Social isolation: Animals that break away from the pack can influence evolution

This photo shows a cane toad. Cane toads (Rhinella marina) at the leading edge of their range expansion in Australia are more cut off from other individuals. Males from these peripheral populations display stronger social attraction than do toads from longstanding populations. Their enhanced social behavior might give them an advantage in conditions of relative social isolation by increasing the chances that they will transfer useful information, be protected against predators, and mate.

For some animals -- such as beetles, ants, toads, and primates -- short-term social isolation can be just as vital as social interaction to development and long-term evolution. In a review published July 17 in the journal Trends in Ecology & Evolution, two evolutionary biologists describe approaches for testing how an animal's isolation might impact natural selection and evolution. This framework can help design more effective breeding, reintroduction, and conservation strategies.

Research on evolution typically focuses on the importance of social interactions, including parent-offspring bonding, competition for resources, and courtship and mating rituals. But Nathan Bailey at the University of St Andrews in Scotland and his colleague Allen Moore at the University of Georgia realized that isolation must then be an extreme condition worthy of equal attention.

"The environment an animal experiences can influence which genes it expresses, when, and how much, so conditions of social isolation might cause expression of different traits," says Bailey. "This in turn could affect responses to natural selection in terms of survival and reproduction, which has evolutionary consequences. For some species, it might even mean that temporary social isolation is favorable."

The invasive cane toad Rhinella marina of Australia, for instance, will venture off on its own to expand into new territory, but the isolation this causes drives an uncharacteristically strong attraction to members of the opposite sex upon the toad's return to a social environment. This boosts the likelihood of both communication and successful mating, which are necessary for survival as the toads expand into new regions. This means that social isolation itself provides the conditions for natural selection to favor adaptations to cope with it.

Likewise, when poisoned, the European ant Temnothorax unifasciatus secludes itself from its kin until death. This eliminates contact with its nestmates, protecting them from the infection, ensuring its relatives' survival, and overall lessening some of the costs associated with social living, such as spreading disease.

"Traits expressed during social interactions might exist because they've been shaped by selection, but at the same time, social interactions themselves represent a type of environment that can select and shape how individuals behave," says Bailey.

This duality of social interaction as both trait and environment merits further study, and Bailey and Moore propose gaining a more complete understanding of social isolation's effects using a measurement termed the "index of social isolation." The index would allow researchers to compare an animal's ideal amount of isolation with how much it is actually experiencing.

To do this, researchers must first measure the optimal balance of interaction and isolation by testing individuals with different levels of each to find the best possible outcome in terms of survival and reproduction. Comparing this ideal to real observations will help determine whether animals are more or less isolated than they should be and ultimately allow for more effective designs for conservation strategies, reintroduction models, and breeding programs.

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Astronomers find a famous exoplanet's doppelganger

The infrared spectra of 2MASS 0249 c (top) and beta Pictoris b (bottom) are similar, as expected for two objects of comparable mass that formed in the same stellar nursery. Unlike 2MASS 0249 c, beta Pictoris b orbits much closer to its massive host star and is embedded in a bright circumstellar disk.

When it comes to extrasolar planets, appearances can be deceiving. Astronomers have imaged a new planet, and it appears nearly identical to one of the best studied gas-giant planets. But this doppelganger differs in one very important way: its origin.

"We have found a gas-giant planet that is a virtual twin of a previously known planet, but it looks like the two objects formed in different ways," said Trent Dupuy, astronomer at the Gemini Observatory and leader of the study.

Emerging from stellar nurseries of gas and dust, stars are born like kittens in a litter, in bunches and inevitably wandering away from their birthplace. These litters comprise stars that vary greatly, ranging from tiny runts incapable of generating their own energy (called brown dwarfs) to massive stars that end their lives with supernova explosions. In the midst of this turmoil, planets form around these new stars. And once the stellar nursery exhausts its gas, the stars (with their planets) leave their birthplace and freely wander the Galaxy. Because of this exodus, astronomers believe there should be planets born at the same time from the same stellar nursery, but are orbiting stars that have moved far away from each other over the eons, like long-lost siblings.

"To date, exoplanets found by direct imaging have basically been individuals, each distinct from the other in their appearance and age. Finding two exoplanets with almost identical appearances and yet having formed so differently opens a new window for understanding these objects," said Michael Liu, astronomer at the University of Hawaii Institute for Astronomy, and a collaborator on this work.

Dupuy, Liu and their collaborators have identified the first case of such a planetary doppelganger. One object has long been known: the 13-Jupiter-mass planet beta Pictoris b, one of the first planets discovered by direct imaging, back in 2009. The new object, dubbed 2MASS 0249 c, has the same mass, brightness, and spectrum as beta Pictoris b.

After discovering this object with the Canada-France-Hawaii Telescope (CFHT), Dupuy and collaborators then determined that 2MASS 0249 c and beta Pictoris b were born in the same stellar nursery. On the surface, this makes the two objects not just look-alikes but genuine siblings.

However, the planets have vastly different living situations, namely the types of stars they orbit. The host for beta Pictoris b is a star 10 times brighter than the Sun, while 2MASS 0249 c orbits a pair of brown dwarfs that are 2000 times fainter than the Sun. Furthermore, beta Pictoris b is relatively close to its host, about 9 astronomical units (AU, the distance from the Earth to the Sun), while 2MASS 0249 c is 2000 AU from its binary host.

These drastically different arrangements suggest that the planets' upbringings were not at all alike. The traditional picture of gas-giant formation, where planets start as small rocky cores around their host star and grow by accumulating gas from the star's disk, likely created beta Pictoris b. In contrast, the host of 2MASS 0249 c did not have enough of a disk to make a gas giant, so the planet likely formed by directly accumulating gas from the original stellar nursery. "2MASS 0249 c and beta Pictoris b show us that nature has more than one way to make very similar looking exoplanets," says Kaitlin Kratter, astronomer at the University of Arizona and a collaborator on this work. "beta Pictoris b probably formed like we think most gas giants do, starting from tiny dust grains. In contrast, 2MASS 0249 c looks like an underweight brown dwarf that formed from the collapse of a gas cloud. They're both considered exoplanets, but 2MASS 0249 c illustrates that such a simple classification can obscure a complicated reality."

The team first identified 2MASS 0249 c using images from CFHT, and their repeated observations revealed this object is orbiting at a large distance from its host. The system belongs to the beta Pictoris moving group, a widely dispersed set of stars named for its famous planet-hosting star. The team's observations at W.M. Keck Observatory determined that the host is actually a closely separated pair of brown dwarfs. So, altogether, the 2MASS 0249 system comprises two brown dwarfs and one gas-giant planet. Follow-up spectroscopy of 2MASS 0249 c with the NASA Infrared Telescope Facility and the Astrophysical Research Consortium 3.5-meter Telescope at Apache Point Observatory demonstrated that it shares a remarkable resemblance to beta Pictoris b.

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A dozen new moons of Jupiter discovered, including one 'oddball'

Various groupings of Jovian moons with the newly discovered ones shown in bold. The 'oddball,' called Valetudo after the Roman god Jupiter's great-granddaughter, has a prograde orbit that crosses the retrograde orbits.

Twelve new moons orbiting Jupiter have been found -- 11 "normal" outer moons, and one that they're calling an "oddball." This brings Jupiter's total number of known moons to a whopping 79 -- the most of any planet in our Solar System.

A team led by Carnegie's Scott S. Sheppard first spotted the moons in the spring of 2017 while they were looking for very distant Solar System objects as part of the hunt for a possible massive planet far beyond Pluto.

In 2014, this same team found the object with the most-distant known orbit in our Solar System and was the first to realize that an unknown massive planet at the fringes of our Solar System, far beyond Pluto, could explain the similarity of the orbits of several small extremely distant objects. This putative planet is now sometimes popularly called Planet X or Planet Nine. University of Hawaii's Dave Tholen and Northern Arizona University's Chad Trujillo are also part of the planet search team.

"Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System," said Sheppard.

Gareth Williams at the International Astronomical Union's Minor Planet Center used the team's observations to calculate orbits for the newly found moons.

"It takes several observations to confirm an object actually orbits around Jupiter," Williams said. "So, the whole process took a year."

Nine of the new moons are part of a distant outer swarm of moons that orbit it in the retrograde, or opposite direction of Jupiter's spin rotation. These distant retrograde moons are grouped into at least three distinct orbital groupings and are thought to be the remnants of three once-larger parent bodies that broke apart during collisions with asteroids, comets, or other moons. The newly discovered retrograde moons take about two years to orbit Jupiter.

Two of the new discoveries are part of a closer, inner group of moons that orbit in the prograde, or same direction as the planet's rotation. These inner prograde moons all have similar orbital distances and angles of inclinations around Jupiter and so are thought to also be fragments of a larger moon that was broken apart. These two newly discovered moons take a little less than a year to travel around Jupiter.

"Our other discovery is a real oddball and has an orbit like no other known Jovian moon," Sheppard explained. "It's also likely Jupiter's smallest known moon, being less than one kilometer in diameter."

This new "oddball" moon is more distant and more inclined than the prograde group of moons and takes about one and a half years to orbit Jupiter. So, unlike the closer-in prograde group of moons, this new oddball prograde moon has an orbit that crosses the outer retrograde moons.

As a result, head-on collisions are much more likely to occur between the "oddball" prograde and the retrograde moons, which are moving in opposite directions.

"This is an unstable situation," said Sheppard. "Head-on collisions would quickly break apart and grind the objects down to dust."

It's possible the various orbital moon groupings we see today were formed in the distant past through this exact mechanism.

The team think this small "oddball" prograde moon could be the last-remaining remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. The name Valetudo has been proposed for it, after the Roman god Jupiter's great-granddaughter, the goddess of health and hygiene.

Elucidating the complex influences that shaped a moon's orbital history can teach scientists about our Solar System's early years.

For example, the discovery that the smallest moons in Jupiter's various orbital groups are still abundant suggests the collisions that created them occurred after the era of planet formation, when the Sun was still surrounded by a rotating disk of gas and dust from which the planets were born.

Because of their sizes -- one to three kilometers -- these moons are more influenced by surrounding gas and dust. If these raw materials had still been present when Jupiter's first generation of moons collided to form its current clustered groupings of moons, the drag exerted by any remaining gas and dust on the smaller moons would have been sufficient to cause them to spiral inwards toward Jupiter. Their existence shows that they were likely formed after this gas and dust dissipated.

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Archaeologists discover bread that predates agriculture by 4,000 years

One of the stone structures of the Shubayqa 1 site. The fireplace, where the bread was found, is in the middle.

At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.

A team of researchers from the University of Copenhagen, University College London and University of Cambridge have analysed charred food remains from a 14,400-year-old Natufian hunter-gatherer site -- a site known as Shubayqa 1 located in the Black Desert in northeastern Jordan. The results, which are published today in the journal Proceedings of the National Academy of Sciences, provide the earliest empirical evidence for the production of bread:

"The presence of hundreds of charred food remains in the fireplaces from Shubayqa 1 is an exceptional find, and it has given us the chance to characterize 14,000-year-old food practices. The 24 remains analysed in this study show that wild ancestors of domesticated cereals such as barley, einkorn, and oat had been ground, sieved and kneaded prior to cooking. The remains are very similar to unleavened flatbreads identified at several Neolithic and Roman sites in Europe and Turkey. So we now know that bread-like products were produced long before the development of farming. The next step is to evaluate if the production and consumption of bread influenced the emergence of plant cultivation and domestication at all," said University of Copenhagen archaeobotanist Amaia Arranz Otaegui, who is the first author of the study.

University of Copenhagen archaeologist Tobias Richter, who led the excavations at Shubayqa 1 in Jordan, explained:

"Natufian hunter-gatherers are of particular interest to us because they lived through a transitional period when people became more sedentary and their diet began to change. Flint sickle blades as well as ground stone tools found at Natufian sites in the Levant have long led archaeologists to suspect that people had begun to exploit plants in a different and perhaps more effective way. But the flat bread found at Shubayqa 1 is the earliest evidence of bread making recovered so far, and it shows that baking was invented before we had plant cultivation. So this evidence confirms some of our ideas. Indeed, it may be that the early and extremely time-consuming production of bread based on wild cereals may have been one of the key driving forces behind the later agricultural revolution where wild cereals were cultivated to provide more convenient sources of food."

Charred remains under the microscope

The charred food remains were analysed with electronic microscopy at a University College London lab by PhD candidate Lara Gonzalez Carratero (UCL Institute of Archaeology), who is an expert on prehistoric bread:

"The identification of 'bread' or other cereal-based products in archaeology is not straightforward. There has been a tendency to simplify classification without really testing it against an identification criteria. We have established a new set of criteria to identify flat bread, dough and porridge like products in the archaeological record. Using Scanning Electron Microscopy we identified the microstructures and particles of each charred food remain," said Gonzalez Carratero.

"Bread involves labour intensive processing which includes dehusking, grinding of cereals and kneading and baking. That it was produced before farming methods suggests it was seen as special, and the desire to make more of this special food probably contributed to the decision to begin to cultivate cereals. All of this relies on new methodological developments that allow us to identify the remains of bread from very small charred fragments using high magnification," said Professor Dorian Fuller (UCL Institute of Archaeology).

Research into prehistoric food practices continues

A grant recently awarded to the University of Copenhagen team will ensure that research into food making during the transition to the Neolithic will continue:

"The Danish Council for Independent Research has recently approved further funding for our work, which will allow us to investigate how people consumed different plants and animals in greater detail. Building on our research into early bread, this will in the future give us a better idea why certain ingredients were favoured over others and were eventually selected for cultivation," said Tobias Richter.

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A step closer to quantum computers: Researchers show how to directly observe quantum spin effects

With companies like Google, Microsoft, and IBM all racing to create the world's first practical quantum computer, scientists worldwide are exploring the potential materials that could be used to build them.

Now, Associate Professor Yang Hyunsoo and his team from the Department of Electrical and Computer Engineering at the National University of Singapore (NUS) Faculty of Engineering have demonstrated a new method which could be used to bring quantum computing closer to reality.

"The NUS team, together with our collaborators from Rutgers, The State University of New Jersey in the United States and RMIT University in Australia, showed a practical way to observe and examine the quantum effects of electrons in topological insulators and heavy metals which could later pave the way for the development of advanced quantum computing components and devices," explained Assoc Prof Yang.

The findings of the study were published in the scientific journal Nature Communications in June 2018.

The advantage of quantum computers

Quantum computers are still in the early stages of development but are already displaying computing speeds millions of times faster than traditional technologies. As such, it is predicted that when quantum computing becomes more readily available, it will be able to answer some of the world's toughest questions in everything from finance to physics. This remarkable processing power is made possible by the radical way that quantum computers operate -- using light rather than electricity.

Classical computers push electrons through devices which code information into binary states of ones and zeros. In contrast, quantum computers use laser light to interact with electrons in materials to measure the phenomenon of electron "spin." These spinning electron states replace the ones and zeros used as the basis for traditional computers, and because they can exist in many spin states simultaneously, this allows for much more complex computing to be performed.

However, harnessing information based on the interactions of light and electrons is easier said than done. These interactions are incredibly complex and like anything in the quantum world there is a degree of uncertainty when trying to predict behaviour. As such, a reliable and practical way to observe these quantum effects has been sought-after in recent research to help in the discovery of more advanced quantum computing devices.

Visualising quantum spin effects

The real breakthrough from the scientists at NUS was the ability to "see" for the first time particular spin phenomena in topological insulators and metals using a scanning photovoltage microscope.

Topological insulators are electronic materials that are insulating in their interior but support conducting states on their surface, thus enabling electrons to flow along the surface of the material.

Assoc Prof Yang and his team examined platinum metal as well as topological insulators Bi2Se3 and BiSbTeSe2. An applied electrical current influenced the electron spin at the quantum level for all of these materials and the scientists were able to directly visualise this change using polarised light from the microscope.

Additionally, unlike other observational techniques, the innovative experimental setup meant that the results could be gathered at room temperature, making this a practical method of visualisation which is applicable to many other materials.

Mr Liu Yang, who is a PhD student with the Department and first author of the study, said, "Our method can be used as a powerful and universal tool to detect the spin accumulations in various materials systems. This means that developing better devices for quantum computers will become easier now that these phenomena can be directly observed in this way."

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Sound waves reveal enormous diamond cache deep in Earth's interior

There may be more than a quadrillion tons of diamond hidden in the Earth's interior.

There may be more than a quadrillion tons of diamond hidden in the Earth's interior, according to a new study from MIT and other universities. But the new results are unlikely to set off a diamond rush. The scientists estimate the precious minerals are buried more than 100 miles below the surface, far deeper than any drilling expedition has ever reached.

The ultradeep cache may be scattered within cratonic roots -- the oldest and most immovable sections of rock that lie beneath the center of most continental tectonic plates. Shaped like inverted mountains, cratons can stretch as deep as 200 miles through the Earth's crust and into its mantle; geologists refer to their deepest sections as "roots."

In the new study, scientists estimate that cratonic roots may contain 1 to 2 percent diamond. Considering the total volume of cratonic roots in the Earth, the team figures that about a quadrillion (1016) tons of diamond are scattered within these ancient rocks, 90 to 150 miles below the surface.

"This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it's relatively common," says Ulrich Faul, a research scientist in MIT's Department of Earth, Atmospheric, and Planetary Sciences. "We can't get at them, but still, there is much more diamond there than we have ever thought before."

Faul's co-authors include scientists from the University of California at Santa Barbara, the Institut de Physique du Globe de Paris, the University of California at Berkeley, Ecole Polytechnique, the Carnegie Institution of Washington, Harvard University, the University of Science and Technology of China, the University of Bayreuth, the University of Melbourne, and University College London.

A sound glitch

Faul and his colleagues came to their conclusion after puzzling over an anomaly in seismic data. For the past few decades, agencies such as the United States Geological Survey have kept global records of seismic activity -- essentially, sound waves traveling through the Earth that are triggered by earthquakes, tsunamis, explosions, and other ground-shaking sources. Seismic receivers around the world pick up sound waves from such sources, at various speeds and intensities, which seismologists can use to determine where, for example, an earthquake originated.

Scientists can also use this seismic data to construct an image of what the Earth's interior might look like. Sound waves move at various speeds through the Earth, depending on the temperature, density, and composition of the rocks through which they travel. Scientists have used this relationship between seismic velocity and rock composition to estimate the types of rocks that make up the Earth's crust and parts of the upper mantle, also known as the lithosphere.

However, in using seismic data to map the Earth's interior, scientists have been unable to explain a curious anomaly: Sound waves tend to speed up significantly when passing through the roots of ancient cratons. Cratons are known to be colder and less dense than the surrounding mantle, which would in turn yield slightly faster sound waves, but not quite as fast as what has been measured.

"The velocities that are measured are faster than what we think we can reproduce with reasonable assumptions about what is there," Faul says. "Then we have to say, 'There is a problem.' That's how this project started."

Diamonds in the deep

The team aimed to identify the composition of cratonic roots that might explain the spikes in seismic speeds. To do this, seismologists on the team first used seismic data from the USGS and other sources to generate a three-dimensional model of the velocities of seismic waves traveling through the Earth's major cratons.

Next, Faul and others, who in the past have measured sound speeds through many different types of minerals in the laboratory, used this knowledge to assemble virtual rocks, made from various combinations of minerals. Then the team calculated how fast sound waves would travel through each virtual rock, and found only one type of rock that produced the same velocities as what the seismologists measured: one that contains 1 to 2 percent diamond, in addition to peridotite (the predominant rock type of the Earth's upper mantle) and minor amounts of eclogite (representing subducted oceanic crust). This scenario represents at least 1,000 times more diamond than people had previously expected.

"Diamond in many ways is special," Faul says. "One of its special properties is, the sound velocity in diamond is more than twice as fast as in the dominant mineral in upper mantle rocks, olivine."

The researchers found that a rock composition of 1 to 2 percent diamond would be just enough to produce the higher sound velocities that the seismologists measured. This small fraction of diamond would also not change the overall density of a craton, which is naturally less dense than the surrounding mantle.

"They are like pieces of wood, floating on water," Faul says. "Cratons are a tiny bit less dense than their surroundings, so they don't get subducted back into the Earth but stay floating on the surface. This is how they preserve the oldest rocks. So we found that you just need 1 to 2 percent diamond for cratons to be stable and not sink."

In a way, Faul says cratonic roots made partly of diamond makes sense. Diamonds are forged in the high-pressure, high-temperature environment of the deep Earth and only make it close to the surface through volcanic eruptions that occur every few tens of millions of years. These eruptions carve out geologic "pipes" made of a type of rock called kimberlite (named after the town of Kimberley, South Africa, where the first diamonds in this type of rock were found). Diamond, along with magma from deep in the Earth, can spew out through kimberlite pipes, onto the surface of the Earth.

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Buried internet infrastructure at risk as sea levels rise

Seawater inundation projected for New York City by 2033 and its effect on internet infrastructure. Anything in the blue shaded areas is estimated to be underwater in 15 years.

Thousands of miles of buried fiber optic cable in densely populated coastal regions of the United States may soon be inundated by rising seas, according to a new study by researchers at the University of Wisconsin-Madison and the University of Oregon.

The study, presented July 16, 2018 at a meeting of internet network researchers, portrays critical communications infrastructure that could be submerged by rising seas in as soon as 15 years, according to the study's senior author, Paul Barford, a UW-Madison professor of computer science.

"Most of the damage that's going to be done in the next 100 years will be done sooner than later," says Barford, an authority on the "physical internet" -- the buried fiber optic cables, data centers, traffic exchanges and termination points that are the nerve centers, arteries and hubs of the vast global information network. "That surprised us. The expectation was that we'd have 50 years to plan for it. We don't have 50 years."

The study, conducted with Barford's former student Ramakrishnan Durairajan, now of the University of Oregon, and Carol Barford, who directs UW-Madison's Center for Sustainability and the Global Environment, is the first assessment of risk of climate change to the internet. It suggests that by the year 2033 more than 4,000 miles of buried fiber optic conduit will be underwater and more than 1,100 traffic hubs will be surrounded by water. The most susceptible U.S. cities, according to the report, are New York, Miami and Seattle, but the effects would not be confined to those areas and would ripple across the internet, says Barford, potentially disrupting global communications.

The peer-reviewed study combined data from the Internet Atlas, a comprehensive global map of the internet's physical structure, and projections of sea level incursion from the National Oceanic and Atmospheric Administration (NOAA). The study, which only evaluated risk to infrastructure in the United States, was shared today with academic and industry researchers at the Applied Networking Research Workshop, a meeting of the Association for Computing Machinery, the Internet Society and the Institute of Electrical and Electronics Engineers.

Much of this infrastructure is buried and follows long-established rights of way, typically paralleling highways and coastlines, says Barford. "When it was built 20-25 years ago, no thought was given to climate change."

Many of the conduits at risk are already close to sea level and only a slight rise in ocean levels due to melting polar ice and thermal expansion as climate warms will be needed to expose buried fiber optic cables to sea water. Hints of the problems to come, says Barford, can be seen in the catastrophic storm surges and flooding that accompanied hurricanes Sandy and Katrina.

Buried fiber optic cables are designed to be water-resistant, but unlike the marine cables that ferry data from continent to continent under the ocean, they are not waterproof.

Risk to the physical internet, says Barford, is coupled to the large population centers that exist on the coasts, which also tend to be the same places where the transoceanic marine cables that underpin global communication networks come ashore. "The landing points are all going to be underwater in a short period of time," he notes.

Moreover, much of the data that transits the internet tends to converge on a small number of fiber optic strands that lead to large population centers like New York, one of the more vulnerable cities identified in the study.

The impact of mitigation such as sea walls, according to the study, are difficult to predict. "The first instinct will be to harden the infrastructure," Barford says. "But keeping the sea at bay is hard. We can probably buy a little time, but in the long run it's just not going to be effective."

In addition to looking at the risk to local and long-haul infrastructure in the nation's coastal areas, the study examined the risk to the buried assets of individual internet service providers. It found the networks of CenturyLink, Inteliquent and AT&T to be at highest risk.

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5,300-year-old Iceman's last meal reveals remarkably high-fat diet

This photograph was taken during the stomach content sampling campaign in November 2010 in Bolzano, Italy.

In 1991, German tourists discovered, in the Eastern Italian Alps, a human body that was later determined to be the oldest naturally preserved ice mummy, known as Otzi or the Iceman. Now, researchers reporting in the journal Current Biology on July 12 who have conducted the first in-depth analysis of the Iceman's stomach contents offer a rare glimpse of our ancestor's ancient dietary habits. Among other things, their findings show that the Iceman's last meal was heavy on the fat.

The findings offer important insights into the nutritional habits of European individuals, going back more than 5,000 years to the Copper Age. They also offer clues as to how our ancient ancestors handled food preparation.

"By using a complementary multi-omics approach combined with microscopy, we reconstructed the Iceman's last meal, showing that he has had a remarkably high proportion of fat in his diet, supplemented with wild meat from ibex and red deer, cereals from einkorn, and with traces of toxic bracken," says Frank Maixner of the Eurac Research Institute for Mummy Studies in Bolzano, Italy. Bracken is a genus of large ferns.

Maixner and colleagues, including Albert Zink, explains that the analysis hadn't happened earlier because scientists were initially unable to identify the Iceman's stomach. That's because it had moved up during the mummification process. In 2009, his stomach was spotted during a re-investigation of CT scans, and an effort to analyze its contents was launched.

"The stomach material was, compared to previously analyzed lower intestine samples, extraordinarily well preserved, and it also contained large amounts of unique biomolecules such as lipids, which opened new methodological opportunities to address our questions about Otzi's diet," Maixner says.

The researchers combined classical microscopic and modern molecular approaches to determine the exact composition of the Iceman's diet prior to his death. The broad-spectrum approach allowed them to make inferences based on ancient DNA, proteins, metabolites, and lipids.

The analysis identified ibex adipose tissue as the most likely fat source. In fact, about half of the stomach contents were composed of adipose fat. While the high-fat diet was unexpected, the researchers say it "totally makes sense" given the extreme alpine environment in which the Iceman lived and where he was found.

"The high and cold environment is particularly challenging for the human physiology and requires optimal nutrient supply to avoid rapid starvation and energy loss," says Albert Zink, also at the Eurac Research Institute for Mummy Studies. "The Iceman seemed to have been fully aware that fat represents an excellent energy source."

The analysis indicated that the wild meat was eaten fresh or perhaps dried. While the presence of toxic bracken particles is more difficult to explain, the researchers say it's possible that the Iceman suffered from intestinal problems related to parasites found earlier in his gut and took the bracken as a medicine. On the other hand, he may have used the fern's leaves to wrap food and ingested toxic spores unintentionally.

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84 highly endangered amur leopards remain in China and Russia

Scientists estimate there are only 84 remaining highly endangered Amur leopards (Panthera pardus orientalis) remaining in the wild across its current range along the southernmost border of Primorskii Province in Russia and Jilin Province of China.

Scientists estimate there are only 84 remaining highly endangered Amur leopards (Panthera pardus orientalis) remaining in the wild across its current range along the southernmost border of Primorskii Province in Russia and Jilin Province of China.

This new estimate of the Amur leopard population was recently reported in the scientific journal, Conservation Letters by scientists from China, Russia, and the United States. The scientists combined forces to collate information from camera traps on both sides of the border of China and Russia to derive the estimate. Because there are no records of leopards in other parts of its former range, this estimate represents the total global population of this subspecies in the wild.

Although numbers are small, previous estimates in Russia were even less, ranging from 25 to 50 individuals. However, those surveys, based on tracks left in the snow, were extremely difficult to interpret due to the unclear relationship between numbers of tracks and number of individuals. With camera traps, each individual can be identified by its unique spot pattern, providing a much more precise estimate.

Combining data from both countries increased precision of the estimate, and provided greater accuracy. Surprisingly, about one-third of the leopards were photographed on both sides of the Sino-Russian border.

Anya Vitkalova, a biologist at Land of the Leopard National Park in Russia, and one of the two lead authors of the publication said: "We knew that leopards moved across the border, but only by combining data were we able to understand how much movement there really is."

Despite the movement, there were differences in population dynamics in Russia versus China. Leopards are currently recolonizing habitat in China by dispersing from the Russian side, where leopard numbers appear to be close to the maximum that can be supported.

Because of these transboundary movements of leopards, simply adding results from both sides would have greatly exaggerated the estimate.

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Obesity alone does not increase risk of death

Healthy woman. 1 out of 20 individuals with obesity had no other metabolic abnormalities.

Researchers at York University's Faculty of Health have found that patients who have metabolic healthy obesity, but no other metabolic risk factors, do not have an increased rate of mortality.

The results of this study could impact how we think about obesity and health, says Jennifer Kuk, associate professor at the School of Kinesiology and Health Science, who led the research team at York University.

"This is in contrast with most of the literature and we think this is because most studies have defined metabolic healthy obesity as having up to one metabolic risk factor," says Kuk. "This is clearly problematic, as hypertension alone increases your mortality risk and past literature would have called these patients with obesity and hypertension, 'healthy'. This is likely why most studies have reported that 'healthy' obesity is still related with higher mortality risk."

Kuk's study showed that unlike dyslipidemia, hypertension or diabetes alone, which are related with a high mortality risk, this isn't the case for obesity alone.

The study followed 54,089 men and women from five cohort studies who were categorized as having obesity alone or clustered with a metabolic factor, or elevated glucose, blood pressure or lipids alone or clustered with obesity or another metabolic factor. Researchers looked at how many people within each group died as compared to those within the normal weight population with no metabolic risk factors.

Current weight management guidelines suggest that anyone with a BMI over 30 kg/m2 should lose weight. This implies that if you have obesity, even without any other risk factors, it makes you unhealthy. Researchers found that 1 out of 20 individuals with obesity had no other metabolic abnormalities.

"We're showing that individuals with metabolically healthy obesity are actually not at an elevated mortality rate. We found that a person of normal weight with no other metabolic risk factors is just as likely to die as the person with obesity and no other risk factors," says Kuk. "This means that hundreds of thousands of people in North America alone with metabolically healthy obesity will be told to lose weight when it's questionable how much benefit they'll actually receive."

From Science Daily