Jan 16, 2017

Seeing the quantum future, literally

Trapped Ytterbium ions were used as one of the most advanced laboratory quantum systems for this study. Professor Biercuk's research laboratories are now located in the Sydney Nanoscience Hub, after six years as a visiting scientist at the National Measurement Institute.
Scientists at the University of Sydney have demonstrated the ability to "see" the future of quantum systems, and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.

The applications of quantum-enabled technologies are compelling and already demonstrating significant impacts -- especially in the realm of sensing and metrology. And the potential to build exceptionally powerful quantum computers using quantum bits, or qubits, is driving investment from the world's largest companies.

However a significant obstacle to building reliable quantum technologies has been the randomisation of quantum systems by their environments, or decoherence, which effectively destroys the useful quantum character.

The physicists have taken a technical quantum leap in addressing this, using techniques from big data to predict how quantum systems will change and then preventing the system's breakdown from occurring.

The research is published today in Nature Communications.

"Much the way the individual components in mobile phones will eventually fail, so too do quantum systems," said the paper's senior author Professor Michael J. Biercuk.

"But in quantum technology the lifetime is generally measured in fractions of a second, rather than years."

Professor Biercuk, from the University of Sydney's School of Physics and a chief investigator at the Australian Research Council's Centre for Engineered Quantum Systems, said his group had demonstrated it was possible to suppress decoherence in a preventive manner. The key was to develop a technique to predict how the system would disintegrate.

Professor Biercuk highlighted the challenges of making predictions in a quantum world: "Humans routinely employ predictive techniques in our daily experience; for instance, when we play tennis we predict where the ball will end up based on observations of the airborne ball," he said.

"This works because the rules that govern how the ball will move, like gravity, are regular and known. But what if the rules changed randomly while the ball was on its way to you? In that case it's next to impossible to predict the future behavior of that ball.

"And yet this situation is exactly what we had to deal with because the disintegration of quantum systems is random. Moreover, in the quantum realm observation erases quantumness, so our team needed to be able to guess how and when the system would randomly break.

"We effectively needed to swing at the randomly moving tennis ball while blindfolded."

The team turned to machine learning for help in keeping their quantum systems -- qubits realised in trapped atoms -- from breaking.

What might look like random behavior actually contained enough information for a computer program to guess how the system would change in the future. It could then predict the future without direct observation, which would otherwise erase the system's useful characteristics.

The predictions were remarkably accurate, allowing the team to use their guesses preemptively to compensate for the anticipated changes.

Doing this in real time allowed the team to prevent the disintegration of the quantum character, extending the useful lifetime of the qubits.

"We know that building real quantum technologies will require major advances in our ability to control and stabilise qubits -- to make them useful in applications," Professor Biercuk said.

Read more at Science Daily

First humans arrived in North America a lot earlier than believed

This horse mandible from Cave 2 shows a number of cut marks on the lingual surface. They indicate that the animal's tongue was cut out with a stone tool.
The timing of the first entry of humans into North America across the Bering Strait has now been set back 10,000 years.

This has been demonstrated beyond a shadow of a doubt by Ariane Burke, a professor in Université de Montréal's Department of Anthropology, and her doctoral student Lauriane Bourgeon, with the contribution of Dr. Thomas Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit.

The earliest settlement date of North America, until now estimated at 14,000 years Before Present (BP) according to the earliest dated archaeological sites, is now estimated at 24,000 BP, at the height of the last ice age or Last Glacial Maximum.

The researchers made their discovery using artifacts from the Bluefish Caves, located on the banks of the Bluefish River in northern Yukon near the Alaska border. The site was excavated by archaeologist Jacques Cinq-Mars between 1977 and 1987. Based on radiocarbon dating of animal bones, the researcher made the bold hypothesis that human settlement in the region dated as far back as 30,000 BP.

In the absence of other sites of similar age, Cinq-Mars' hypothesis remained highly controversial in the scientific community. Moreover, there was no evidence that the presence of horse, mammoth, bison and caribou bones in the Bluefish Caves was due to human activity.

To set the record straight, Bourgeon examined the approximate 36,000 bone fragments culled from the site and preserved at the Canadian Museum of History in Gatineau -- an enormous undertaking that took her two years to complete. Comprehensive analysis of certain pieces at UdeM's Ecomorphology and Paleoanthropology Laboratory revealed undeniable traces of human activity in 15 bones. Around 20 other fragments also showed probable traces of the same type of activity.

"Series of straight, V-shaped lines on the surface of the bones were made by stone tools used to skin animals," said Burke. "These are indisputable cut-marks created by humans."

Bourgeon submitted the bones to further radiocarbon dating. The oldest fragment, a horse mandible showing the marks of a stone tool apparently used to remove the tongue, was radiocarbon-dated at 19,650 years, which is equivalent to between 23,000 and 24,000 cal BP (calibrated years Before Present).

"Our discovery confirms previous analyses and demonstrates that this is the earliest known site of human settlement in Canada," said Burke. It shows that Eastern Beringia was inhabited during the last ice age."

Beringia is a vast region stretching from the Mackenzie River in the Northwest Territories to the Lena River in Russia. According to Burke, studies in population genetics have shown that a group of a few thousand individuals lived in isolation from the rest of the world in Beringia 15,000 to 24,000 years ago.

"Our discovery confirms the 'Beringian standstill [or genetic isolation] hypothesis,'" she said, "Genetic isolation would have corresponded to geographical isolation. During the Last Glacial Maximum, Beringia was isolated from the rest of North America by glaciers and steppes too inhospitable for human occupation to the West. It was potentially a place of refuge."

The Beringians of Bluefish Caves were therefore among the ancestors of people who, at the end of the last ice age, colonized the entire continent along the coast to South America.

Read more at Science Daily

How to be winner in the game of evolution

Jellyfish, polyps and the like belong to a phylum called Cnidaria, one of about 30 major groups that make up the animal kingdom.
A new study by University of Arizona biologists helps explain why different groups of animals differ dramatically in their number of species, and how this is related to differences in their body forms and ways of life.

For millennia, humans have marveled at the seemingly boundless variety and diversity of animals inhabiting the Earth. So far, biologists have described and catalogued about 1.5 million animal species, a number that many think might be eclipsed by the number of species still awaiting discovery.

All animal species are divided among roughly 30 phyla, but these phyla differ dramatically in how many species they contain, from a single species to more than 1.2 million in the case of insects and their kin. Animals have incredible variation in their body shapes and ways of life, including the plant-like, immobile marine sponges that lack heads, eyes, limbs and complex organs, parasitic worms that live inside other organisms (e.g. nematodes, platyhelminths), and phyla with eyes, skeletons, limbs and complex organs that dominate the land in terms of species numbers (arthropods) and body size (chordates).

Amidst this dazzling array of life forms, one question has remained as elusive as it is obvious: why is it that some groups on the evolutionary tree of animals have branched into a dizzying thicket of species while others split into a mere handful and called it a day?

From the beginnings of their discipline, biologists have tried to find and understand the patterns underlying species diversity. In other words, what is the recipe that allows a phylum to diversify into many species, or, in the words of evolutionary biologists, to be "successful?" A fundamental but unresolved problem is whether the basic biology of these phyla is related to their species numbers. For example, does having a head, limbs, and eyes allow some groups to be more successful and thus have greater species numbers?

In the new study, Tereza Jezkova and John Wiens, both in the University of Arizona's Department of Ecology and Evolutionary Biology, have helped resolve this problem. They assembled a database of 18 traits, including traits related to anatomy, reproduction, and ecology. They then tested how each trait was related to the number of species in each phylum, and to how quickly species in each phylum multiplied over time (diversification). The results are published in the journal American Naturalist.

Jezkova and Wiens found that just three traits explained most variation in diversification and species numbers among phyla: the most successful phyla have a skeleton (either internal or external), live on land (instead of in the ocean), and parasitize other organisms. Other traits, including those that might seem more dramatic, had surprisingly little impact on diversification and species numbers: evolutionary accomplishments such as having a head, limbs, and complex organ systems for circulation and digestion don't seem to be primary accessories in the evolutionary "dress for success."

"Parasitism isn't correlated with any of the other traits, so it seems to have a strong effect on its own," said Wiens.

He explained that when a host species splits into two species, it takes its parasite population(s) with it.

"You can have a number of parasite species living inside the same host," he said, "for example, there could be ten species of nematodes in one host species, and if that host species splits into two, there are 20 species of nematodes. So that really multiplies the diversity."

The researchers used a statistical method called multiple regression analysis to tease out whether a trait such as parasitic lifestyle is a likely driver of species diversification.

"We tested all these unique traits individually," Wiens explained, "for example, having a head, having eyes, where the species in a phylum tend to live, whether they reproduce sexually or asexually, whether they undergo metamorphosis or not; and from that we picked six traits that each had a strong effect on their own. We then fed those six traits into a multiple regression model. And then we asked, 'what combination of traits explains the most variation without including any unnecessary variables?' -- and from that we could reduce it down to three key variables."

The authors point out that the analysis does not make any assumptions about the fossil record, which is not a true reflection of past biodiversity as it does not reveal most soft-bodied animals or traits like a parasitic lifestyle.

"We wanted to know what explains the pattern of diversity in the species we see today," said Wiens. "Who are the winners, and who are the losers?"

Marine biodiversity is in jeopardy from human activities such as acidification from carbon emissions, posing an existential threat to many marine animals, Wiens said.

Read more at Science Daily

Martin Luther King, Jr.'s Legacy Remembered

Forty-eight years after his death, Martin Luther King, Jr. still stands as one of the most symbolic, most loved and most tragic of figures of the Civil Rights Movement.

This year, the home where the civil rights leader was born in some 88 years ago, will reopen after being closed since August for repairs. The modest Atlanta, Ga. home at at 450 Auburn Ave. N.E., was originally built in 1895. The historic site typically draws up to 20,000 visitors on Martin Luther King, Jr. Day, which caused some wear and tear. After repairs to the first floor of the house, where King lived until age 12, it will open again to the public in time for the MLK holiday.

Across the country, Americans are honoring King through rallies, services and days of service. Here, in honor of Martin Luther King, Jr. Day, take a look back at his life and some of his greatest accomplishments.

Son of a Preacher Man

King was born Jan. 15, 1929, in Atlanta, Ga., to Rev. Martin Luther King, Sr. and Alberta Williams King.

He studied theology, eventually earning a Ph.D. and following in his father's footsteps, becoming a preacher. Eventually, the two Rev. Kings would co-pastor Ebenezer Baptist Church in Atlanta until the younger King's death in 1968.

In the photo below, Martin Luther King, Jr. looks on as his father delivers a sermon.

A Family of Kings

King married Coretta Scott on June 18, 1953. The couple would go on to have four children. After his death, the King family, led by Coretta, took on his mission of promoting racial equality.

Peaceful Protest

In this photo from June 1963, King leads a march of mourners in a funeral procession for fellow civil rights leader Medgar Evers.

Known for his marches and peaceful protests, King was still arrested 30 times, according to the King Center.

A Fitting Farewell
King delivered his "I Have a Dream" speech to a crowd of civil rights activists gathered at the Lincoln Memorial on Aug. 28, 1963.

The moment and the phrase, "I have a dream..." have gone down in history as the pinnacle moment of his career.

Peace Prize

Famous for his non-violent protests, King was awarded the Nobel Peace Prize in 1964. At age 35, he was the youngest man, the second American and the third black man to be so honored, according to the King Center.

Voting Rights

In this photo, dated Aug. 5, 1965, King meets with President Lyndon B. Johnson and other civil rights leaders.

The following day, President Johnson signed the 1965 Voting Rights Act, outlawing discriminatory voting practices.

A Fitting Farewell

King was shot and killed while standing on the balcony of the Lorraine Motel in Memphis, Tenn., on April 4, 1968.

Thousands of mourners, including the Rev. Jesse Jackson (pictured at right) attended the funeral.

A Lasting Legacy

Mourners at King's funeral procession show their support for the iconic figure.

Only four days after his death, the first legislation providing for a Martin Luther King, Jr. federal holiday was filed. It would take until June 7, 1999 for all 50 states to recognize the holiday, according to the King Center. The third Monday of January is now officially Martin Luther King, Jr. Day across the country.

From Discovery News

Prickly Pluto Could Reveal Ice Spikes Are Common on Other Worlds

When New Horizons whizzed by Pluto in 2015, images from the spacecraft revealed a geologist's dream. Icy mountains, a nitrogen glacier and a surprisingly youthful surface changed our notions of the distant dwarf planet forever. And even 18 months after the flyby, discoveries continue to pour in as scientists analyze the treasure trove of data.

The latest Pluto finding is evidence of features called "penitentes" — if confirmed this would be the first time these icy formations have been found beyond Earth. On our home planet, we know these icy spikes can grow up to several feet tall. They form in high-altitude environments, where the atmosphere is thinner and melting ice moves directly to vapor without a liquid phase in between. This sublimation (as the process is called) leaves bowl-shaped depressions behind.

But that's not all. John Moores, the lead author of the discovery paper in the journal Nature, says these features may well be in other locations across the solar system. Jupiter's Europa, for example, is a prime suspect given that radar signatures from the Galileo spacecraft suggest they could be there. But he says penitentes may even lurk in more familiar realms — even on Mars.

"We want to investigate other places in the solar system, or perhaps other solar systems, where you expect these features to show up," said Moores, who is with Canada's York University. He pointed out that penitentes may even lurk below the resolution of photos we took at planets and moons in the past. "If they were to be small, they may be in places we feel we already understand."

This is "bladed terrain" on Pluto seen by the New Horizons Ralph/Multispectral Visual Imaging Camera. Images of the dwarf planet appear to show terrain consistent with a feature called penitentes
Regardless of whether penitentes are common — or unique to Earth and Pluto — the find on the dwarf planet shows some remarkable characteristics. Pluto's penitentes are made of methane ice, while on Earth they're composed of water ice. Pluto's are more widely spread apart than what we find on Earth, where Moores says graduate students have trouble clambering among the spikes. On Pluto, by contrast, it appears the features are separated by a couple of miles. So there's plenty of room to set down a lander if we wanted.

What's more, the penitentes suggest that Pluto had calm atmospheric conditions over long periods of time, perhaps tens of millions of years. Regularly spaced and shaped penitentes, like what we see on Pluto, require an atmosphere; irregularly ones could develop where no substantial atmosphere is present, like Europa. Pluto's atmosphere expands and collapses as it gets further and closer from the sun in its nearly 248-year orbit. From numerical models, the team suggests that the penitentes could start growing (and continue developing) given warm enough atmospheric conditions for just a few years at a time.

Read more at Discovery News

Jan 15, 2017

Scientists tie the tightest knot ever achieved

Abstract spheres
Scientists at The University of Manchester have produced the most tightly knotted physical structure ever known -- a scientific achievement which has the potential to create a new generation of advanced materials.

The University of Manchester researchers, led by Professor David Leigh in Manchester's School of Chemistry, have developed a way of braiding multiple molecular strands enabling tighter and more complex knots to be made than has previously been possible.

The breakthrough knot has eight crossings in a 192-atom closed loop -- which is about 20 nanometres long (ie 20 millionths of a millimeter).

Being able to make different types of molecular knots means that scientists should be able to probe how knotting affects strength and elasticity of materials which will enable them to weave polymer strands to generate new types of materials.

Professor David Leigh said: "Tying knots is a similar process to weaving so the techniques being developed to tie knots in molecules should also be applicable to the weaving of molecular strands.

"For example, bullet-proof vests and body armour are made of kevlar, a plastic that consists of rigid molecular rods aligned in a parallel structure -- however, interweaving polymer strands have the potential to create much tougher, lighter and more flexible materials in the same way that weaving threads does in our everyday world.

"Some polymers, such as spider silk, can be twice as strong as steel so braiding polymer strands may lead to new generations of light, super-strong and flexible materials for fabrication and construction."

Professor David Leigh said he and his team were delighted to have achieved this scientific landmark.

He explained the process behind their success: "We 'tied' the molecular knot using a technique called 'self-assembly', in which molecular strands are woven around metal ions, forming crossing points in the right places just like in knitting -- and the ends of the strands were then fused together by a chemical catalyst to close the loop and form the complete knot.

"The eight-crossings molecular knot is the most complex regular woven molecule yet made by scientists."

The research breakthrough will be published in the journal Science on 13 January 2017 in a paper entitled: 'Braiding a molecular knot with eight crossings'

From Science Daily

Scientists engineer animals with ancient genes to test causes of evolution

Transgenic fruitfly engineered to carry the alcohol dehydrogenase gene as it existed about 4 million years ago. Thousands of these “ancestralized” flies were bred and studied for their ability to metabolize alcohol and to survive on an alcohol-rich food source.
Scientists at the University of Chicago have created the first genetically modified animals containing reconstructed ancient genes, which they used to test the evolutionary effects of genetic changes that happened in the deep past on the animals' biology and fitness.

The research, published early online in Nature Ecology & Evolution on Jan. 13, is a major step forward for efforts to study the genetic basis of adaptation and evolution. The specific findings, involving the fruit fly's ability to break down alcohol in rotting fruit, overturn a widely-held hypothesis about the molecular causes of one of evolutionary biology's classic cases of adaptation.

"One of the major goals of modern evolutionary biology is to identify the genes that caused species to adapt to new environments, but it's been hard to do that directly, because we've had no way to test the effects of ancient genes on animal biology," said Mo Siddiq, a graduate student in the Department of Ecology and Evolution at the University of Chicago, one of the study's lead scientists.

"We realized we could overcome this problem by combining two recently developed methods -- statistical reconstruction of ancient gene sequences and engineering of transgenic animals," he said.

Until recently, most studies of molecular adaptation have analyzed gene sequences to identify "signatures of selection" -- patterns suggesting that a gene changed so quickly during its evolution that selection is likely to have been the cause. The evidence from this approach is only circumstantial, however, because genes can evolve quickly for many reasons, such as chance, fluctuations in population size, or selection for functions unrelated to the environmental conditions to which the organism is thought to have adapted.

Siddiq and his advisor, Joe Thornton, PhD, professor of ecology and evolution and human genetics at the University of Chicago, wanted to directly test the effects of a gene's evolution on adaptation. Thornton has pioneered methods for reconstructing ancestral genes -- statistically determining their sequences from large databases of present-day sequences, then synthesizing them and experimentally studying their molecular properties in the laboratory. This strategy has yielded major insights into the mechanisms by which biochemical functions evolve.

Thornton and Siddiq reasoned that by combining ancestral gene reconstruction with techniques for engineering transgenic animals, they could study how genetic changes that occurred in the deep past affected whole organisms-their development, physiology, and even their fitness.

"This strategy of engineering 'ancestralized animals' could be applied to many evolutionary questions," Thornton said. "For the first test case, we chose a classic example of adaptation-how fruit flies evolved the ability to survive the high alcohol concentrations found in rotting fruit. We found that the accepted wisdom about the molecular causes of the flies' evolution is simply wrong."

The fruitfly Drosophila melanogaster is one of the most studied organisms in genetics and evolution. In the wild, D. melanogaster lives in alcohol-rich rotting fruit, tolerating far higher alcohol concentrations than its closest relatives, which live on other food sources. Twenty-five years ago at the University of Chicago, biologists Martin Kreitman and John McDonald invented a new statistical method for finding signatures of selection, which remains to this day one of the most widely used methods in molecular evolution. They demonstrated it on the alcohol dehydrogenase (Adh) gene -- the gene for the enzyme that breaks down alcohol inside cells -- from this group of flies. Adh had a strong signature of selection, and it was already known that D. melanogaster flies break down alcohol faster than their relatives. So, the idea that the Adh enzyme was the cause of the fruit fly's adaptation to ethanol became the first accepted case of a specific gene that mediated adaptive evolution of a species.

Siddiq and Thornton realized that this hypothesis could be tested directly using the new technologies. Siddiq first inferred the sequences of ancient Adh genes from just before and just after D. melanogaster evolved its ethanol tolerance, some two to four million years ago. He synthesized these genes biochemically, expressed them, and used biochemical methods to measure their ability to break down alcohol in a test tube. The results were surprising: the genetic changes that occurred during the evolution of D. melanogaster had no detectable effect on the protein's function.

Working with collaborators David Loehlin at the University of Wisconsin and Kristi Montooth at the University of Nebraska, Siddiq then created and characterized transgenic flies containing the reconstructed ancestral forms of Adh. They bred thousands of these "ancestralized" flies, tested how quickly they could break down alcohol, and how well the larvae and adult flies survived when raised on food with high alcohol content. Surprisingly, the transgenic flies carrying the more recent Adh were no better at metabolizing alcohol than flies carrying the more ancient form of Adh. Even more strikingly, they were no better able to grow or survive on increasing alcohol concentrations. Thus, none of the predictions of the classic version of the story were fulfilled. There is no doubt that D. melanogaster did adapt to high-alcohol food sources during its evolution, but not because of changes in the Adh enzyme.

"The Adh story was accepted because the ecology, physiology, and the statistical signature of selection all pointed in the same direction. But three lines of circumstantial evidence don't make an airtight case," Thornton said. "That's why we wanted to test the hypothesis directly, now that we finally have the means to do so."

Siddiq and Thornton hope that the strategy of making ancestralized transgenics will become the gold standard in the field to decisively determine the historical changes in genes to their changes on organisms' biology and fitness.

Read more at Science Daily

Jan 14, 2017

Searching for planets in the Alpha Centauri system

This image shows the closest stellar system to the Sun, the bright double star Alpha Centauri AB and its distant and faint companion Proxima Centauri. In late 2016 ESO signed an agreement with the Breakthrough Initiatives to adapt the VLT instrumentation to conduct a search for planets in the Alpha Centauri system. Such planets could be the targets for an eventual launch of miniature space probes by the Breakthrough Starshot Initiative.
ESO has signed an agreement with the Breakthrough Initiatives to adapt the Very Large Telescope instrumentation in Chile to conduct a search for planets in the nearby star system Alpha Centauri. Such planets could be the targets for an eventual launch of miniature space probes by the Breakthrough Starshot initiative.

ESO, represented by the Director General, Tim de Zeeuw, has signed an agreement with the Breakthrough Initiatives, represented by Pete Worden, Chairman of the Breakthrough Prize Foundation and Executive Director of the Breakthrough Initiatives. The agreement provides funds for the VISIR (VLT Imager and Spectrometer for mid-Infrared) instrument, mounted at ESO's Very Large Telescope (VLT) to be modified in order to greatly enhance its ability to search for potentially habitable planets around Alpha Centauri, the closest stellar system to the Earth. The agreement also provides for telescope time to allow a careful search programme to be conducted in 2019.

The discovery in 2016 of a planet, Proxima b, around Proxima Centauri, the third and faintest star of the Alpha Centauri system, adds even further impetus to this search.

Knowing where the nearest exoplanets are is of paramount interest for Breakthrough Starshot, the research and engineering programme launched in April 2016, which aims to demonstrate proof of concept for ultra-fast light-driven "nanocraft," laying the foundation for the first launch to Alpha Centauri within a generation.

Detecting a habitable planet is an enormous challenge due to the brightness of the planetary system's host star, which tends to overwhelm the relatively dim planets. One way to make this easier is to observe in the mid-infrared wavelength range, where the thermal glow from an orbiting planet greatly reduces the brightness gap between it and its host star. But even in the mid-infrared, the star remains millions of times brighter than the planets to be detected, which calls for a dedicated technique to reduce the blinding stellar light.

The existing mid-infrared instrument VISIR on the VLT will provide such performance if it were enhanced to greatly improve the image quality using adaptive optics, and adapted to employ a technique called coronagraphy to reduce the stellar light and thereby reveal the possible signal of potential terrestrial planets. Breakthrough Initiatives will pay for a large fraction of the necessary technologies and development costs for such an experiment, and ESO will provide the required observing capabilities and time.

The new hardware includes an instrument module contracted to Kampf Telescope Optics (KTO), Munich, which will host the wavefront sensor, and a novel detector calibration device. In addition, there are plans for a new coronagraph to be developed jointly by University of Liège (Belgium) and Uppsala University (Sweden).

Detecting and studying potentially habitable planets orbiting other stars will be one of the main scientific goals of the upcoming European Extremely Large Telescope (E-ELT). Although the increased size of the E-ELT will be essential to obtaining an image of a planet at larger distances in the Milky Way, the light collecting power of the VLT is just sufficient to image a planet around the nearest star, Alpha Centauri.

Read more at Science Daily

India was by no means as isolated as we thought

Gedanohelea gerdesorum in 54 million-year-old Cambay amber from India: The insects are only around a millimeter large and can often be found in Indian amber. Today, too, other biting midge species are widespread and well researched.
India gradually drifted away from Africa and Madagascar towards the north and collided with the Eurasian plate. Scientists assumed for a long time that the subcontinent was largely isolated during its long journey through the ocean and unique species of plants and animals were therefore able to develop on it. However, paleontologists at the University of Bonn are now showing using tiny midges encased in amber that there must have been a connection between the apparently cut off India and Europe and Asia around 54 million years ago that enabled the creatures to move around. The surprising results are now presented in the journal PLOS ONE.

India harbours many unique species of flora and fauna that only occur in this form on the subcontinent. The prerequisite for such a unique development of species is that no exchange takes place with other regions. For a long time, scientists assumed that India was isolated in this way due to continental drift. The supercontinent Gondwana, which included South America, Africa, Antarctica, Australia, Madagascar and India, broke up over the course of geological history. What is now India also began moving towards the north east around 130 million years ago. It was common belief among researchers that, before it collided with the Eurasian plate, India was largely isolated for at least 30 million years during its migration.

However, according to current findings by paleontologists at the University of Bonn, the Indian subcontinent may not have been as isolated on its journey as we have thought. "Certain midges that occurred in India at this time display great similarity to examples of a similar age from Europe and Asia," says lead author Frauke Stebner from the working group of Prof. Jes Rust at the Steinmann Institute at the University of Bonn. These findings are a strong indicator that an exchange did occur between the supposedly isolated India, Europe and Asia.

Mining for amber in the Indian coal seams

The scientist from the University of Bonn mined for amber in seams of coal near the Indian city of Surat. Small midges, among other things, were encased in tree resin 54 million years ago and preserved as fossils. The tiny insects, which are often not even a millimeter large, are "biting midges." Their descendants can still be found today in Germany in meadows and forests -- where the little beasts attack you in swarms and suck your blood.

The paleontologist investigated a total of 38 biting midges encased in amber and compared them with examples of a similar age from Europe and China. Scientists from the University of Gda?sk (Poland) and Lucknow (India) were also involved in this. It has been possible to assign a total of 34 of these insect fossils to genera that are already known. "There was significant conformity with biting midges in amber from the Baltic and Fushun in north-east China," reports Stebner.

Chains of islands presumably created a link to India

How the insects were able to spread between drifting India and Eurasia has not yet been clarified fully. "Nevertheless, it also seems to have been possible for birds and various groups of mammals to cross the ocean between Europe and India at the time," the paleontologist refers to studies by other scientists. However, it has now been possible for the first time, with the aid of biting midge fossils, to also demonstrate an exchange between India and Asia in this period.

Read more at Science Daily

Jan 13, 2017

The Dark and Extreme Cold Killed Off the Dinosaurs

The chill that enveloped Earth 66 million years ago, after an asteroid struck and ushered the dinosaur era to a close, lasted longer, with greater consequences, than previously thought.

That's according to new research by scientists with the Potsdam Institute for Climate Impact Research (PKI), who argue, in a new study published in the journal Geophysical Research Letters, that droplets of sulfuric acid forming high in the air after the impact brought about a long-lasting plunge in temperatures, playing a key role in the demise of the dinosaurs at the end of the Cretaceous.

"The long-term cooling caused by the sulfate aerosols was much more important for the mass extinction than the dust that stays in the atmosphere for only a relatively short time," said study lead Georg Feulner, in a statement. "It was also more important than local events like the extreme heat close to the impact, wildfires or tsunamis."

Existing studies, the PKI team wrote, "focused on the effect of dust or used one-dimensional, non-coupled atmosphere models." Feulner and his team instead used new computer models that coupled atmosphere, ocean and sea ice data in order to run their simulations.

The resulting post-impact computer models painted a dire picture for dinosaurs accustomed to a lush environment: a global mean surface air temperature drop of at least 26 degrees C.; three to 16 years of sub-freezing temperatures; and a climate recovery time of more than 30 years.

Computer modeling showed an enduring chill passing over the planet after the asteroid strike.
(The PKI team has created a time-lapse animation of the cooling that can be viewed here.)

All was chaos in the oceans, too, the models showed. As surface waters cooled, they grew heavier and denser, sinking. Meanwhile warmer waters farther below rose, bringing with them nutrients that created huge algae blooms. The blooms could have created toxic substances that impacted life along the coastlines, the scientists suggested.

Read more at Discovery News