before the peak in volcanic eruptions.

Flood basalts

Renne, Sprain and their colleagues are using a precise dating method, argon-argon dating, to determine when the impact occurred and when the Deccan Traps erupted to clarify the sequence of catastrophes at the end of the Cretaceous Period and beginning of the Tertiary Period -- the K-Pg boundary, formerly referred to as the K-T boundary.

In 2013, using rocks from Montana, they obtained the most precise date yet for the impact, and in 2018, they updated that to 66,052,000 years ago, give or take 8,000 years. Then, in 2015, they determined from a handful of samples in India that, in at least one spot, the peak of the Deccan Traps eruptions occurred within about 50,000 years of that date, which means, in geologic time, that the incidents were basically simultaneous.

Now, with three times more rock samples from areas covering more of the Deccan Traps, the researchers have established that the time of peak eruptions was the same across much of the Indian continent. This supports the group's hypothesis that the asteroid impact triggered super-earthquakes that caused a strong burst of volcanism in India, which is almost directly opposite the impact site, the Chicxulub crater in the Caribbean Sea.

Sprain and Renne argue that the coincident catastrophes likely delivered a one-two punch to life on Earth, but the details are unclear. Volcanic eruptions produce lots of gases, but some, like carbon dioxide and methane, warm the planet, while others, like sulfur aerosols, are cooling. The impact itself would have sent dust into the atmosphere that blocked sunlight and cooled the Earth, though no one knows for how long.

"Both the impact and Deccan volcanism can produce similar environmental effects, but these are occurring on vastly differing timescales," Sprain said. "Therefore, to understand how each agent contributed to the extinction event, assessing timing is key."

Which gases in the Deccan Traps are emitted when is a question that's hard to answer, because there are no flood basalt eruptions going on today, despite numerous ones in Earth's history. The most recent, near the Columbia River in the Pacific Northwest, dwindled 15 million years ago after 400,000 years of eruptions.

The paucity of information about flood basalts is one reason Renne and Sprain are interested in the Deccan Traps, which are still young enough to contain information about the sequence, effects and scale of the eruptions, and perhaps the cause.

"It makes we wonder whether we may see some external forcing mechanism, like the impact for the Deccan Traps, for other flood basalts that lead up to major peaks in eruptions, like the Columbia River basalts or the Siberian Traps," Renne said. "Could a major earthquake in nearby subduction zones or the accumulation of pressure due to rising magma unleash these major episodes in flood basalts?"

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Earliest example of animal nest sharing revealed by scientists

Two of the fossilized enantiornithine eggs.

An international team of scientists, including researchers from the University of Southampton, has shown that fossilised eggshells unearthed in western Romania represent the earliest known nest site shared by multiple animals.

The shells -- some complete and others broken into thousands of pieces -- are densely packed and encased in mudstone which formed part of the remains of a bird breeding colony, probably comprising hundreds of seperate nests.

Now in the collections of the Transylvanian Museum Society in Cluj Napoca, Romania, the samples date from the late-Cretaceous period (approx. 70 million years ago) and were discovered near the city of Sebeş in Transylvania by local palaeontologist Mátyás Vremir about nine years ago.

Led by Centro Regional Universitario Bariloche in Argentina, the scientists examined sophisticated electron microscope images of the unique, fossilised material from the site. They established it contains four different types of egg shell, indicating that four types of animals all shared the same nesting site; extinct birds within a group known as enantiornithes, birds of undetermined classification, gecko-like lizards and smaller predecessors of today's crocodiles.

Christian Laurent, Tizard Scholar and member of the Aerodynamics and Flight Mechanics Group at the University of Southampton, comments: "We know very little about the parental behaviour of Mesozic birds, We know they had nests, laid eggs and hatched young which were relatively mature and able to move around after hatching -- but evidence is scant beyond this. This research suggests they were tolerant of creating their nests, not only alongside other birds, but also reptiles."

The team, which also includes researchers from the University of Jinan (China), the Transylvanian Museum Society (Romania), the Royal British Columbia Museum (Canada), the University of Debrecen (Hungary), and Pavol Jozef Safarik University (Slovak Republic), has published its findings in the journal Nature Scientific Reports.

Their paper speculates that an area of plain created by seasonal flooding offered the enantiornithes safety from predators. It's also believed that their nest environments afforded shelter to smaller reptiles which benefitted from the security of the birds guarding their own nests. The researchers suggest that the lizard and crocodile type animals were not perceived as a threat to the bird eggs and nestlings -- possibly because they were much smaller than the adult birds and so not a predatory threat to them or their hatchlings. To date, this is the oldest example of this kind of ecological strategy.

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Homo sapiens colonized South Asian rainforest by hunting small mammals 45,000 years ago

This is an example of tools manufactured from monkey bones and teeth recovered from the Late Pleistocene layers of Fa Hien Cave, Sri Lanka.

A multidisciplinary study has found evidence for humans hunting small mammals in the forests of Sri Lanka at least 45,000 years ago. The researchers discovered the remains of small mammals, including primates, with evidence of cut-marks and burning at the oldest archaeological site occupied by humans in Sri Lanka, alongside sophisticated bone and stone tools. The hunting of such animals is an example of the uniquely human adaptability that allowed H. sapiens to rapidly colonize a series of extreme environments apparently untouched by its hominin relatives.

In a new paper published in Nature Communications, an international team of scientists has revealed novel evidence for the unique adaptability of Homo sapiens. The study, led by scientists from the Max Planck Institute for the Science of Human History, alongside colleagues from Sri Lankan and other international institutions, shows that human populations were able to specialize in the hunting of small arboreal animals for tens of thousands of years. This is the oldest and longest record of sophisticated, active primate hunting by foragers. This work also highlights the distinctive ecological capacities of H. sapiens relative to its hominin ancestors and relatives.

Tropical rainforests: a unique challenge

Recent research has demonstrated that our species adapted to a diversity of extreme environments as they spread around the world, including deserts, high altitude settings, palaeoarctic conditions, and tropical forests. Previously, however, discussion of the migration of our species into Europe, the Middle East, and Asia has often focused on our increased efficiency in hunting, butchering, and consuming medium to large game in open 'savanna' settings. Alternatively, coastal settings have been seen as important sources of protein, stimulating human evolution and migration.

Tropical rainforests have been somewhat neglected in discussions of human migrations and dispersal. In public and academic perception, these environments are often seen as isolated barriers to human movement, with disease, dangerous animals, and limited resources all posing challenges. In particular, when compared to the large animals of open savannas, small, fast forest monkeys and squirrels are difficult to capture and provide smaller amounts of protein.

Small mammals and hunting complexity

The procurement of small mammals has long been considered a feature of technological and behavioural 'complexity' or 'modernity' unique to our species. Previous research in Europe and West Asia has linked increased capture and consumption of agile small mammals both to human population growth and to climatically-driven crises. Traditionally, these have been considered to be particularly extreme ~20,000 years ago.

However, the onset and behavioural context of small mammal hunting in other parts of the world, particularly Asia, has remained poorly studied. This is particularly the case outside of temperate environments. "Over the last two decades, research has highlighted human occupation of tropical rainforests in South Asia, Southeast Asia, and Melanesia at least as early as 45,000 years ago, so the potential for human reliance on small mammals in these settings prior to 20,000 years ago seems likely," says co-senior author Dr. Patrick Roberts of the Max Planck Institute for the Science of Human History.

A Sri Lankan specialty

Sri Lanka has been a prominent part of discussions of early human adaptations to tropical rainforests, though there has been a general lack of systematic, detailed analysis of animal remains associated with archaeological sites on the island. For the current study, the researchers produced new chronological information, analysis of animal remains, and studies of lithic and bone tool assemblages from Fa-Hien Lena Cave, the site of the earliest fossil and archaeological evidence of H. sapiens in Sri Lanka.

"The results demonstrate specialized, sophisticated hunting of semi-arboreal and arboreal monkey and squirrel populations from 45,000 years ago in a tropical rainforest environment," says Oshan Wedage, lead author of the study, of the Max Planck Institute for the Science of Human History. Co-author Dr. Noel Amano, also of the Max Planck Institute for the Science of Human History, adds, "This was complemented by sophisticated bone tool technologies which were, in turn, created from the bones of hunted monkeys."

Fine-tuned adaptations, not 'monkey business'

Together, the results of this new work demonstrate a highly tuned focus on monkey and other small mammal hunting over 45,000 years. A sustained focus on adult monkeys throughout this time period suggests that this strategy continued to be sustainable during this lengthy period and that the tropical rainforests were not over-taxed by human presence and practices.

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Origins of giant extinct New Zealand bird traced to Africa

Adzebill skeleton on display in the Canterbury Museum, New Zealand. Among the giant bird's closest living relatives are the tiny flufftails from Madagascar and Africa.

Scientists have revealed the African origins of New Zealand's most mysterious giant flightless bird -- the now extinct adzebill -- showing that some of its closest living relatives are the pint-sized flufftails from Madagascar and Africa.

Led by the University of Adelaide, the research in the journal Diversity showed that among the closest living relatives of the New Zealand adzebills -- which weighed up to 19 kilograms -- are the tiny flufftails, which can weigh as little as 25 grams. The closeness of the relationship strongly suggests that the ancestors of the adzebills flew to New Zealand after it became physically isolated from other land.

This finding mirrors the close relationship between New Zealand's kiwi and the extinct Madagascan elephant birds, published by University of Adelaide researchers in 2014, hinting at an unappreciated biological connection between Madagascar and New Zealand.

Like the better-known moa, the two species of adzebill -- the North Island adzebill and South Island adzebill -disappeared following the arrival of early Maori in New Zealand, who hunted them and cleared their forest habitats. Unlike the moa, adzebills were predators and not herbivores.

"The adzebill were almost completely wingless and had an enormous reinforced skull and beak, almost like an axe, which is where they got their English name," says Alexander Boast, lead author and former Masters student at the University of Adelaide.

"If they hadn't gone extinct, they would be among the largest living birds."

A team of researchers from Australia, New Zealand, and the US analysed genetic data from the two adzebill species.

"A lot of past genetic research and publicity has focused on the moa, which we know were distant relatives of the ostrich, emu, and cassowary," says co-author Dr Kieren Mitchell, postdoctoral researcher at the University of Adelaide.

"But noone had analysed the genetics of the adzebill, despite a lot of debate about exactly what they were and where they came from."

"We know that adzebills have been in New Zealand for a relatively long time, since we previously discovered a 19 million-year-old adzebill fossil on the South Island," says co-author Associate Professor Trevor Worthy, a palaeontologist at Flinders University.

"A key question is whether they've been present since New Zealand broke away from the other fragments of the supercontinent Gondwana or whether their ancestors flew to New Zealand from elsewhere later on."

Researchers at both the University of Adelaide's Australian Centre for Ancient DNA and Curtin University's Ancient DNA Lab sequenced adzebill DNA from fragments of bone and eggshell. They compared this to DNA from living birds to discover the identity and origin of the adzebill.

"It's possible that ancient migration of birds between Madagascar and New Zealand may have occurred via Antarctica," says Dr Mitchell.

"Some coastal regions of the continent remained forested and ice free until as recently as 30 million years ago."

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Ingredients for water could be made on surface of moon, a chemical factory

Waxing gibbous moon.

When a stream of charged particles known as the solar wind careens onto the Moon's surface at 450 kilometers per second (or nearly 1 million miles per hour), they enrich the Moon's surface in ingredients that could make water, NASA scientists have found.

Using a computer program, scientists simulated the chemistry that unfolds when the solar wind pelts the Moon's surface. As the Sun streams protons to the Moon, they found, those particles interact with electrons in the lunar surface, making hydrogen (H) atoms. These atoms then migrate through the surface and latch onto the abundant oxygen (O) atoms bound in the silica (SiO2) and other oxygen-bearing molecules that make up the lunar soil, or regolith. Together, hydrogen and oxygen make the molecule hydroxyl (OH), a component of water, or H2O.

"We think of water as this special, magical compound," said William M. Farrell, a plasma physicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who helped develop the simulation. "But here's what's amazing: every rock has the potential to make water, especially after being irradiated by the solar wind."

Understanding how much water -- or its chemical components -- is available on the Moon is critical to NASA's goal of sending humans to establish a permanent presence there, said Orenthal James Tucker, a physicist at Goddard who spearheaded the simulation research.

"We're trying to learn about the dynamics of transport of valuable resources like hydrogen around the lunar surface and throughout its exosphere, or very thin atmosphere, so we can know where to go to harvest those resources," said Tucker, who recently described the simulation results in the journal JGR Planets.

Several spacecraft used infrared instruments that measure light emitted from the Moon to identify the chemistry of its surface. These include NASA's Deep Impact spacecraft, which had numerous close encounters with the Earth-Moon system en route to comet 103P/Hartley 2; NASA's Cassini spacecraft, which passed the Moon on its way to Saturn; and India's Chandrayaan-1, which orbited the Moon a decade ago. All found evidence of water or its components (hydrogen or hydroxyl).

But how these atoms and compounds form on the Moon is still an open question. It's possible that meteor impacts initiate the necessary chemical reactions, but many scientists believe that the solar wind is the primary driver.

Tucker's simulation, which traces the lifecycle of hydrogen atoms on the Moon, supports the solar wind idea.

"From previous research, we know how much hydrogen is coming in from the solar wind, we also know how much is in the Moon's very thin atmosphere, and we have measurements of hydroxyl in the surface," Tucker said. "What we've done now is figure out how these three inventories of hydrogen are physically intertwined."

Showing how hydrogen atoms behave on the Moon helped resolve why spacecraft have found fluctuations in the amount of hydrogen in different regions of the Moon. Less hydrogen accumulates in warmer regions, like the Moon's equator, because hydrogen atoms deposited there get energized by the Sun and quickly outgas from the surface into the exosphere, the team concluded. Conversely, more hydrogen appears to accumulate in the colder surface near the poles because there's less Sun radiation and the outgassing is slowed.

Overall, Tucker's simulation shows that as solar wind continually blasts the Moon's surface, it breaks the bonds among atoms of silicon, iron and oxygen that make up the majority of the Moon's soil. This leaves oxygen atoms with unsatisfied bonds. As hydrogen atoms flow through the Moon's surface, they get temporarily trapped with the unhinged oxygen (longer in cold regions than in warm). They float from O to O before finally diffusing into the Moon's atmosphere, and, ultimately, into space. "The whole process is like a chemical factory," Farrell said.

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Tiny Neptune moon spotted by Hubble may have broken from larger moon

An artist's concept of the tiny moon Hippocamp that was discovered by the Hubble Space Telescope in 2013. Only 20 miles across, it may actually be a broken-off fragment from a much larger neighboring moon, Proteus, seen as a crescent in the background. This is the first evidence for a moon being an offshoot from a comet collision with a much larger parent body.

Astronomers call it "the moon that shouldn't be there."

After several years of analysis, a team of planetary scientists using NASA's Hubble Space Telescope has at last come up with an explanation for a mysterious moon around Neptune that they discovered with Hubble in 2013.

The tiny moon, named Hippocamp, is unusually close to a much larger Neptunian moon called Proteus. Normally, a moon like Proteus should have gravitationally swept aside or swallowed the smaller moon while clearing out its orbital path.

So why does the tiny moon exist? Hippocamp is likely a chipped-off piece of the larger moon that resulted from a collision with a comet billions of years ago. The diminutive moon, only 20 miles (about 34 kilometers) across, is 1/1000th the mass of Proteus (which is 260 miles [about 418 kilometers] across).

"The first thing we realized was that you wouldn't expect to find such a tiny moon right next to Neptune's biggest inner moon," said Mark Showalter of the SETI Institute in Mountain View, California. "In the distant past, given the slow migration outward of the larger moon, Proteus was once where Hippocamp is now."

This scenario is supported by Voyager 2 images from 1989 that show a large impact crater on Proteus, almost large enough to have shattered the moon. "In 1989, we thought the crater was the end of the story," said Showalter. "With Hubble, now we know that a little piece of Proteus got left behind and we see it today as Hippocamp." The orbits of the two moons are now 7,500 miles (about 12,070 kilometers) apart.

Neptune's satellite system has a violent and tortured history. Many billions of years ago, Neptune captured the large moon Triton from the Kuiper Belt, a large region of icy and rocky objects beyond the orbit of Neptune. Triton's gravity would have torn up Neptune's original satellite system. Triton settled into a circular orbit and the debris from shattered Neptunian moons re-coalesced into a second generation of natural satellites. However, comet bombardment continued to tear things up, leading to the birth of Hippocamp, which might be considered a third-generation satellite.

"Based on estimates of comet populations, we know that other moons in the outer solar system have been hit by comets, smashed apart, and re-accreted multiple times," noted Jack Lissauer of NASA's Ames Research Center in California's Silicon Valley, a coauthor on the new research. "This pair of satellites provides a dramatic illustration that moons are sometimes broken apart by comets."

Hippocamp is a half-horse half-fish from Greek mythology. The scientific name for the seahorse is Hippocampus, also the name of an important part of the human brain. The rules of the International Astronomical Union require that the moons of Neptune are named after Greek and Roman mythology of the undersea world.

The team of astronomers in this study consists of M. Showalter (SETI Institute, Mountain View, California), I. de Pater (University of California, Berkeley, California), J. Lissauer (NASA Ames Research Center, Silicon Valley, California), and R. French (SETI Institute, Mountain View, California).

The paper will appear in the February 21 issue of the science journal Nature.

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Earth may be 140 years away from reaching carbon levels not seen in 56 million years

Blue Marble Earth montage, created from photographs taken by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on board the new Suomi NPP satellite.

Total human carbon dioxide emissions could match those of Earth's last major greenhouse warming event in fewer than five generations, new research finds.

A new study finds humans are pumping carbon dioxide into the atmosphere at a rate nine to 10 times higher than the greenhouse gas was emitted during the Paleocene-Eocene Thermal Maximum (PETM), a global warming event that occurred roughly 56 million years ago.

The results suggest if carbon emissions continue to rise, the total amount of carbon dioxide injected into the atmosphere since humans started burning fossil fuels could equal the amount released during the PETM as soon as 2159.

"You and I won't be here in 2159, but that's only about four generations away," said Philip Gingerich, a paleoclimate researcher at the University of Michigan and author of the new study in the AGU journal Paleoceanography and Paleoclimatology. "When you start to think about your children and your grandchildren, and your great-grandchildren, you're about there."

Scientists often use the PETM as a benchmark against which to compare modern climate change. But the new study shows we're on track to meet this benchmark much sooner than previously thought, as the pace of today's warming far outstrips any climate event that has happened since the extinction of the dinosaurs.

"Given a business-as-usual assumption for the future, the rates of carbon release that are happening today are really unprecedented, even in the context of an event like the PETM," said Gabriel Bowen, a geophysicist at the University of Utah who was not connected to the new study. "We don't have much in the way of geologic examples to draw from in understanding how the world responds to that kind of perturbation."

The exact environmental consequences of PETM-like carbon levels are unclear, but the increased temperatures will likely drive many species to extinction with the lucky ones being able to adapt or migrate, according to Larisa DeSantis, a paleontologist at Vanderbilt University who was not connected to the new study. In addition, it will take thousands of years for the climate system cool down, she said.

"It's not just about 100 years from now; it's going to take significant periods of time for that carbon dioxide to make its way back into the Earth's crust," DeSantis said. "It's not a short-term event. We're really committing ourselves to many thousands of years of a warmer world if we don't take action quickly."

Studying past climate change

The PETM was a global warming event that occurred roughly 56 million years ago. Scientists are unsure what caused it, but during the event massive quantities of carbon dioxide were released into Earth's atmosphere, rapidly spiking global temperatures by 5 to 8 degrees Celsius (9 to 14 degrees Fahrenheit). Average global temperatures during the PETM peaked at about 23 degrees Celsius (73 degrees Fahrenheit), about 7 degrees Celsius (13 degrees Fahrenheit) higher than today's average.

Scientists think that during this time and the warm period that followed, the poles were ice-free and the Arctic was home to palm trees and crocodiles. It's not the hottest Earth has ever been, but the PETM was the warmest period since the extinction of the dinosaurs 66 million years ago.

Scientists can't pin down exactly how much carbon was injected into the atmosphere during the PETM or exactly how long the event lasted. But their best estimates say between 3,000 and 7,000 gigatons of carbon accumulated over a period of 3,000 to 20,000 years, based on ocean sediment cores that show changes to carbonate minerals laid down during this time.

The massive carbon release and temperature spike drastically altered Earth's climate, causing a major extinction of organisms in the deep ocean that are a key link in the marine food web. Land animals got smaller and migrated north to cooler climates. Some groups of modern mammals, including primates, appeared for the first time soon after the PETM, but scientists are unsure whether this happened as a direct result of the rapid environmental change.

Comparing past with present

Climate scientists use the PETM as a case study for understanding what environmental changes might happen under current human-caused climate change and when those changes might take effect. But they can only average carbon emissions during the PETM over the whole duration of the event -- thousands of years. They don't know what those emissions rates were like on a yearly basis, so it's difficult to compare them to the pace of carbon emissions today.

In the new study, Gingerich found a way to mathematically compare modern carbon emissions to PETM emissions on the same time scale. The results showed current carbon emission rates are nine to 10 times higher than those during the PETM.

"To me, it really brought home how rapidly and how great the consequences are of the carbon we're producing as a people," Gingerich said.

Projecting current emissions into the future, Gingerich found that if emissions continue to rise, we could be facing another PETM-like event in fewer than five generations. The total carbon accumulated in the atmosphere could hit the lowest estimate of carbon accumulated during the PETM -- 3,000 gigatons -- in the year 2159. It would hit the maximum estimated emissions -- 7,126 gigatons -- in 2278, based on Gingerich's calculations. Humans have emitted roughly 1,500 gigatons of carbon as of 2016.

"The fact that we could reach warming equivalent to the PETM very quickly, within the next few hundred years, is terrifying," DeSantis said.

The findings suggest scientists may not be able to predict the environmental or biological changes that will happen in the coming years based on what happened during the PETM because today's warming is occurring so much faster, according to DeSantis. What makes predictions harder is that today's climate starts from a cooler baseline than the PETM and the species that inhabit Earth are different than those of 56 million years ago.

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Citizen scientist finds ancient white dwarf star encircled by puzzling rings

In this illustration, an asteroid (bottom left) breaks apart under the powerful gravity of LSPM J0207+3331, the oldest, coldest white dwarf known to be surrounded by a ring of dusty debris. Scientists think the system's infrared signal is best explained by two distinct rings composed of dust supplied by crumbling asteroids.

A volunteer working with the NASA-led Backyard Worlds: Planet 9 project has found the oldest and coldest known white dwarf -- an Earth-sized remnant of a Sun-like star that has died -- ringed by dust and debris. Astronomers suspect this could be the first known white dwarf with multiple dust rings.

The star, LSPM J0207+3331 or J0207 for short, is forcing researchers to reconsider models of planetary systems and could help us learn about the distant future of our solar system.

"This white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales," said John Debes, an astronomer at the Space Telescope Science Institute in Baltimore. "Most of the models scientists have created to explain rings around white dwarfs only work well up to around 100 million years, so this star is really challenging our assumptions of how planetary systems evolve."

A paper detailing the findings, led by Debes, was published in the Feb. 19 issue of The Astrophysical Journal Letters and is now available online.

J0207 is located around 145 light-years away in the constellation Capricornus. White dwarfs slowly cool as they age, and Debes' team calculated J0207 is about 3 billion years old based on a temperature just over 10,500 degrees Fahrenheit (5,800 degrees Celsius). A strong infrared signal picked up by NASA's Wide-field Infrared Survey Explorer (WISE) mission -- which mapped the entire sky in infrared light -- suggested the presence of dust, making J0207 the oldest and coldest white dwarf with dust yet known. Previously, dust disks and rings had only been observed surrounding white dwarfs about one-third J0207's age.

When a Sun-like star runs out of fuel, it swells into a red giant, ejects at least half of its mass, and leaves behind a very hot white dwarf. Over the course of the star's giant phase, planets and asteroids close to the star become engulfed and incinerated. Planets and asteroids farther away survive, but move outward as their orbits expand. That's because when the star loses mass, its gravitational influence on surrounding objects is greatly reduced.

This scenario describes the future of our solar system. Around 5 billion years from now, Mercury, then Venus and possibly Earth will be swallowed when the Sun grows into a red giant. Over hundreds of thousands to millions of years, the inner solar system will be scrubbed clean, and the remaining planets will drift outward.

Yet some white dwarfs -- between 1 and 4 percent -- show infrared emission indicating they're surrounded by dusty disks or rings. Scientists think the dust may arise from distant asteroids and comets kicked closer to the star by gravitational interactions with displaced planets. As these small bodies approach the white dwarf, the star's strong gravity tears them apart in a process called tidal disruption. The debris forms a ring of dust that will slowly spiral down onto the surface of the star.

J0207 was found through Backyard Worlds: Planet 9, a project led by Marc Kuchner, a co-author and astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, that asks volunteers to sort through WISE data for new discoveries.

Melina Thévenot, a co-author and citizen scientist in Germany working with the project, initially thought the infrared signal was bad data. She was searching through the ESA's (European Space Agency's) Gaia archives for brown dwarfs, objects too large to be planets and too small to be stars, when she noticed J0207. When she looked at the source in the WISE infrared data, it was too bright and too far away to be a brown dwarf. Thévenot passed her findings along to the Backyard Worlds: Planet 9 team. Debes and Kuchner contacted collaborator Adam Burgasser at the University of California, San Diego to obtain follow-up observations with the Keck II telescope at the W. M. Keck Observatory in Hawaii.

"That is a really motivating aspect of the search," said Thévenot, one of more than 150,000 citizen scientists on the Backyard Worlds project. "The researchers will move their telescopes to look at worlds you have discovered. What I especially enjoy, though, is the interaction with the awesome research team. Everyone is very kind, and they are always trying to make the best out of our discoveries."

The Keck observations helped confirm J0207's record-setting properties. Now scientists are left to puzzle how it fits into their models.

Debes compared the population of asteroid belt analogs in white dwarf systems to the grains of sand in an hourglass. Initially, there's a steady stream of material. The planets fling asteroids inward towards the white dwarf to be torn apart, maintaining a dusty disk. But over time, the asteroid belts become depleted, just like grains of sand in the hourglass. Eventually, all the material in the disk falls down onto the surface of the white dwarf, so older white dwarfs like J0207 should be less likely to have disks or rings.

J0207's ring may even be multiple rings. Debes and his colleagues suggest there could be two distinct components, one thin ring just at the point where the star's tides break up the asteroids and a wider ring closer to the white dwarf. Follow-up with future missions like NASA's James Webb Space Telescope may help astronomers tease apart the ring's constituent parts.

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20-million-year-old tusked sea cow is Central America's oldest marine mammal

About 19-21 million years old, this dugong is the oldest marine mammal found in Central America and the first from the Pacific side of the Panama Canal. Here, the skull is seen from the side with the snout pointing to the right.

Steven Manchester didn't set out to discover Central America's oldest known marine mammal. He was hoping to find fossil plants.

Manchester, curator of paleobotany at the Florida Museum of Natural History, had left a group of vertebrate paleontologists uphill of the Panama Canal to do his own prospecting, clambering down onto the narrow, exposed shoreline to look for fossil leaves, petrified wood and mineralized fruits and nuts.

It was a dangerous place to be: The rolling wake from passing ships could sweep a person off shore and into the canal. Manchester noticed that people were occasionally shouting at him through megaphones as they cruised past, but not understanding Spanish, he continued to comb the shore when he spotted bone.

"He quickly walked us over to where he'd found a skeleton sticking out of the rock exposure," said Aaron Wood, then a museum postdoctoral researcher leading fieldwork in Panama. "There were two or three vertebrae, orange-ish in color, dipping into the black rock on the side of the canal and a couple of ribs around them. We guessed that there would be more under the rock."

What Wood described as an "emergency fossil excavation" due to rising water levels yielded a remarkably complete skeleton of an ancient sea cow, estimated to be about 20 million years old, the first evidence of a marine mammal from the Pacific side of the canal.

The fossil skull, vertebrae, ribs and other bones belong to a new genus and species, Culebratherium alemani, a tusked seagrass-grazing relative of modern dugongs, which live in the warm coastal waters of the Indo-Pacific.

Wood and lead author Jorge Velez-Juarbe, also a former museum postdoctoral researcher, published their findings in the Journal of Vertebrate Paleontology.

About 15 feet long, this C. alemani was not done growing, Velez-Juarbe said. Its tusks had only begun to protrude and its newest molars showed little wear, indicating it was not yet an adult.

But it was a powerful eater. The researchers propose that its thick neck muscles, tusks and downward-pointing snout were adaptations for digging pits in the ocean floor to get to the underground stems of seagrass, the plants' most nutritional parts.

"Finding C. alemani is pretty good evidence that there was seagrass in this region 20 million years ago," said Velez-Juarbe, now assistant curator of marine mammals at the Natural History Museum of Los Angeles County. "This particular group of sirenians" -- the order that includes dugongs and manatees -- "are seagrass specialists."

While only one species of dugong is alive today -- a second, Steller's sea cow, was hunted to extinction within 27 years of its discovery -- about 30 species have been recovered in the fossil record, Velez-Juarbe said. The group originated in the West Atlantic and Caribbean and dispersed westward through Panama, whose seaway did not close until a few million years ago, and south to Brazil.

"Today, Panama is the juncture between two continents, and that's where we have a mixture of mammals between North and South America," said Wood, now director of Iowa State University's Carl F. Vondra Geology Field Station and a lecturer in the department of geological and atmospheric sciences. "In the early Miocene, when this dugong lived, it wasn't a land connection but a sea connection between the Atlantic and Pacific. We would expect to see communities of sea cows there, too."

Previous research shows that multiple species of dugongs commonly lived together, each with slightly differently shaped tusks, snouts and body sizes that would have enabled them to divide up food resources, Velez-Juarbe said.

"Some would eat larger species of seagrass buried deeply in the sand while others would feed on smaller grasses closer to the surface," he said. "Evidence from many other places in the world shows that multispecies communities were the norm. To only have one species of dugong now is freaky."

These communities also made for healthier seagrass beds, he said. Whereas a single seagrass species, Thalassia testudinum, dominates the Caribbean and West Atlantic, grass beds in Australia have a better balance of species because modern dugongs feed on the larger grass species, keeping them in check and giving smaller grasses a shot at flourishing.

The researchers named C. alemani after the Culebra Formation where it was found and Alberto Aleman Zubieta, the former chief executive officer of the Panama Canal, whose support they described as essential to the fieldwork's success.

C. alemani was excavated as part of a large-scale, years-long project to salvage fossils during the expansion of the Panama Canal, which temporarily exposed fresh outcrops. Wood said that while he and the rest of the field crew understood the significance of their work, the discovery of the dugong "really brought that home."

"We found the fossil dugong when water levels were at their lowest," he said. "After the first day, they steadily rose. We put sandbags on the edge of the site just to keep water out long enough for us to collect it. Within a week, the site was flooded. We couldn't go back. The idea that this was a once-in-a-century opportunity was wrapped up in this one specimen."

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Neanderthals' main food source was definitely meat

Tooth of an adult Neanderthal from Les Cottés in France. Her diet consisted mainly of the meat of large herbivore mammals.

Neanderthals' diets are highly debated: they are traditionally considered carnivores and hunters of large mammals, but this hypothesis has recently been challenged by numerous pieces of evidence of plant consumption. Ancient diets are often reconstructed using nitrogen isotope ratios, a tracer of the trophic level, the position an organism occupies in a food chain. Neanderthals are apparently occupying a high position in terrestrial food chains, exhibiting slightly higher ratios than carnivores (like hyenas, wolves or foxes) found at the same sites. It has been suggested that these slightly higher values were due to the consumption of mammoth or putrid meat. And we also know some examples of cannibalism for different Neanderthal sites.

Paleolithic modern humans, who arrived in France shortly after the Neanderthals had disappeared, exhibit even higher nitrogen isotope ratios than Neanderthals. This is classically interpreted as the signature of freshwater fish consumption. Fishing is supposed to be a typical modern human activity, but again, a debate exists whether or not Neanderthals were eating aquatic resources. When Klervia Jaouen, a researcher at the Max Planck Institute for Evolutionary Anthropology and first author of the study, and collaborators discovered high nitrogen isotope ratios in the collagen of two Neanderthals falling in the range of modern humans, they wondered whether this could a signature of regular fish consumption.

The Neanderthals come from Les Cottés and Grotte du Renne, in France, two sites where no fish remains have been found. However, the measurements were performed on a tooth root, which recorded the diet between four to eight years of the individual's life, and on a bone of a one-year-old baby. These high nitrogen isotope ratios could also indicate that the Neanderthals were not weaned at this age, contradicting in the case of the Les Cottés Neanderthal (the one whose tooth root was analyzed) former pieces of evidence of early weaning around one year of age. In other words, many explanations (e.g. freshwater fish consumption, putrid meat, late weaning or even cannibalism) could account for such high values, and identifying the factor involved could change our understanding of Neanderthals' lifestyles.

Analysis of amino acids

In order to explain these exceptionally high nitrogen isotope ratios, Jaouen and collaborators decided to use a novel isotope technique. Compound-specific isotope analyses (CSIA) allow to separately analyze the amino acids contained in the collagen. Some of the amino acid isotope compositions are influenced by environmental factors and the isotope ratios of the food eaten. Other amino acid isotope ratios are in addition influenced by the trophic level. The combination of these amino acid isotope ratios allows to decipher the contribution of the environment and the trophic level to the final isotope composition of the collagen.

"Using this technique, we discovered that the Neanderthal of Les Cottés had a purely terrestrial carnivore diet: she was not a late weaned child or a regular fish eater, and her people seem to have mostly hunted reindeers and horses," says Jaouen. "We also confirmed that the Grotte du Renne Neanderthal was a breastfeeding baby whose mother was a meat eater." Interestingly, this conclusion matches with the observations of the zooarcheologists.

The study also illustrates the importance of this new isotope technique for future investigations into ancient human and Neanderthal diets. Using compound-specific isotope analysis allowed the researchers not to misinterpret the global nitrogen isotope ratio which was exceptionally high. Michael P. Richards of the Simon Fraser University in Canada comments: "Previous isotope results indicated a primarily carnivorous diet for Neanderthals, which matches the extensive archaeological record of animal remains found and deposited by Neanderthals. There has recently been some frankly bizarre interpretations of the bulk isotope data ranging from Neanderthals primarily subsisting on aquatic plants to eating each other, both in direct contrast to the archaeological evidence. These new compound-specific isotope measurements confirm earlier interpretations of Neanderthal diets as being composed of mainly large herbivores, although of course they also consumed other foods such as plants."

Monotonous diet

In addition to confirming the Neanderthals as terrestrial carnivores, this work seems to indicate that these hominins had a very monotonous diet over time, even once they had started to change their material industry, possibly under the influence of modern humans. The baby Neanderthal of Grotte du Renne was indeed found associated to the Châtelperronian, a lithic technology similar to that of modern humans. Late Neanderthals were therefore very humanlike, painting caves and wearing necklaces, but unlike their sister species, did not seem to enjoy fishing.

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Spherical display brings virtual collaboration closer to reality

Virtual reality spherical display.

Virtual reality can often make a user feel isolated from the world, with only computer-generated characters for company. But researchers at the University of British Columbia and University of Saskatchewan think they may have found a way to encourage a more sociable virtual reality.

The researchers have developed a ball-shaped VR display that supports up to two users at a time, using advanced calibration and graphics rendering techniques that produce a complete, distortion-free 3D image even when viewed from multiple angles.

Most spherical VR displays in the market are capable of showing a correct image only from a single viewpoint, said lead researcher Sidney Fels, an electrical and computer engineering professor at UBC.

"When you look at our globe, the 3D illusion is rich and correct from any angle," explained Fels. "This allows two users to use the display to do some sort of collaborative task or enjoy a multiplayer game, while being in the same space. It's one of the very first spherical VR systems with this capability."

The system, which the researchers are calling Crystal, includes a 24-inch (600 millimetre) hollow ball-shaped display. The display surface was custom-made to specifications in Ottawa, while four high-speed projectors and one camera used for creating the images, calibration and touch sensing were purchased off-the-shelf.

The researchers are working on a four-person system and see many potential uses for their display in the future, including multiplayer virtual reality games, virtual surgery and VR-aided learning. However, they are focusing on teleconferencing applications and computer-aided design for now.

"Imagine a remote user joining a meeting of local users. At either location you can have a Crystal globe, which is great for seeing people's heads and faces in 3D," said Ian Stavness, a computer science professor at the University of Saskatchewan and a member of the research team. "Or you can have a team of industrial designers in a room, perfecting a design with the help of VR and motion tracking technology."

While the technology is young, the researchers are forecasting a good future for it.

"We're not saying that spherical VR will replace flat screens or headsets," said Fels, adding "but we think it can be a good option for VR activities where you still want to see and talk to other people -- be it at home or in the office, for work or play."

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Biodiversity on land is not higher today than in the past, study shows

The rich levels of biodiversity on land seen across the globe today are not a recent phenomenon: diversity on land has been similar for at least the last 60 million years, since soon after the extinction of the dinosaurs.

According to a new study led by researchers at the University of Birmingham and involving an international team of collaborators, the number of species within ecological communities on land has increased only sporadically through geological time, with rapid increases in diversity being followed by plateaus lasting tens of millions of years.

Previously, many scientists have argued that diversity increased steadily through geological time, which would mean that biodiversity today is much greater than it was tens of millions of years ago. But building an accurate picture of how land diversity was assembled is challenging because the fossil record generally becomes less complete further back in time. By using modern computing techniques, capable of analysing hundreds of thousands of fossils, patterns are starting to emerge that challenge this view.

The researchers, from the University of Birmingham's School of Geography, Earth and Environmental Sciences and other institutions in the UK, USA and Australia, were able to study fossil data collected by palaeontologists over the past 200 years at around 30,000 different fossil sites around the globe. The team focused on data from land vertebrates dating back to the very earliest appearance of this group nearly 400 million years ago.

They found that the average number of species within ecological communities of land vertebrates have not increased for tens of millions of years. Their results, published in Nature Ecology & Evolution, suggest that interactions between species, including competition for food and space, will limit the overall number of species that can co-exist.

Lead researcher, Dr Roger Close, says: "Scientists often think that species diversity has been increasing unchecked over millions of years, and that diversity is much greater today than it was in the distant past. Our research shows that numbers of species within terrestrial communities are limited over long timescales, which contradicts the results of many experiments in modern ecological communities -- now we need to understand why."

One reason why diversity within ecological communities does not increase unchecked on long timescales could be because resources used by species, such as food and space, are finite. Competition for these resources may prevent new species invading ecosystems and lead to a balance between rates of speciation and extinction. After the origins of major groups of animals, or large-scale ecological disruptions like mass extinctions, though, increases in diversity may happen abruptly -- on geological, if not human timescales -- and are again followed by long periods where no increases occur.

He adds: "Contrary to what you might expect, the largest increase in diversity within land vertebrate communities came after the mass extinction that wiped out the dinosaurs, 66 million years ago, at the end of the Cretaceous period. Within just a few million years, local diversity had increased to two or three times that of pre-extinction levels -- driven primarily by the spectacular success of modern mammals."

Professor Richard Butler, who was also part of the research team, said "Our work provides an example of the combined power of the fossil record and modern statistical approaches to answer major questions about the origins of modern biodiversity. By understanding how biodiversity has changed in the past, we may be able to better understand the likely long-term impact of the current biodiversity crisis."

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Climate change makes summer weather stormier yet more stagnant

Summer thunderstorm in the city.

Climate change is shifting the energy in the atmosphere that fuels summertime weather, which may lead to stronger thunderstorms and more stagnant conditions for midlatitude regions of the Northern Hemisphere, including North America, Europe, and Asia, a new MIT study finds.

Scientists report that rising global temperatures, particularly in the Arctic, are redistributing the energy in the atmosphere: More energy is available to fuel thunderstorms and other local, convective processes, while less energy is going toward summertime extratropical cyclones -- larger, milder weather systems that circulate across thousands of kilometers. These systems are normally associated with winds and fronts that generate rain.

"Extratropical cyclones ventilate air and air pollution, so with weaker extratropical cyclones in the summer, you're looking at the potential for more poor air-quality days in urban areas," says study author Charles Gertler, a graduate student in MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS). "Moving beyond air quality in cities, you have the potential for more destructive thunderstorms and more stagnant days with perhaps longer-lasting heat waves."

Gertler and his co-author, Associate Professor Paul O'Gorman of EAPS, are publishing their results in the Proceedings of the National Academy of Sciences.

A shrinking gradient

In contrast to more violent tropical cyclones such as hurricanes, extratropical cyclones are large weather systems that occur poleward of the Earth's tropical zone. These storm systems generate rapid changes in temperature and humidity along fronts that sweep across large swaths of the United States. In the winter, extratropical cyclones can whip up into Nor'easters; in the summer, they can bring everything from general cloudiness and light showers to heavy gusts and thunderstorms.

Extratropical cyclones feed off the atmosphere's horizontal temperature gradient -- the difference in average temperatures between northern and southern latitudes. This temperature gradient and the moisture in the atmosphere produces a certain amount of energy in the atmosphere that can fuel weather events. The greater the gradient between, say, the Arctic and the equator, the stronger an extratropical cyclone is likely to be.

In recent decades, the Arctic has warmed faster than the rest of the Earth, in effect shrinking the atmosphere's horizontal temperature gradient. Gertler and O'Gorman wondered whether and how this warming trend has affected the energy available in the atmosphere for extratropical cyclones and other summertime weather phenomena.

They began by looking at a global reanalysis of recorded climate observations, known as the ERA-Interim Reanalysis, a project that has been collecting available satellite and weather balloon measurements of temperature and humidity around the world since the 1970s. From these measurements, the project produces a fine-grained global grid of estimated temperature and humidity, at various altitudes in the atmosphere.

From this grid of estimates, the team focused on the Northern Hemisphere, and regions between 20 and 80 degrees latitude. They took the average summertime temperature and humidity in these regions, between June, July, and August for each year from 1979 to 2017. They then fed each yearly summertime average of temperature and humidity into an algorithm, developed at MIT, that estimates the amount of energy that would be available in the atmosphere, given the corresponding temperature and humidity conditions.

"We can see how this energy goes up and down over the years, and we can also separate how much energy is available for convection, which would manifest itself as thunderstorms for example, versus larger-scale circulations like extratropical cyclones," O'Gorman says.

Seeing changes now

Since 1979, they found the energy available for large-scale extratropical cyclones has decreased by 6 percent, whereas the energy that could fuel smaller, more local thunderstorms has gone up by 13 percent.

Their results mirror some recent evidence in the Northern Hemisphere, suggesting that summer winds associated with extratropical cyclones have decreased with global warming. Observations from Europe and Asia have also shown a strengthening of convective rainfall, such as from thunderstorms.

"Researchers are finding these trends in winds and rainfall that are probably related to climate change," Gertler says. "But this is the first time anyone has robustly connected the average change in the atmosphere, to these subdaily timescale events. So we're presenting a unified framework that connects climate change to this changing weather that we're seeing."

The researchers' results estimate the average impact of global warming on summertime energy of the atmosphere over the Northern Hemisphere. Going forward, they hope to be able to resolve this further, to see how climate change may affect weather in more specific regions of the world.

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Quarrying of Stonehenge 'bluestones' dated to 3000 BC

This is the Stonehenge quarry.

Excavations at two quarries in Wales, known to be the source of the Stonehenge 'bluestones', provide new evidence of megalith quarrying 5,000 years ago, according to a new UCL-led study.

Geologists have long known that 42 of Stonehenge's smaller stones, known as 'bluestones', came from the Preseli hills in Pembrokeshire, west Wales. Now a new study published in Antiquity pinpoints the exact locations of two of these quarries and reveals when and how the stones were quarried.

The discovery has been made by a team of archaeologists and geologists from UCL, Bournemouth University, University of Southampton, University of the Highlands and Islands and National Museum of Wales, which have been investigating the sites for eight years.

Professor Mike Parker Pearson (UCL Archaeology) and leader of the team, said: "What's really exciting about these discoveries is that they take us a step closer to unlocking Stonehenge's greatest mystery -- why its stones came from so far away."

"Every other Neolithic monument in Europe was built of megaliths brought from no more than 10 miles away.

We're now looking to find out just what was so special about the Preseli hills 5,000 years ago, and whether there were any important stone circles here, built before the bluestones were moved to Stonehenge."

The largest quarry was found almost 180 miles away from Stonehenge on the outcrop of Carn Goedog, on the north slope of the Preseli hills.

"This was the dominant source of Stonehenge's spotted dolerite, so-called because it has white spots in the igneous blue rock. At least five of Stonehenge's bluestones, and probably more, came from Carn Goedog," said geologist Dr Richard Bevins (National Museum of Wales).

In the valley below Carn Goedog, another outcrop at Craig Rhos-y-felin was identified by Dr Bevins and fellow geologist Dr Rob Ixer (UCL Archaeology) as the source of one of the types of rhyolite -- another type of igneous rock -- found at Stonehenge.

According to the new study, the bluestone outcrops are formed of natural, vertical pillars. These could be eased off the rock face by opening up the vertical joints between each pillar. Unlike stone quarries in ancient Egypt, where obelisks were carved out of the solid rock, the Welsh quarries were easier to exploit.

Neolithic quarry workers needed only to insert wedges into the ready-made joints between pillars, then lower each pillar to the foot of the outcrop.

Although most of their equipment is likely to have consisted of perishable ropes and wooden wedges, mallets and levers, they left behind other tools such as hammer stones and stone wedges.

"The stone wedges are made of imported mudstone, much softer than the hard dolerite pillars. An engineering colleague has suggested that hammering in a hard wedge could have created stress fractures, causing the thin pillars to crack. Using a soft wedge means that, if anything were to break, it would be the wedge and not the pillar," said Professor Parker Pearson.

Archaeological excavations at the foot of both outcrops uncovered the remains of human-made stone and earth platforms, with each platform's outer edge terminating in a vertical drop of about a metre.

"Bluestone pillars could be eased down onto this platform, which acted as a loading bay for lowering them onto wooden sledges before dragging them away," said Professor Colin Richards (University of the Highlands and Islands), who has excavated Britain's only other identified megalith quarry in the Orkney islands, off the north coast of Scotland.

An important aim of Professor Parker Pearson's team was to date megalith-quarrying at the two outcrops. In the soft sediment of a hollowed-out track leading from the loading bay at Craig Rhos-y-felin, and on the artificial platform at Carn Goedog, the team recovered pieces of charcoal dating to around 3000 BC.

The team now thinks that Stonehenge was initially a circle of rough, unworked bluestone pillars set in pits known as the Aubrey Holes, near Stonehenge, and that the sarsens (sandstone blocks) were added some 500 years later.

The new discoveries also cast doubt on a popular theory that the bluestones were transported by sea to Stonehenge.

"Some people think that the bluestones were taken southwards to Milford Haven and placed on rafts or slung between boats and then paddled up the Bristol Channel and along the Bristol Avon towards Salisbury Plain. But these quarries are on the north side of the Preseli hills so the megaliths could have simply gone overland all the way to Salisbury Plain," said Professor Kate Welham (Bournemouth University).

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