Aug 28, 2015
The crustacean has been named after musician and actor Sir Elton John because its “greatly enlarged appendage” reminded discoverer James Thomas of a popular movie character that Elton John played. The findings are published in the journal ZooKeys.
“I named the species in honor of Sir Elton John because I have listened to his music in my lab during my entire scientific career,” Thomas, a researcher at Halmos College of Natural Sciences and Oceanography, explained in a press release.
He continued, “So, when this unusual crustacean with a greatly enlarged appendage appeared under my microscope after a day of collecting, an image of the shoes Elton John wore as the Pinball Wizard (in the movie “Tommy”) came to mind.”
Welcome then to the known animal kingdom Leucothoe eltoni. Taxonomists, scientists who study and name new species, have the choice to pick names that are relevant to locations, features of the animal, or — in this case — a person to the scientist’s liking.
Elton John was found living inside of “the branchial chambers of solitary tunicates,” so Elton John was basically hanging out in one of the tube-resembling structures of another marine organism.
It has since been found in Indonesia, as well as, surprisingly, Hawaii.
That’s because, in true rock star fashion, the crustacean has already gotten into trouble. Due to the timing of its arrival and possible modes of travel, Thomas and his colleagues believe it hitched a ride inside another tunicate, or sponge, attached to a large floating drydock transported to Hawaii from Subic Bay, Philippines.
Read more at Discovery News
Consisting of just a head and canopic jars containing internal organs, the remains were found in a plundered tomb by the Italian Egyptologist Ernesto Schiaparelli in 1904 in the Valley of the Queens, Luxor, and are now housed at the Egyptian Museum in Turin.
They belong to an Egyptian dignitary named Nebiri, a “Chief of Stables” who lived under the reign of 18th Dynasty pharaoh Thutmoses III (1479-1424 BC).
“The head is almost completely unwrapped, but in a good state of preservation. Since the canopic jar inscribed for Hapy, the guardian of the lungs, is partially broken, we were allowed direct access for sampling,” Raffaella Bianucci, an anthropologist in the legal medicine section at the University of Turin, told Discovery News.
She investigated the mummified remains with researchers from the Universities of Turin, Munich and York.
Detailing the findings at the conference, Bianucci reported that Nebiri was middle aged — 45 to 60 years old — when he died and that he was affected by a severe periodontal disease with massive abscesses, as revealed by Multidetector Computed Tomography (MDCT) and three dimensional skull reconstruction.
The scans showed there was a partial attempt at excerebration (removal of the brain), but a considerable amount of dehydrated brain tissue is still preserved. Linen is packed in the inner skull, eyes, nose, ears, mouth and even fill the cheeks.
The researchers also detected evidence of calcification in the right internal carotid artery, consistent with a mild atherosclerosis.
“We saw only a tiny fleck of calcium. Since the rest of the corpse is missing, it is impossible to establish whether there was calcification in other artery walls,” she added.
Most interestingly, the histology of the lung performed by Andreas Nerlich, professor at the department of pathology at Ludwig-Maximilians-University in Munich, Germany, revealed the presence of “heart failure” cells. A pulmonary edema, which is fluid accumulation in the lungs’s air sacs, was also identified.
“When the heart is not able to pump efficiently, blood can back up into the veins that take it through the lungs. As the pressure increases, fluid is pushed into the air spaces in the lungs,” Bianucci explained.
Since histochemical staining ruled out other possible diseases including tuberculosis, granulomas and acid-fast bacilli indicating mycobacterial infections, the researchers concluded that Nebiri possibly died from acute decompensation of chronic left-sided heart failure, which is a frequent consequence of chronic heart disease.
“Our finding represents the oldest evidence for chronic heart failure in mummified remains,” Bianucci said.
Valvular disease, ischemia, metabolic disorders of the heart muscle, or chronic hypertension are among the causes for the disorder.
In Nebiri’s case, the researchers believe chronic hypertension is the best candidate.
Currently, over 20 million people worldwide, mainly over 65, are affected by chronic heart failure.
“A systematic analysis of canopic jar content could help establish whether the disease was more frequent in our ancestors or its prevalence increased in modern times,” Bianucci said.
The elaborate mummification technique played a crucial role in diagnosing the cause of death, according to the researchers.
“The level of preservation is outstanding and easily equals the standard seen with royals of the time,” Egyptologist Joann Fletcher, professor at the University of York’s Department of Archaeology, told Discovery News.
Read more at Discovery News
A full moon is when the sun, Earth and moon line up, with the Earth in the middle. As seen from the surface of the Earth, the moon is fully illuminated. Because it is opposite the sun in the sky, the moon rises in the east just as the sun sets in the west. And, roughly 12 hours later, the moon sets in the west just as the sun is rising in the east.
Because the Earth is constantly revolving around the sun and the moon is constantly revolving around the Earth, a full moon is an instantaneous event, occurring when the moon is exactly opposite the sun. This week, such an alignment happens at 2:35 p.m. EDT (1835 GMT) on Saturday, Aug. 29.
A minute before that, the moon's phase is "waxing gibbous," and a minute later it is "waning gibbous."
Each full moon occurs roughly 29.53 days after the previous full moon. It's "roughly" because the moon's orbit around the Earth is not a perfect circle, but is instead elliptical in shape. So the exact time of full moon varies a little bit from month to month.
The most important result of the moon's elliptical orbit is that sometimes the moon is closer to the Earth, and sometimes farther away. The time when the satellite is nearest is called "perigee" and the time when it is farthest is called "apogee."
What skywatchers are most interested in is perigee, the date and time when the moon is closest to Earth. This month, perigee occurs on Sunday, Aug. 30, at 11 a.m. EDT (1500 GMT), about 18 hours after full moon. At that time, the moon will be 222,631 miles (358,290 kilometers) away from Earth.
Notice how less than a day's change in position makes it clear that the moon is no longer full: You can see that it is lit more from the left side.
Events like the full moon and perigee occur at exactly the same time when viewed from anywhere on Earth, even though the local time on the clock may be different. This month, both the full moon and perigee occur when it is daytime in North America, and the moon is below the horizon. The best time to see the full moon close to perigee will be on Saturday evening, Aug. 29. The moon will be a few hours past full, and perigee will be a few hours in the future, but that's the closest to simultaneous the events will get this month.
The important thing for astronomers is that the perigee distance is less than 223,690 miles (360,000 km). When the moon gets this close, its most important effect on the Earth — the ocean tides — gets stronger. On the day of perigee and the three days following, Earth will have larger tides than usual.
Looking ahead to next month, full moon will fall on Sunday, Sept. 27, at 10:51 p.m. EDT (0251 GMT on Sept. 28), and perigee just 51 minutes earlier, at 10 p.m. This perigee will be the closest in 2015, at 221,753 miles (356,877 km). The result will be the largest full moon of the year and even larger high tides. Notice that both events happen in the evening, when the moon will be well placed in the sky.
The full moon of September is traditionally called the Harvest Moon, because it rises around sunset on several successive nights, giving farmers extra light in the evening to bring in their harvests.
Read more at Discovery News
An international team looked at data on some 10,000 of the billions of galaxies in the observable Universe today, and then used the Hubble and Herschel telescopes to peer back in time.
They found that 83 percent of stars formed since the Big Bang about 13.7 billion years ago, were initially grouped in flat, rotating, disc-shaped galaxies, according to a statement from the Cardiff University's School of Physics and Astronomy, whose astronomers led the study.
"However, only 49 percent of stars that exist in the Universe today are located in these disc-shaped galaxies, the remainder are located in oval-shaped galaxies," it said.
"The results suggest a massive transformation in which disc-shaped galaxies became oval-shaped galaxies."
The bulk of stars in the Universe are thought to have been formed between 12 billion to eight billion years ago.
The team offered two hypotheses -- oval galaxies may be formed when two disc-shaped clusters move too close to one another and are merged by gravity into a disorderly clump, or the stars in a round, flat galaxy gradually migrate towards the centre to produce a disorderly, roughly oval-shaped pile-up.
Read more at Discovery News
“He knew that these crazy Americans were in the area trying to get a hippo ass leech,” says Siddall, the curator of invertebrates at the American Museum of Natural History. “And they had to cull [a hippo] because it was hanging out in a community of people. So he had the presence of mind to cut its butt out.” You can see that very butt below (it’s not as bad as you think). That big leech is an adult, the others juveniles.
Now, I tend to write about animals that are saddled with unfortunate living situations. A fish, for instance, that lives in water so cold it has antifreeze for blood. And people tend to ask me, “Why on Earth do they even bother? Why not move to warmer waters, or out of a hippo’s rectum?” Well, in the animal kingdom, if a creature can exploit a niche others cannot, it has a huge advantage—a monopoly really. Far from getting a bum deal, it’s safe to say that this leech has cornered the market on hippo rectum flesh.
And anyway, that’s the only good bit of the hippo to feed on. “We believe that that is so because hippos have very, very thick skin and a layer of blubber,” says Siddall. “The only part on the hippo that’s vascularized enough to get a good blood meal would actually be from the rectal region.” And getting there is no real problem at all. “They’re crawling up the hippos hind legs and crawling their way right up.” So these leeches are literally a pain in the ass.
|A hippo rectum with hitchhiking leeches. Bet you ain’t never seen that before.|
So is that a strategy to evict leeches? Nah, Siddall says. “Hippos, especially male hippos, engage in so much combat and they experience so much scraping and ripping and tearing from the teeth of other hippos, the amount of stimulus, negative or otherwise, that a leech in their butthole is going to cause has got to be fairly minimal.”
These leeches are, after all, nice and flat. “Let’s just say they’re very aerodynamic with respect to explosive hippo poo,” Siddall says. “I can’t imagine that explosive pooing has much to do with getting rid of leeches, especially because I don’t think it would be terribly effective at it anyway.” Instead, male hippos fling poo to front on their rivals in confrontations over territory and mates.
Food for Thought
Now, while some leeches have strong jaws that serrate the flesh to get the blood flowing, the hippo-rectum variety just has a proboscis that it snakes into the vascular tissue. But it’s not hard like a mosquito’s mouthparts. Instead, it’s muscular—good and soft and flexible.
You may have heard that leeches, like mosquitoes, produce anticoagulants to keep the blood from clotting in the wound. And leeches do indeed keep the blood from clotting, but not until it’s actually in their bodies. These critters can take in up to 10 times their weight in blood, then drop out of the host and avoid feeding for up to a month. “And over the course of that time they’re digesting the liquid blood meal inside them,” says Siddall. “If that blood meal isn’t liquid they turn into a brick, and they can’t swim, they can’t hide from predators, they can’t go have sex and do all the things that leeches like to do.”
It would seem that a liquid like blood would be an inefficient way to get nutrition, as opposed to, say, just eating the rectum instead. But in fact blood is packed with good stuff—all kinds of proteins and fatty acids. The problem, though, is that it’s missing some key amino acids and vitamins. To solve that problem, leeches have partnered with friendly bacteria. The microbes live inside the leech’s cells and help churn out the nutrition that’s in short supply in the blood.
Read more at Wired Science
Aug 27, 2015
There was a time when, using the rules of general relativity, you could imagine an infinitely-dense singularity surrounded by a gravitational zone of no-escape called the “event horizon.” These components, with a few other details, described the basic anatomy of a black hole.
The textbook explanation is fairly clear: nothing, not even light, can escape the gravitational clutches of the black hole’s event horizon. It’s a one-way ticket; if an astronaut strays too close to the horizon, they get dragged in, eventually falling to his or her doom via the horrific effects of spaghettification.
Although this is an over-simplification, it was a fairly decent explanation about what was going on. But then, in the 1970′s, British theoretical physics guru Stephen Hawking came forward with his bedrock theory of evaporating black holes. And now, as an extension of his theory, Hawking thinks that black holes aren’t the one-way street the textbooks have led us to believe.
Hawking Radiation Trouble
The complication that black holes can evaporate is a consequence of the weirdly wild quantum world. In a vacuum, quantum physicists predict that pairs of “virtual particles” are constantly popping in and out of existence. Therefore, a “true vacuum” is never truly empty; it’s actually buzzing with pairs of quantum particles that pop into existence and then annihilate within a minuscule time frame. Usually this continues without a hitch — particles appear out of the vacuum, they annihilate with their partner and the universe goes about its business.
But if you add a black hole to the mix, things get a bit crazy.
As we’ve already discussed, the black hole’s event horizon is the point of no escape. So what happens when a pair of virtual particles pop into existence at the horizon and only one falls in? Well, the second “virtual” particle, which has lost its annihilation partner, is ejected away from the black hole and becomes “real.” In the process of becoming a real particle, it steals a tiny amount of mass from the black hole (quantum mechanics never pretended to make logical sense). With this process happening all the time at the event horizon, the black hole starts to physically lose mass — it is evaporating via Hawking radiation.
So far I’ve only given you a taste about how weird quantum field theory is, and it’s about to get weirder, but first we need to discuss a little background.
General relativity and quantum field theory don’t play nice. Both areas of physics describe the fundamental nature of space, time and matter over micro (quantum) and macro (cosmological) scales. But after decades of trying to see how the two overlap, physicists have drawn a blank. And with the recent discovery of the Higgs boson, the quantum “recipe book” — called the Standard Model — has once again been proven to represent a very precise description of how our universe works.
The Standard Model seems to have a problem with gravity, fundamentally. So far, physicists have not been able to find a particle that mediates the gravitational force (hypothesized as the “graviton”) and despite their best efforts there seems to be no way to reconcile this conundrum. And in recent years, black holes have become another battleground for general relativity and quantum field theory.
Antithesis of “No Drama”
When matter (and therefore “information”) falls into a black hole, it is removed from the known universe and is effectively destroyed. This is a problem; general relativity cares little for information, which all matter possesses, but quantum theory cares a lot for information and it explicitly states that information cannot be destroyed.
In 2004, Hawking famously conceded a bet with theoretical physicist John Preskill, admitting that information “lost” to the black hole is actually encoded in Hawking radiation (Hawking had originally argued that black holes destroyed information and the information carried away by Hawking radiation was “new” and had no relation to the matter that had fallen in).
But this quick fix created another problem. In 2012, a group of physicists led by Joseph Polchinski of the University of California in Santa Barbara found that for information to be retained by Hawking Radiation, there would be a “firewall” of violent quantum energy churning away just beyond the event horizon.
Thinking back to our unlucky astronaut falling into a black hole’s event horizon, in a general relativity universe, the astronaut would experience nothing when drifting through the event horizon (except if that astronaut was Matthew McConaughey, he’d experience some bright lights and get stuck behind a bookcase). Of course, the astronaut will eventually be ripped to shreds, but he or she wouldn’t be incinerated. This thought experiment is known as the “no drama” postulate.
This is where we hit the firewall impasse. The firewall violates this lack of drama, in fact, it’s the complete opposite of no drama! So the existence of the firewall violates general relativity, the very theory that governs black holes to begin with.
So now physicists are battling with equations trying to solve the “information paradox” and over the last couple of years the greatest minds in theoretical physics have contributed to the firewall showdown, and Hawking has not strayed far from the debate.
Last year, Hawking discussed the possibility of replacing the event horizon with a theoretical construct known as an “apparent horizon” — rather than a definite boundary (the event horizon), perhaps the notion needs to be reworked and there’s in fact a horizon that changes shape in response to quantum fluctuations inside the black hole. This would create a chaotic mess of information beyond the apparent horizon, which doesn’t violate either quantum dynamics or general relativity.
“Thus, like weather forecasting on Earth, information will effectively be lost, although there would be no loss of unitarity,” Hawking wrote in a paper at the time, meaning that although the information can escape from the black hole, its chaotic nature ensures it cannot be interpreted, sidestepping the firewall problem.
Needless to say, this didn’t settle the debate among Hawking’s peers.
And now Hawking is in the news yet again, having appeared at the KTH Royal Institute of Technology in Stockholm on Monday (Aug. 24) discussing his refined explanation at a public lecture for how he thinks information is handled by black holes.
“I propose that the information is stored not in the interior of the black hole as one might expect, but on its boundary, the event horizon,” Hawking said at the lecture, according to Tech Insider.
Hawking elaborated to say that the information retained in objects falling into the black hole is converted into a 2-dimensional “hologram” where it is then captured in Hawking radiation and carried away from the black hole. But don’t go getting romantic notions of using black holes as some kind of super-advanced computer hard-drive, the information will be a jumbled chaotic mess.
“The message of this lecture is that black holes ain’t as black as they are painted,” Hawking said. “They are not the eternal prisons they were once thought. Things can get out of a black hole both on the outside and possibly come out in another universe.”
We have to wait for a paper that Hawking and his collaborators will publish in a few weeks to find out what he means by “another universe,” but some theories behind the nature of black holes suggest that they are gateways to other, parallel universes, or even universes in their own right.
The Event Horizon Telescope Cometh
For now, it seems Hawking may have formulated an “emergency exit” for information falling into a black hole, but we won’t really know what’s going on until we study a black hole up close — a fact that will likely prove to be an impossibility.
But soon, as already reported by Discovery News, we’re going to get a profound direct look at a black hole’s event horizon, albeit from afar.
Astronomers of the world-wide Event Horizon Telescope (EHT) project are close to staring deep into the core of our galaxy to resolve the predicted disk of light surrounding the Milky Way’s supermassive black hole, Sagittarius A*, located over 20,000 light-years away. And it just so happens the team were available for questions at a special Reddit Ask Me Anything (AMA) event on Wednesday (Aug. 26) when the question of Hawking’s take on the black hole information paradox and how the EHT might be able to help was asked.
Read more at Discovery News
Scientists have used high resolution technology for the first time to describe a new millipede species, highlighting features such as genitals in remarkable detail.
The millipede, dubbed Ommatoiulus avatar, was found in an Andalusion pine forest in southern Spain.
Researchers first used iodine to stain different organs in the species and then scanned it using microCT (high-resolution x-ray microtomography)
Data produced by the scans, collectively called a 'cybertype', was then rendered as a 3D image using transparency and colour to reveal different parts of the creature.
The male genitals (gonopods), which are key in the identification of millipedes are seen in orange at the base of the image.
The eyes are seen in yellow at the top of the image and are not, as you might think, where the antennae attach.
Taxonomy can often be a painstaking business. If someone wants to study the original type specimen -- or holotype -- used to identify a species, they may have to travel far to find it, or request a museum send the specimen to them.
And any study, especially dissection, may damage the precious and often fragile original specimen.
But, says biologist Dr Brian Metscher of the University of Vienna, who helped create the new images, microCT scans can help get around this problem.
"If we make images like this, one does not have to dissect the specimen and it can remain intact, happy and safe in the museum."
Instead of actual dissection, researchers can rotate the digital images, change the focus of them, or delete unwanted sections, to get a clear picture of what they need to, says Metscher.
Metscher and colleagues have documented procedures on how to make cybertypes and also share them around the world.
While the holotype specimens are kept in museums in Vienna and Copenhagen, all 3D images and data have been placed on the open access online repository called Dryad.
"We hope that this work will be an example for how to make, use, and share virtual specimens for taxonomy and other purposes, including teaching," says Metscher.
Read more at Discovery News
Paleontologists believe the foot belongs to a new dino, dubbed “Welsh Dragon,” which is the oldest Jurassic dinosaur ever found in the U.K. Based on the foot and other previously excavated remains, the dino was about 20 inches tall when it died, so it’s also one of the smallest.
The student who discovered the foot, Sam Davies of the University of Portsmouth, told Wales Online, “It was pure luck that I found it.”
The discovery occurred on a beach at Lavernock, Vale of Glamorgan, in Wales.
“It was my first day of doing field work for my third year project, and I was just wandering up and down the beach looking for fossils,” Davies said. “It was just sitting on top of a piece of rock. It was obvious the fossil was fingers or toes, because there were three in a row, but the first thing that came to mind was that it was some sort of plesiosaur.”
Paleontologist David Martill of the University of Portsmouth confirmed that it was not part of a plesiosaur, but instead was the long-lost foot of Welsh Dragon, a dinosaur that was partially recovered last year by brothers Robert and Nick Hanigan.
Explaining why they were at this particular beach, Nick said that about 3 years ago he “found an ichthyosaur skull and my brother Robert was looking for the rest of the ichthyosaur.”
Robert continued the story from there: “I was looking for fossils out at the low tide mark, and I was just on my way back to the car. I thought I’d have a look around here in a recent rock fall that had happened. While looking through the rocks, I just noticed a few small bits of what I thought were bone, so I picked up some blocks and took them back to the car.”
Suspecting the bones were important, the brothers brought the fossils to paleontologists for evaluation. The remains were identified as belonging to a carnivorous dinosaur that was an early cousin of Tyrannosaurus rex. Welsh Dragon lived some 130 million years before T. rex emerged. The fossils are now at National Museum Cardiff.
According to the museum, the new dinosaur hunted small mammals, lizards and other reptiles. Crocodiles thrived in its ecosystem.
Welsh Dragon walked on two legs and had a long tail. It was a warm-blooded animal, and much of its body was probably covered in feathery down with quills along its back.
Read more at Discovery News
Taking place after excerebration (brain removal) and evisceration (body organ removal) and before final wrapping, the procedure would force open the mouths of the deceased with a knife and iron chisel, breaking and dislocating teeth in the process.
The procedure appears to be in contrast to the delicate and thoughtful steps taken during the mummification process.
The “opening of the mouth” was so far known to Egyptologists as a central yet innocuous ritual in mummification, aimed at restoring the deceased’s senses for the afterlife.
The symbolic animation of the finished mummy was achieved through a series of ritual actions that involved the repeated touching of the mouth and eyes with various specialized implements.
“These actions were accompanied by recitation of specific formulae and incantations in order to enable the deceased to breathe, eat, drink, hear, and see, and ultimately survive the afterlife,” said Mariam Ayad, associate professor of Egyptology at the American University in Cairo.
Ayad presented a study on the opening of the mouth ritual as seen in scenes from ancient Egyptian mortuary monuments.
But according to mummy expert Frank Rühli, director of the Institute of Evolutionary Medicine at the University of Zurich, parts of the ceremony actually correspond to a physical and sometime probably rather brutal opening of the deceased’s mouth.
“Fractures and avulsions of front teeth, which were up to now not sufficiently taken into consideration, are the first evidence for a real physical opening of the mouth procedure during mummification,” Rühli told Discovery News.
Rühli and dentist Roger Seiler from the Institute of Evolutionary Medicine at the University of Zurich, investigated 51 mummies from the Swiss Mummy project and more than 100 from the skull collection of the University of Zurich Anthropological Institute and Museum.
It emerged that several mummies suffered postmortem (after death) trauma to the teeth, and CT scans even showed that in some cases broken teeth ended up deep down in the throat.
“One learns from the texts of the ritual of embalming that after the surgical treatment and the dehydration, the dead body was again cleaned and anointed before being wrapped,” the researchers wrote in a issue of the journal The Anatomical Record entirely devoted to the study of mummies around the world.
Read more at Discovery News
The research, headed by Henry Lin of the Harvard-Smithsonian Center for Astrophysics (CfA), assumes that this feat may be possible in a generation or so and that the hypothesis of panspermia may act as the delivery system for alien biology to hop from one star system to another.
Panspermia is a process where life is somehow transplanted from planet to planet. This may happen should a planet, rich with life, be hit by a massive asteroid impact; pieces of that planet’s crust will be propelled into space and any life contained within those samples may be transplanted to another world. If these hardy lifeforms make the trip, then perhaps they can gain a foothold and seed life in this new environment.
There are other hypothetical mechanisms by which life could “hop” from one planet to the next — including the fascinating possibility of “directed panspermia” where an intelligent civilization may deliberately seed other star systems with capsules containing its biological image. Other ideas remove the need for this life to survive the trip, allowing the freeze-dried dead biology attached to space rocks to act as a template for life on a newly seeded world, a process called “necropanspermia.”
These processes are pure hypotheses right now, and this new research does not specify how life may spread, but we do know that chunks of planetary bodies can travel from planet to planet. For example, a type of meteorite found on Earth is known to originate from Mars — its isotopic signature is identical to measurements made by the armada of robots currently orbiting and roving on the Red Planet. These meteorites were bits of Mars crust blasted into space by ancient impacts.
It’s not such a stretch to think that chunks of Earth have also been blasted into space and computer simulations suggest that there’s a statistical chance that Earth rocks have drifted to the orbits of Jupiter and Saturn, potentially impacting some of the gas giants’ moons. Whether or not Earth’s abundant life was contained within these rocks is not known and it’s quite a stretch to think that a secondary genesis of life may have been spawned.
But say if life can hitch a ride on space rocks and this life can seed new biospheres on other worlds… how would astrobiologists recognize that life is being spread from one star system to the next? Well, like a common cold, the spread would appear viral.
“Life could spread from host star to host star in a pattern similar to the outbreak of an epidemic. In a sense, the Milky Way galaxy would become infected with pockets of life,” said co-author Avi Loeb, also of the CfA, in a press release.
Using a computer model, Lin and Loeb assumed that the “seeds” from one planet’s biosphere spreads in all directions over time. Should one of those seeds reach a habitable planet, there’s a chance it may take root. This creates several life-giving oases that could be detected by future space telescopes peering into these exoplanetary atmospheres. And should several of these life-endowed worlds be found, a pattern may emerge.
“In our theory clusters of life form, grow, and overlap like bubbles in a pot of boiling water,” said Lin.
Read more at Discovery News
Aug 26, 2015
Concentrations of mercury and selenium in canyon’s food webs — the interconnected food chains in the environment — regularly exceed levels considered risky for fish and wildlife. Those findings are from a study from the U.S. Geological Survey scientists published in the journal Environmental Toxicity and Chemistry.
“Managing exposure risks in the Grand Canyon will be a challenge, because sources and transport mechanisms of mercury and selenium extend far beyond Grand Canyon boundaries,” said Dr. David Walters, USGS research ecologist and lead author of the study.
Researchers collected data from six sites along along the Colorado River, which winds through the Canyon. They found that the mercury and selenium concentrations in minnows, invertebrates and fish exceeded dietary toxicity thresholds set for fish and fish-eating wildlife.
The data also revealed that the average mercury concentrations in many of the fish studied would make them unsafe for humans to eat as well.
As this handout from the National Wildlife Federation details, mercury is a highly potent neurotoxin that adversely affects the central nervous system in both people and wildlife. Selenium can cause a variety of health problems in humans, ranging from hair and tooth loss to problems with alertness, and some selenium compounds are linked to liver tumors in humans, according to the EPA.
There was one bit of good news for anglers who visit the canyon. The mercury levels in rainbow trout, the most common species caught, were below the EPA threshold that would trigger advisories for human consumption. Also, the researchers didn’t observe the level of deformities usually associated with high levels of mercury, because high levels of toxic selenium seem to protect fish from the effects of mercury toxicity, according to an article in the Arizona Daily Sun.
Humans who ate the fish, however, wouldn’t necessarily be protected from the toxic substances.
Read more at Discovery News
The Sydney Morning Herald reports that the worrisome population count was taken by the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
The handfish survives today only in Tasmanian waters, in the Hobart's Derwent estuary. The hand count has researchers considering urgent methods to keep the species alive.
"It would be very prudent to think about captive breeding of the fish at this stage," CSIRO researcher Tim Lynch told the newspaper. "We're organising a workshop to cost it out, and see what we can do."
In the video below, you can see the fish "walking."
Local environmental changes to the fish's habitat also seem to be playing a role.
From Discovery News
The palace, likely built around the 17th-16th centuries BC, had around 10 rooms and was discovered near Sparta in southern Greece.
At the site, archaeologists found objects of worship, clay figurines, a cup adorned with a bull’s head, swords and fragments of murals.
Since 2009, excavations in the area have unearthed inscriptions on tablets detailing religious ceremonies and names and places in a script called Linear B, the oldest script to be discovered in Europe. It first appears in Crete from around 1375 BC and was only deciphered in the mid 20th century.
The new discovery will allow for more research on the “political, administrative, economic and societal organization of the region”, and provide “new information on the beliefs and language systems of the Mycenean people,” the ministry said in a statement.
According to the culture ministry, more than 150 archaeological excavations were have been carried out in Greece so far this year, “demonstrating the importance of the archaeological wealth and cultural heritage of the country.”
From Discovery News
However, astronomers would love to measure gravitational waves in space with even better resolution, but that requires two satellites separated by millions of miles. Even over these extreme distances, the gravitational wave's influence on the warping of spacetime will be minuscule, requiring precise measurements.
Luckily for science, the European Space Agency will launch a large-scale gravitational wave observatory in 2034, although the design of it isn't yet finalized. Previous concepts called Laser Interferometer Space Antenna (LISA) and New Gravitational wave Observatory (NGO) have been studied in detail but were not selected.
That's where LISA Pathfinder comes in. It won't actually hunt for gravitational waves, but will work out the kinks for the much larger mission in a couple of decades. And project scientist Paul McNamara plans to be there for both launches.
"What I really wanted to do (with my career) is gravitational wave astrophysics," McNamara told Discovery News, adding he started working on LISA at age 21, in 1994. That will put him close to retirement age when the 2034 mission gets off the ground.
LISA Pathfinder will need to be an extraordinarily quiet and stable spacecraft. It will carry two 2 kilogram (4.4-pound) precious payloads -- test masses of a gold-platinum alloy -- that it needs to shield from the stresses of launch, the pressure of solar radiation, and the extreme environment of space. Also, no magnetic materials can be used during construction, among other requirements.
Read more at Discovery News
Einstein’s theory of general relativity predicts that the physical information about material gobbled up by a black hole is destroyed, but the laws of quantum mechanics stipulate that information is eternal. Therein lies the paradox.
Hawking — working with Malcolm Perry, of the University of Cambridge in England, and Harvard University’s Andrew Stromberg — has come up with a possible solution: The quantum-mechanical information about infalling particles doesn’t actually make it inside the black hole.
“I propose that the information is stored not in the interior of the black hole, as one might expect, but on its boundary, the event horizon,” Stephen Hawking said during a talk Tuesday at the Hawking Radiation conference, which is being held at the KTH Royal Institute of Technology in Stockholm, Sweden.
The information is stored at the boundary as two-dimensional holograms known as “super translations,” he explained. But you wouldn’t want super translations, which were first introduced as a concept in 1962, to back up your hard drive.
“The information about ingoing particles is returned, but in a chaotic and useless form,” Hawking said. “For all practical purposes, the information is lost.”
Hawking also discussed black holes — whose gravitational pull is so intense that nothing, not even light, can escape once it passes the event horizon — during a lecture Monday night in Stockholm.
It’s possible that black holes could actually be portals to other universes, he said.
Read more at Discovery News
Aug 25, 2015
There has been a sharp plunge in the population of honey bees, which pollinate about 70 percent of global crops, or one-third of food that humans eat including fruits and vegetables, raising fears over food security.
Researchers have said the falling hive numbers were caused by threats such as the sudden death of millions of adult insects in beehives -- known as "colony collapse disorder" -- a blood-sucking mite called Varroa, pesticides and climate change.
"The micro-sensors that we are using help us to ask different questions that we couldn't ask before because we've never really been able to quantify the behavior of bees both out in the environment and in their hives," Gary Fitt from Australia's national science agency CSIRO told AFP.
The sensors, 2.5 millimeters (0.1 inches) in width and breadth and weighing 5.4 milligrams (0.0002 ounces) -- lighter than pollen that bees collect -- are glued to the back of European honey bees. Sophisticated data collection receptors are also built into hives.
The CSIRO -- working together with US technology firm Intel and Japanese conglomerate Hitachi -- is now offering free access to the sensor technology and data analytics to identify global patterns.
"What we are gathering with the sensors is environmental information from where the bees have been," said Fitt, the science director of the CSIRO's health and biosecurity division.
"It tells us about their changes in behavior -- how often and how long they're foraging, whether they're feeding, whether they're collecting pollen, what they're doing in the hives.
"We can then see if we can interpret those changes to tell us how they are responding to different stresses."
About 10,000 bees and their hives in the southern island state of Tasmania have been tagged, with others set to be monitored in the cities of Sydney and Canberra.
Around the same number of bees in Brazil were also being monitored by researchers, with interest expressed from scientists in Europe and North America, Fitt said.
"(We'll) use the same approaches and ask similar questions but in different parts of the world to get a much bigger picture of the problem and collectively find solutions," he added.
Read more at Discovery News
Over a period of several months, biologists subjected different groups of female guppies to varying levels of harassment from males. At the end of the trial period, the frequently harassed females swam much more efficiently than their undisturbed peers.
"An important factor appears to be swimming technique, and female guppies that experienced lower levels of harassment spent more time swimming with their pectoral fins extended, an indicator of an inefficient swimming technique," study author Shaun Killen explained in a news release.
Killen and his colleagues likened the guppy's improvement in swimming technique to an athlete that trains to improve performance.
From Discovery News
A rain-flooded river has deluged the Kaziranga National Park in remote Assam state, home to the largest concentration of the world's remaining one-horned rhinoceros.
"More than half of the Kaziranga National Park is under water. Animals are migrating from the sanctuary to adjoining hills for safety," Assam forest and wildlife minister Etuwah Munda told AFP.
"We are taking all precautionary measures and I myself will be camping in the park to monitor the situation."
The park, spread over 450 square kilometres (173 square miles), is prone to flooding during the annual monsoon rains.
Some 14 rhinos and hundreds of other animals died during floods in 2012, many of them mown down on a nearby highway by speeding vehicles as they left the park for higher ground.
Park officials have this year taken precautions, including erecting barricades along sections of the highway.
"Forest guards are asking drivers to drive under 40 kilometres (25 miles) an hour as the animals use the highway to cross over to the hill to escape the floods," the minister said.
A recent census estimated there were 2,400 one-horned rhinos in the park out of a global population of around 3,300.
Park officials are worried about poachers targeting them and other animals as they leave the sanctuary for the hills.
"Poachers have a tendency to target animals by taking advantage of the floods. We have put forest guards on alert in the hills where the animals take refuge," Munda said.
Read more at Discovery News
Debate about the credibility of the “gospel” began as soon as Harvard University professor Karen King reported her discovery of the papyrus in September 2012. Written in Coptic (an Egyptian language), the papyrus fragment contains a translated line that reads, “Jesus said to them, ‘My wife …’” and also refers to a “Mary,” possibly Mary Magdalene.
King had tentatively dated the papyrus to the fourth century, saying it may be a copy of a gospel written in the second century in Greek.
Analysis of the papyrus, detailed last year in the Harvard Theological Review journal, suggested the papyrus dates back around 1,200 years (somewhere between the sixth and ninth centuries) while the ink is of a type that could have been created at that time. These findings have led King to support the text’s authenticity.
However over the past year many scholars have come to the conclusion that the papyrus is a modern-day forgery, though King and a few other researchers say they are not ready to concede this: “At this point, when discussions and research are ongoing, I think it is important, however difficult, to stay open regarding the possible dates of the inscription and other matters of interpretation,” wrote King in a letter recently published in the magazine Biblical Archaeological Review. King has not responded to several interview requests from Live Science.
Now, researchers at Columbia University are running new tests on the ink used on the papyrus. Initial tests published by the Columbia University team in 2014 indicated the ink could have been made in ancient times. Researchers are saying little until their report is published; however they did talk about one finding that could provide some support for its authenticity.
A gospel steeped in mystery
The current owner of the papyrus has insisted on remaining anonymous, claiming that he bought the Gospel of Jesus’s Wife, along with other Coptic texts, in 1999 from a man named Hans-Ulrich Laukamp. This person, in turn, got it from Potsdam, in what was East Germany, in 1963, the owner said.
Laukamp died in 2002, and the claim that he owned the text has been strongly disputed: Rene Ernest, the man whom Laukamp and his wife Helga charged with representing their estate, said that Laukamp had no interest in antiquities, did not collect them and was living in West Berlin in 1963. Therefore, he couldn’t have crossed the Berlin Wall into Potsdam. Axel Herzsprung, a business partner of Laukamp’s, similarly said that Laukamp never had an interest in antiquities and never owned a papyrus. Laukamp has no children or living relatives who could verify these claims.
Over the past few months, new documents have been found that not only reconstruct Laukamp’s life in greater detail, but also provide a new way to check the anonymous owner’s story.
King reported in a 2014 Harvard Theological Review article that the anonymous owner “provided me with a photocopy of a contract for the sale of ’6 Coptic papyrus fragments, one believed to be a Gospel’ from Hans-Ulrich Laukamp, dated Nov. 12, 1999, and signed by both parties.” King also notes that “a handwritten comment on the contract states, ‘Seller surrenders photocopies of correspondence in German. Papyri were acquired in 1963 by the seller in Potsdam (East Germany).’”
After searching public databases in Florida a Live Science reporter uncovered seven signatures signed by Laukamp between 1997 and 2001 on five notarized documents. Anyone can search these databases and download these documents. These signatures can be compared with the signature recording the sale of the Gospel of Jesus’s Wife — providing another way to verify or disprove the story of how the “gospel” made its way to Harvard.
While Harvard University would have to work with forensic handwriting experts to verify the signature, the fact that these notarized documents exist, and are publicly available, presents the opportunity to see if Laukamp really did own the Gospel of Jesus’s Wife. Forensic handwriting analysis, while not always conclusive, has been used to determine if signatures made on documents or works of art are authentic or forged.
If Laukamp did own the papyrus, authentic or not, then the origins of the enigmatic text lie with him. The new Laukamp documents allow the story of his life between 1995 and 2002 to be told in some detail. However if Laukamp didn’t own the papyrus and the anonymous owner has not been truthful, then further doubt would be cast on the papyrus’ authenticity, and information leading to the identity, motives and techniques of the forgers could be found.
One important find, which indicates the Gospel of Jesus’s Wife is a fake, was made last year by Christian Askeland, a research associate with the Institute for Septuagint and Biblical Research in Wuppertal, Germany. He examined a second Coptic papyrus containing part of the Gospel of John, which the anonymous owner of the Gospel of Jesus’s Wife had also given to Harvard. This text was likewise supposedly purchased from Laukamp, and radiocarbon testing of that papyrus similarly found that it dates back around 1,200 years.
Askeland found that the text and line breaks— where one line of a text ends and another begins — are identical to those of another papyrus, published in a 1924 book. That second papyrus was written in a dialect of Coptic called Lycopolitan, which went extinct around 1,500 years ago. Askeland concluded that the John papyrus is a forgery. Furthermore, it shares other features with the Gospel of Jesus’s Wife, Askeland said, suggesting both are forgeries.
“The two Coptic fragments clearly shared the same ink, writing implement and scribal hand. The same artisan had created both essentially at the same time,” Askeland wrote in a paper recently published in the journal New Testament Studies.
King objected to this conclusion in her Biblical Archaeology Review letter, noting that the John fragment could have been copied in ancient times, long after Lycopolitan went extinct, from a text that had similar line breaks.
In addition, James Yardley, a senior research scientist at Columbia University, told Live Science that the new tests confirm that the Gospel of Jesus’s Wife holds different ink than the John papyrus. This could undercut Askeland’s argument that the two papyri were written by the same person.
“In our first exploration, we did state that the inks used for the two documents of interest [the John papyrus and the Gospel of Jesus's Wife] were quite different. The more recent results do confirm this observation strongly,” Yardley told Live Science.
He added that until his new research is published in a peer-reviewed journal, he doesn’t want to say anything more publicly. And once it’s published, Askeland and other researchers will have a chance to respond.
Read more at Discovery News
It will take a whole new generation of “big-eyed” telescopes to learn more, such as the James Webb Space Telescope that launches in 2018. But here’s a twist — one European team says it can do exoplanet science for a lot less.
With a budget of just 50 million pounds ($79 million), the Twinkle satellite team plans to launch into low-Earth orbit in three to four years if it can get the funding. There, it will study the infrared (heat) signatures of at least 100 nearby worlds a few hundred light-years away. This will be possible even with a tiny mirror of 50 centimeters (20 inches) compared to a larger telescope like Hubble (2.4 meters/8 feet), the lead scientist told Discovery News.
“We have identified a niche of science that could be done very well even with a relatively more modest instrument,” said Giovanna Tinetti, an astrophysicist at University College London. Because the planets will be hothouse worlds that are relatively close by Earth, their infrared signatures are so strong that astronomers can infer the presence of molecules, clouds, weather and climate even in a small telescope, she said.
But money (as always) will be the challenge. Twinkle is much cheaper than a previous planet-studying mission called EChO that Tinetti and collaborators proposed to the European Space Agency in 2011, a half-billion Euro ($0.57 billion) mission that was not selected. Key differences include not sending Twinkle out to Lagrangian point L2 (1.5 million kilometers or 932,000 miles from Earth), a smaller telescope and a narrower wavelength range, using commercial off-the-shelf components, and suggesting “trades” to international scientific organizations such as providing money for telescope time. Funding is ongoing, but there is a commercial partner involved – Surrey Satellite Technology Ltd. – that has participated in numerous space missions.
Read more at Discovery News
Aug 24, 2015
Logic gates perform operations on input data to create new outputs. In classical computers, logic gates take the form of diodes or transistors. But quantum computer components are made from individual atoms and subatomic particles. Information processing happens when the particles interact with one another according to the strange laws of quantum physics.
Light particles -- known as "photons" -- have many advantages in quantum computing, but it is notoriously difficult to get them to interact with one another in useful ways. This experiment demonstrates how to create such interactions.
"We've seen the effect of a single particle of light on another optical beam," said Canadian Institute for Advanced Research (CIFAR) Senior Fellow Aephraim Steinberg, one of the paper's authors and a researcher at U of T's Centre for Quantum Information & Quantum Computing. "Normally light beams pass through each other with no effect at all. To build technologies like optical quantum computers, you want your beams to talk to one another. That's never been done before using a single photon."
The interaction was a two-step process. The researchers shot a single photon at rubidium atoms that they had cooled to a millionth of a degree above absolute zero. The photons became "entangled" with the atoms, which affected the way the rubidium interacted with a separate optical beam. The photon changes the atoms' refractive index, which caused a tiny but measurable "phase shift" in the beam.
Read more at Science Daily
The Wildlife Conservation Society (WCS) was in the midst of its multi-year "Identidad Madidi" expedition in Madidi National Park when they spied Anoura fistulata for the first time ever there.
The bat was discovered just 10 years ago in Ecuador. It lives in the Ecuadorian Andes and is known from only three other records. The International Union for Conservation of Nature and Natural Resources (IUCN) lists Anoura fistulata as "Data Deficient" because not enough is known about the creature's abundance and distribution to reliably categorize its conservation status.
The tube-lipped nectar bat's tongue is a world beater. It extends 3.3 inches (8.5 centimeters) -- the longest tongue, relative to its size (about 1.5 times its own body), of any mammal, according to the researchers. All the better for the nectar fan to reach well into the deepest flowers.
The WCS expedition said it also discovered a new species of robber frog (Oreobates sp. nov.) and marked the presence of an annellated coral snake (Micrurus annellatus); the Hagedorn's tube-snouted ghost knifefish (Sternarchorhynchus hagedornae); and the long-tailed rice rat (Nephelomys keaysi).
Wildlife Conservation Society's Dr. Robert Wallace called his team's discoveries "just the beginning," in a press release, adding that the number of species confirmed during the group's ongoing expedition make Madidi "the world's most biologically diverse park."
From Discovery News
Famed for well-preserved Greco-Roman ruins, Palmyra was seized from government forces in May, fuelling fears the IS jihadists might destroy its priceless heritage as it had done in other parts of Syria and Iraq.
Until Sunday, most of Palmyra’s most famous sites had been left intact, though there were reports IS had mined them and the group reportedly destroyed a famous statue of a lion outside the city’s museum.
“The cella (inner area of the temple) was destroyed and the columns around collapsed,” he said.
The Syrian Observatory for Human Rights, a Britain-based group that monitors the country’s civil war, confirmed the destruction of the temple.
IS, which controls swathes of Syria and neighbouring Iraq, captured Palmyra on May 21, sparking international concern about the fate of the heritage site described by UNESCO as of “outstanding universal value.”
Baal Shamin was built in 17 A.D. and it was expanded under the reign of Roman emperor Hadrian in 130 A.D.
Known as the “Pearl of the desert," Palmyra, which means City of Palms, is a well-preserved oasis 130 miles northeast of Damascus.
Its name first appeared on a tablet in the 19th century B.C. as a stopping point for caravans traveling on the Silk Road and between the Gulf and the Mediterranean.
But it was during the Roman Empire — beginning in the first century B.C. and lasting another 400 years — that Palmyra rose to prominence.
Before the arrival of Christianity in the second century, Palmyra worshipped the trinity of the Babylonian god Bel, as well Yarhibol (the sun) and Aglibol (the moon).
Prior to the outbreak of the Syrian conflict in March 2011, more than 150,000 tourists visited Palmyra every year, admiring its beautiful statues, over 1,000 columns, and formidable necropolis of over 500 tombs.
IS had mined the ancient site in June before destroying the Lion Statue of Athena — a unique piece made of limestone that stood more than three metres high (10 feet) outside a museum.
Funerary busts were also destroyed by IS in Palmyra.
Most of the pieces in the museum were evacuated by antiquities staff before IS arrived, though the group has blown up several historic Muslim graves.
IS’s harsh version of Islam considers statues and grave markers to be idolatrous, and the group has destroyed antiquities and heritage sites in territory under its control in Syria and Iraq.
The latest developments come just days after IS jihadists beheaded the 82-year-old retired chief archaeologist of Palmyra.
IS has also executed hundreds of people in the city and surrounding area, many of them government employees, and infamously used child members to shoot dead 25 Syrian government soldiers in Palmyra’s ancient amphitheater.
Read more at Discovery News
The image above shows what the crowded center of the galaxy looks like to XMM-Newton in x-rays, emitted en masse by extremely active and hot areas like the accretion disks that surround feeding black holes.
And right at the very heart of the Milky Way, 26,000 light-years from Earth, lies the galactic granddaddy of them all: Sagittarius A* (pronounced “A-star”), a supermassive black hole that contains more mass than 4.5 million suns.
As super and massive as it is, though, Sgr A* isn’t anywhere near the biggest supermassive black hole out there (some contain tens of billions of solar masses) nor is it brightest object in this XMM-Newton image. This is because it, not unlike other active galactic nuclei, is relatively faint in x-rays. This may be because it’s a sloppy eater, ejecting much of its accumulated material before it gets a chance to get close enough to its event horizon to accelerate, heat up, and start shining with x-rays.
What XMM-Newton has revealed though are “lobes” of x-ray-bright gas around the area of Sgr A*. These may be evidence of material that has either been ejected from the black hole or else being rapidly pushed away the powerful winds from it and other nearby stellar emissions.
A bright area, much brighter that Sgr A* in fact, can be seen to the lower right of the galactic center. This is the glow from what has now been confirmed to be a literal cluster of supernovas. Talk about hot stuff!
The view is the result of a month and a half of observations by XMM-Newton, which orbits Earth at distances ranging from 4,300 miles (7,000 km) to as far as 71,000 miles (114,000 km).
From Discovery News
Taking advantage of new analysis techniques, scientists re-analyzed the contents of green and orange glass beads discovered in soil samples brought back from the moon by the Apollo 15 and Apollo 17 missions, which took place in the early 1970s.
“The lunar volcanic glasses are thought to be the product of fire-fountain eruptions, in which a jet of basaltic lava erupts through a vent, spattering droplets of lava that cool quickly to form glass,” Bruno Scaillet, with the University of Orleans in France, wrote in an article in this week’s Nature Geoscience.
The process is similar to shaking a can of soda and taking off the cap.
On Earth, the gas that triggers fire fountains is typically carbon dioxide or water.
The new analysis of the lunar samples showed that concentrations of carbon and water decreased toward the center of the beads, an indication of degassing. Follow-on studies with computer models show the fire fountains were most likely fed by carbon monoxide gas.
“It was debated it could be carbon monoxide, but there was no evidence,” Brown University lunar scientist Alberto Saal wrote in an email to Discovery News.
Another option is hydrogen gas, but there is not geologic evidence of a fluid rich in hydrogen, he added.
The researchers also point out that the concentrations of carbon in the lunar melts is basically the same as what is found in Earth basalts that erupted from the mid-ocean ridges.
Saal and colleagues previously showed that Earth and the moon have similar concentrations of water and other volatiles, as well as similar ratios of hydrogen isotopes.
Read more at Discovery News
Aug 23, 2015
In a world without humans, most of northern Europe would probably now be home to not only wolves, Eurasian elk (moose) and bears, but also animals such as elephants and rhinoceroses.
This is demonstrated in a new study conducted by researchers from Aarhus University, Denmark. In a previous analysis, they have shown that the mass extinction of large mammals during the Last Ice Age and in subsequent millennia (the late-Quaternary megafauna extinction) is largely explainable from the expansion of modern man (Homo sapiens) across the world. In this follow-up study, they investigate what the natural worldwide diversity patterns of mammals would be like in the absence of past and present human impacts, based on estimates of the natural distribution of each species according to its ecology, biogeography and the current natural environmental template. They provide the first estimate of how the mammal diversity world map would have appeared without the impact of modern man.
"Northern Europe is far from the only place in which humans have reduced the diversity of mammals -- it's a worldwide phenomenon. And, in most places, there's a very large deficit in mammal diversity relative to what it would naturally have been," says Professor Jens-Christian Svenning, Department of Bioscience, Aarhus University, who is one of the researchers behind the study.
Africa is the last refuge
The current world map of mammal diversity shows that Africa is virtually the only place with a high diversity of large mammals. However, the world map constructed by the researchers of the natural diversity of large mammals shows far greater distribution of high large-mammal diversity across most of the world, with particularly high levels in North and South America, areas that are currently relatively poor in large mammals.
"Most safaris today take place in Africa, but under natural circumstances, as many or even more large animals would no doubt have existed in other places, e.g., notably parts of the New World such as Texas and neighboring areas and the region around northern Argentina-Southern Brazil. The reason that many safaris target Africa is not because the continent is naturally abnormally rich in species of mammals. Instead it reflects that it's one of the only places where human activities have not yet wiped out most of the large animals," says Postdoctoral Fellow Soren Faurby, Department of Bioscience, Aarhus University, who is the lead author on the study.
The existence of Africa's many species of mammals is thus not due to an optimal climate and environment, but rather because it is the only place where they have not yet been eradicated by humans. The underlying reason includes evolutionary adaptation of large mammals to humans as well as greater pest pressure on human populations in long-inhabited Africa in the past.
Better understanding helps nature preservation
The study's openly accessible data set of natural range maps for all late-Quatenary mammals provides researchers with the first opportunity to analyse the natural patterns in the species diversity and composition of mammals worldwide. Hereby, it can be used to provide a better understanding of the natural factors that determine the biodiversity in a specific area.
Today, there is a particularly large number of mammal species in mountainous areas. This is often interpreted as a consequence of environmental variation, where different species have evolved in deep valleys and high mountains. According to the new study, however, this trend is much weaker when the natural patterns are considered.
"The current high level of biodiversity in mountainous areas is partly due to the fact that the mountains have acted as a refuge for species in relation to hunting and habitat destruction, rather than being a purely natural pattern. An example in Europe is the brown bear, which now virtually only live in mountainous regions because it has been exterminated from the more accessible and most often more densely populated lowland areas," explains Soren Faurby.
Read more at Science Daily
Benjamin Blencowe, a professor in the University of Toronto's Donnelly Centre and Banbury Chair in Medical Research, and his team have uncovered how a small change in a protein called PTBP1 can spur the creation of neurons -- cells that make the brain -- that could have fuelled the evolution of mammalian brains to become the largest and most complex among vertebrates.
The study is published in the August 20 issue of Science.
Brain size and complexity vary enormously across vertebrates, but it is not clear how these differences came about. Humans and frogs, for example, have been evolving separately for 350 million years and have very different brain abilities. Yet scientists have shown that they use a remarkably similar repertoire of genes to build organs in the body.
So how is it that a similar number of genes, that are also switched on or off in similar ways in diverse vertebrate species, generate a vast range of organ size and complexity?
The key lays in the process that Blencowe's group studies, known as alternative splicing (AS), whereby gene products are assembled into proteins, which are the building blocks of life. During AS, gene fragments -- called exons -- are shuffled to make different protein shapes. It's like LEGO, where some fragments can be missing from the final protein shape.
AS enables cells to make more than one protein from a single gene, so that the total number of different proteins in a cell greatly surpasses the number of available genes. A cell's ability to regulate protein diversity at any given time reflects its ability to take on different roles in the body. Blencowe's previous work showed that AS prevalence increases with vertebrate complexity. So although the genes that make bodies of vertebrates might be similar, the proteins they give rise to are far more diverse in animals such as mammals, than in birds and frogs.
And nowhere is AS more widespread than in the brain.
"We wanted to see if AS could drive morphological differences in the brains of different vertebrate species," says Serge Gueroussov, a graduate student in Blencowe's lab who is the lead author of the study. Gueroussov previously helped identify PTBP1 as a protein that takes on another form in mammals, in addition to the one common to all vertebrates. The second form of mammalian PTBP1 is shorter because a small fragment is omitted during AS and does not make it into the final protein shape.
Could this newly acquired, mammalian version of PTBP1 give clues to how our brains evolved?
PTBP1 is both a target and major regulator of AS. PTBP1's job in a cell is to stop it from becoming a neuron by holding off AS of hundreds of other gene products.
Gueroussov showed that in mammalian cells, the presence of the second, shorter version of PTBP1 unleashes a cascade of AS events, tipping the scales of protein balance so that a cell becomes a neuron.
What's more, when Gueroussov engineered chicken cells to make the shorter, mammalian-like, PTBP1, this triggered AS events that are found in mammals.
"One interesting implication of our work is that this particular switch between the two versions of PTBP1 could have affected the timing of when neurons are made in the embryo in a way that creates differences in morphological complexity and brain size," says Blencowe, who is also a professor in the Department of Molecular Genetics.
Read more at Science Daily