Oct 22, 2016

Climate change impairs survival instincts of fish and can make them swim towards predators

Carbon dioxide levels are predicted to be 2.5 times higher in the oceans by the end of this century.
Climate change is disrupting the sensory systems of fish and can even make them swim towards predators, instead of away from them, a paper by marine biologists at the University of Exeter says.

Research into the impact of rising CO2 has shown it can disrupt the senses of fish including their smell, hearing and vision.

High CO2 levels can impair the way they behave, including making them swim towards predator smells instead of away and even ignoring the sounds that normally deter them from risky habitats.

According to a paper published in the journal Global Change Biology by Dr Robert Ellis and Dr Rod Wilson, climate-change marine biologists at Exeter University, these abnormal behaviours have been linked to the effect of CO2 on how the brain processes signals from sensory organs.

CO2 levels are predicted to be 2.5 times higher in the oceans by the end of this century.

The report's authors Dr Robert Ellis and Dr Rod Wilson believe that fish farms, may be the key to establishing the long-term impact of CO2 on marine life.

In their paper, Lessons from two high CO2 worlds: future oceans and intensive aquaculture, Dr. Ellis and Dr. Wilson, alongside a colleague from Chile (Dr. Urbina), show that farmed fish often live in CO2 conditions 10 times higher than their wild cousins.

The scientists believe that further study of farmed fish -- which already provides as much seafood for human consumption as that caught in the wild -- may be crucial for understanding how aquatic species will evolve to climate change.

The captive fish farm populations living in high CO2 levels already amount to "a giant long-term laboratory experiment."

"Aquaculture may provide an 'accidental' long-term experiment that can help climate-change predictions," said Dr. Ellis. "There is the enticing possibility that fish and shellfish previously grown in high CO2 aquaculture conditions over multiple generations can offer valuable insights regarding the potential for aquatic animals in the wild to adapt to the predicted further increases in CO2."

The aquaculture industry may also benefit from what the climate change scientists study too. The abnormal behaviour seen in wild fish may not matter in farmed fish, as they are provided with abundant food and shelter and they have no predators to avoid. But while extremely high CO2 can reduce digestion efficiency in cod, recent research suggests that relatively small increases in CO2 may actually act as a growth stimulant in some fish.

Read more at Science Daily

New evolutionary finding: Species take different genetic paths to reach same trait

Jay Storz (left), Susan J. Rosowski professor of biological sciences, and Chandrasekhar Natarajan, research assistant professor in biological sciences.
Biologists have been contemplating evolutionary change since Charles Darwin first explained it.

Using modern molecular tools and fieldwork, University of Nebraska-Lincoln biologist Jay Storz and colleagues have demonstrated for the first time that different species can take different genetic paths to develop the same trait. The team's findings appear in the Oct. 21 issue of the journal Science.

"There's this really long-standing question in evolutionary genetics about the predictability of genetic change," said Storz, Susan J. Rosowski professor of biological sciences.

In other words, did species with a common, beneficial trait undergo the same genetic changes to evolve that trait? Or did the trait develop through different, and therefore unpredictable, genetic paths?

It turns out that natural selection, a primary evolutionary process, can dependably produce similar, beneficial traits in different species. But at the molecular level, the evolutionary changes tend to be highly idiosyncratic, and are therefore far less predictable.

To find that out, Storz turned to birds living in South America's Andes Mountains. Comparing high-altitude bird species with their lowland counterparts, his team determined that the high-altitude birds had evolved red blood cells with hemoglobin proteins that more readily bind oxygen molecules. This trait benefits species living in low-oxygen settings, such as the mountains.

Storz and his team tested the hemoglobin proteins from numerous high-altitude bird species and identified which differences, or mutations, in the proteins' makeup were responsible for the high-altitude trait. In most cases, the change in protein function among the different species was caused by different mutations.

"What this indicates is that there are many possible mutations that can all produce the same phenotypic effect (trait)," Storz said. "We can't predict which particular mutations are responsible for these changes." One possible reason for this variability is that during evolution, the hemoglobins of different species have each accumulated their own unique set of mutations. Given these distinct genetic backgrounds, a mutation that produces a beneficial effect in one species may produce a detrimental effect in a different species.

To test this theory, Storz's team used genetic engineering tools to reconstruct and resurrect the hemoglobin proteins of several ancestral bird species, including the ancestor common to all birds, which existed more than 100 million years ago. Engineering the high-altitude hemoglobin mutations into the ancient bird proteins resulted in vastly different effects than in contemporary birds.

As evolution advances through time, different mutations accumulate in distinct species and settings. Natural selection applies similar pressures for species to adapt as they move to higher altitudes, for example, but the adaptation must take different genetic paths to get there.

Read more at Science Daily

Oct 21, 2016

Earliest evidence in fossil record for right-handedness

David Frayer, KU professor emeritus of anthropology, is lead author on a recent study published in the Journal of Evolution that found striations on teeth of a Homo habilis fossil 1.8 million years old moved from left to right, indicating the earliest evidence in the fossil record for right-handedness. Researchers believe the marks came from using a tool to try to cut food being pulled from the mouth with the left hand.
Perhaps the bias against left-handers dates back much further than we thought.

By examining striations on teeth of a Homo habilis fossil, a new discovery led by a University of Kansas researcher has found the earliest evidence for right-handedness in the fossil record dating back 1.8 million years.

"We think that tells us something further about lateralization of the brain," said David Frayer, a KU professor emeritus of anthropology and the lead author of the study. "We already know that Homo habilis had brain lateralization and was more like us than like apes. This extends it to handedness, which is key."

The findings were published online this week in the Journal of Human Evolution. The researchers made the discovery after analyzing small cut marks, or labial striations, which are the lip side of the anterior teeth in an intact upper jaw fossil, known as OH-65, found in a stream channel of the Olduvai Gorge in Tanzania.

Frayer said among the network of deep striations found only on the lip face of the upper front teeth most cut marks veered from left down to the right. Analysis of the marks makes it likely they came from when OH-65 used a tool with its right hand to cut food it was holding in its mouth while pulling with the left hand. The scratches can be seen with the naked eye, but a microscope was used to determine their alignment and to quantify their angulation.

"Experimental work has shown these scratches were most likely produced when a stone tool was used to process material gripped between the anterior teeth and the tool occasionally struck the labial face leaving a permanent mark on the tooth's surface," Frayer said.

Based on the direction of the marks, it's evident the Homo habilis was right-handed. It's a sample of one, but because this is the first potential evidence of a dominant handed pre-Neanderthal, Frayer said, the study could lead to a search for the marks in other early Homo fossils.

"Handedness and language are controlled by different genetic systems, but there is a weak relationship between the two because both functions originate on the left side of the brain," he said. "One specimen does not make an incontrovertible case, but as more research is done and more discoveries are made, we predict that right-handedness, cortical reorganization and language capacity will be shown to be important components in the origin of our genus."

Multiple lines of research point to the likelihood that brain reorganization, the use of tools and use of a dominant hand occurred early in the human lineage. Today, researchers estimate that 90 percent of humans are right-handed, and this differs from apes which are closer to a 50-50 ratio. Until now, no one looked for directionality of striations in the earliest specimens representing our evolutionary lineage.

Read more at Science Daily

Oldest known planet-forming disk discovered

An artist's conception of this unusual system.
A group of citizen scientists and professional astronomers, including Carnegie's Jonathan Gagné, joined forces to discover an unusual hunting ground for exoplanets. They found a star surrounded by the oldest known circumstellar disk -- a primordial ring of gas and dust that orbits around a young star and from which planets can form as the material collides and aggregates.

Led by Steven Silverberg of University of Oklahoma, the team described a newly identified red dwarf star with a warm circumstellar disk, of the kind associated with young planetary systems. Circumstellar disks around red dwarfs like this one are rare to begin with, but this star, called AWI0005x3s, appears to have sustained its disk for an exceptionally long time. The findings are published by The Astrophysical Journal Letters.

"Most disks of this kind fade away in less than 30 million years," said Silverberg. "This particular red dwarf is a candidate member of the Carina stellar association, which would make it around 45 million years old [like the rest of the stars in that group]. It's the oldest red dwarf system with a disk we've seen in one of these associations."

The discovery relied on citizen scientists from Disk Detective, a project led by NASA/GSFC's Dr. Marc Kuchner that's designed to find new circumstellar disks. At the project's website, DiskDetective.org, users make classifications by viewing ten-second videos of data from NASA surveys, including the Wide-field Infrared Survey Explorer mission (WISE) and Two-Micron All Sky Survey (2MASS) projects. Since the launch of the website in January 2014, roughly 30,000 citizen scientists have participated in this process, performing roughly 2 million classifications of celestial objects.

"Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object," Kuchner said. "The WISE mission alone found 747 million [warm infrared] objects, of which we expect a few thousand to be circumstellar disks."

"Unraveling the mysteries of our universe, while contributing to the advancement of astronomy, is without a doubt a dream come true," says Hugo Durantini Luca from Argentina, one of eight citizen scientist co-authors.

Determining the age of a star can be tricky or impossible. But the Carina association, where this red dwarf was found, is a group of stars whose motions through the Galaxy indicate that they were all born at roughly the same time in the same stellar nursery.

Carnegie's Gagné devised a test that showed this newly found red dwarf and its disk are likely part of the Carina association, which was key to revealing its surprising age.

"It is surprising to see a circumstellar disk around a star that may be 45 million years old, because we normally expect these disks to dissipate within a few million years," Gagné explained. "More observations will be needed to determine whether the star is really as old as we suspect, and if it turns out to be, it will certainly become a benchmark system to understand the lifetime of disks."

Knowing that this star and its disk are so old may help scientists understand why M dwarf disks appear to be so rare.

Read more at Science Daily

Early fossil fish from China shows where our jaws came from

Life reconstruction of Qilinyu along with Guiyu and Entelognathus in Silurian waters.
Where did our jaws come from? The question is more complicated than it seems, because not all jaws are the same. In a new article, published in Science, palaeontologists from China and Sweden trace our jaws back to the extinct placoderms, armoured prehistoric fish that lived over 400 million years ago.

Jaws are an iconic and defining feature, not only of our own anatomy but of all jawed vertebrates: not for nothing did Steven Spielberg use "Jaws" as the one-word title of his immortal shark epic.

Jaws first appear in the developing embryo as a cartilage bar similar to a gill arch. In a shark, this develops directly into the adult jaws, but in an embryo of a bony fish or a human being new bones appear on the outside of the cartilage. In our own skull, these bones -- the dentary, maxilla and premaxilla -- make up the entire jaws and carry our teeth.

It is universally accepted that the dentary, maxilla and premaxilla are a shared heritage of bony fishes and tetrapods: you will find these same bones in a crocodile or a cod. But what about further back? Only one other group of fishes, the extinct placoderms, have a similar set of jaw bones. But these bones, known as 'gnathal plates' and shown to spectacular effect in the giant placoderm Dunkleosteus where they are developed into blades like sheet-metal cutters, have always been regarded as unrelated to the dentary, maxilla and premaxilla. For one thing they are located slightly further inside the mouth, and in any case the general opinion has been that placoderms and bony fishes are only very distantly related.

The picture began to change fundamentally in 2013 with the description of Entelognathus, a Silurian (423 million year old) fossil fish from Yunnan in China which combines a classic placoderm skeleton with presence of a dentary, maxilla and premaxilla. Together with the discovery of placoderm-like characteristics in some of the earliest bony fishes, this began to build a strong case for a close relationship between placoderms and bony fishes, accompanied by a substantial carry-over of placoderm characteristics into bony fishes (and hence ultimately to us). But what about those jaws, where did they come from?

This is where the new fossil, Qilinyu, comes in. Qilinyu, described this week in Science by palaeontologists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing and Uppsala University in Sweden, comes from the same place and time period as Entelognathus, and also combines a placoderm skeleton with dentary, maxilla and premaxilla, though the two fishes otherwise look quite different and must have had different lifestyles. Looking at the jaw bones of Entelognathus and Qilinyu we can see that they, in both fishes, combine characters of the bony fish jaw bones (they contribute to the outer surface of the face and lower jaw) and placoderm gnathal plates (they have broad biting surfaces inside the mouth). Another thing becomes apparent as well: it has been argued that placoderm gnathal plates represent an inner jaw arcade, similar in position to the 'coronoid bones' of bony fishes, and if that were true we would expect to find gnathal plates just inside of the dentary, maxilla and premaxilla of Entelognathus and Qilinyu; but there is nothing there.

Read more at Science Daily

New Aussie Dinosaur Was Half a Basketball Court Long

A new species of giant long-necked dinosaur revealed today sheds light on the likely origin of Australian sauropods.

The creature was called Savannasaurus elliottorum after grazier David Elliott, chairman of the Australian Age of Dinosaurs Museum (AAOD) in Winton, Queensland, who first found the fossil bones in the area during a sheep muster in 2005.

While the discovery site was excavated in September of that year by a team from the AAOD and Queensland Museum, it has taken the decade since to remove the bones from the rocks in which they were encased.

Savannasaurus belonged to a branch of sauropods known as titanosaurs, the largest land animals ever to have lived, said Dr Stephen Poropat of the AAOD Museum, who is lead author of a paper describing the findings in today's Scientific Reports.

He said only about 20 to 25 per cent of Savannasaurus' skeleton had been recovered with most of the torso, front limbs and pelvis intact.

"Because they are very large animals it would take a fair bit of sediment to bury it before predators come along," Dr Poropat said.

He said a tooth of a carnivorous dinosaur had been found at the fossil site, which suggested there had been some scavenging on the remains.

Dr Poropat said Savannasaurus would have been a medium-sized titanosaur about half the length of Diplodocus, measuring between 12 to 15 meters in length, with a long neck and relatively short tail.

However, he said its most distinctive feature was its hip width, which measured up to 1.5 meters.

Dr Poropat and colleagues also described another dinosaur, Diamantinasaurus matildae, first discovered in 2009, whose skeleton includes the first sauropod skull found in Australia.

Savannsaurus and the new Diamantinasaurus specimen shed light on a debate over the origin of Australian titanosaurs.

Previous studies of Australia's megafauna have suggested they were most similar to dinosaurs from Laurasia — the ancient continental mass in the Northern Hemisphere.

But Dr Poropat said this had never really made sense given the two super continents of Gondwana and Laurasia were separated.

He said the new study showed Savannasaurus and Diamantinasaurus were in fact more closely related to species from South America.

"But as the South American fossil record has improved and the Australian fossil record continues to grow, we are getting a better understanding of how close our dinosaurs were to those from South America."

Dr Poropat said it appeared Savannasaurus came to Australia around 105 million years ago from South America.

He said it appeared as if these titanosaurs took advantage of the warmer global temperatures at the time to disperse from South America through Antarctica to Australia at a time when all three continents were connected.

Dr Adam Yates, senior curator of earth sciences at the Northern Territory Museum, said he believed the paper's findings were valid.

Titanosaurs in particular represented one of the "last grey areas" of understanding in the dinosaur story.

"They are abundant and found all over the world, but their remains are often very incomplete, and as a consequence our understanding of the interrelationship of different titanosaurs is quite puzzling and we don't have a good family tree worked out yet," he said.

Read more at Discovery News

Oct 20, 2016

Curious tilt of the Sun traced to undiscovered planet

Artist’s illustration of a possible ninth planet in our solar system. A recent study has revealed that the unexpected behavior of some Kuiper belt objects could be explained by the presence of a distant, planet-sized object yet undetected in our solar system.
Planet Nine the undiscovered planet at the edge of the solar system that was predicted by the work of Caltech's Konstantin Batygin and Mike Brown in January 2016 appears to be responsible for the unusual tilt of the Sun, according to a new study.

The large and distant planet may be adding a wobble to the solar system, giving the appearance that the Sun is tilted slightly.

"Because Planet Nine is so massive and has an orbit tilted compared to the other planets, the solar system has no choice but to slowly twist out of alignment," says Elizabeth Bailey, a graduate student at Caltech and lead author of a study announcing the discovery.

All of the planets orbit in a flat plane with respect to the Sun, roughly within a couple degrees of each other. That plane, however, rotates at a six-degree tilt with respect to the Sun giving the appearance that the Sun itself is cocked off at an angle. Until now, no one had found a compelling explanation to produce such an effect. "It's such a deep-rooted mystery and so difficult to explain that people just don't talk about it," says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy.

Brown and Batygin's discovery of evidence that the Sun is orbited by an as-yet-unseen planet that is about 10 times the size of Earth with an orbit that is about 20 times farther from the Sun on average than Neptune's changes the physics. Planet Nine, based on their calculations, appears to orbit at about 30 degrees off from the other planets' orbital plane in the process, influencing the orbit of a large population of objects in the Kuiper Belt, which is how Brown and Batygin came to suspect a planet existed there in the first place.

"It continues to amaze us; every time we look carefully we continue to find that Planet Nine explains something about the solar system that had long been a mystery," says Batygin, an assistant professor of planetary science.

Their findings have been accepted for publication in an upcoming issue of the Astrophysical Journal, and will be presented this week at the American Astronomical Society's Division for Planetary Sciences 48th annual meeting, held jointly in Pasadena, California, with the 11th European Planetary Science Congress.

The tilt of the solar system's orbital plane has long befuddled astronomers because of the way the planets formed: as a spinning cloud slowly collapsing first into a disk and then into objects orbiting a central star.

Planet Nine's angular momentum is having an outsized impact on the solar system based on its location and size. A planet's angular momentum equals the mass of an object multiplied by its distance from the Sun, and corresponds with the force that the planet exerts on the overall system's spin. Because the other planets in the solar system all exist along a flat plane, their angular momentum works to keep the whole disk spinning smoothly.

Planet Nine's unusual orbit, however, adds a multi-billion-year wobble to that system. Mathematically, given the hypothesized size and distance of Planet Nine, a six-degree tilt fits perfectly, Brown says.

The next question, then, is how did Planet Nine achieve its unusual orbit? Though that remains to be determined, Batygin suggests that the planet may have been ejected from the neighborhood of the gas giants by Jupiter, or perhaps may have been influenced by the gravitational pull of other stellar bodies in the solar system's extreme past.

Read more at Science Daily

Amazonian frog has its own ant repellent

This is the Lithodytes lineatus.
Special chemicals covering the skin of a tiny yellow-striped Amazonian frog provide a protective shield that wards off leaf-cutting ants allowing it to live comfortably among them. "It helps the frog blend in, because it imitates the ants own chemical signals," says André Barros of the National Institute of Amazonian Research in Brazil. He led a study in Springer's journal Behavioral Ecology and Sociobiology. The ants do not give it even a single bite, but will quite aggressively attack all other types of frogs or other animals that cross their path.

This type of chemical-based mimicry and camouflage is often used by parasitic invertebrates and allows them to live unhindered within the protective confines of social insect-colonies. However, the strategy is not often seen in vertebrates, much less among frogs, and is only known in two other African frog species.

Lithodytes lineatus is a South American frog that is mainly found in the Amazon region. In Spanish the frog is known as "Sapito Listado." It shelters, breeds and builds its nest peacefully in the midst of leaf-cutting ants of the genus Atta without ever being attacked by them.

Leaf-cutting ants use chemical odors, such as pheromones, to recognize and communicate with members of their colony. Barros' team therefore speculated that the skin of Lithodytes lineatus must also be covered with a similar type of chemical that makes leaf-cutting ants recognize them as "friendly" and cheats them into allowing the frog into their midst.

They ran two sets of field experiments to test this. First Lithodytes lineatus frogs and four similar species were held in a glass vessel for ten minutes along with leaf-cutting ants. The Lithodytes lineatus frogs made no escape plans, in contrast with the members of the four other species that tried to jump or climb out and that were attacked by the ants.

The researchers then watched what happened when they covered 20 Rhinella major frogs that are common in the Amazon region with either the skin extract of Lithodytes lineatus or with ultrapure water. The skin extract protected the 10 frogs that were covered with it and that were placed within the nests, while the rest was attacked by the ants.

"Our results demonstrate that the skin of frog Lithodytes lineatus has chemicals that prevent the attack of two species of leaf-cutting ants," says Barros. "It therefore seems that Lithodytes lineatus has chemical skin compounds that are recognized by ants of genus Atta, which may allow for coexistence between ants and frogs."

Read more at Science Daily

African clawed frog genome contains two full sets of chromosomes from 2 two extinct ancestors

The genome of the frog X. laevis (top) is roughly double that of its relative, X. tropicalis (bottom).
Millions of years ago, one species of frog diverged into two species. Millions of years later, the two frogs became one again, but with a few extra chromosomes due to whole genome duplication. Such is the curious case of the African clawed frog, Xenopus laevis, a frog whose genome contains nearly double the number of chromosomes as the related Western clawed frog, Xenopus tropicalis.

In the evolution of species, different events have occurred over millions of years that have increased the number of chromosomes in some organisms. Polyploidy describes an event that increases the number of copies of each chromosome. Vertebrates have undergone at least two different polyploidy events since their original divergence. While it is relatively rare nowadays to observe a mammal, reptile or bird with an abnormal number of chromosomes, polyploidy is common in fish, amphibians and plants.

Prof. Daniel Rokhsar, Professor of Genetics, Genomics and Development at the University of California, Berkeley and head of the Molecular Genetics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), Prof. Masanori Taira from the University of Tokyo and Prof. Richard M. Harland from the University of California at Berkeley led groups of researchers in examining the genome evolution of the African clawed frog. This large, collaborative project included scientists from a variety of universities and institutions across the globe. The study, published in Nature and featured on the cover, revealed that the X. laevis genome is composed of two different sets of chromosomes from two extinct ancestors.

Dr. Oleg Simakov, a postdoctoral scholar in the Molecular Genetics Unit at OIST, developed an algorithm to determine the length of time, in millions of years, between the divergence and subsequent fusion of the X. laevis ancestral species. In order to be able to calculate these times, the X. laevis genome had to be correctly annotated. Annotation involves identifying which regions of DNA contain coding genes or non-coding regions. While automation can simplify this process, many mistakes are made. Dr. Yuuri Yasuoka of the Marine Genomics Unit at OIST helped to manually correct the gene annotation. His graduate studies at the University of Tokyo under the guidance of Prof. Masanori Taira allowed him to develop the skills necessary for his role in this project. "Taking advantage of my experiences on the field of developmental biology, I examined genes involved in developmental processes," he clarified.

Dr. Adam Session, a former graduate student in Prof. Rokhsar's lab at the University of California at Berkeley and co-lead author of the Nature publication, elaborated "The most exciting finding from our study is that we can partition the current X. laevis genome into two distinct sets of chromosomes, each descended from a unique ancestral species. While plant studies have been able to show similar results using related species still in existence, this study is the first time this has been done with two extinct progenitor species."

Read more at Science Daily

Early humans used innovative heating techniques to make stone blades

Extensive heat treatment in Middle Stone Age shows that controlled use of fire may have occurred at early stage of tool and blade production. The photo shows heated artefacts in silcrete made by Homo sapiens at Klipdrift Shelter, South Africa.
Humans living in South Africa in the Middle Stone Age used advanced heating techniques that vastly improved living conditions during the era.

According to a new study published in the open-access journal PLOS ONE, humans living in South Africa in the Middle Stone Age after 65,000 years ago deliberately heated silcrete, a hard, fine-grained, local rock used in stone tool manufacture, so that they could more easily obtain blades from the core material.

A major effect on hunting

These blades were then crescent shaped and glued into arrow heads. This era, known as the Howiesons Poort, has produced the first known evidence for the use of the bow and arrow.

“This is the first time anywhere that bows and arrows were used. This would have had a major effect on hunting practices as both spears and bow and arrow could be used to hunt animals,” says Professor Christopher Henshilwood.

He and Postdoctoral Fellow Karen van Niekerk, from the Department of Archaeology, History, Cultural Studies and Religion at the University of Bergen (UiB) in Norway, are among the co-authors of the study.

Creating early transformative technology

The heat treatment enabled early humans to produce tougher, harder tools – the first evidence of a transformative technology. However, the exact role of this important development in the Middle Stone Age technological repertoire was not previously clear.

Novel analytical research approach

Delagnes, Henshilwood, van Niekerk and the rest of the research team, from South Africa and Germany, used a novel non-destructive approach to analyse the heating technique used in the production of silcrete artefacts at the Klipdrift Shelter, a recently discovered Middle Stone Age site located on the southern Cape of South Africa, including unheated and heat-treated comparable silcrete samples from 31 locations around the site. The site was discovered by Henshilwood and van Niekerk and first excavated in 2011.

“Based on the development of a non-destructive method using geological heated and unheated comparative reference samples, we have shown that more than 90 per cent of the silcrete used for the production of blades has been intentionally heated,” says Henshilwood.

“Heating was applied, non-randomly, at an early stage of core exploitation and was sometimes preceded by an initial knapping stage. As a consequence, the whole operational chain, from core preparation to blade production and tool manufacturing, benefited from the advantages of the heating process,” explains van Niekerk.

The hardening, toughening effect of the heating step would therefore have impacted all subsequent stages of silcrete tool production and use.

Heat treatment: a major asset

The authors suggest that silcrete heat treatment at the Klipdrift Shelter may provide the first direct evidence of the intentional and extensive use of fire applied to a whole lithic chain of production. Along with other fire-based activities, intentional heat treatment was a major asset for Middle Stone Age humans in southern Africa, and has no known contemporaneous equivalent elsewhere.

“The advantages of the heating process are multiple: by reducing the material’s fracture toughness and increasing its hardness, less force was needed to detach blades after heat treatment, resulting in better control and precision during percussion,” explains Henshilwood.

“An additional advantage relates to the heat-induced fracturing of the silcrete blocks at an early stage of core exploitation,” adds van Niekerk.

Read more at Science Daily

Tasmanian Devils in the Wild Beat Back Deadly Cancer

Scientists reported Wednesday the first evidence that the immune systems of wild Tasmanian devils can fight back against the contagious face cancer that has pushed the species to the brink of extinction.

In a race against the clock, scientists have been looking for a way—a cure or vaccine—to save the carnivorous marsupials, which live exclusively on the Australian island state with which they share a name.

Strange facial tumors showed up in the mid-1990s, and have since wiped out some 80 percent of the population.

The disease—nearly 100 percent fatal—spreads through facial biting, a common behavior among both males and females.

Some 20,000 individuals are thought to remain.

In the study, a team led by Ruth Pye of the University of Tasmania collected blood samples from 52 closely monitored wild animals from 2008 through 2014.

The scientists checked for the presence of cancer cells, and antibodies that might attack them.

Thirty-four of the animals either had the disease at the outset or developed it during the monitoring period.

The researchers were surprised to find six devils that developed serum antibodies against the cancer cells.

Such a response has been induced in captivity through immunization with killed cancer cells, but had not—before this—been observed in the wild.

The result "suggests that a proportion of wild devils can produce a protective immune response against naturally acquired devil facial tumor disease," the researchers concluded.

A study published in August reported that the famously aggressive animals, the size of a heavy-set small dog, seem to be pulling back from the brink through lightning-fast genetic evolution.

A detailed comparison of the genomes of 294 devils—before and after the cancer emerged 20 years ago—revealed species-wide adaptations in seven genes in a span of just a handful of generations.

From Discovery News

Oct 19, 2016

Weird Deep Space X-Ray Flashes Stump Astronomers

Jimmy Irwin wasn't looking to get a paper published in Nature when he gave three of his University of Alabama undergraduate students an assignment.

He told them to comb through archived Chandra and XMM-Newton telescope data for examples of bright X-ray emissions coming from galaxies beyond the Milky Way. The catch was to find examples emanating from globular cluster galaxies, a type of very old galaxy.

"It seemed like a suitably straightforward project for undergraduates who can only dedicate a few hours a week to work on," Irwin wrote in an email to Seeker.

Chandra had picked up a puzzling signal once before.

In 2005, astronomers detected a flare from the general direction of galaxy NGC4697, a globular cluster located some 40 million to 50 million light-years away in the constellation Virgo.

"Two brief flares were seen, separated by four years," Irwin writes in this week's Nature.

Both times, the flares grew 90 times brighter in less than a minute, and there were no associated optical emissions in the position of the flares.

"It is still a bit of a mystery," Irwin said. "It is possible that (the flare) lies far beyond NGC4697, along the same line of sight, making it much more luminous than is believed, or the opposite case -- it is much closer to us, within our own Milky Way galaxy in fact, in which case it would be much less luminous than we think."

So the students went hunting.

"We were only hoping to find objects that varied by modest factors of three – to five or so on time scales of an hour or so," Irwin said.

But the searching software Irwin wrote for them to use could search for variability on all time scales, and the kids pulled in two whoppers: X-ray flares that brightened 100- to 200 percent in less than a minute.

"We were quite surprised," Irwin said.

At its peak, one source, located in Virgo galaxy NGC4636, was 30 times brighter than the X-ray luminosity of the entire Milky Way, he said.

The second source, located near the Centaurus A galaxy NGC 5181, had a big surprise too. So far, it has flared six times in X-ray light, with some pulses as short as 22 seconds. All flares peaked in less than a minute and lasted for about an hour.

Read more at Discovery News

Humans Are Eating Wild Mammals Into Extinction

Some 300 wild mammal species in Asia, Africa and Latin America are being driven to extinction by humanity's voracious appetite for bushmeat, according to a world-first assessment released Wednesday.

The species at risk range from rats to rhinoceros, and include docile, ant-eating pangolins as well as flesh-ripping big cats.

The findings, published in the journal Royal Society Open Science, are evidence of a "global crisis" for warm-blooded land animals, 15 top conservation scientists concluded.

"Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world," the study warned.

This decline, it said, was part of a larger trend known as a "mass extinction event," only the sixth time in half a billion years that Earth's species are dying out at more than 1,000 times the usual rate.

Besides eating them, humans are robbing mammals of their natural habitats through agriculture and urbanization, and decimating them through pollution, disease and climate change.

According to the Union for the Conservation of Nature's (IUCN) Red List of endangered species, a quarter of 4,556 land mammals assessed are on the road to annihilation.

For 301 of these threatened species, "hunting by humans" -- mainly for food, but also as purported health and virility boosters, and trophies such as horns or pelts -- is the main threat, according to the comprehensive review of scientific literature.

The likelihood of extinction, the team found, depends on body size: the bigger the animals, the greater the danger.

More than 100 primates, including gorillas and snub-nosed monkeys, and dozens of hoofed animals from oxen to antelope, are at dire risk from hunting.

"These species will continue to decline unless there is major global action to save them," Bill Ripple, a professor at Oregon State University and lead author of the study, told AFP.

All 301 species identified are found exclusively in developing countries, with the highest concentration in southeast Asia (113), followed by Africa (91), the rest of Asia (61) and Latin America (38).

The countries with the most native species under siege from hunting were Madagascar (46), Indonesia (37), the Philippines (14) and Brazil (10).

The scale of the problem is daunting: some 89,000 tonnes of wild meat -- with a market value of about $200 million (180 million euros) -- is butchered every year from the Brazilian Amazon alone, the study found.

On current trends, the prospects for these and other mammals is not bright, the authors said.

"Forty of these species were already classed as critically endangered by 1996, indicating that there has been little or no conservation progress in reversing their fate," they note.

This, despite dozens of major conservation conferences and summits, and the expansion of protected areas.

The impact of extinction may be felt well beyond the loss of individual species, the scientists cautioned.

"Through cascading effects, the loss of these mammals is altering the structure and function of the environments in which they occur," the study notes.

Read more at Discovery News

Mastodon Skeleton in Michigan Best Since 1940s

The most complete mastodon skeleton found in Michigan in some 75 years has been unearthed in the state's "Thumb" region, according to paleontologists from the University of Michigan (UM).

Researchers with the university say about 70% of the creature's skeletal mass has been recovered from the Fowler Center for Outdoor Learning, near Mayville.

While parts of hundreds of mastodons have been found in Michigan, the researchers estimate that the new find is more complete than all but a handful of them.

"This is the most complete Michigan mastodon skeleton in many decades," said UM paleontologist and leader of the dig, Daniel Fisher, in a statement. "I think the last time a mastodon this complete was found in Michigan was in the 1940s."

Mastodons, extinct relatives of modern elephants, roamed North and Central America in grazing herds and died out about 10,000 to 11,000 years ago.

Further testing will be done to narrow its age estimate and even the season in which it died, but much is already known about the skeleton. It belonged to a male estimated to have lived between 11,000 and 13,000 years ago, and the animal was likely around 30 years old at time of death, based on tooth size and wear.

What's more, the mastodon looks to have been the victim of early human hunters.

"I would say it is roughly 80 percent likely that humans were involved and responsible for major portions of what we see at this site," Fisher said.

Fisher and his team noted that the mastodon's bones were still aligned correctly, relative to each other. Had it died of natural causes, they said, the animal's carcass would have been scavenged and the bones scattered from their original location. Indeed early indications are the creature was processed by humans, with some fully aligned bone sections seemingly separated into piles.

The location of the bones, near a lake that no longer exists, suggests another intriguing possibility.

The mastodon was "apparently brought to a lake and, we think, stored in this lake as a strategy for meat storage by early humans who lived in this part of the world at that same time," Fisher said. The researcher has studied other Great Lakes pond-storage sites, where the cold pond bottom, coupled with lowered oxygen, would have helped keep the meat from spoiling.

"Finding a specimen like this also tells us something about human history," Fisher said. "What did it take to feed a family, to raise a family? What did it take to make a life in early Michigan, soon after the recession of the ice at the end of the ice age?"

Read more at Discovery News

New View of Mars Reveals Ghostly Ultraviolet Glow

Mars in ultraviolet light is a wondrous place. By night, the dark side of the planet is aglow with nitric oxide. By day, clouds quickly merge together into banks that stretch 1,000 miles long.

The new view of Mars comes from the orbiting MAVEN spacecraft, which this month begins a third year of studies about how the planet most like Earth in the solar system lost most of its atmosphere.

When the spacecraft reaches the most distant part its orbit — MAVEN travels as far as 3,900 miles from Mars — its global view of the planet is giving scientists new insights, and in some cases first looks, at global wind circulation, ozone distribution and cloud formation.

The data about the winds comes from MAVEN images of "nightglow," a common phenomenon in which an atmosphere shines at night, despite the complete absence of illumination, MAVEN scientist Nicholas Schneider, with the University of Colorado, Boulder, told reporters at the American Astronomical Society meeting in Pasadena, Calif., this week.

"Nightglow is the result of chemical reactions in an atmosphere," Schneider said. "In the case of Mars, the molecules are broken apart on the day side of the planet … and those atoms are carried by the winds to the night side, primarily the winter pole, where they then descend to higher density and recombine. In that act of re-combining, they have enough energy to give off ultraviolet photons."

The nightglow molecules are nitric oxide and how they apparently spread over Mars means that computer models of the planet's flowing winds are in need of an upgrade.

The new data indicates that the winds around the planet, already subject to strong seasonal changes, are more irregular than expected, Schneider said.

That, in turn, raises questions about the transport of atmospheric molecules, and especially the chemistry that happens as a result, he said.

MAVEN's UV view of Mars also confirms theories that what little ozone Mars has is concentrated in the dry, polar regions where there is little water vapor to break up the molecules.

"The nature of the polar vortex and how long the ozone lasts through Spring provides insight into the evolution of ozone and water vapor, a coupled chemistry in the Mars atmosphere," Schneider said.

Perhaps the most striking new look at Mars is time-lapse imagery of clouds forming and moving across the planet.

Clouds provide a way to trace atmospheric flows, and they affect the planet's energy balance, depending on whether sunlight is absorbed or reflected back into space, Schneider said.

"They also tell us about the inventory of water vapor that would be available for forming clouds," he added.

The images show which regions of Mars are relatively thick with atmosphere, such as the low-lying Meridiani Planum, where Europe's Schiaparelli lander will attempt to touch down on Wednesday.

Read more at Discovery News

Oct 18, 2016

Modeling floods that formed canyons on Earth, Mars

Larsen and Lamb apply their new model to the “channeled scablands” in eastern Washington State, an area that, like some on Mars, has very deep canyons cut into fractured basalt bedrock.
Geomorphologists who study Earth's surface features and the processes that formed them have long been interested in how floods, in particular catastrophic outbursts that occur when a glacial lake ice dam bursts, for example, can change a planet's surface, not only on Earth but on Mars.

Now geoscience researchers Isaac Larsen at the University of Massachusetts Amherst and Michael Lamb at the California Institute of Technology have proposed and tested a new model of canyon-forming floods which suggests that deep canyons can be formed in bedrock by significantly less water than previously thought. They point out that "reconstructing the magnitude of the canyon-forming floods is essential for understanding how floods modify planetary surfaces, the hydrology of early Mars, and abrupt climate change."

Larsen and Lamb apply their new model to the "channeled scablands" in eastern Washington State, an area that, like some on Mars, has very deep canyons cut into fractured basalt bedrock. The researchers say their results suggest "there may be a rich imprint of both the history and discharge of flooding in the morphology of canyons" such as terraces, valley shapes and slope profiles on Earth and on Mars "that warrant further investigation." Details appear in the current issue of Nature.

The researchers say channels in the scablands today, which are up to 650 feet (200 meters) deep and 3 miles (5 km) wide, were likely formed by flood discharges five- to tenfold smaller than brimful estimates, that is by "significantly lower megaflood discharges than previously thought. The channeled scablands are a classic landscape in the history of geomorphology and we're bringing new views of how it was formed."

Until the 1920s, scientists did not understand what could have formed the tortured landscape of eastern Washington studied for decades by J Harlen Bretz, a giant figure in geosciences, Larsen recalls. Bretz was the first to suggest that they were formed by catastrophic flooding of unknown origin. His views were dismissed for years, but Bretz was later vindicated when glacial Lake Missoula was identified as the floodwater source.

As most scientists came to accept the catastrophic flood explanation for the canyons and then tried to estimate floodwater discharges, they assumed that floods filled canyons to the brim, a huge amount of water. But an alternate hypothesis proposed and now tested by Lamb and and Larsen posits that as floodwater cuts into bedrock, the canyon deepens, meaning less water is required to shape it.

In areas underlain by fractured bedrock, Larsen says, "our general concept is that the channel floor was being cut and lowered as the floods were happening, and you need to account for that when reconstructing the scenario of flood magnitude. This applies to the scablands, to Mars and other areas where there have been catastrophic outburst floods."

He and Lamb combine numerical flood models with estimates of the force required to erode basalt bedrock to show that for Moses Coulee, a canyon carved by catastrophic Lake Missoula floods in eastern Washington when an ice dam repeatedly broke and reformed around 15,000 years ago, their "threshold shear stress model" explains the shape and depth of currently observed channels better than the brimful model.

"We numerically routed floods through the canyon in different states, from current configuration and at four different past scenarios," Larsen notes. "We predicted the discharge from two models and tested which one is most reasonable, based on the depositional evidence from the current bars seen today in the canyons. The size of floods our model predicts from the basalt erosion better match locations of depositional flood bars in the canyon than the brimful model predicts."

Read more at Science Daily

Biodiversity loss in forests will be pricey

A new global assessment of forests -- perhaps the largest terrestrial repositories of biodiversity -- suggests that, on average, a 10% loss in biodiversity leads to a 2 to 3% loss in the productivity, including biomass, that forests can offer. Based on these results, the authors estimate the value of biodiversity in maintaining commercial productivity to be 166 to 490 billion (USD), which would be considerably greater than the total cost of effective global conservation. The results could be used to better inform forest management and restoration.

The biodiversity-productivity relationship (BPR) has gained the interest of scientists and policy-makers over recent years, but most BPR assessments of forests have been regional to date. To gain more insights into BPR on a global scale, Jingjing Liang et al compiled data from 777,126 sample plots across 44 countries and 13 ecoregions. In total, more than 30 million trees across 8,737 species were tallied and measured.

Their assessment reveals that, in general, on a global scale, a 10% decrease in tree species richness would cause a 2 to 3% decline in productivity, which is the rate of biomass production in an ecosystem.

A 99% decrease in tree species richness, by contrast, results in productivity declines of 62 to 78%. While productivity trends consistently decrease with increased biodiversity loss across nearly all regions of the world, the areas that would experience the greatest productivity decline in absolute terms include the Amazon, West Africa's Gulf of Guinea, Southeastern Africa, Southern China, Myanmar, Nepal, and the Malay Archipelago.

From Science Daily

Astronomers predict possible birthplace of Rosetta-probed comet 67P

Using statistical analysis and scientific computing, astronomers at Western University have charted a path that most likely pinpoints the very origins of comet 67P/Churyumov-Gerasimenko, which is vital information in discovering what kind of material it is made from and just how long it has been present in our solar system.
When the Rosetta spacecraft successfully touched down on comet 67P/Churyumov-Gerasimenko on September 30, 2016, the news was shared globally via Twitter in dozens of languages. Citizens the world over were engaged by the astronomical achievement, and now the European Space Agency and NASA are eager to learn as much as possible about the critically important celestial body of ice.

Using statistical analysis and scientific computing, astronomers at Western University have charted a path that most likely pinpoints the very origins of comet 67P/Churyumov-Gerasimenko, which is vital information in discovering what kind of material it is made from and just how long it has been present in our solar system.

Mattia Galiazzo, a postdoctoral fellow in Western's Department of Physics & Astronomy, presented his findings at the joint 48th annual meeting of the Division for Planetary Sciences (DPS) of the American Astronomical Society (AAS) and 11th annual European Planetary Science Congress (EPSC) in Pasadena, California. Galiazzo collaborated on the findings with solar system expert Paul Wiegert from Western's Centre for Planetary Science & Space Exploration.

"These results come from computations of the comet's orbit from the present to the past, which is computationally difficult due to the chaosity of the orbit caused by close encounters with Jupiter," says Galiazzo. "Thus the details are obscure but we can establish a dynamical pathway from its current orbit back to the Kuiper belt."

Galiazzo and Wiegert think that 67P/Churyumov-Gerasimenko is relatively new to the inner parts of our solar system, having only arrived about 10,000 years ago. Prior to this time, the comet would have been inactive in frozen storage far from the Sun.

Previous studies show that similar comets -- known as Jupiter Family comets -- historically stay in the inner parts of our solar system for 12,000 years, therefore recognizing comet 67P/Churyumov-Gerasimenko as a member of the Jupiter Family makes sense.

The majority of the Jupiter Family comets are thought to come from the Kuiper belt -- a ring-shaped accumulation of comets, asteroids and other space bodies in the solar system beyond the known planets -- and Galiazzo and Wiegert believe, based on initial analysis of their investigation, that this is the case for 67P/Churyumov-Gerasimenko, as well.

Read more at Science Daily

New Human Cell Atlas Is Like Google Maps for the Body

Imagine having the level of detail in Google Maps but for the inner workings of the human body. A new international initiative is creating an atlas that will chart every single cell in the human body, encompassing all of the tissues within Homo sapiens, scientists announced last week at a meeting in London.

The revolutionary project, called the Human Cell Atlas, will help biologists and doctors understand, diagnose and treat diseases with the help of high-resolution images of healthy and atypical cells from every structure in the body.

"In sickness and in health, cells are the fundamental units of life, and only by knowing our cells will we be able to fully comprehend the mechanisms of human disease," Sten Linnarsson, a professor of molecular systems biology at the Karolinska Institutet in Sweden, who is participating in the initiative, said in a statement.

The initiative was formally announced at an international meeting convened by the Broad Institute of the Massachusetts Institute of Technology and Harvard University, Wellcome Trust Sanger Institute, and Wellcome Trust on Oct. 13 and 14.

At the meeting, researchers decided what to include in the initiative's first phase. The scientists said the project is expected to be as ambitious in scope as the Human Genome Project, which was the first successful undertaking to sequence the human genome — all of the 3 billion "letters" in human DNA.

There are trillions of cells within the human body, but each person came from just two cells: an egg and sperm cell. Once the egg and sperm combine to make an embryo, these cells divide, grow and give rise to new types of cells that form tissues and organs, the project's scientists said.

However, there isn't much detailed knowledge about the body's countless cells. Earlier studies have described what certain cells look like under a microscope, and more recent analyses have found the average properties of cells by examining clumps of hundreds or thousands of them. But there isn't yet an entity that shows a magnified image of every cell and what molecules are produced in each cell, the researchers said.

For instance, the atlas will include messenger RNA that gives each cell its unique identity. Collecting this information would have been impossible a few years ago, but new advances in single-cell genomics now allow researchers to separate individual cells from different tissues and organs, and to measure the transcriptome (the body's messenger RNA molecules) and other important molecules, the researchers said.

"We are currently limited in our understanding of how cells differ across each organ, or even how many cell types there are in the body, said Sarah Teichmann, head of cellular genetics at the Wellcome Trust Sanger Institute in the United Kingdom. "The Human Cell Atlas initiative is the beginning of a new era of cellular understanding, as we will discover new cell types; find how cells change across time, during development and disease; and gain a better understanding of biology."

The new atlas will identify each cell's type, such as whether it is an immune cell or brain cell. The map will also show where these cells are located within the body's tissues. In addition, it will distinguish among cell states, for instance, what a naive immune cell looks like before it has encountered any pathogens and how a seasoned immune cell appears after it has been activated by a bacterium, the researchers said.

Moreover, the atlas will capture key characteristics of cells as they transition, for instance, the changes that occur as a stem cell becomes a specific type of cell, the scientists said. This will help researchers trace the lineage of each cell, such as how a predecessor stem cell in bone marrow turns into a functional red blood cell, the researchers said.

Read more at Discovery News

Volcanoes in Ethiopia Shook Up Early Human Evolution

Dramatic and rapid changes from volcanic activity in Ethiopia appear to have set the stage for the emergence of Homo sapiens around 200,000 years ago. The first known fossil evidence for our species was unearthed there, where explosive volcanic activity was dramatically changing the landscape and environment, according to new research published in the journal Nature Communications.

"Pyroclastic flows -- hot currents of gas, ash and rock -- would have inundated large tracts of the rift floor while ash and pumice fallout from larger plumes are likely to have covered regions to at least 100 kilometers (62 miles) from the vent," lead author William Hutchison of the University of Oxford's Department of Earth Sciences told Seeker.

While all of this was going on, the earliest-known members of our species were not very far away. The fossils from the Omo Kibish rock formation of southern Ethiopia date to 195,000 years ago. These early humans likely viewed the eruptions from a safe enough distance -- but their presence in the region as the volcanic activity took place seems to be too coincidental to ignore.

Hutchison said that the volcano eruptions occurred along the East African Rift System, which is a still-active continental rift where Africa is slowly being pulled apart. One segment runs through Ethiopia, where a population of around 10 million people live alongside it.

As the continent gradually pulls apart, Earth's crust along the rift is extended and thinned, allowing molten rock (magma) to rise.

Hutchison and his team reconstructed the eruptive history of a 124-mile-long segment of the rift in Ethiopia by studying the Aluto and Corbetti volcanoes there. The researchers used two techniques, argon isotopes and radiocarbon analysis, to determine the dates of erupted rocks. They also analyzed the sizes of eruptions along the rift over time.

"We suggest that an increased flux of melt from the mantle into the crust generated the large magma chambers that over-pressured and erupted 320,000–170,000 years ago," Hutchison said. "These events are called flare-ups and have been identified before in other rift zones such as the Taupo Volcanic Zone in New Zealand."

The caldera walls of Corbetti volcano, Ethiopia. The caldera was created 200,000 years ago during a colossal volcanic eruption.
Ancestors of our species and other members of the human family tree collectively known as "hominins," as well as other animals, were already in the region, so there could have been sudden devastation as when Italy's Mount Vesuvius erupted and killed nearly everyone in its path.

"Major volcanic eruptions and the environmental devastation that followed might have greatly reduced hominin populations living in the rift zone," Hutchison said. "The eruptions themselves would have made certain sections of the rift uninhabitable, potentially for many thousands of years. These mechanisms provide a means of reducing and isolating certain populations which might have promoted human adaptation and evolution at this time."

"This suggests," he added, "that our earliest ancestors not only had to deal with changing climate but also (with) the environmental devastation caused by major explosive eruptions."

Earlier research supports that the region was heavily populated with hominins long before our species emerged on the scene. Yohannes Haile-Selassie and Denise Su of the Cleveland Museum of Natural History said "more than one species of early hominin co-existed during Lucy's time" starting at about 3.8 million years ago. Lucy (Australopithecus afarensis), they explained, "was the only potential human ancestor species that roamed in what is now the Afar region of Ethiopia."

Read more at Discovery News

Oct 17, 2016

Land of Giants Located in Ireland

The land of giants. It sounds like something from a fairy tale, but it arguably exists in a region of Northern Ireland where a cluster of people with a genetic predisposition grow abnormally tall.

In Mid-Ulster, about 1 in 150 people carry a genetic mutation to the AIP gene that leads to an overproduction of growth hormone resulting in acromegaly, also known as gigantism. The hormone disorder is spurred by a tumor on the pituitary gland, a pea-sized organ at the base of the brain.

"This is probably the highest proportion of giants in the whole world in that little part of Northern Ireland," Marta Korbonits, professor of endocrinology at Barts and the London School of Medicine Queen Mary, tells Seeker. Korbonits led the team that discovered the link between the AIP gene defect in Irish populations and gigantism in 2011.

In their latest research, Korbonits and her team calculated that the AIP gene defect traces back 2,500 years. The team found the variant in Charles Byrne, a man born in 1761 who grew to be 7 feet, 6 inches tall and was known as the "Irish giant," as well as in 18 other Irish families.

Symptoms vary depending on whether the disease first appears in childhood or as an adult. "The disease usually develops in children between 10 and 20, although we have a few cases younger than 10, and some between 20 and 30," Korbonits explained.

In children, there's rapid growth, which can be accompanied by joint pain, disabling headaches, vision problems, type II diabetes, facial distortion and enlarged hands and feet. In adults, if symptoms develop late, adults don't get taller, because their bones are already fused and may in fact shrink due to developing a curvature in the spine. Other symptoms include muscle weakness, hypertension and difficulty sleeping.

"While these people might look big and powerful and strong, the long-term effects of excess IGF-1 and growth hormone are very disabling for these patients," explains Anthony Heaney, endocrinologist and professor at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA).

"We have this fascination with these really large, powerful people, and yet they themselves have a lot of morbidity and potential mortality from this disorder," Heaney continues.

Treatments are available and include surgery, medication or radiation therapy, but how effective those options are depends largely on the progression of the disease. Usually by the time clinicians get involved, patients have already developed large tumors, and complete control of the tumor and hormone regulation is hard to achieve. Even the best surgical centers in the world are just 50 percent effective at achieving that control, Heaney notes.

Monitoring the lineage of the gene variant lets researchers keep an eye out for children who inherit the defect. Early clinical intervention can help to prevent the worst of the symptoms.

Read more at Discovery News

T. Rex Had Little Use for Its Puny Arms

Sue the Tyrannosaurus rex — the most complete and best-preserved T. rex skeleton ever found — temporarily surrendered her arm to science. And the preliminary results suggest it wasn't doing her much good anyway.

Tests on Sue's arms at Argonne National Laboratory in Illinois showed few signs of stress, according to The Field Museum in Chicago, where this giant beast dominates the museum's main hall. The tests suggest that when this fearsome predator was alive more than 65 million years ago, she didn't use those itty-bitty arms very often, museum scientists said.

"It's very early yet, but it seems like there aren't many signs of stress on the bones that would indicate frequent use," Peter Makovicky, associate director of dinosaurs at the museum, said in a statement. "Based on what we know now, it looks like T. rex didn't use its arms much, at least not as an adult, but there's still a lot to learn."

T. rex's comically small front limbs have long stumped scientists. Some have argued that the arms had a purpose, pointing out that the bones are short but thick and could have supported bulging muscles. Others think the arms were basically vestigial (a small remnant of an ancestor). T. rex wasn't the only carnivorous dinosaur to have stubby limbs. An allosaur called Gualicho shinyae discovered in Argentina this year also had surprisingly small arms for its body size. G. shinyae is only distantly related to T. rex.

The finding shows that "tyrannosaurs' [arms] really aren't unusual," biologist Thomas Carr told Live Science when the allosaur discovery was announced. "It's not just a one-off [finding]," he said.

Sue the T. rex was unearthed in Montana in 1990. She's 40.5 feet (12.3 meters) long and 13 feet (4 m) tall, and her skull alone weighs 600 lbs. (270 kilograms). Sue's jaw is pockmarked with holes that may have been caused by a parasitic infection. If so, the disease was serious and may have killed the mighty predator.

But it's Sue's arms that are getting all the attention now. This month, researchers removed the arm bones from the skeleton and transported them to the Advanced Photon Source at Argonne National Laboratory. This instrument creates extra-bright X-rays, which researchers are using to study where muscles would have attached to the bone and where blood vessels would have penetrated.

"Understanding the fine internal morphology of the skeleton will give us clues about how the arm could move and what it was used for," paleontologist Carmen Soriano, a scientist at the Advanced Photon Source, said in a statement released Oct. 12.

The final results of the scans are months away, according to the statement.

From Discovery News

Ancient Man Killed by Boomerang

When thrown properly, boomerangs can be lethal weapons. In fact, cave paintings in Australia show that they've been used as such for thousands of years, during hunting and war.

Now, scientists think they might have the remains of a boomerang-attack victim, with the discovery of an 800-year-old skeleton that has a long gash in its skull.

The bones were found eroding out of a riverbank in New South Wales' Toorale National Park two years ago. The skeleton — a male, likely between 25 and 35 years old when he died —was well preserved and appeared to have been carefully buried in a tightly flexed position. He was named "Kaakutja," a term from the local Baakantji people meaning "older brother."

Researchers found that Kaakutja ate crayfish and possum for his last meal, and that conflict was part of his lifestyle; he had two head injuries that had partially healed and fresh deadly wounds that had no signs of healing.

He had rib fractures and a wound to his upper arm. His skull was sliced down the right side of his face, from the frontal bone of his skull to his jaw, with the type of cut that's usually inflicted by a sharp-edged metal weapon. Radiocarbon dating, however, showed that Kaakutja died in the mid-13th century, 600 years before Europeans brought metal weapons to Australia.

For answers, the researchers, led by palaeoanthropologist Michael Westaway of Griffith University in Australia, turned to aboriginal weapons like stone axes and a type of wooden club known as a lil-lil.

Kaakutja's main head wound was about 6 inches (15 centimeters) long, meaning the weapon must have had a blade at least this length, the scientists reasoned. In their study, which is detailed in the October issue of the journal Antiquity, the team concluded that the sharp edge of a wooden boomerang most likely caused this lengthy cut. The researchers added, however, that they could not say for certain whether this was the fatal blow that killed Kaakutja. "Multiple wounds probably led to significant blood loss and eventual death,"they wrote.

One ethnographic account from the early 20th century claims aboriginal Australians used a type of boomerang for fighting or hunting. It was bigger and heavier with a more open curve than the typical returning boomerang and "reminds one of the blade of a sabre and its inner edge is sharp and dangerous." The case of Kaakutja could attest to the lethal power of such a weapon.

"The nature and expression of trauma suggests that some edged weapons from traditional Aboriginal culture had the capacity to inflict injuries similar to those produced by edged metal weapons," the researchers wrote.

Read more at Discovery News

Craze for Hornbill's 'Red Ivory' Pushes Bird toward Extinction

A striking bird with monochrome plumage and a formidable "beak," the helmeted hornbill is being hunted to extinction, one of the latest victims of a thriving global trade in exotic wildlife.

For decades poachers in Borneo's western forests focused on capturing orangutans and sun bears, but in the past few years a surge in demand for hornbill "ivory" has pushed the avian species to the brink. The product has become so popular in China, where wealthy collectors are keen to show off their status by acquiring rare or unusual animals, that it is fetching up to five times the price of elephant tusk on the black market.

"The demand for these luxury items is just going through the roof," Chris Shepherd, from wildlife trade watchdog TRAFFIC, told AFP. "In Asia, it's really at a scale where species like the helmeted hornbill are just being completely decimated."

Poachers aren't interested in their brilliant plumage or large bills, but a helmet-like block of reddish-gold keratin at the front of the skulls known as a casque. It's this soft, ivory-like substance that's carved by craftsmen in China into luxury ornaments, statues and jewelry — trendy top-shelf trinkets that have soared in value as so-called "red ivory" has grown more prestigious.

Experts say a single casque can fetch up to $1000, eclipsing the average black market price of traditional "white" ivory sourced from elephant tusk several times over. Researchers say thousands of these majestic birds have been killed in half a decade alone as demand for red ivory has taken off.

Yokyok Hadiprakarsa, a leading expert in helmeted hornbills, estimates as many as 500 were killed every month in 2013 — or 6,000 annually — just in West Kalimantan, a jungle-clad province in Indonesia's half of Borneo.

Helmeted hornbills had been traditionally hunted in the past by Borneo's indigenous tribes, but never at levels that posed any conservation risk. This "complete, systematic slaughter of the species" came virtually out of nowhere, Shepherd said. It wasn't until 2011 that red ivory first began showing up on websites catering to Chinese buyers and at high-end wildlife markets along the country's borders, such as in Myanmar and Laos.

Hunting rapidly intensified, especially among trafficking networks already well entrenched in West Kalimantan, a key wildlife smuggling hub with an international airport in the capital Pontianak. By the close of 2015, the species had progressed from vulnerable to critically endangered — leapfrogging two threat levels to the highest possible risk category on the International Union for Conservation of Nature's "red list."

Now the elite rangers of the government's Forest Police Rapid Reaction Unit (SPORC) rarely spot these distinctive birds during jungle patrols, SPORC commander David Muhammad told AFP in Pontianak. Instead, they're uncovering just the skulls during raids on smuggler hideouts, the decapitated corpses dumped unceremoniously elsewhere.

"There is a high value placed on the heads by hunters and collectors," said Muhammad. "That's the only thing they want. The rest has no value."

The commercial trade of helmeted hornbills is prohibited by law in China and across its habitat zones in Southeast Asia: Thailand and Myanmar, as well as Malaysia, Brunei and Indonesia — the three countries that share Borneo island.

But the rate of seizures — a "tip of the iceberg" indicator of the trade, said Shepherd — suggests business is booming. In the 18 months to August 2014, nearly 2,200 casques were confiscated by law enforcement in China and Indonesia, around a third just in West Kalimantan.

In one case, SPORC units intercepted four Chinese nationals at Pontianak's international airport with nearly 250 casques stashed in their luggage.

Read more at Discovery News

Great Pyramid Find: Two Mysterious Cavities With Unusual Features

The Great Pyramid at Giza, Egypt, has long been rumored to contain hidden passageways leading to secret chambers. Now a team of researchers has confirmed the 4,500-year-old pharaonic mausoleum contains two unknown cavities, possibly hiding a corridor-like structure and more mysterious features.

The announcement by the ScanPyramids project comes at the end of a year-long effort to use various scanning technology on Old Kingdom pyramids, including the Great Pyramid, Khafre or Chephren at Giza, the Bent pyramid and the Red pyramid at Dahshur.

Carried out by a team from Cairo University's Faculty of Engineering and the Paris-based non-profit organization Heritage, Innovation and Preservation (HIP Institute) under the authority of the Egyptian Ministry of Antiquities, the ScanPyramids project used three innovative techniques — muography, thermography and 3-D simulation — to deeply investigate the Great Pyramid of Giza.

An unknown cavity was detected at a height of about 345 feet from the ground on the northeastern edge of the monument, while a "void" was found behind the northern side at the upper part of the entrance gate.

"Such void is shaped like a corridor and could go up inside the pyramid," Mehdi Tayoubi, founder of the Paris-based Heritage Innovation Preservation Institute, told Seeker.

He added that no link can be made between the two cavities at the moment.

Built for the pharaoh Cheops, also known as Khufu, the Great Pyramid is the largest of a family of three pyramids on the Giza plateau, on the outskirts of Cairo. It's the last remaining wonder of the ancient world.

A striking thermal anomaly was detected in November 2015 by French infrared specialist Jean-Claude Barré on the northern side of the monument, right where four chevrons — blocks placed according to an inverted V-shaped pattern — overhang the descending corridor.

When the pyramid was finished some 4,500 years ago, the chevrons were not visible in that area, but were hidden under casing stones that were dismantled over the centuries.

"Today we still see the remains of those chevrons and oblique stones which most probably are parts of propped missing chevrons covering a kind of void that might have existed before stones were dismantled," the researchers wrote in a statement.

In the construction of the pyramid, chevrons were not used for decoration, but to protect a void and prevent the roof from collapsing.

"Why many chevrons are put to protect such a small area at the beginning of the descending corridor?" the researchers wondered.

 After carrying out a 3-D reconstruction of the area, they decided to install three aluminum plates at the bottom of the descending corridor in an attempt to capture cosmic particles.

The technology, known as muography, relies on the muons that continually shower the Earth's surface. They emanate from the upper layers of Earth's atmosphere, where they are created from collisions between cosmic rays of our galactic environment and the nuclei of atoms in the atmosphere.

"Just like X rays pass through our bodies allowing us to visualize our skeleton, these elementary particles, weighing around 200 times more than electrons, can very easily pass through any structure, even large and thick rocks, such as mountains," Tayoubi said.

Tayoubi and his colleagues placed detectors sensitive to muons, called emulsion plates, inside the pyramid to discern dense areas from less dense areas — essentially the bones and tissue of the pyramid. When the films from the detectors were analyzed at Nagoya University in Japan, they revealed a significant excess of muons in the same direction, strongly pointing to a corridor-like void.

"The precise shape, size and exact position of this void is now under further investigation," the researchers said.

To that end, they added 12 new muon emulsion plates in the descending corridor.

"They will be collected by the end of October," Tayoubi said.

The investigation of the Great Pyramid also involved muon gas detectors, basically telescopes pointed on the northeastern side of monument from the outside.

Overall, they accumulated around 50 million muon cosmic particles, revealing muon excess at a spot close to the edge, at around 345 feet from the ground.

"This excess corresponds to an unknown cavity, measuring about 30 square feet. It's the same volume as another known cavity located on the same edge," Tayoubi said.

"Several studies from The French Alternative Energies and Atomic Energy Commission (CEA) and Nagoya university were conducted to confirm the excess of muons was not statistical fluctuation or noise," he added.

The excess was measured to be largely above 5 sigmas, corresponding to an effect with a probability above 99.9999%. In other words, the findings don't seem to have been some odd fluctuation of muons.

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