Sep 13, 2014
That's the recommendation of a diverse group of researchers, in a paper published today in the online version of the journal Science. A majority of the nine authors on the paper have received funding from the National Science Foundation (NSF).
"Evolution isn't just about the past anymore, it's about the present and the future," said Scott Carroll, an evolutionary ecologist at University of California-Davis and one of the paper's authors. Addressing societal challenges--food security, emerging diseases, biodiversity loss--in a sustainable way is "going to require evolutionary thinking."
The paper reviews current uses of evolutionary biology and recommends specific ways the field can contribute to the international sustainable development goals (SDGs), now in development by the United Nations.
Evolutionary biology has "tremendous potential" to solve many of the issues highlighted in the SDGs, said Peter Søgaard Jørgensen, another Science author from the University of Copenhagen's Center for Macroecology, Evolution and Climate. The field accounts for how pests may adapt rapidly to our interventions and how vulnerable species struggle to adapt to global change. The authors even chose this release date to coincide with the upcoming meeting of the UN General Assembly, which starts September 24.
Their recommendations include gene therapies to treat disease, choosing drought-and-flood-resistant crop varieties and altering conservation strategies to protect land with high levels of genetic diversity.
"Many human-engineered solutions to societal problems have turned out to have a relatively short useful life because evolution finds ways around them," said George Gilchrist, program officer in NSF's Division of Environmental Biology, which funded many of the Science authors. "Carroll and colleagues propose turning the tables and using evolutionary processes to develop more robust and dynamic solutions."
Applied evolutionary biology just recently made the leap from an academic discipline to a more-practical one, spurred by an effort within the community to better synthesize and share research insights. And--above all--increasing environmental pressures.
"The fact that we're changing the world means that evolutionary processes are going to be affected," said Thomas Smith, of the Department of Ecology and Evolutionary Biology at the University of California, Los Angeles (UCLA) and another Science author. The question is, according to Smith: Do we want to be engaged in this change, or not?
The paper also serves as a platform for establishing a cross-disciplinary field of applied evolutionary biology, Carroll said, and a way to promote the field as a path to sustainable development solutions.
"Evolutionary biology touches on many elements of the life sciences, from medicine to conservation biology to agriculture," said Smith. "And unfortunately, there hasn't been an effort to unify across these fields."
This disconnect exists despite the use of evolutionary tactics in many disciplines: treating HIV with a cocktail of drugs, for example, to slow pathogen resistance. And the effects of evolution already swirl in the public consciousness--and spark debate. Think of the arguments for and against genetically modified crops, or warnings about the increasing price of combating drug resistance (which costs more than $20 billion in the U.S. each year, according to the nonprofit Alliance for Prudent Use of Antibiotics).
Seldom are these issues described in an evolutionary context, said Smith. "We're missing an opportunity to educate the public about the importance of evolutionary principles in our daily lives."
In conservation, evolutionary approaches are often disregarded because of the belief that evolution is beyond our ability to manage and too slow to be useful, according to a paper Smith co-authored in the journal Annual Review of Ecology, Evolution and Systematics (AREES).
That article, recently published online, also tackles applied evolution. It was co-authored by Carroll, University of Maine Biologist Michael Kinnison, Sharon Strauss--of the Department of Evolution and Ecology at University of California-Davis--and Trevon Fuller of UCLA's Tropical Research Institute. All are NSF-funded. Kinnison and Strauss are also co-authors on the Science paper.
Yet contemporary evolution--what scientists are observing now--happens on timescales of months to a few hundred years, and can influence conservation management outcomes, according to the AREES paper.
Considering the evolutionary potential and constraints of species is also essential to combat "evolutionary mismatch." This means the environment a species exists in, and the one it has evolved to exist in, no longer match.
Such disharmony can be "dire and costly," the authors write in Science, citing the increasingly sedentary lifestyles--and processed food diets--of modern humans. These lifestyles are linked with increasing rates of obesity, diabetes and cardiovascular disorders. Restoring our health requires greater physical activity and less refined carbohydrates: "Diets and activity levels closer to those of the past, to which we are better adapted," the Science paper said.
Read more at Science Daily
The results of the study were published in Nature Biotechnology in three separate research articles.
These results should provide assurance to patients, clinicians and the research community that genomic sequencing is accurate, says E. Aubrey Thompson, Ph.D., a professor of cancer biology at Mayo Clinic in Florida, one of three institutions that led the study. Dr. Thompson is a study co-author and member of the project leadership.
"It seems very likely that decisions about patient care are going to be influenced by genomic data, derived from sequencing both RNA and DNA from patient samples, and we now know the extent to which these sequence-based analyses can be relied upon within a given laboratory or from laboratory to laboratory," he says.
"That means that results of a patient's sample, from which clinical management decisions will likely be made, will be accurate worldwide," says Dr. Thompson.
RNA sequencing is being used with increasing frequency to characterize a growing array of conditions -- everything from prenatal birth defects to disorders of the elderly.
The other institutions involved in the study are the Beijing Genomic Institute and Weill Cornell Medical School. All three institutions have extensive experience in sequencing RNA and have helped develop novel analytical tools for interpreting the data.
The U.S. Food and Drug Administration (FDA) funded the research, given its need to understand the accuracy of such data submitted in applications for approval of new drugs, clinical applications and genomic diagnostic procedures, Dr. Thompson says.
The purpose of this project, known as Sequence Quality Control (SEQC), was to rigorously define both the scope and the sources of variation in RNA sequencing data.
Laboratory groups at the three leading institutions sequenced the same two RNA samples multiple times.
More than 1 billion nucleotides of sequencing data were generated by each site. The data were then analyzed under the direction of the FDA with the assistance of a large group of academic and industrial statisticians. The researchers also examined the current technologies and major biochemical methods of 30 RNA-sequencing labs and hundreds of researchers. The researchers also found that RNA can be accurately extracted and analyzed from severely degraded genetic samples, such as from tissue samples that have been stored for many years.
Read more at Science Daily
Sep 12, 2014
The female sculptures were found inside a mysterious burial mound in Amphipolis that dates from the time of Alexander the Great.
Carved in high relief of Thassos marble, the twin guards stand between two marble pillars supporting a beam.
On Saturday, the archeologists led by Katerina Peristeri could only see the figures as busts, wearing a sleeved tunic and boasting long, thick hair covering their shoulders.
Indeed, the sculptures were “buried” in the ground, sandwiched between two walls, one sealing the statues off and the other closing another chamber.
As the first wall and sandy soil covering the sculptures was removed, the sculptures appeared in full glory, revealing the continuity of their robes.
“Their drapes bear exceptionally crafted folds,” the culture ministry said.
The archaeologists also found part of the face of one figure which was missing (the face of the other was found mostly intact).
According to Peristeri’s team, the sculptures appear to slightly lift their chitons -- a sleeveless garment from the Archaic period -- with the corresponding hand.
At the same time, they determined that the alternate inner arms of the statues were not raised to support the superstructure, as with those described by the first century B.C. Roman architect Vitruvius.
“There are no indications of lead moldings or processing of the lower surface of the beam to justify such support,” the culture ministry said.
Read more at Discovery News
Dating to between 3,900 and 3,500 years old, the armor was buried without its owner at a depth of 5 feet near the Irtysh River in Omsk. Analysis is underway to determine what kind of animal bones were used for the protective outfit, but it was likely assembled with bones from elk, deer and horse.
"At the moment we can only fantasize — who dug it into the ground and for what purpose. Was it some ritual or sacrifice? We do not know yet," Yury Gerasimov of the Omsk branch of the Institute of Archaeology and Ethnography told The Siberian Times.
|A reconstruction of the Bronze Age bone armor.|
"Armor had great material value. There was no sense to dig it in the ground or hide it for a long time — because the fixings and the bones would be ruined," Gerasimov said.
The archaeological site is known for findings dating from the Early Neolithic to the Middle Ages.
During the Bronze Age, the region was inhabited by animal breeder members of the Krotov culture.
The armor, however, resembles artifacts from the Samus-Seyminskaya culture, whose members originated in the Altai Mountain, about 620 miles to the south east, and who later migrated to Omsk.
If this is the case, the bone outfit could have been a gift, an item obtained through trade, or a spoil of war.
Most likely it belonged to an elite warrior and would have offered protection from Bronze Age weapons such as bone and stone arrowheads, bronze knives, spears tipped with bronze, and bronze axes.
"It was more precious than life, because it saved life," Boris Konikov, curator of the excavations, said.
Read more at Discovery News
Now, scientists find this mystery can be solved by looking at two simple features of quasars — how quickly matter is getting fed into the quasars and the direction from which the quasars are seen.
Quasars are supermassive black holes up to billions of times the mass of the sun that live at the hearts of distant, massive galaxies. They release extraordinarily large amounts of light as they rip apart stars and gobble matter.
Past studies of quasars have found that the physical properties of the objects follow definite, regular trends — for instance, a quasar's size is linked with its mass. However, despite such trends, for some puzzling reason, quasars can vary greatly in appearance in visible and ultraviolet light.
To help solve this mystery, scientists examined the largest sample of quasar observations yet — data from more than 20,000 quasars captured by the Sloan Digital Sky Survey. The collaboration's statistical analyses revealed that the appearance of quasars could mostly be explained by two basic factors.
"Our work solves a two-decade-long mystery in quasar research," lead study author Yue Shen, an astronomer at the Carnegie Observatories in Pasadena, Calif.,told Space.com.
The first factor is the so-called Eddington ratio — the luminosity of a quasar compared with its mass. This ratio predicts how quickly matter is falling into a quasar, and was long suspected to play a major role in why quasars often varied in appearance.
The other factor is the direction from which astronomers look at a quasar, which influences how much they can see of the clouds of gas closest to the black hole. This fast-moving gas produces a broad range of wavelengths of light, greatly affecting a quasar's appearance, and these findings suggest that these clouds are arranged in a flattened disk, explaining why the direction from which they are seen can matter so much.
"Our findings have profound implications for quasar research," Shen said in a statement. "This simple unification scheme presents a pathway to better understand how supermassive black holes accrete matter and interplay with their environments."
Read more at Discovery News
|The naked mole rat’s teeth are situated outside of its lips, preventing the critter from eating dirt. Which is quite lucky—I’ve eaten dirt before. It’s nothing to write home about.|
You see, this nearly hairless critter, which is indeed a rodent but not technically a rat, is one of only two mammals on Earth that live in what are known as eusocial societies—think bee and ant colonies ruled by a queen, with multitudes of workers underneath. But instead of being born into royalty, female naked mole rats fight to the death to take the throne, using their enormous chompers to puncture the lungs and other vital organs of their foes.
For a queen, it’s an existence fraught with hazard. But for all of her subjects, there’s little to worry about. They live their entire lives underground, well beyond reach of predators. As such, their lifespans are ridiculously long for so tiny a creature: up to 30 years (if that doesn’t sound high to you, consider that British men in the Middle Ages had the same life expectancy, and probably did the same amount of toiling in mud). Oh, and it doesn’t hurt that they never get cancer. And that nice little trick, ladies and gentlemen, could one day teach us how to eradicate the disease from our own bodies.
Biologist Vera Gorbunova studies these creatures at the University of Rochester. She says naked mole rat societies, which can reach 300 individuals, are more like dictatorships than monarchies because anyone with the gumption can ascend the throne, even if she doesn’t have a fancy III or IV after her name. Any female can, in theory, depose the queen, and males can rise up to become one of just two or three allowed to breed with her. Most females are perfectly happy not ovulating, “but occasionally,” Gorbunova says, “especially if the queen is getting weak, either from a disease or for example she’s just given birth—then another female may start ovulating all of a sudden.”
|A good look at the many fine hairs that the naked mole rat uses to feel its way around its burrow. It’s hard to tell if this is a live or taxidermy specimen, which says a lot about the naked mole rat.|
Death matches and punctured lungs aside, Gorbunova insists naked mole rats are quite pleasant toward the humans in her lab, unlike typical lab rats, which “bite viciously when they’re upset.” But in the wild, naked mole rats from other colonies are less than welcome—to say the least. Just like in ant societies, each colony has soldiers that aggressively defend entrances to the burrow, snapping and maiming with their huge incisors.
Sometimes, though, they’ll make an exception for a certain kind of intruder: the disperser male. It’s pretty rare, but from time to time a male in a colony will start packing on fat, then up and wander out of the borrow in search of another colony. If he finds one that accepts him, he’ll usually become a breeder there. Scientists don’t understand the hormonal changes that trigger a male to leave, or why this makes evolutionary sense. The odds of surviving above ground are, after all, quite slim for a nearly blind creature with almost no fur to protect it from the elements, or the sharp teeth of predators for that matter.
The Nudie Medical Miracle
For all their eusocial weirdness (it’s seriously weird for a mammal, but equally weird for the ornery pistol shrimp, the only marine animal that forms such societies), naked mole rats belong to another extremely exclusive club in nature: Like the remarkable salamander known as the axolotl, they don’t develop cancer. Even if you pump them with carcinogens, nothing happens. Their secret, Gorbunova has found, is a starch called hyaluronan. Engineer a naked mole rat’s cells to stop producing this compound and suddenly a cancer-free critter is capable of developing tumors.
|Naked mole rats sleeping, photographed with a nice soap opera filter.|
But why would this evolve in the first place? It’s entirely uncommon in the rest of the animal kingdom. So what makes the naked mole rat different?
The answer could be its stretchy, pale, flabby skin—and another burrowing mammal called the blind mole rat (which, by the way, has found its eyes to be so useless that they’re now completely covered over with skin and fur). Despite their names, these creatures are unrelated, but blind mole rats also are long-lived, call the underground their home, and don’t get cancer. “And when we took their cells they also make very long molecules of hyaluronan,” said Gorbunova. “So how come these species are not related at all, but they independently both evolved this unusual molecule?”
|Blind mole rats have lost their eyes entirely, and therefore never need to worry about getting red eyes in photographs like this one.|
And that is very interesting indeed to cancer researchers. There is still much work to be done on understanding hyaluronan, not to mention figuring out how to develop drugs to exploit it, “but I think there is a very good potential here,” said Gorbunova. “Because if we find a way … to increase levels of hyaluronan in human bodies, we may be able to stop tumors from growing.” Consider families with high hereditary cancer expectancy: Doctors might one day use hyaluronan to stop their tumors from growing in the first place.
Read more at Wired Science
Sep 11, 2014
These are the stories forever linked with the September 11, 2001, terror attacks in New York, Washington and western Pennsylvania.
In some cases, they are tales of ordinary people caught in extraordinary circumstances -- people who became symbols of comfort and hope for a grieving nation.
Then there were those who were behind the attacks, people who have become the emblem of evil.
On the 13th anniversary of the attacks, here is a look at some of those people -- then and now:
Lisa Jefferson, the voice
Hers was the voice on the other end of the line for Todd Beamer, the passenger aboard United Flight 93 whose last purported words -- "let's roll" -- became a rallying cry for the nation in the days following the terror attacks.
It was 9:45 a.m., when Beamer placed a call to an operator at a Verizon Airfone call center in Chicago and relayed that the airplane bound for San Francisco had been hijacked. The operator turned the call over to Jefferson, the supervisor on duty.
Beamer was calm as he detailed how three men had taken over the flight. Two had knives and had locked themselves in the cockpit, and one had a bomb strapped to his waist.
He told Jefferson about his children and his wife, Lisa.
"I had asked him, did he want me to place his call through to his wife for him. He told me that he didn't want me to put him through to her in case he didn't have to. He had hoped on landing that plane safely. And he told me if I didn't make it, would I please call her and let her know how much he loved her and his family," she told CNN in 2002.
"... After we said 'The Lord's Prayer,' the plane took another dive. And Todd said they had a plan. The next thing he said, 'Are you ready? OK, let's roll,'" she told CNN in 2001.
"And that's the last I heard from him.''
In the days that followed, she relayed Beamer's message to his wife.
Jefferson, 57, no longer answers telephone calls at the call center. She's changed jobs.
Most of her colleagues now don't know that she was the calm, caring voice who prayed with Beamer in his final minutes.
Sure, she's talked about it in the years since. At the urging of others, she even told her story in the book "Called: Hello, My Name is Mrs. Jefferson, I Understand Your Plane is Being Hijacked?"
The story of that conversation has been told and retold -- in books and articles, in movies and television shows.
But during a recent interview, Jefferson asked that no details about her current job or employer be made public.
"Every time I tell the story, it's like the first time," she said. "... I'm not a hero. I was just doing my job."
That day, after she took over the call, she said she turned around to hand off the phone to someone else. But, she says, there was no one there.
"I had to stay on the line," she said. "I stayed with him until the end."
She has credited her faith with giving her the strength to offer comfort and care during that 15-minute call.
"God had a purpose for me with the Beamer family," she said.
Josephine Harris, the angel
Her story of survival is wrapped up with six firefighters who say they made it through the collapse of the World Trade Center's North Tower because they were trying to rescue her.
Harris, like so many, was trying to make her way down the stairwell of the North Tower.
Flight after flight, she descended. She stopped on the 20th floor, physically unable to take another step on her own.
The firefighters of Ladder Company 6 were on the 27th floor or so of the building and still climbing when then-Capt. Jay Jonas got a call on the radio that the South Tower had collapsed and he needed to get his men out of the North Tower.
"It was an almost empty feeling that we couldn't help anyone," Jonas, now a deputy chief, said this week.
As they were making their way down the stairwell, they found Harris. There she was, crying in the doorway, Jonas said.
"Hey Cap, what do you want us to do?" one of the firefighters asked. "Take her with us," Jonas said.
Half-carrying Harris, the firefighters continued to make their way down, slowly.
The clock was ticking.
By the time they made it to the fourth floor, Harris fell to the ground.
Leave me, she ordered the firefighters. They, of course, refused.
Then it happened. The 110-story building collapsed.
"It seemed like forever," Jonas said. It was only 13 seconds.
When it was over, Harris and the men of Ladder 6 were alive, entombed in the debris.
"There was only one time she lost her composure," Jonas said. "She said she was afraid, and she started to cry."
Without orders from the captain, the firefighters took turns caring for Harris until hours later when the thick dust settled and they were able to see a way to get out and get help.
"She was definitely alive because of us," Jonas said.
And they were alive because of her.
"She chose the fourth floor to stop, to fall to the floor," he said. "... Nobody survived above the fifth floor or on the first floor. If we hadn't stopped there, who knows? We probably wouldn't have survived."
In the years that followed, Harris became known at the "Angel of Ladder Company 6," and she and the firefighters stayed in contact.
Their story resonated with many people post-September 11, and they made appearances together at parades and dedications.
"If Josephine got a call to do an interview or an appearance, she would always call and make sure we were OK with it," Jonas said. "We would always tell her yes, and we'll be there with you."
On Jan. 12, 2011, Harris called 911 from her Brooklyn apartment.
By the time firefighters arrived, she had died of an apparent heart attack.
Jonas got the news in a telephone call from a firefighter. "It was like losing a member of your family, and she really was a member of the (Ladder 6) family," he said.
What neither he nor the other firefighters knew was that Harris was destitute. "She was an intensely private person," Jonas said.
For days, her body lay uncollected at the city morgue. Her family didn't have enough money to bury her.
"I thought 'Man, she's going to Potter's Field, if we don't do something," Jonas said.
So he got on the phone to the other firefighters, and they started to spread the word across the city.
They were soon contacted by the owner of Greenwich Village Funeral Home, who had heard of Harris' death. He remembered the story of the "guardian angel" of Ladder 6 and offered to pick up the entire cost of the service.
Jonas and the firefighters carried Harris one last time. They served as pallbearers, carrying her casket engraved with the words "guardian angel.''
George Johnson, Daniel McWilliams and William Eisengrein, the firefighters
It was late afternoon, hours after the attacks, and the three firefighters joined the rush to what would become known as ground zero.
Eisengrein was sitting on his truck when he saw McWilliams carrying an American flag, he told ABCNews.com in 2011. Walking alongside McWilliams was another firefighter, Johnson.
Eisengrein knew McWilliams but had never met Johnson.
It is believed McWilliams found the flag from a yacht, "Star of America," docked nearby on the Hudson River, according to the CNN documentary "The Flag."
Eisengrein told ABC News he just knew McWilliams was going to hang it somewhere, and shouted out to him: "Do you need help?"
The three men found a flagpole leaning against a construction trailer, he said.
"So we put a piece of tin on the ground up to the trailer and hiked up that, and raised it," Eisengrein said.
"... We stood there and looked at it for a second and went about our ways."
None of them knew that their picture had been taken by Tom Franklin, a photographer with The Record in Bergen County, New Jersey.
Soon the picture was picked up by The Associated Press and splashed across newspaper front pages, becoming one of the iconic images associated with September 11.
Much has been made about the flag, and its whereabouts.
Within hours of its raising, the flag disappeared from the World Trade Center site.
The makers of "The Flag" spoke with several photographers about going to ground zero and the heartbreaking scenes that awaited.
Among those interviewed was the couple who owned the yacht from which the flag was taken.
The couple wanted to donate the flag to the Smithsonian Institution and asked about a year after the attacks to borrow the signed flag briefly for a ceremony.
"When we got the flag, we were quite stunned that it was the wrong flag," said Shirley Dreifus. "... This wraps around the two of us, and we're not the thinnest people on Earth ... So we knew right away it was the wrong flag."
While the search for the flag continues, Johnson, McWilliams and Eisengrein rarely talk publicly about that day and the flag. They have routinely declined media requests for interviews over the years.
The firefighters "in question have repeatedly expressed no interest in interviews or additional media coverage," the FDNY said in an email response to a CNN request this week.
Maybe we know all we need to know about the three men: They did their job, and they reminded everyone by raising the flag that the country was still standing.
Rudy Giuliani, the mayor
Giuliani was in the final days of his second term as mayor when an airplane crashed into the World Trade Center's North Tower. Giuliani was at the World Trade Center, getting an update on the rescue effort, when a second plane struck the South Tower.
The mayor, like many that day, was forced to run for his life when the tower came down.
He was engulfed in a cloud of debris, but famously kept his composure.
"This is a vicious, unprovoked act, a horrible attack on innocent men, women and children. It's one of the most heinous acts, certainly, in world history," he told CNN that day.
As New York mourned the loss of thousands of lives and cleaned up the debris, Giuliani seemed to be everywhere -- holding news conferences, giving interviews and attending funerals and fundraisers.
In the aftermath of the attacks, he earned the moniker "America's mayor" for the comfort he offered not only to city of more than 8 million, but to a shell-shocked nation.
Giuliani's popularity soared, spurring him to make a bid for the Republican presidential nomination in 2008.
But his campaign stumbled, badly.
Giuliani skipped the early primary states, staking his bid on a win in Florida. He finished third and pulled out of the campaign.
He quickly reinvented himself as a political pundit, becoming a regular on television news programs.
These days, the former mayor balances running Giuliani Partners, a security consulting firm, and working as a managing partner in the Bracewell & Giuliani law firm.
He even did a stint as a pitchman for LifeLock, the identify theft protection company. The company was a client of Giuliani Partners, he has said.
Even now, more than a decade later, the events of September 11 are never far from his thoughts.
"I think the most difficult moment I had as mayor of New York City was when I arrived at the World Trade Center," Giuliani said during a 2013 interview on "Oprah: Where Are They Now."
"Not really knowing how bad it was, not really emotionally grasping all of that until I saw a man throw himself out of the 100th floor. And that's an image -- that's an image that stayed with me forever, almost every day it comes up in my mind somehow. And then, after that, I just decided well, it's part of me and I have to live with it."
Read more at CNN
Sep 10, 2014
The fossils, described in the latest issue of the journal Nature, belonged to three newly named mammals that lived 160 million years ago in China.
Given the animals' relationship to other early known species, researchers now believe that mammals as a whole originated at least 208 million years ago during the Triassic. This corresponds with some other studies that used DNA data.
Most prior studies based on the fossil record, however, previously concluded that mammals originated during the middle Jurassic, between 176 and 161 million years ago.
"For decades, scientists have been debating whether the extinct group, called Haramiyida, belongs within or outside of Mammalia," co-author Jin Meng, a curator in the American Museum of Natural History's Division of Paleontology, said in a press release.
"Previously, everything we knew about these animals was based on fragmented jaws and isolated teeth," he continued. "But the new specimens we discovered are extremely well preserved. And based on these fossils, we now have a good idea of what these animals really looked like, which confirms that they are, indeed, mammals."
The three new species -- Shenshou lui,Xianshou linglong and Xianshou songae -- weighed only 1 to 10 ounces and had tails and feet that indicate they were tree dwellers. If you saw one in a tree today, you’d probably mistake it for a squirrel.
"They were good climbers and probably spent more time than squirrels in trees," Meng said. "Their hands and feet were adapted for holding branches, but not good for running on the ground."
They, and other members of their clade Euharamiyida, likely ate insects, nuts, and fruit with what the researchers say were "strange" teeth. Their teeth had many cusps, or raised points, on the crowns.
Mammals are thought to have evolved from a common ancestor that had three cusps; human molars can have up to five. The newly discovered species, however, had two parallel rows of cusps on each molar, with up to seven cusps on each side. No one knows yet how this complex tooth pattern evolved in relation to those of other mammals.
Read more at Discovery News
The desert is a haven for marine fossil hunters — paleontologists have found whales with fossilized baleen, a giant raptorial sperm whale and a dolphin that resembles a walrus, researchers say.
The new findings include the fossils of three dolphins, two of which have well-preserved skulls. A thorough skeletal analysis suggests the dolphins are not only a new species but also related to the endangered South Asian river dolphins living in the Indus and Ganges rivers in India today, the researchers found.
"The quality of the fossils places these specimens as some of the best-preserved members of this rare family," lead study author Olivier Lambert, of the Institut Royal des Sciences Naturelles de Belgique, said in a statement.
River dolphins are an unusual breed. Unlike other dolphins, they live in muddy freshwater rivers and estuaries, and they have a long, narrow, toothy beak and small eyes with poor vision, said Jonathan Geisler, an associate professor of anatomy at the New York Institute of Technology, who was not involved in the study.
The three fossils do not appear to be ancestors of other river dolphins, including those of the Amazon or the Yangtze rivers, the latter of which may be extinct, said John Gatesy, an associate professor of biology at University of California, Riverside, who was not involved in the study.
"They're three of a kind," Gatesy said. "Three independent lineages."
Researchers have long tried to determine how river dolphins fit into the family tree. "It's not normal for a whale or a dolphin to live in freshwater these days," Gatesy said. "What seems to have happened is they've independently adapted to living in freshwater conditions."
The new findings help answer that question, at least for the South Asian river dolphins, experts say.
"It's helping flesh out this pretty poorly known extinct family that helps tie this oddball living species into the evolutionary tree," Geisler said.
Researchers have uncovered other squalodelphinid specimens in Argentina, France, Italy and on the East Coast of the United States, but fossils of these medium-size dolphins are still rare. The modern families of tooth whales, porpoises and dolphins diverged in the early Miocene epoch, about 20 million to 24 million years ago, making any marine fossils from that time period valuable, Geisler said.
The new, extinct species was named Huaridelphis raimondii, after the ancient Huari culture of the south-central Andes and coastal area of Peru that existed from A.D. 500 to 1000, and "delphis," which is Latin for dolphin. The species name celebrates Italian scientist Antonio Raimondi (1826-1890), who found fossils of whales in Peru, the study reports.
Read more at Discovery News
During studies of photographs taken by NASA’s Galileo spacecraft that orbited the gas giant from 1995 to 2003, planetary geologists have found it hard to explain why most of the crust was relatively new ice (on average, the icy surface is 40-90 million years old) and yet there was little evidence of old ice that had been crushed up on the surface to make way for the new material.
“We have been puzzled for years as to how all this new terrain could be formed, but we couldn’t figure out how it was accommodated,” said Louise Prockter, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “We finally think we’ve found the answer.”
Prockter and co-investigator Simon Kattenhorn, of the University of Idaho, Moscow, were able to seek out some curious features in the Galileo imagery that may explain what is going on. Their research was published Sunday in the journal Nature Geoscience.
Their conclusion is that, like Earth’s rocky crust, there must be subduction zones where old material is pushed against plate boundaries, making the ice sink into the subsurface ocean, where it melts and gets cycled.
On Earth, subduction zones are associated with mountain ranges, volcanoes and earthquakes — e.g. the Andean Volcanic Belt that stretches down the west coastal region of South America where the Nazca Plate and Antarctic Plate is continually being subducted under the South American Plate. One plate edge is pushed under a neighboring plate, causing the rock to be melted by the Earth’s interior and recycled. The motion of the two plates rubbing along one another triggers quakes and provides energy for volcanic eruptions.
Like the Earth example, the researchers discovered features that provide evidence for subduction zones on Europa, including subsumption bands (where the ice gets bunched up, much like a mountain range) and “ice volcanoes” (where melt-water from the diving ice plate is forced to the surface to create “cryolava”):
By carefully reconstructing the configuration of Europa’s plates, Kattenhorn and Prockter were able to determine that the old ice was being forced under neighboring plates, causing it to dive deep into the crustal ice below or even completely entering the subsurface ocean.
“Europa may be more Earth-like than we imagined, if it has a global plate tectonic system,” said Kattenhorn. “Not only does this discovery make it one of the most geologically interesting bodies in the solar system, it also implies two-way communication between the exterior and interior — a way to move material from the surface into the ocean — a process which has significant implications for Europa’s potential as a habitable world.”
Read more at Discovery News
Some of these beasts, though, are more grounded in reality than others. And none of these are more famed or feared or strangely real than the kraken, also known somewhat awesomely in lore as the “sea-mischief,” a legendary tentacled giant so powerful that it could pull down ships. Cross this monster and you’ll find yourself praying there’s a sea bishop or two in the depths to attend to your corpse.
This is a decidedly Nordic tale, contrary to the supposed rampages of the kraken around Greece in 1981’s awesome film Clash of the Titans and its recent remake that should have been loaded onto a ship and sunk to the bottom of the ocean while it was still just a script. The kraken, however, is many beasts in one, a perfectly terrifying amalgamation of the worst sea monsters humanity has ever dreamed up.
|An illustration from Victor Hugo’s novel Les Travailleurs de la Mer shows a man named Gilliatt battling a giant octopus.|
You’ll know when you start reeling in an inordinate amount of fish. It’s the kraken, you see, that’s scaring them toward the surface. But escaping from its clutches is not impossible. Accomplished rowers can hightail it out of there, and when they “find themselves out of danger, they lie upon their oars,” and after a few minutes “they see this enormous monster come up to the surface of the water.” Its back is a mile and a half in circumference, and “looks at first like a number of small islands.” This is an echo of another mythical sea critter: the island whale, a beast so huge that sailors mistake it for land and anchor to it. Once they build a fire on its back, though, it heaves up and drags them all to their doom.
|A rather more fanciful kraken from Olaus Magnus’ Carta Marina, a masterful Scandinavian map from the 16th century. For more info, check out Joseph Nigg’s Sea Monsters: A Voyage Around the World’s Most Beguiling Map. It’s seriously excellent.|
|The crew of the Nautilus battles a giant squid in Jules Verne’s 20,000 Leagues Under the Sea. That guy is in serious trouble, but someone should really get those birds some medical attention. They look unwell.|
The kraken, though, is happy to make do just eating fish. Pontoppidan notes that it has a “strong and peculiar scent, which it can emit at certain times, and by means of which it beguiles and draws other Fish to come in heaps about it.” And, appropriately enough, it uses the fish it has devoured to lure even more fish by … using its poo as a lure. A “great many old fishermen,” Pontoppidan claims, say that its “evacuation” colors the surface of the water, which “appears quite thick and turbid.” He explains in rather colorful detail: “This muddiness is said to be so very agreeable to the smell or taste of other Fishes, or to both, that they gather together from all parts to it, and keep for that purpose directly over the Kraken: He then opens his arms, or horns, seizes and swallows his welcome guests, and converts them, after the due time, by digestion, into a bait for other Fish of the same kind.” Ah, the circle of life.
|A giant squid popsicle at the Melbourne Aquarium.|
These muddied waters are a glaring clue as to the real-life inspirations for the kraken, which is based, as you might have guessed by this point, on sightings of the giant squid, which can grow to an astounding 43 feet long. Such a creature is in no way capable of totally mucking up the waters around it with poop, but it certainly is with a blast of ink. Almost all cephalopods, a family that in addition to squid contains octopuses and cuttlefish, will ink in self-defense if, say, hauled up by fishermen. Some species will quite cleverly also deploy mucus with the ink to create pseudomorphs, false bodies that distract would-be predators.
Though no one has seen it first-hand, scientists speculate that the giant squid hunts by hanging motionless in the water column, with the tip of its mantle pointed up and its two long tentacles dangling below (all of its other much shorter tentacles aren’t actually tentacles, they’re referred to as arms). Here it simply waits for fish or other squid to meander into its grasp of suction cups, which are lined with tiny teeth. The giant squid then reels its prey to the beak that is its mouth—and to a pretty horrible death by being slowly pecked away, mouthful by mouthful.
|The first-ever image of a living adult giant squid.|
There is a squid, though, that makes the giant squid look downright cuddly. Stalking the waters of Antarctica is the colossal squid (let’s hope they don’t find an even bigger species, because we’re kinda running out of adjectives), which while measuring about the same length as the giant squid, has a far more robust mantle. Oh, and also swiveling hooks on its suction cups instead of serrated edges. Swiveling hooks. But—and I hate to disappoint you here—the colossal squid is probably extremely lackadaisical, by one estimate using up to 600 times less energy than similarly sized predators. Like the giant squid, it likely sits in wait for prey instead of running them down.
Read more at Wired Science
Sep 9, 2014
A team of four mathematicians and a biologist from the US have shown that the creatures' technique is highly efficient and is hard-wired in a simple neural circuit.
The work is one of only a few examples where a neural circuit underlying a particular behaviour has been understood, the authors write in Proceedings of the National Academy of Sciences.
Crayfish (including yabbies), prawns, lobsters and other crustaceans swim using a Mexican wave-style motion of four or five pairs of small paddle-like limbs called 'swimmerets', explains lead author and mathematician Professor Timothy Lewis of the University of California, Davis.
Each paddle does a 'power stoke', which pushes water backwards, followed by a 'recovery stroke', in which the paddle is pulled forwards (in a curled position to reduce drag), ready for the cycle to start again.
The paddles can be moved quickly. "The frequency can vary from less than one stroke per second to as much as ten strokes per second," says Professor Brian Mulloney, the biologist on the team.
Surprisingly, the Mexican-wave starts at the paddles farthest back on the abdomen and travels towards the head of the crayfish. The wave occurs because each pair of paddles starts their 'power stroke' a quarter of a cycle later than the pair of paddles behind them.
Using computer modelling of fluid flow, the team examined three ways a crayfish might swim: moving its paddles in unison; a Mexican wave travelling from head-to-tail; and a Mexican wave travelling from tail-to-head (as actually occurs).
"When I first started thinking about it, I thought the head-to-tail one would be the one with most mechanical advantage, but the modelling showed that wasn't true," says Lewis.
The researchers found the tail-to-head Mexican wave was 30 per cent more efficient than moving the paddles in unison and between 300 per cent and 550 per cent more efficient than a head-to-tail wave.
Having found that crustaceans swim very efficiently, Mulloney dissected out the crayfish neural circuit that is known to control the swimming movements and then he and colleagues used mathematics to analyse the circuit.
In the circuit, each paddle is controlled by a pair of nerve cells that mutually inhibit each other, explains Mulloney. One neurone controls the power stroke and the other the return stroke. The result, he says, is a rhythmic pulse, rather like a metronome, which keeps switching the paddle between power and recovery strokes.
Since there are four or five pairs of paddles (depending on the crustacean), you can think of the complete neural circuit "as four or five pairs of metronomes," says Mulloney.
The Mexican wave happens because each pair of metronomes controlling a pair of paddles is wired to the metronomes of the next paddles along - in a very specific and asymmetrical way.
The mathematics showed that this asymmetrical wiring was ideally suited to stabilising the quarter cycle delay in the timing of adjacent paddle pairs that makes the Mexican wave.
Read more at Discovery News
The 3,000-year-old bowl became an object of fascination once word got to the press. The next year, it graced the pages of Life magazine in a full-color spread alongside an article about the discoveries at Hasanlu.
But the story behind the prized find is less glossy. The bowl was uncovered just beyond the fingertips of a dead soldier and two of his comrades, who were crushed under bricks and burned building material around 800 B.C. Scholars have debated whether these three men were defenders of the citadel or enemy invaders running off with looted treasures. A new interpretation suggests the soldiers were no heroes.
Hasanlu is sometimes described as the Pompeii of the ancient Near East, because of its so-called "burn layer," which contains more than 200 bodies preserved in ash and rubble, explained Michael Danti, an archaeologist at Boston University. The archaeological evidence provides a rather disturbing snapshot of the closing hours of the siege of the citadel.
Located on the shores of Lake Urmia, Hasanlu seems to have been first occupied about 8,000 years ago. But by the ninth or 10th century B.C., there was a bustling, fortified town at the site.
Within the town's walls were houses, treasuries, horse stables, military arsenals and temples, many of which had towers or multiple stories. The mudbrick architecture likely resembled the adobe buildings of the American Southwest, but many roofs, floors and structural supports at Hasanlu consisted of timber and reed matting — all of which would have been tinder in a blaze, Danti said.
Other central details about life at Hasanlu are less clear. Archaeologists don't know the ethnicity of the people who lived there or what language they spoke.
"Despite the really rich material record, they didn't really find any indigenous writing at all," Danti said.
The burn layer at Hasanlu suggests a surprise attack destroyed the citadel. Archaeologists who excavated the site in the 1950s, '60s and '70s found corpses that were beheaded and others that were missing hands. Danti said he has seen a fairly clear example of a person who was cut in half.
"The students that were working there would have nightmares at night, because they were spending hours and hours out there excavating murder victims," Danti told Live Science. Many of the victims were women and children. And in mass graves on top of the burned layer, excavators found the remains of people who tended to be very young or old and seemed to have suffered fatal, blunt-force trauma head wounds. These victims likely survived the initial attack only to be killed when their captors realized they would be of little use as slaves, Danti said.
"This was warfare that was designed to wipe out people's identity and terrify people into submission," Danti said.
Danti, who has been piecing together a history of the site from excavation archives as part of a larger, more daunting project, published a study on Hasanlu in the September 2014 issue of the journal Antiquity. The site was primarily excavated between 1956 and 1977 under the direction of Robert H. Dyson, who led a team from the University of Pennsylvania, the Metropolitan Museum of Art in New York and the Archaeological Service of Iran. Because of security pressures and the overwhelming amount of material found at the site, the pace of their work was often hurried, and their record-keeping methods were not always meticulous. Some artifacts were pulled from the ground before they were documented or photographed in situ. There are no photographs of the gold bowl before it was taken out of the ground, for example.
In revisiting Hasanlu, Danti has taken a closer look at the three warriors. He said it seems likely they were climbing up a wooden staircase inside of a home when the building collapsed. The men fell through what was probably a waste-disposal chute and were buried by debris. Besides the gold bowl, there are other treasures scattered around their bodies, including textiles, fancy armored belts, metal vessels and delicately carved cylinder seals.
The outfits and weapons of the warriors look like standardized military equipment, Danti said. The men wore crested helmets with earflaps, and they carried spiked maces. They appear to have been well-prepared for battle.
"I doubt these men were rescuing a valued bowl and many other fine objects with little hope of egress as the citadel burned and its remaining occupants were slaughtered or taken captive," Danti wrote in his conclusion.
Read more at Discovery News
The news was reported in the Daily Mail, and a piece on Discovery News noted that “Molecular biologist Dr. Jari Louhelainen tells the Mail on Sunday that he used a technique called ‘vacuuming’ to remove DNA from a stained shawl purportedly belonging to one of the victims, Catherine Eddowes. Businessman Russell Edwards had bought the shawl at an auction in 2007, and had asked Louhelainen to help him find any clues that may be connected with the Ripper case.”
There is of course a book deal in the works for Edwards, and these “revelations” have been met with skepticism for many reasons, including the fact that the shawl that provided the DNA implicating Kosminski has a dubious provenance — there’s no clear or proven connection between the shawl and Ripper victim Eddowes. It might have been hers found at the crime scene, or it might not. Even if it was hers, it might have Jack the Ripper’s blood on it — or it might not. A study published in a peer-reviewed science journal would bolster its credibility.
Still, if the case seems compelling to you, there’s a good reason why, and it has less to do with the evidence than psychology. Dozens of books have been written, each claiming to reveal the true identity of Jack the Ripper and offering what seems to be strong evidence for their suspect. The problem is that most of them point the finger at different people. Each writer selectively chooses what evidence to present that supports their suspect, and ignores or dismisses evidence to the contrary.
This isn’t an attempt to cover anything up, but instead a common and powerful psychological phenomenon called confirmation bias. When it comes to researching information, we tend to seek out information that supports our beliefs and assumptions. Psychologist Thomas Gilovich, in his book “How We Know What Isn’t So: The Fallibility of Reason in Everyday Life,” notes:
“When examining evidence relevant to a given belief, people are inclined to see what they expect to see, and conclude what they expect to conclude. Information that is consistent with our pre-existing beliefs is often accepted as face value, whereas evidence the contradicts them is critically scrutinized and discounted.”
In legal terms, writers and researchers are acting as prosecutors, presenting evidence that their favored suspect is guilty. But there’s no real defense, since the person being identified as the Ripper is long dead and no one is doing an equal amount of research trying to prove that the suspect is innocent (aside, perhaps, from a token effort by rival authors who have their own agendas). When you only hear one side of the story of course it’s convincing — until you read the next book or see the next Ripper-based movie.
Edwards’s DNA identification of Kosminski may seem very compelling — until, for example, you read the 400-page, 1998 book “Prisoner 1167: The Madman Who Was Jack the Ripper,” which builds a convincing case that a man named James Kelly was the infamous killer. Kelly was an upholsterer who killed his wife by cutting her throat, and who was then committed to a mental institution, escaping just before the Ripper’s bloody spree started.
The evidence laid out seems persuasive — but then again so did the two-part TV miniseries that aired a decade earlier titled “Jack the Ripper,” starring Michael Caine. The series began with a based-on-a-true-story tone assuring viewers that the Ripper had finally been unmasked: “Our story is based on extensive research, including a review of the official files by special permission of the Home Office and interviews with leading criminologists and Scotland Yard officials.”
This time the evidence suggested that the killer was Sir William Gull, Royal Surgeon to Queen Victoria, whose crimes were covered up in a conspiracy of silence.
Yet the implication of Gull as the Ripper had been made decades earlier by several writers, including Stephen Knight, author of the now-discredited 1976 book “Jack the Ripper: The Final Solution.” Despite such bold claims and breathless titles, many researchers doubt that Gull was involved.
Given the exhaustive research brought to bear on the Ripper killings, it’s virtually certain that Jack the Ripper has already been identified. Over a hundred people have, at one time or another — and with wildly varying degrees of evidence and certitude — been implicated as Jack the Ripper.
At this point, over 125 years after the murders, it’s unlikely that any new, credible suspects will be added to the list. Ripperologists, as they call themselves, have identified about a dozen or so most likely suspects, and most “new” revelations and evidence is simply additional support for one of those previously identified.
Read more at Discovery News
This discovery centers around the gas giant’s F-ring where, over the course of 30 years, has dramatically changed its morphology.
“The F ring is a narrow, lumpy feature made entirely of water ice that lies just outside the broad, luminous rings A, B, and C,” said Robert French of the SETI Institute, at Mountain View, Calif., in a news release “It has bright spots. But it has fundamentally changed its appearance since the time of Voyager. Today, there are fewer of the very bright lumps.”
French and co-investigator Mark Showalter (also from the SETI Institute) studied photographs of the F-ring taken by NASA’s twin Voyager spacecraft when they encountered the ringed planet in the early 1980s. On comparison with photographs from NASA’s Cassini spacecraft that is currently in orbit around Saturn, the F-ring has changed appearance extensively.
Further investigations revealed that bright lumps in the ring come and go over periods of only hours or days — features that the researchers believe are small moons.
“We believe the most luminous knots occur when tiny moons, no bigger than a large mountain, collide with the densest part of the ring,” said French. “These moons are small enough to coalesce and then break apart in short order.”
The researchers believe the F-ring’s surprising dynamic behavior is down to its special location. This particular ring occupies a region of tidal chaos called the “Roche limit” — a distance from a gravitational body (a planet) below which the tidal forces are too strong for moons to form. Beyond the Roche limit, moons can readily coalesce, overcoming powerful tidal forces. The F-ring is located right at this boundary, so moonlets (no bigger than 3 miles wide) that coalesce are inherently unstable and may succumb to the rough tides.
Adding to the complexity of this region is Saturn’s innermost moon Prometheus, a 60 mile-wide moon that patrols the outer edge of the F-ring once every 17 years. Prometheus’ weak gravitational field aligns with the ring in such a way that it can stabilize the region, catalyzing moonlet formation.
Read more at Discovery News
Sep 8, 2014
As demonstrated in a series of experiments published today in Current Biology, coral trout not only solicit the help of moray eels when they hunt, but also pick their hunting partners wisely. They know when they need help, and quickly learn which eels best provide it. It’s a seemingly simple yet surprisingly sophisticated cognitive trick.
“Prior to our study, chimpanzees an humans were the only species known to possess both of these abilities,” said zoologist Alex Vail of England’s University of Cambridge. “I think the evidence is mounting that fish have more going on in their heads in terms of cognition than they have been given credit for.”
In earlier research, Vail and colleagues observed that coral groupers and coral trout—two closely-related species of large, reef-dwelling predatory fish found in the Indian and western Pacific oceans—used their bodies to point moray eels at prey hiding in otherwise inaccessible seabed holes. The eels followed directions, flushing prey from the holes and giving groupers an easy meal.
In the cognitive argot, this appeared to be evidence of referential communication: groupers didn’t merely express an emotional state or some straightforward want, as with a mating display. Rather, their gestures referred to an external object, and seemed to display conscious intent. It was not the behavior of a stimulus-response machine.
It was an exciting finding. In recent years, even as scientific journals burst with studies of clever crows and empathic rats and tool-using dolphins, fish remained at the back of the class. Yet that may say more about our own assumptions than anything else. Fish have been around for more than 500 million years, and have as much evolutionary incentive as other creatures to smarten up.
In the new study, Vail and his colleagues, fellow Cambridge zoologist Andrea Manica and biologist Redouan Bshary of Switzerland’s University of Neuchatel, decided to give coral trout an especially challenging test, adapting an experiment originally conducted with chimpanzees.
That experiment, published to widespread scientific acclaim in 2006, involved one chimp freeing another from a cage in order to jointly tug on a rope, thus releasing food that couldn’t be reached by a single chimp’s efforts. Chimps figured out when they needed help and learned which other chimps best provided it—aptitudes that until then had been considered uniquely human.
'Coming years will see the discovery of a lot more surprising cognitive abilities.'
In the new experiment, the scientists placed coral trout in an aquarium containing a plastic moray model and a frozen baitfish. Fishing lines attached to the eel and baitfish allowed researchers to control them and mimic the movements of a real-world hunt. Sometimes the bait was placed under a container, forcing the coral trout to enlist the moray’s assistance in chasing it out.
Just like the chimps, coral trout at first sought the moray’s help indiscriminately, but within a day learned to ask for help only when necessary. Then, in a second experiment, the researchers put two moray models in the aquarium: one was controlled so as to be an efficient prey-chaser, the other less so. Again, within a day, trout learned to seek help from the more helpful eel.
“Our study strengthens the case that a relatively small brain (compared to warm-blooded species) does not preclude at least some fish species from possessing cognitive abilities that compare to or surpass those of apes,” wrote Vail and colleagues.
Brian Hare, a Duke University evolutionary anthropologist who worked on the original chimpanzee study, called the new findings “exciting.” The fish indeed appear to be collaborating in a manner “similar to what we see in apes,” said Hare, a result which challenges the notion “that only animals that look like us can be smart.”
Vail and colleagues do caution that they don’t know exactly what’s happening in the coral trout’s minds. They might be thinking along the same lines we do when cooperating. It’s also possible that they achieve the same result through a very different thought process.
Read more at Wired Science
This new dinosaur, Rukwatitan bisepultus, as well as most other extremely large dinosaurs, are titanosaurs. These were big-bodied, four-legged plant eaters that thrived during the final period of the dinosaur age.
Thirty titanosaur species have been found in South America compared to just four in Africa, making this discovery all the more noteworthy.
“Much of what we know regarding titanosaurian evolutionary history stems from numerous discoveries in South America — a continent that underwent a steady separation from Africa during the first half of the Cretaceous Period,” lead author Eric Gorscak, an Ohio University biologist, said in a press release. “With the discovery of Rukwatitan and study of the material in nearby Malawi, we are beginning to fill a significant gap from a large part of the world.”
Gorscak and his team estimate that the new dinosaur weighed as much as several elephants and had forelimbs that were over 6.5 feet long.
Remains for the dinosaur were embedded in a cliff wall in the Rukwa Basin of southwestern Tanzania (hence the dino’s name). Coal miners from the area and professional excavators managed to get the fossils out. The remains include vertebrae, ribs, limbs and pelvic bones.
“Using both traditional and new computational approaches, we were able to place the new species within the family tree of sauropod dinosaurs and determine both its uniqueness as a species and to delineate others species with which it is most closely related,” Gorscak said.
R. bisepultus has some features in common with another titanosaur from Malawi, Malawisaurus dixeyi, but the two southern African dinosaurs are still distinct. They are also very different from titanosaurs known from northern Africa.
The researchers also mention that fossils of middle Cretaceous crocodile relatives from the Rukwa Rift Basin exhibit distinctive features when compared to crocs from elsewhere on the continent.
Read more at Discovery News
"Holy... smoking Toledos," says one remarkably calm tourist as the ash flies. "Watch out for the shock -- it's coming."
Australian taxi driver Phil McNamara was vacationing with friends when he decided to get a closer look at the active volcano, which leveled the town of Rabaul in 1994.
"I thought I might as well try and capture something you rarely get to see."
From Discovery News
Instead of arriving at a bright, reflective, ice-covered heavenly body, the European Space Agency's Rosetta probe found that its target comet, 67P/Churyumov-Gerasimenko (or 67P/C-G), appears darker than charcoal in some wavelengths of light, according to new data collected by an instrument on the spacecraft. And, so far, scientists working with the Alice instrument on Rosetta have not found any large patches of water-ice on Comet 67P/C-G's surface.
"We're a bit surprised at just how unreflective the comet's surface is and how little evidence of exposed water-ice it shows," Alan Stern, Alice principal investigator at the Southwest Research Institute in Boulder, Colorado, said in a statement.
Researchers expected to see ice patches on the surface of the comet because of the body's distance from the sun. At the moment, that distance is so great that the sun can't warm ice on the comet's surface, which would turn it into water vapor; therefore, scientists thought there would be ice patches on the comet's surface, according to NASA.
The comet and Rosetta are currently flying about 318 million miles (512 million kilometers) from the sun, on their way to the comet's closest approach to the star, in August 2015. When Comet 67P/C-G makes its flyby of the sun, Rosetta will be able to measure the way the comet changes. The new data should help researchers learn more about the origin of comets, remnants from the beginnings of the solar system.
"As the mission progresses, we will continue to search for surface ice patches and ultraviolet color and composition variations across the surface of the comet," Lori Feaga, Alice co-investigator at the University of Maryland, said in a statement.
Alice has also identified hydrogen and oxygen in the comet's atmosphere, according to NASA.
In November, the Philae lander — currently tucked inside Rosetta — will fly down to the comet's surface to make measurements while attached to Comet 67P/C-G. Scientists are currently examining five potential Philae landing sites in order to decide where the lander should park on the comet's face. The European Space Agency is expected to announce its top choice for a landings site on Sept. 15.
Read more at Discovery News
Sep 7, 2014
Working with Professors Joydip Mukhopadhyay and Gautam Ghosh and other colleagues from the Presidency University in Kolkata, India, the geologists found evidence for chemical weathering of rocks leading to soil formation that occurred in the presence of O2. Using the naturally occurring uranium-lead isotope decay system, which is used for age determinations on geological time-scales, the authors deduced that these events took place at least 3.02 billion years ago. The ancient soil (or paleosol) came from the Singhbhum Craton of Odisha, and was named the 'Keonjhar Paleosol' after the nearest local town.
The pattern of chemical weathering preserved in the paleosol is compatible with elevated atmospheric O2 levels at that time. Such substantial levels of oxygen could only have been produced by organisms converting light energy and carbon dioxide to O2 and water. This process, known as photosynthesis, is used by millions of different plant and bacteria species today. It was the proliferation of such oxygen-producing species throughout Earth's evolutionary trajectory that changed the composition of our atmosphere -- adding much more O2 -- which was as important for the development of ancient multi-cellular life as it is for us today.
Quentin Crowley, Ussher Assistant Professor in Isotope Analysis and the Environment in the School of Natural Sciences at Trinity, is senior author of the journal article that describes this research which has just been published online in the world's top-ranked Geology journal, Geology. He said: "This is a very exciting finding, which helps to fill a gap in our knowledge about the evolution of the early Earth. This paleosol from India is telling us that there was a short-lived pulse of atmospheric oxygenation and this occurred considerably earlier than previously envisaged."
The early Earth was very different to what we see today. Our planet's early atmosphere was rich in methane and carbon dioxide and had only very low levels of O2. The widely accepted model for evolution of the atmosphere states that O2 levels did not appreciably rise until about 2.4 billion years ago. This 'Great Oxidation Event' event enriched the atmosphere and oceans with O2, and heralded one of the biggest shifts in evolutionary history.
Micro-organisms were certainly present before 3.0 billion years ago but they were not likely capable of producing O2 by photosynthesis. Up until very recently however, it has been unclear if any oxygenation events occurred prior to the Great Oxidation Event and the argument for an evolutionary capability of photosynthesis has largely been based on the first signs of an oxygen build-up in the atmosphere and oceans.
"It is the rare examples from the rock record that provide glimpses of how rocks weathered," added Professor Crowley. "The chemical changes which occur during this weathering tell us something about the composition of the atmosphere at that time. Very few of these 'paleosols' have been documented from a period of Earth's history prior to 2.5 billion years ago. The one we worked on is at least 3.02 billion years old, and it shows chemical evidence that weathering took place in an atmosphere with elevated O2 levels."
Read more at Science Daily