Cells carry 'memory' of injury, which could reveal why chronic pain persists

A new study from King's College London offers clues as to why chronic pain can persist, even when the injury that caused it has gone. Although still in its infancy, this research could explain how small and seemingly innocuous injuries leave molecular 'footprints' which add up to more lasting damage, and ultimately chronic pain.

All of us are likely to know someone who suffers from persistent pain -- it is a very common condition, which can be caused by sports injuries, various diseases and the process of ageing. Treatment options are limited and doctors are often unable to offer anything more than partial relief with painkillers, leaving their patients resigned to suffering.

While chronic pain can have many different causes, the outcome is often the same: an overly sensitive nervous system which responds much more than it normally would. However, a question still remains as to why the nervous system should remain in this sensitive state over long periods of time, especially in instances where the underlying injury or disease has gone.

Researchers from King's sought to answer this question by examining immune cells in the nervous system of mice, which are known to be important for the generation of persistent pain.

In the study, published today in Cell Reports, they found that nerve damage changes epigenetic marks on some of the genes in these immune cells. Epigenetics is the process that determines which gene is expressed and where. Some epigenetic signals have direct functional consequences, while others are just primers: flags that indicate a potential to act or be modified.

The cells examined in this King's study still behaved as normal, but the existence of these novel epigenetic marks may mean that they carry a 'memory' of the initial injury.

Dr Franziska Denk, first author of the study, from the Wolfson Centre for Age Related Diseases at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, said: 'We are ultimately trying to reveal why pain can turn into a chronic condition. We already knew that chronic pain patients have nerves that are more active, and we think this is probably due to various proteins and channels in those nerves having different properties.

However, it is unclear why these nerves should remain in this overactive, highly sensitive state, even when the initial injury or disease has gone: the back pain from two years ago that never quite went away or the joints that are still painful despite your rheumatoid arthritis being in remission.'

Dr Denk added: 'We want to know why these proteins and channels should maintain their altered function over such a long period of time. Cells have housekeeping systems by which the majority of their content are replaced and renewed every few weeks and months -- so why do crucial proteins keep being replaced by malfunctioning versions of themselves? Our study is the very first step towards trying to answer this question by exploring the possibility that changes in chronic pain may persist because of epigenetics. We hope that future research in this area could help in the search for novel therapeutic targets.'

Professor Stephen McMahon from the IoPPN at King's College London said: 'This research raises many interesting questions: do neurons also acquire epigenetic footprints as a result of nerve injury? Do these molecular footprints affect the function of proteins? And are they ultimately the reason that chronic pain persists in patients over such long periods of time?

'The last question is particularly hard to answer, because to study epigenetics we need access to pure cell populations. Obviously, many of these are only accessible in postmortem tissue. However, colleagues at King's are already doing this in psychiatry, through studies such as the The PsychENCODE project, so it is possible.'

Dr Giovanna Lalli, Neuroscience & Mental Health Senior Portfolio Developer at the Wellcome Trust, which part-funded the study, said: 'People develop chronic pain for a huge variety of reasons. We therefore need an equally diverse range of treatments to tackle the different root causes.

Read more at Science Daily

Small blue galaxy could shed new light on Big Bang

A faint blue galaxy about 30 million light-years from Earth and located in the constellation Leo Minor could shed new light on conditions at the birth of the universe.

Astronomers at Indiana University recently found that a galaxy nicknamed Leoncino, or "little lion," contains the lowest level of heavy chemical elements, or "metals," ever observed in a gravitationally bound system of stars.

The study appears today in the Astrophysical Journal. The lead author on the paper is Alec S. Hirschauer, a graduate student in the IU Bloomington College of Arts and Sciences' Department of Astronomy. Other IU authors on the paper are professor John J. Salzer and associate professor Katherine L. Rhode in the Department of Astronomy.

"Finding the most metal-poor galaxy ever is exciting since it could help contribute to a quantitative test of the Big Bang," Salzer said. "There are relatively few ways to explore conditions at the birth of the universe, but low-metal galaxies are among the most promising."

This is because the current accepted model of the start of the universe makes clear predictions about the amount of helium and hydrogen present during the Big Bang, and the ratio of these atoms in metal-poor galaxies provides a direct test of the model.

In astronomy, any element other than hydrogen or helium is referred to as a metal. The elemental make-up of metal-poor galaxies is very close to that of the early universe.

To find these low-metal galaxies, however, astronomers must look far from home. Our own Milky Way galaxy is a poor source of data due to the high level of heavier elements created over time by "stellar processing," in which stars churn out heavier elements through nucleosynthesis and then distribute these atoms back into the galaxy when they explode as supernovae.

"Low metal abundance is essentially a sign that very little stellar activity has taken place compared to most galaxies," Hirschauer said.

Leoncino is considered a member of the "local universe," a region of space within about 1 billion light years from Earth and estimated to contain several million galaxies, of which only a small portion have been cataloged. A galaxy previously recognized to possess the lowest metal abundance was identified in 2005; however, Leoncino has an estimated 29 percent lower metal abundance.

The abundance of elements in a galaxy is estimated based upon spectroscopic observations, which capture the light waves emitted by these systems. These observations allow astronomers to view the light emitted by galaxies like a rainbow created when a prism disperses sunlight.

Regions of space that form stars, for example, emit light that contains specific types of bright lines, each indicating the atoms from various gases: hydrogen, helium, oxygen, nitrogen and more. In the light of the star-forming region in Leoncino, IU scientists detected lines from these elements, after which they used the laws of atomic physics to calculate the abundance of specific elements.

"A picture is worth a thousand words, but a spectrum is worth a thousand pictures," Salzer said. "It's astonishing the amount of information we can gather about places millions of light years away."

The study's observations were made by spectrographs on two telescopes in Arizona: the Mayall 4-meter telescope at the Kitt Peak National Observatory and the Multiple Mirror Telescope at the summit of Mount Hopkins near Tucson. The galaxy was originally discovered by Cornell University's Arecibo Legacy Fast ALFA, or ALFALFA, radio survey project.

Officially, the "little lion" is named AGC 198691. The scientists who conducted the metal abundance analysis nicknamed the galaxy Leoncino in honor of both its constellation location and in recognition of the Italian-born radio astronomer, Riccardo Giovanelli, who led the group that first identified the galaxy.

Read more at Discovery News

Arctic Bird Shrinking as Planet Warms

Just as canaries once warned miners of the lack of oxygen, an iconic shorebird that migrates from Siberia to West Africa is sending warning signals about the impact of climate change on the planet.

In a new study published today in the journal Science, an international team details how the warming of the Arctic by climate change could be responsible for drops in the population of a sub-species of red knot bird (Calidris canutus canutus).

As the Arctic has warmed, red knots — which breed in Siberia — have grown smaller with shorter bills.

When the birds arrive at their winter feeding grounds in tropical West Africa, their bills are too short to reach the best food, resulting in higher mortality among the juvenile population, the researchers found.

They suggest the red knot’s experience could hold the key to understanding declining populations worldwide of migratory shore birds.

Senior author Marcel Klaassen, at the Center for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, said the Arctic was warming more rapidly than any place on the globe.

In response, many species were adapting through a process known as “body shrinkage”, Klassen said.

“We observed this in the red knot bird and found they are also starting to pay the price [of this body shrinkage] once they arrive in the tropical feeding grounds,” he said.

The red knot breeds in the Taimyr Peninsula in Siberia during the Arctic summer, before flying around 9,000 kilometers to Banc d’Arguin in Mauritania, West Africa.

Using satellite data from the past 33 years, the researchers found snowmelt in the high-Arctic breeding grounds of the red knot was starting earlier, changing at a rate of about half a day each year.

Over those three decades Polish researchers on the team caught and measured 1,990 red knots as the birds stopped over in Gdansk Bay on their first migration southward.

These measurements showed the body mass and bill size of juvenile birds were smaller after Arctic summers with early snowmelts.

Klaassen said the red knot breeding season was timed so that chicks would hatch when food in the form of insects was at its most abundant. “It is a very short season where there is light for 24 hours of the day and the insect life bursts at a certain moment,” he said.

The earlier onset of snowmelt meant the chicks hatched after this “peak food” period and had less food available, which then impacted on their growth. This had an effect further downstream when the juvenile birds flew to their tropical non-breeding grounds where they used their tapered bills to detect and retrieve molluscs buried in mudflats.

An analysis of the birds’ blood showed individuals with a 40-millimeter bill had access to about two-thirds of the bivalves, whereas a bird with a 30-millimeter bill was able to access only one-third.

“The short bills can’t reach the good food which is the shellfish and essentially become vegetarians,” he said. As a result there was a massive increase in mortality rates.

Klaassen said tagging of 2,381 red knots from 2002 to 2013 and subsequent re-sightings suggested the shorter-billed birds had a 40 per cent chance of survival. This compared with longer-billed juveniles who had an 80 per cent chance of living.

He said the finding was unexpected as it was previously believed the drop-off in bird populations was due to changes in the migratory paths linked to increased human activity and changes to the environment. “This is additional bad news,” he said.

Two different sub-species of red knot also migrate from Siberia to Australia during their non-breeding season. The birds were one of 49 species recently added to the endangered list. Klaassen said in Australia there was masses of data on migratory birds already collected by “legions of volunteers."

However while counts among migratory birds in Australia were also on the decline no one had looked at whether there had been changes in their body architecture.

“This study has opened our eyes. I really hadn’t expected this and am keen to learn if there are similar issues here [among migratory birds],” he said.

Klaassen said more and more of these migratory birds in Australia were being placed on the list of critically endangered animals.

“Doing these long distances they need places where there is plenty of food and safety so they can concentrate on growing fat for the journey,” he said. “We need to set aside areas so we can give them a chance of coping with these changes.”

In an accompanying opinion piece in Science, Professor Martin Wikelski, from Germany’s University of Konstanz and Grigori Tertitski, from the Russian Academy of Sciences write that the results show global warming affects life on our planet in unanticipated ways.

Read more at Discovery News

Climate Change May Have Finished Off Neanderthals

Global warming is threatening the existence of a lot of species on the planet right now. But climate change of a different sort -- cooling -- may have contributed to the demise of the Neanderthals, a species that’s an extinct relative of modern humans, around 40,000 years ago.

In a study recently published in Journal of Human Evolution, Jamie Hodgkins, a zooarchaeologist and assistant professor in the Zoology department at the University of Colorado-Denver, studied bones from caves once inhabited by Neanderthals in southwest France. In particular, Hodgkins looked at how the carcasses of deer and other animals were butchered and used for food.

Hodgkins found that during colder, glacial periods, Neanderthals processed the bones more heavily, splitting them for marrow — a sign of food scarcity in the colder climate.

“Our research uncovers a pattern showing that cold, harsh environments were stressful for Neanderthals,” Hodgkins said in a press release. “As the climate got colder, Neanderthals had to put more into extracting nutrients from bones. This is especially apparent in evidence that reveals Neanderthals attempted to break open even low marrow yield bones, like the small bones of the feet.”

Hodgkins’ findings add more evidence to support the hypothesis that climate change may have been a significant factor in the demise of the Neanderthals.

“Our results illustrate that climate change has real effects,” said Hodgkins. “Studying Neanderthal behavior is an opportunity to understand how a rapidly changing climate affected our closest human relatives in the past. If Neanderthal populations were already on the edge of survival at the end of the Ice Age, the increased competition that occurred when modern humans appeared on the scene may have pushed them over the edge.”

According to this hypothesis, as the temperature dropped, both Neanderthals and modern humans were compelled to move around more in search of food, and encountered each other more often. That would have led to inter-species breeding over a 5,000-year period that eventually resulted in the extinction of the Neanderthals as a separate species.

Read more at Discovery News

Ancient Humans, Dogs Hunted Mastodon in Florida

Hunter-gatherers pursuing big game and likely accompanied by dogs were the first known human settlers of the American Southeast, stone tools and the remains of a butchered mastodon show.

The findings, reported in the journal Science Advances, provide intriguing clues about the migration paths of the earliest Americans, how they lived, and what led to the extinction 12,600 years ago of several large native mammals.

The stone tools and mastodon remains date to about 14,600 years ago and were discovered in a Florida river at a site near Tallahassee called Page-Ladson, which is now one of the oldest radiocarbon-dated sites in the Americas.

Navy Seal diver Buddy Page first spotted the underwater site on property owned by the Ladson family, hence the location's name. It predates the widespread Native American Clovis culture and is the same age as another pre-Clovis site, Monte Verde in Chile.

Florida and Chile are clearly a long way from Asia, where genetic testing suggests the first Americans came from via the Bering Land Bridge area of Alaska, but the researchers suggest a few possible migration routes.

"The only logical way people could have come to Florida by 14,600 years ago is if their ancestors entered the Americas by boat along the Pacific Coast," Michael Waters of Texas A&M University told Discovery News. "They could have traveled by boat to central Mexico, crossed and come along the Gulf Coast. They could have entered the Americas via the Columbia River and then traveled inland to the Mississippi River and followed it down and entered the Gulf Coast, eventually making their way to Florida."

Waters, Jessi Halligan of Florida State University, and their team worked in near zero visibility waters in Florida's murky Aucilla River over a two-year period to excavate animal remains and stone tools, which included a biface -- a knife used for cutting and butchering meat.

Deep, parallel linear grooves on the end of the mastodon's found tusk suggest that the animal was butchered or scavenged and literally eaten to the bone, with the hunters likely eating tender meat at the tusk's base.

The geology of the site, as well as pollen and algae finds, suggest that the hunter-gatherers encountered the mastodon next to a small pond that both humans and animals used as a water source, the researchers believe.

Waters said that the prehistoric "people knew how to find game, fresh water and materials for making tools. These people were well adapted to this environment. The site is a slam-dunk pre-Clovis site with unequivocal artifacts, clear stratigraphy and thorough dating."

Another research team previously excavated the site and found what they believed were dog remains, so dogs "would most likely have been associated with the early hunters," Waters said, indicating that the remains would be studied further. If confirmed, they could be the earliest known evidence for dogs in the Americas.

In terms of other animals, he said, "The animal bones from the site tell us that mastodon, sloth, giant armadillo, dire wolf, mammoth, horse, camel and giant bison were present. These and other animals became extinct by 12,600 years ago."

So humans co-existed with all of these animals for at least 2,000 years before they died out, Halligan said.

Read more at Discovery News

Mystery of Bizarre Radar Echoes Solved, 50 Years Later

More than 50 years after weird radio echoes were detected coming from Earth’s upper atmosphere, two scientists say they’ve pinpointed the culprit. And it’s complicated.

In 1962, after the Jicamarca Radio Observatory was built near Lima, Peru, some unexplainable phenomenon was reflecting the radio waves broadcast by the observatory back to the ground to be picked up by its detectors. The mysterious cause of these echoes was sitting at an altitude of between 80 and 100 miles (130 and 160 kilometers) above sea level.

“As soon as they turned this radar on, they saw this thing,” study researcher Meers Oppenheim, of the Center for Space Physics at Boston University, said, referring to the anomalous echo. “They saw all sorts of interesting phenomena that had never been seen before. Almost all of it was explained within a few years.”

Peculiar radar echoes

Though the other phenomena detected by the observatory got explanations, these radar echoes continued to baffle scientists.

To see what was happening at that altitude, researchers at the time sent rockets, equipped with antennas and particle detectors, through the region. The instruments, which were designed to detect radar waves, “saw almost nothing,” Oppenheim said.

Adding more peculiarity to the puzzle, the phenomenon showed up only during daylight hours, vanishing at night. The echo would appear at dawn every day at about 100 miles (160 km) above the ground, before descending to about 80 miles (130 km) and getting stronger. Then at Noon, the echo would start to rise back again toward its starting point at 100 miles above the ground. When plotted on a graph, the echoes appeared as a necklace shape.

And in 2011, during a partial solar eclipse seen over the National Atmospheric Research Laboratory in India, the echo went silent.

“And then there was a solar flare, and it sort of went a little nuts,” Oppenheim said. “There was a solar flare, and the echo got really strong.”

The sun takes charge

Now, with a lot of supercomputing effort, Oppenheim and Yakov Dimant, also at the Center for Space Physics, have simulated the bizarre radar echoes to find the culprit — the sun.

Ultraviolet radiation from the sun, it seems, slams into the ionosphere (the part of Earth’s upper atmosphere located between 50 and 370 miles, or 80 and 600 km, above sea level), where the radio echoes were detected, they said. Then, the radiation, in the form of photons (particles of light), strips molecules in that part of the atmosphere of their electrons, resulting in charged particles called ions — primarily, positively charged of their electrons, resulting in charged particles called ions, primarily positively charged oxygen — and a free electron (a negatively charged particle that is not attached to an atom or molecule).

That ultra-energized electron, or photoelectron, zips through the atmosphere, which, at this altitude, is much cooler than the photoelectron, Oppenheim said.

Making waves

Using a computer simulation, the scientists allowed these high-energy electrons to interact with other, less energized particles.

Because these high-energy electrons are racing through a cool, slow environment in the ionosphere, so-called kinetic plasma instabilities (turbulence, in a sense) occur. The result: The electrons start vibrating with different wavelengths.

“One population of very energetic particles moving through a population of much less energetic particles — it’s like running a violin bow across the strings. The cold population will start developing resonant waves,” Oppenheim explained.

“The next step is that those electron waves have to cause the ions to start forming waves too, and they do,” Oppenheim said.

Though this last step isn’t clearly understood, he explained that periodic waves of ions bunch up with no dominant wavelength winning out. “It’s a whole set of wavelengths; it’s a whole froth of wavelengths,” he said.

That “froth” of wavelengths was strong enough to reflect radio waves back to the ground and to form the mysterious radar echoes.

“The reason it wasn’t figured out for a long time is that it’s a complicated mechanism,” Oppenheim said.

Read more at Discovery News

Starfish Baby Boom Gives Hope Amid Wasting Disease

For the past two years, a mysterious wasting disease has devastated starfish living along the West Coast, turning countless individual animals into goo. But now, a record number of surviving starfish babies is giving some researchers reason for cautious optimism.

The Oregon coast currently has a thriving community of juvenile starfish (or sea stars), with some places seeing populations with as many as 300 times the typical number, researchers said. That’s welcome news, as up to 90 percent of sea stars in Oregon showed signs of the deadly wasting disease from June to August 2014, reports a new study published May 4 in the journal PLOS ONE.

The high starfish numbers don’t mean the deadly disease is gone, however, the researchers said. Another round of the wasting illness could kill the juvenile sea stars, including the purple ochre (Pisaster ochraceus), known as a “keystone” species because of its influence on the marine ecosystem, the researchers said.

“When we looked at the settlement of the larval sea stars on rocks in 2014 during the epidemic, it was the same or maybe even a bit lower than previous years,” study lead author Bruce Menge, a professor of marine biology at Oregon State University, said in a statement. “But a few months later, the number of juveniles was off the charts — higher than we’d ever seen.”

The juvenile starfish aren’t the result of elevated starfish births or a massive re-settlement. Rather, these particular sea stars “just had an extraordinary survival rate into the juvenile stage,” Menge said. The big question is “whether they can make it into adulthood and replenish the population without succumbing to sea star wasting disease,” he said.

Perhaps this generation had a high survival rate because there was more food available, the researchers said. After the wasting disease killed off the majority of adult starfish, the young sea stars would have had more mussels and barnacles to eat, the scientists said.

The wasting disease left innumerable starfish with twisted arms that eventually disintegrated into slimy ooze. The epidemic spanned from Alaska to Baja California and also sickened sea stars on the East Coast.

But it’s anyone’s guess what causes the disease, scientists said. Some attribute it to sea star-associated densovirus, and others said warmer waters triggered the disease’s spread. But the new study found no association between water temperatures and the epidemic in Oregon, Menge said.

“The sea temperatures were warmer when the outbreak first began,” he said. “But Oregon wasn’t affected as early as other parts of the West Coast, and the outbreak reached its peak here when the sea temperature plummeted and was actually cooler than normal.”

Interestingly, researchers at Cornell University in New York found evidence of densovirus in sea stars, the water column and marine sediments. The virus occurs naturally, but may become harmful to starfish experiencing stress, the researchers said.

“Something triggered that virulence, and it happened on a coast-wide basis,” Menge said. “Ocean acidification is one possibility, and we’re looking at that now. Ultimately, the cause seems likely to be multifaceted.”

Read more at Discovery News

Dog Fossil Represents New Species of 'Bone Crusher'

A 12-million-year-old fossil unearthed in Maryland represents a new dog species with a strong bite.

In a study published in the Journal of Paleontology, researchers from the University of Pennsylvania describe Cynarctus wangi, a creature roughly the size of a modern coyote that likely would have behaved a bit like a hyena.

The canid lived during the middle Miocene and was part of an extinct family of dogs known as bone crushers, due to their strong jaws and big teeth.

The “bone crusher” family of dogs (Borophaginae) lived all over North America between 10 million to 30 million years ago. The researchers think the new dog likely went the way of extinction because it wasn’t able to compete with the ancestors of modern wolves, coyotes and foxes.

Notwithstanding the fierce nickname of its overarching family, the scientists don’t think C. wangi was 100-percent carnivorous. Its teeth lead the researchers to believe about two-thirds of the dog's meals would have been non-meat, the animal getting by on plants and insects and “living more like a mini-bear than like a dog,” according to the study’s lead author, Penn doctoral student Steven E. Jasinski.

The specimen was found in the Choptank Formation of Maryland’s Calvert Cliffs, on the western shore of the Chesapeake Bay.

According to Jasinski, the location of the find was especially significant, offering a new window into the North America of 12 to 13 million years ago. Fossils from the region and time in history, he said, tend to be of seafaring creatures.

“Most fossils known from this time period represent marine animals, who become fossilized more easily than animals on land,” he said in a statement. “It is quite rare we find fossils from land animals in this region during this time, but each one provides important information for what life was like then.”

From Discovery News

Mummified Fetus From Ancient Egypt Found

Curators at a British museum have discovered what they claim is the youngest mummy from ancient Egypt — a mummified fetus believed to be between 16 and 18 weeks old.

For more than 2,500 years, the tiny body has been resting in a small wooden coffin, the arms crossed over its chest. The coffin was excavated at Giza in 1907 by the British School of Archaeology and came into the collection of the Fitzwilliam Museum in Cambridge, U.K., the same year.

“It is a perfect miniature example of a wooden coffin of the ancient Egyptian Late Period, dating from 664-525 BC. The lid and box are both made from cedar wood,” the museum said in a statement.

“Although the coffin is deteriorated, it is clear that the wood was carefully carved on a painstakingly small scale and decorated,” it added.

Until now it was believed the coffin, which is a little more than 17 inches long, contained the mummified remains of internal organs that were routinely removed during the embalming of bodies. Indeed, only a wrapped package could be seen inside.

Such package was “carefully bound in bandages, over which molten black resin had been poured before the coffin was closed,” the museum said.

But when curators asked the Cambridge University’s Department of Zoology to CT scan the coffin for a forthcoming exhibition, they were presented with pictures of the remains of a tiny human body.

Although the skull and pelvis had collapsed, five digits on both hands and feet and the long bones of the legs and arms were all clearly visible.

“From the micro CT scan it is noticeable that the fetus has its arms crossed over its chest. This, coupled with the intricacy of the tiny coffin and its decoration, are clear indications of the importance and time given to this burial in Egyptian society,” the museum said.

Experts estimate the fetus, whose gender is unknown, died as the result of a miscarriage at no more than 18 weeks gestation.

“This discovery is the only academically verified specimen to exist at only sixteen to eighteen weeks of gestation,” the museum said.

Indeed, two mummified fetuses, placed in individual coffins, were found in King Tutankhamun’s tomb, but they were more developed at about 25 weeks and 37 weeks into gestation. DNA analysis in 2010 revealed the fetuses can be Tutankhamun’s daughters.

Read more at Discovery News

World's Oldest Ground-Edge Stone Axe Found in Australia

Work by the team of researchers showed the fragment came from an axe that had been shaped out of basalt then polished by grinding it on a softer rock such as sandstone until it was very smooth.

Professor Hiscock said experimental work confirmed the smoothness of the basalt fragment could not have been achieved accidentally through natural processes.

He took basalt from the same area as where the artefact was found and rubbed it on sandstone.

“It took 800 double strokes to get the same smoothness [as the axe fragment],” he said.

“It’s not the kind of thing that happens accidentally.”

Professor O’Connor said the discovery showed early Aboriginal technology was not as simple as has been previously suggested.

“Australian stone artefacts have often been characterised as being simple. But clearly that’s not the case when you have these hafted axes earlier in Australia than anywhere else in the world,” she said.

Professor Hiscock said the find cast doubt on prevailing views around the dispersal of modern humans out of Africa.

He said it was believed that as modern humans dispersed “they maintained and employed a cultural system from Africa and used it everywhere”.

“In evolutionary terms it is hard to imagine how one way of doing things works in every environment,” he said.

Professor Hiscock said the Australian find supported the idea that modern humans employed “ingenuity and flexibility” as they dispersed.

“The moment people set foot on Australia we now have them adapting to survive,” he said.

But, he said, the technology did not spread across Australia with humans as the earliest axes in the southern two-thirds of Australia date to about 3,000 years ago.

Read more at Discovery News

Geysers on Saturn Moon Enceladus Hint at Plumbing Mystery

A small water jet on Enceladus, an icy moon of Saturn, spews its fiercest eruptions when the moon is farthest from the planet, a new study suggests, but the overall gas output doesn’t increase much during that time. The study points to a mystery in Enceladus’ plumbing.

The surprise observation came after looking at the moon using the Saturn-orbiting Cassini spacecraft in March. Enceladus is considered a prime potential location for life because under its icy surface is a global, salty water-ocean that could have the right ingredients for microbes.

Cassini has seen Enceladus erupt many times since arriving in 2004. More than 90 percent of the material in the observed plumes contains water vapor, which researchers said they believe is vented from Enceladus’ subsurface ocean.

Previous Cassini observations showed there is three times as much dust sprayed into space when Enceladus is furthest away from Saturn than when it’s close by. The new work focused on how much gas erupted along with that dust, propelling it outward. Cassini observed the plume from Enceladus as it blasted in front of Epsilon Orionis, the central star in Orion’s belt, and measured the light that passed through that plume using the ultraviolet imaging spectrometer, UVIS. The researchers expected quite a lot more gas expelled at the far part of Enceladus’s orbit, to help explain the outpouring of dust, but they found the gas output had bumped up by just 20 percent, far less than expected.

“We went after the most obvious explanation first, but the data told us we needed to look deeper,” Cassini UVIS scientist Candy Hansen said in a statement. Hansen, who is based at the Planetary Science Institute in Arizona, led the study’s observational planning.

Hansen’s team zeroed in on an individual jet nicknamed “Baghdad I.” The researchers discovered that this particular jet was four times more active when Enceladus is furthest from Saturn, compared with other times in the moon’s orbit.

When Enceladus is furthest from Saturn, Baghdad I’s water output alone makes up 8 percent of the observed water plume, which consists of several jets located along “tiger stripes” or cracks in the ice of the moon. At other points in the orbit, Baghdad I’s water represents only 2 percent.

Read more at Discovery News

70-Year-Old Woman Gives Birth to First Baby

An Indian woman who gave birth at the age of 70 said Tuesday she was not too old to become a first-time mother, adding that her life was now complete.

Daljinder Kaur gave birth last month to a boy following two years of IVF treatment at a fertility clinic in the northern state of Haryana with her 79-year-old husband.

Kaur said the couple, married for 46 years, had almost lost hope of ever having a child and had faced ridicule in a country where infertility is sometimes seen as a curse from God.

“God heard our prayers. My life feels complete now. I am looking after the baby all by myself, I feel so full of energy. My husband is also very caring and helps me as much as he can,” Kaur told AFP from the northern city of Amritsar.

“When we saw the (IVF) advert, we thought we should also give it a try as I badly wanted to have a baby of my own,” she said.

Kaur put her age at about 70, a common scenario in India where many people don’t have birth certificates, while the clinic said in a statement that she was 72.

The baby was conceived using the couple’s own egg and sperm and was now “healthy and hearty” after weighing just two kilograms (4.4 pounds) at birth on April 19, the National Fertility and Test Tube center said.

Kaur’s husband, Mohinder Singh Gill, who owns a farm outside Amritsar, said he was unfazed about their age, saying God would watch over their child whom they named Armaan.

“People say what will happen to the child once we die. But I have full faith in God. God is omnipotent and omnipresent, he will take care of everything,” he told AFP.

Anurag Bishnoi, who runs the fertility clinic, said he was initially skeptical about going ahead with in vitro fertilization (IVF), but tests showed Kaur was able to carry the unborn baby.

Read more at Discovery News

Rare Devil's Hole Pupfish Dead After Park Break-In

The National Park Service (NPS) is investigating an incident of vandalism and trespassing in Death Valley National Park that may have led to the death of an extremely rare fish, the Devil’s Hole pupfish.

According to an NPS release, on April 30 three men, likely drunk, broke into the special, detached Devil’s Hole unit of the park, which contains the only habitat of the pupfish (Cyprinodon diabolis).

The critically endangered fish live in a 500-foot-deep cavern filled with water, Devil’s Hole. One of the men swam in its waters, leaving behind articles of clothing.

One of the pupfish was found dead in the water after the men visited the site. Officials say a necropsy is being performed on the fish to see if the men’s actions caused its death.

The pupfish is native to Devil’s Hole and is often described as the world’s rarest fish. Its population varies seasonally, from 100-200 in the winter to 300-500 in the late summer.

The fish colonized Devil’s Hole anywhere from 100 to 800 years ago, according to researchers who studied its breeding earlier this year.

The men, who left behind multiple beer cans, carried guns they fired at least 10 times while shooting at signs, the locks of chained gates and motion sensors.

Investigators are poring over remote camera video footage of the intruders, including the scene included here, and are asking for help identifying them via phone (888-653-0009), email, Facebook, or via a tip form. There is a $5,000 reward for information leading to their arrest.

From Discovery News

Did a Stroke Kill Leonardo da Vinci?

Leonardo Da Vinci may have suffered from a recurrent stroke that considerably reduced his motor activity in the last two years of his life and eventually caused his death, according to a historic viewpoint published in the June issue of The Lancet Neurology.

The study, carried out by two Italian medical doctors, examined ancient sources to reconstruct Da Vinci’s health from 1517 until his death in 1519 aged 67.

“The diary of Louis d’Aragona’s journey, written by Antonio de Beatis, tells us that Leonardo had a right hand’s paralysis when he was 65 years old,” Antonio Perciaccante, at the department of medicine of Gorizia hospital, told Discovery News.

“Nevertheless, the ancient document reports Da Vinci continued to paint, draw, and teach,” he added.

Perciaccante and co-author Alessia Coralli, at the department of surgery of Civita Castellana hospital, noted the account indicates that Leonardo suffered from a right hand’s paralysis with partial physical, but not cognitive, consequences.

Da Vinci’s health must have however deteriorated, following the report of 15th-century painter, architect and writer Giorgio Vasari.

In his 1550 book “Lives of the Artists,” Vasari described Leonardo as a sick and bedridden man, unable to stand up without being “supported by the arms of his servants and his friends.”

“He was ill for many months,” Vasari wrote.

According to Perciaccante and Coralli, something happened that compromized the general autonomy of the Renaissance genius.

“Our hypothesis is that a first stroke caused the hand’s paralysis. Other stroke events then followed, deteriorating Da Vinci’s health and motor activity,” Perciaccante said.

Da Vinci died in Amboise, France, on May 2, 1519, in the arms of King Francis I of France, according to Vasari. He attributed the death to a “paroxysm.”

“The term refers to a sudden attack or increase of symptoms of a disease that often recurs. Thus, it can adequately describe a stroke,” Perciaccante said.

According to the researchers, the hypothesis of a recurrent stroke is supported by medical literature.

Read more at Discovery News

Earth's Thin Early Atmosphere Revealed in Bubbles

Air bubbles trapped in 2.7 billion-year-old lava flows in the Pilbara suggest the Earth’s atmosphere weighed less than half that of today and was far thinner than previously thought.

The discovery has forced a rethink of how the Earth managed to stay relatively ice-free during that period, despite the sun being much cooler than it is today.

In a study published today in Nature Geoscience, researchers analysed the relative sizes of air bubbles across ancient lava flows along the Beasley River in Western Australia’s Pilbara region.

The lava flows — discovered by Australian researcher Dr Tim Blake, then at the University of Western Australia — bear distinctive features such as lava “toes” with cracked, glassy rinds, which suggested the molten rock once flowed over a beach.

Astrobiologist Professor David Catling, one of the study’s authors from the University of Washington, said the Sun was roughly 20 percent less luminous 2.7 billion years ago, so if Earth had an atmosphere similar to today it would have been covered in ice. Yet similar conditions as today prevailed.

“All the signs are that it wasn’t that different, in terms of the climate system from today; there was rainfall and rivers, there might have been polar ice caps, but it was warm enough ... for the whole world (not) to be covered in ice,” Professor Catling said.

Until now, the prevailing hypothesis to explain these warmer-than-expected conditions was that the atmosphere at that time had been much thicker, which would have insulated the Earth.

But the bubbles preserved in the rock at what would have been sea level paint a very different picture of the Earth’s atmospheric pressure during the Archean period, which extends from the formation of the Earth’s crust 4 billion years ago to around 2.5 billion years ago.

The researchers compared the size of air bubbles trapped at the surface of the lava — whose size is constrained only by air pressure — and those at the base, which are constrained both by atmospheric pressure and the weight of the lava itself, to work out the air pressure at the time the lava flow happened.

“We found the atmosphere basically was a lot thinner back then and weighed less than half of what it does today,” Dr Catling said.

He said the finding raised the question of what exactly was keeping the Earth warm enough for liquid water to flow.

“The first thing is the air must have had a lot of proportions of greenhouse gases like carbon dioxide or methane, so even though the air is thin if you stuff it full enough of greenhouse gases it can still warm the Earth,” he said.

Read more at Discovery News

Atomic Oxygen Detected on Mars

A specially-equipped 747 has detected atomic oxygen in Mars’ upper atmosphere, NASA reported, marking the first time that the space agency has made that observation in four decades.

The California-based NASA plane that made the measurements is called the Stratospheric Observatory for Infrared Astronomy, or SOFIA. NASA reports that using an instrument on board the plane, they found the atomic oxygen in the planet’s mesosphere, which is its upper atmosphere— but only saw about half of what they thought they would.

“Atomic oxygen in the Martian atmosphere is notoriously difficult to measure,” Pamela Marcum, a project scientist with SOFIA, said in a statement. “To observe the far-infrared wavelengths needed to detect atomic oxygen, researchers must be above the majority of Earth’s atmosphere and use highly sensitive instruments, in this case a spectrometer. SOFIA provides both capabilities.”

The SOFIA airplane that made the measurements of Mars conducts its research while flying at an altitude of between 37,000 and 45,000 feet.

On Earth, two oxygen atoms join together to form O2, which is what we breathe. Atomic oxygen, however, is just a single oxygen atom. When atomic oxygen was last detected in the atmosphere of the red planet, it was because of the Viking and Mariner missions.

“Atomic oxygen affects how other gases escape Mars and therefore has a significant impact on the planet’s atmosphere,” NASA said.

From Discovery News

Intense wind found in the neighborhood of a black hole

an artistic view of the accretion disc surrounding the black hole V404 Cygni, where the intense wind detected by GTC becomes evident.

An international team of astrophysicists, including Professor Phil Charles from the University of Southampton, have detected an intense wind from one of the closest known black holes to the Earth.

During observations of V404 Cygni, which went into a bright and violent outburst in June 2015 after more than 25 years of quiescence, the team began taking optical measurements of the black hole's accretion disc using the 10.4m Gran Telescopio CANARIAS (GTC) -- the biggest optical-infrared telescope in the world, situated at the Roque de los Muchachos Observatory (Garafía, La Palma) in the Canary Islands.

The results, which are published today in Nature, show the presence of a wind of neutral material (unionised hydrogen and helium), which is formed in the outer layers of the accretion disc, regulating the accretion of material by the black hole. This wind, detected for the first time in a system of this type, has a very high velocity (3,000 kilometres per second) so that it can escape from the gravitational field around the black hole.

Professor Charles, from Physics and Astronomy at the University of Southampton, said: "Its presence allows us to explain why the outburst, in spite of being bright and very violent, with continuous changes in luminosity and ejections of mass in the form of jets, was also very brief, lasting only two weeks."

At the end of this outburst the GTC observations revealed the presence of a nebula formed from material expelled by the wind. This phenomenon, which has been observed for the first time in a black hole, also allows scientists to estimate the quantity of mass ejected into the interstellar medium.

Teo Muñoz Darias, a researcher at the Instituto de Astrofísica de Canarias (IAC) and the lead author of the study (and also a former Marie Curie Fellow at Southampton), said: "The brightness of the source and the large collecting area of the GTC allowed us not only to detect the wind, but also to measure the variation of its properties on time-scales of minutes. The database obtained is probably the best ever observed for an object of this kind.

"This outburst of V404 Cygni, because of its complexity and because of the high quantity and quality of the observations, will help us understand how black holes swallow material via their accretion discs."

"We think that what we have observed with the GTC in V404 Cygni happens, at least, in other black holes with large accretion discs," concluded Professor Charles and Jorge Casares from IAC, two of the discoverers of V404 Cygni in 1992, and co-authors of the study.

V404 Cygni is a black hole within a binary system located in the constellation of Cygnus. In such systems, of which less than 50 are known, a black hole of around 10 times the mass of the Sun is swallowing material from a very nearby star, its companion star. During this process material falls onto the black hole and forms an accretion disc, whose hotter, innermost zones emit in X-rays. In the outer regions, however, we can study the disc in visible light, which is the part of the spectrum observable with the GTC.

V404 Cygni, at only 8,000 light years away, is one of the closest known black holes to the Earth, and has a particularly large accretion disc (with a radius of about ten million kilometres), making its outbursts especially bright at all wavelengths (X-rays, visible, infrared and radio waves).

On 15 June 2015, V404 Cygni went into outburst after a quiescence of over 25 years. During this period its brightness increased one million fold in a few days, becoming the brightest X-ray source in the sky. The GTC began taking spectroscopic observations on 17 June via the activation of a "target of opportunity" programme, designed by IAC researchers for this kind of event.

Read more at Science Daily

Leprosy Threatens Red Squirrels in UK

A squirrel native to Britain that was already in trouble now needs help with another threat: leprosy.

The disease results in swelling in the animal’s snout, feet and ears, as well as hair loss, and wildlife officials in the United Kingdom are launching a study to figure out how it is being transmitted, according to the Daily Mail.

The major problem for the ruddy creatures is that their historic turf has been overrun by grey squirrels introduced from the United States. There are just an estimated 140,000 red squirrels left in the U.K., compared to some 2.5 million grey squirrels, according to England’s forestry commission.

Leprosy was first discovered in the U.K.’s red squirrels in Scotland in 2014, although experts think it has been around for a long time – perhaps hundreds of years — and simply gone undiagnosed.

According to Dorset Wildlife Trust, which will participate in the study, the leprosy bacteria is "widespread" among the squirrels but "neglible" in terms of risk to humans. Scientists with the organization aren't sure yet how the disease is being transmitted among the squirrels.

Ground zero for the leprosy study will be Brownsea Island, a site thought to be a hotbed for the disease and one that will enable the scientists to study it in a contained setting.

Researches from the University of Edinburgh, alongside local wildlife managers from Brownsea Island, will conduct the study using humane traps. They'll capture the animals long enough for blood tests and basic health exams to be administered, before returning them to the wild.

From Discovery News

520-Million-Year-Old Fossil Larva Preserved in 3D

If you think finding a needle in a haystack sounds challenging, try searching for fossils the size of fingernail clippings in massive slabs of rock.

But that’s just what a team of scientists is doing at a site in Chengjiang, China. And they recently struck a fossil jackpot, discovering an extremely rare arthropod larva fossil measuring a mere 0.08 inches (2 millimeters) long.

The fossil, estimated to be 520 million years old, was preserved in 3D, presenting the researchers with an exceptional level of detail for this very early stage of the creature’s development. It also provided them with a first glimpse of ancestral larval forms in arthropods, the invertebrate animal group with exoskeletons and segmented bodies that includes arachnids, crustaceans and insects.

The larva has a segmented body, with two large structures on its head, four pairs of branching legs and three additional pairs of legs that are much less developed. Its posterior is tipped with a “dagger-like” appendage, framed by two triangular forms resembling paddles, which the scientists suggest may have been used for swimming.

This is the first fossil of its kind to be found at Chengjiang since the site’s discovery in 1984, according to Yu Liu, the study’s lead author and a postdoctoral researcher at the Ludwig-Maximilians-Universität in Munich.

The researchers identified the tiny fossil as a known species — Leanchoilia illecebrosa, a member of the “short great appendage arthropods,” which earned their name due to the large claw-like structures attached to their heads, likely used for feeding or for sensing their environment.

In fact, it was the shape of those appendages in the larva fossil that helped the scientists with their identification, Liu told Live Science in an email.

But compared to adult forms, other limbs in the fossil were not as well developed. This told the scientists that the new discovery represented an early larval stage, Liu said.

Hidden in rock

Finding fossils this small is no easy task. It begins with removing large slabs of rock, splitting them into somewhat smaller slabs, and then reviewing them with a magnifying lens to see if there might be “something interesting” preserved in them, according to Liu.

“As you may imagine, the chance of finding a fossil is not very high,” Liu told Live Science. “In most cases, you get one fossil after separating tens of slabs. The chance of finding a GOOD fossil is even lower. You need to separate hundreds or even thousands of slabs for that.”

Such tiny and delicate specimens like this one can’t be isolated from the rocky material around them with the methods traditionally used for chipping out larger fossils. Paleontologists use microphotography and scanning technology rather than picks, drills, or chisels to “penetrate” the rock and show them the remains of once-living animals preserved inside.

3D surprise

And finding such a small fossil preserved in 3D was unexpected and exciting, Liu said. Micro computed tomography — micro-CT scans — of the larva offered a highly detailed picture of its body, with an interesting surprise as a result.

This particular larva’s body type — one in which body segments are added as the creature grows to adulthood — was already thought to be typical for modern crustaceans, Liu said. But, finding one this far back in the fossil record hints that this was a feature in all other arthropod ancestors, as well.

Read more at Discovery News

King Tut Tomb Secret Chambers? Not So Fast

The theory that King Tut’s tomb contains secret chambers has been greeted with skepticism at an international conference in Cairo dedicated to the boy king.

The growing doubts prompted the Egyptian antiquities minister Khaled El-Enany to reassure that no physical exploration inside the tomb is planned at this time.

“I will not make any drills until I am sure 100 percent that there is a cavity behind the wall,” El-Enany said.

Already last month, El-Enany appeared to cool down the expectations that rose after his predecessor Mamdouh Eldamaty revealed there was a “90 percent chance” that King Tut’s tomb concealed two chambers.

Indeed, Eldamaty had confirmed that analysis of radar scans carried out by Japanese specialist Hirokatsu Watanabu revealed two hidden spaces on the north and eastern walls that could contain metal or organic material.

Begun last summer, the investigation inside King Tut’s burial follows a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona. He believes the hidden chambers contain the remains, and possibly the intact grave goods, of Queen Nefertiti, wife of the “heretic” monotheistic pharaoh Akhenaten, Tutankhamun’s father.

Reeves speculated that the tomb of King Tut was not ready when he died unexpectedly at 19 in 1323 B.C.; consequently, he was buried in a rush in what was originally the tomb of Nefertiti, who had died 10 years earlier.

Friederike Seyfried, director of the Egyptian Museum and Papyri in Berlin, described Reeves’s claim as a mere hypothesis and argued the radar survey can’t prove the existence of a hidden tomb.

“The sudden death of the boy-king led the tomb’s builders to finish the tomb quickly and close it up, which is why a cavity was found,” he told Ahram Online.

According to former Antiquities Minister Zahi Hawass, “the project wasn’t done scientifically at all. ” He stressed that radar scan is not sufficient alone to make a new archaeological discovery.

“In my entire career, I have never come across any discovery in Egypt made by radar scans,” Hawass said.

He noted that a follow up radar scan failed to replicate Watanabu’s promising results.

“If there is any masonry or partition wall, the radar signal should show an image,” the National Geographic reported him to say.

“We don’t have this, which means there is nothing there,” Hawass said.

Read more at Discovery News

Pluto's Moon Coated in Nearly Pure Water Ice

Discovered in June 2005, Pluto’s outermost moon Hydra is thought to have formed four billion years ago during a massive impact event that created Pluto and Charon.

Despite its age, this 31-mile-wide moon appeared remarkably clean and bright in New Horizons images during the spacecraft’s historic close pass through the Pluto system in July 2015.

Scientists’ initial speculation was proved right when data from the spacecraft was analyzed and revealed that Hydra, like its name, is covered in nearly pure water ice.

Measured with the Linear Etalon Imaging Spectral Array (LEISA) on New Horizons’ Ralph instrument, the spectral signature of water ice on Hydra is even stronger than that seen on Pluto’s much larger satellite Charon, indicating a surface coated with bigger ice particles and less dusty, dark material.

Spectral data gathered by New Horizons shows Hydra to be coated in a much more pure ice material than the larger Charon.

“Perhaps micrometeorite impacts continually refresh the surface of Hydra by blasting off contaminants,” said Simon Porter, a New Horizons science team member from the Southwest Research Institute (SwRI) in Boulder, Colorado. “This process would have been ineffective on the much larger Charon, whose much stronger gravity retains any debris created by these impacts.”

Read more at Discovery News

Scientists cite evidence that mosasaurs were warm-blooded

Fossilize teeth of a mosasaur (stock image). Mosasurs were large aquatic reptiles that went extinct at the end of the Cretaceous period, about 66 million years ago.

Mosasaurs -- an extinct group of aquatic reptiles that thrived during the Late Cretaceous period -- possibly were "endotherms," or warm-blooded creatures, a paper co-written by a UA professor suggests.

Dr. Alberto Perez-Huerta's paper on endothermic mosasaurs -- co-written with now-graduated doctoral student Dr. T. Lynn Harrell Jr. and Dr. Celina Suarez of the University of Arkansas -- was published in a March issue of Palaeontology, a journal published by the Palaeontological Association.

Mosasurs were large aquatic reptiles that went extinct at the end of the Cretaceous period, about 66 million years ago. The paper focuses on a debate in the paleontological community over how mosasaurs employed "thermaregulation," or how they controlled their body heat -- whether mosasaurs were endotherms (warm-blooded) or ectotherms, cold-blooded creatures taking their body temperature from the surrounding sea.

A paper published in 2010 suggested that mosasaurs were ectotherms, but Harrell and Perez-Huerta thought otherwise.

"There was a paper published in Science in 2010 reporting the thermoregulation in marine reptiles at the time of the dinosaurs focusing on the iconic extinct taxa: ichthyosaurs, plesiosaurs and mosasaurs," said Perez-Huerta, a UA associate professor of geology. "This conclusion bothered me a bit because there was not a warm-blooded member organism used for comparison, and we know that size can matter in terms of thermoregulation."

The study by Harrell (lead author), Perez-Huerta and Suarez used an oxygen isotope analysis on mosasaurs fossils in the collection of UA's Alabama Museum of Natural History and compared them to fossils of known cold-blooded animals, such as fish and turtles, from the same period, as well as the bones of such contemporary warm-blooded organisms represented by birds -- "true" endotherms.

"Lynn came up with good ideas for two chapters of his dissertation, already published as well," Perez-Huerta said. "We discussed looking for endothermy in mosasaurs given his knowledge on this group of extinct marine reptiles, the large collections of these fossil organisms in the Alabama Museum of Natural History and the scientific controversy related to the Science paper."

The study states that mosasurs' body-temperatures compared to the temperatures of modern, warm-blooded sea birds, suggesting that mosausurs were indeed warm-blooded. The study found that this tendency toward higher body temperature held despite the size of the particular mosasur genus or species -- body size (gigantothermy) didn't matter.

"The findings of the present study support that mosasaurs were able to maintain a higher internal temperature independent of the ambient seawater temperature and were likely endotherms, with values closer to contemporaneous fossil and modern birds and higher than fish and turtles," the researchers said. "Although there are small differences of body temperature among mosasaur genera, these are independent of size, and thus inferred body mass, suggesting that mosasaurs were not gigantotherms."

Perez-Huerta noted that the study was possible thanks to the Alabama Museum of Natural History's extensive collection.

Read more at Science Daily

Simulation of prehistoric population dynamics using current topographical satellite data

This image shows a) the current British population density, b) the genetic map, c) the habitability of the landmass, and d) simulated distribution in population after 2,000 steps.

In a recent breakthrough, scientists from the Tata Institute of Fundamental Research, and the Centre for Excellence in Basic Sciences, Mumbai, demonstrate an accurate method to simulate prehistoric movements of people based upon current topographical satellite data. Recently published in the journal PLOS ONE, population dynamics of prehistoric human migration into the island comprising England, Scotland and Wales was simulated by applying a diffusion equation tempered by geographical data determined from satellite-based information.

Importantly, these findings are validated by recently-available genetic data. This method may prove useful in determining early human population dynamics even when no genetic information is available.

Movement of people in prehistoric times was almost entirely determined by geography and human needs, both deterministic parameters when small populations move into unoccupied areas where conflicts and large group dynamics are not important. The early period of human migration into the British Isles provides a near-ideal laboratory which, because of its relative geographical isolation, may allow some insights into the complex dynamics of early human migration and interaction.

Commenting on the simulation used in this study, Professor Vahia, the lead scientist of this work, says, "Our simulation code is based on human affinity to habitable land, as defined by availability of water sources, altitude, and flatness of land. These parameters temper the diffusion of people and allow us to follow their path of migration." The initial entry points of people into the main British island were determined using data from the megalithic period. Topographical and hydro-shed data from satellite databases was used to define habitability, based on distance from water bodies, flatness of the terrain, and altitude above sea level.

Read more at Science Daily