Is being a night owl bad for your health?

Night owls may have a higher risk of suffering from heart disease and type 2 diabetes than early risers.

In the first ever international review of studies analysing whether being an early riser or a night owl can influence your health, researchers have uncovered a growing body of evidence indicating an increased risk of ill health in people with an evening preference as they have more erratic eating patterns and consume more unhealthy foods.

The findings have been reported in Advances in Nutrition today (Friday 30 November)

The human body runs on a 24-hour cycle which is regulated by our internal clock, which is known as a circadian rhythm, or chronotype. This internal clock regulates many physical functions, such as telling you when to eat, sleep and wake. An individual's chronotype leads to people having a natural preference towards waking early or going to bed late.

The researchers found increasing evidence emerging from studies linking conditions such as heart disease and type 2 diabetes to people with the evening chronotype -- a natural preference for evenings.

People who go to bed later tend to have unhealthier diets, consuming more alcohol, sugars, caffeinated drinks and fast food than early risers. They consistently report more erratic eating patterns as they miss breakfast and eat later in the day. Their diet contains less grains, rye and vegetables and they eat fewer, but larger, meals. They also report higher levels of consumption of caffeinated beverages, sugar and snacks, than those with a morning preference, who eat slightly more fruit and vegetables per day. This potentially explains why night owls have a higher risk of suffering from chronic disease.

Eating late in the day was also found to be linked to an increased risk of type 2 diabetes because the circadian rhythm influences the way glucose is metabolised in in the body.

Glucose levels should naturally decline throughout the day and reach their lowest point at night. However, as night owls often eat shortly before bed, their glucose levels are increased when they are about to sleep. This could negatively affect metabolism as their body isn't following its normal biological process.

One study showed that people with an evening preference were 2.5 times more likely to have type 2 diabetes than those with a morning preference.

This also impacts on people who work shifts -- particularly rotating shifts -- as they are constantly adjusting their body clock to fit with their working hours. The researchers found that this reduces their sensitivity to insulin and affects their glucose tolerance, putting them at greater risk of developing type 2 diabetes.

The review also uncovered interesting trends:

• People's preferences to rising early and going to bed later change at varying points in the life cycle. The morning chronotype is more common in children and can appear when a baby is just three-weeks old. This changes during childhood. While over 90% of two-year-olds have a morning preference, this declines to 58% by the age of six, and shifts further towards an evening preference during puberty. This evening preference continues until an adult reaches their early 50's and they then begin to revert back to a morning preference.
• Ethnicity and society can also influence your chronotype. For example, studies have revealed that Germans are more likely to have an evening preference in comparison to Indians and Slovakians. There can also be differences between people living in urban and rural areas in the same country.
• Another study noted that being exposed to daylight influenced sleep. Every additional hour spent outdoors was associated with 30 minutes of 'advance sleep' and that the noise, ambient lighting and crowding of urban environments can make people in some areas more likely to have a morning or evening preference.
• The researchers also found evidence that night owls would accumulate 'sleep debt' during the working week and would sleep longer at weekends to compensate for this, whereas early birds had smaller differences in their sleeping patterns across the week.

The study was led by Dr Suzana Almoosawi from Northumbria University, Newcastle in the UK and Dr Leonidas Karagounis, Nestle Health Science in Switzerland with academics representing Nestle Research (Switzerland) the University of Surrey (UK), Orebro University (Sweden), the National University of Singapore, the London School of Hygiene and Tropical Medicine, Ecole Polytechnique Federale de Lausanne (Switzerland) and Plymouth Marjon University (UK).

Dr Almoosawi, a Research Fellow in Northumbria's Brain, Performance and Nutrition Research Centre, explained: "We have found that your genes, ethnicity and gender determine the likelihood of you being a morning or evening type. In adulthood, being an evening chronotype is associated with greater risk of heart disease and type 2 diabetes, and this may be potentially due to the poorer eating behaviour and diet of people with evening chronotype. Our review also found that people who have a poorer control of their diabetes are more likely to be evening types.

"The review has highlighted a major gap in our understanding as to how our biological clock affects food intake in infants, children and the elderly. While most infants synchronise their body clock to that of their mothers, as they reach six-years of age, we observe that a large proportion begin to show signs of developing an evening chronotype. Whether physiological changes, school timings or social schedules determine this change, we do not know.

Dr Almoosawi added: "In teenagers, we also find that evening chronotype is related to more erratic eating behaviour and poorer diet. This could have important implications to health in adulthood as most dietary habits are established in adolescence."

The review team have called for more studies in the general population that define people's body clock and how this relates in the long-term to their dietary habits and health.

Dr Leonidas G Karagounis of Nestle Health Science, said: "Scientific evidence is providing increasing insight into the relationship between your chronotype, diet and cardiometabolic health. Overall, cross-sectional studies suggest that an evening chronotype is associated with lower intake of fruits and vegetables, and higher intake of energy drinks, alcoholic, sugary and caffeinated beverages, as well as higher energy intake from fat.

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The whole of Africa was the cradle of humankind

Members of Ain Hanech team excavating at Ain Boucherit.

A team of scientists led by Mohamed Sahnouni, archaeologist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has just published a paper in the journal Science which breaks with the paradigm that the cradle of Humankind lies in East Africa, based on the archaeological remains found at sites in the region of Ain Hanech (Algeria), the oldest currently known in the north of Africa.

For a long time, East Africa has been considered the place of origin of the earliest hominins and lithic technology, because up to now, very little was known about the first hominin occupation and activities in the north of the continent. Two decades of field and laboratory research directed by Dr. Sahnouni have shown that ancestral hominins actually made stone tools in North Africa that are near contemporary with the earliest known stone tools in East Africa dated to 2.6 million years.

These are stone artifacts and animal bones bearing marks of cutting by stone tools, with an estimated chronology of 2.4 and 1.9 million years, respectively, found at two levels at the sites of Ain Boucherit (within the Ain Hanech study area), which were dated using Paleomagnetism, Electron Spin Resonance (ESR), and the Biochronology of large mammals excavated together with the archaeological materials.

Fossils of animals such as pigs, horses and elephants, from very ancient sites, have been used by the paleontologist Jan van der Made, of the Museo Nacional de Ciencias Naturales in Madrid, to corroborate the ages yielded by Paleomagnetism, obtained by the CENIEH geochronologist Josep Parés, and ESR, found by Mathieu Duval, of Griffith University.

Oldowan technology

The artifacts of Ain Boucherit were manufactured of locally available limestone and flint and include faces worked into choppers, polyhedra and subspheroids, as well as sharp-edged cutting tools used to process animal carcasses. These artifacts are typical of the Oldowan stone technology known from 2.6-1.9 million-year-old sites in East Africa, although those from Ain Boucherit show subtle variations.

"The lithic industry of Ain Boucherit, which is technologically similar to that of Gona and Olduvai, shows that our ancestors ventured into all corners of Africa, not just East Africa. The evidence from Algeria changes the earlier view that East Africa was the cradle of Humankind. Actually, the whole of Africa was the cradle of humankind," states Sahnouni, leader of the Ain Hanech project.

Not mere scavengers

Ain Boucherit is one of the few archaeological sites in Africa which has provided evidence of bones with associated marks of cutting and percussion in situ with stone tools, which shows unmistakably that these ancestral hominins exploited meat and marrow from animals of all sizes and skeletal parts, which implied skinning, evisceration and defleshing of upper and intermediate extremities.

Isabel Cáceres, taphonomist at the IPHES, has commented that "the effective use of sharp-edged tools at Ain Boucherit suggests that our ancestors were not mere scavengers. It is not clear at this moment whether they hunted, but the evidence clearly shows that they were successfully competing with carnivores and enjoyed first access to animal carcasses."

The tool-makers

At this moment, the most important question is who made the stone tools discovered in Algeria. Hominin remains have still not been found in North Africa which are contemporary with the earliest stone artifacts. As a matter of fact, nor have any hominins yet been documented in direct association with the first stone tools known from East Africa.

Nevertheless, a recent discovery in Ethiopia has shown the presence of early Homo dated to 2.8 million years, most likely the best candidate also for the materials from East and North Africa.

Scientists thought for a long time that the hominins and their material culture originated in the Great Rift Valley in East Africa. Surprisingly, the earliest known hominin, dated to 7.0 million years, and the 3.3 million years Australopithecus bahrelghazali, have been discovered in Chad, in the Sahara, 3000 km from the rift valleys in the east of Africa.

As Sileshi Semaw, scientist at the CENIEH and a co-author of this paper, explains that the hominins contemporary with Lucy (3.2 million years), were probably roamed over the Sahara, and their descendants might have been responsible for leaving these archaeological puzzles now discovered in Algeria, that are near contemporaries of those of East Africa.

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Black hole 'donuts' are actually 'fountains'

The three gaseous components form the long-theorized 'donut' structure: (1) a disk of infalling dense cold molecular gas, (2) outflowing hot atomic gas, and (3) gas returning to the disk.

Based on computer simulations and new observations from the Atacama Large Millimeter/submillimeter Array (ALMA), researchers have found that the rings of gas surrounding active supermassive black holes are not simple donut shapes. Instead, gas expelled from the center interacts with infalling gas to create a dynamic circulation pattern, similar to a water fountain in a city park.

Most galaxies host a supermassive black hole, millions or billions of times as heavy as the Sun, in their centers. Some of these black holes swallow material quite actively. But astronomers have believed that rather than falling directly into the black hole, matter instead builds up around the active black hole forming a donut structure.

Takuma Izumi, a researcher at the National Astronomical Observatory of Japan (NAOJ), led a team of astronomers that used ALMA to observe the supermassive black hole in the Circinus Galaxy located 14 million light-years away from the Earth in the direction of the constellation Circinus. The team then compared their observations to a computer simulation of gas falling towards a black hole made with the Cray XC30 ATERUI supercomputer operated by NAOJ. This comparison revealed that the presumptive "donut" is not actually a rigid structure, but instead a complex collection of highly dynamic gaseous components. First, cold molecular gas falling towards the black hole forms a disk near the plane of rotation. As it approaches the black hole, this gas is heated until the molecules break down into the component atoms and ions. Some of these atoms are then expelled above and below the disk, rather than being absorbed by the black hole. This hot atomic gas falls back onto the disk creating a turbulent three dimensional structure. These three components circulate continuously, similar to a water fountain in a city park.

"Previous theoretical models set a priori assumptions of rigid donuts," explains Keiichi Wada, a theoretician at Kagoshima University in Japan, who lead the simulation study and is a member of the research team. "Rather than starting from assumptions, our simulation started from the physical equations and showed for the first time that the gas circulation naturally forms a donut. Our simulation can also explain various observational features of the system."

"By investigating the motion and distribution of both the cold molecular gas and warm atomic gas with ALMA, we demonstrated the origin of the so-called 'donut' structure around active black holes," said Izumi. "Based on this discovery, we need to rewrite the astronomy textbooks."

From Science Daily

Fires fueled spread of grasslands on ancient Earth

Outcrops in Pakistan provided paleosol, or fossil soil samples, used to test the role of fire in the spread of grasslands nearly 10 million years ago.

Ancient wildfires played a crucial role in the formation and spread of grasslands like those that now cover large parts of the Earth, according to scientists at Penn State and the Smithsonian National Museum of Natural History.

A new study links a large rise in wildfires nearly 10 million years ago, in the late Miocene, with a major shift in vegetation on land, as indicated by carbon isotopes of plant biomarkers found in the fossil record. Frequent, seasonal fires helped turn forested areas into open landscapes, and drove the expansion of grasslands, the researchers said.

The team developed an innovative approach to test the role of fire in the rise of early grasslands. They analyzed tracers of ancient leaves and of burned organic matter left behind in paleosols, or fossil soils, in northern Pakistan.

"The tools we use are molecules and biomarkers produced by organisms in Earth history and preserved in rocks," said Allison Karp, a graduate student in geosciences at Penn State and lead author on the paper. "We can use these as clues to figure out what was happening with climate and ecology in the past."

The new technique has broad implications as a tool for scientists seeking to answer questions about past vegetation and climate change, the researcher said.

This shows that the tool can pinpoint the location of a fire where it occurred, according to Karp. "In a paleosol record you are really capturing an integrated picture of what was happening when the soil was forming," she said.

The researchers recently reported their findings in the Proceedings of the National Academy of Sciences. Katherine Freeman, Evan Pugh University Professor of Geosciences at Penn State and Karp's adviser, is a co-author on the paper.

"This is one of the biggest ecological changes in the last 66 million years," said Karp. "None of the open grassland systems we have today existed before this transition. It was a very different looking world, especially in sub-tropical places like Pakistan."

Scientists have long studied the rise of C4 grasslands, named after plants that evolved a new way to handle photosynthesis that allows them to thrive in dry, tropical conditions and with lower amounts of carbon dioxide. These plants include modern crops like corn and sugarcane.

A drop in global carbon dioxide levels was once believed to be behind the rise of C4 grasslands. More recent research has shown that the grasses spread at different rates on different continents, indicating that regional factors, like rain patterns -- and potentially fire -- played important roles. But there had been little direct evidence that linked a rise in wildfires to this transition.

"We were interested in reconstructing fire and the expansion of grasslands in the same geologic record to see if we could find proxy evidence of the role fire played," Karp said. "We now have a nice line of observational evidence to compare to what the models have said."

Karp and her collaborators used polycyclic aromatic hydrocarbons (PAHs), found in paleosols, as fire proxies. PAHs are chemicals that are created by the burning of organic matter like wood and plants. They also are naturally found in coal and crude oil.

PAHs increased five-fold across the study area while evidence of conifer trees declined and ultimately disappeared. The heavily forested landscape opened up in two stages. Around 10 million years ago, forests were replaced by more fire-prone, open woodlands or grasslands, and between six and eight million years ago, C4 grasslands became dominant just as the quantity of fire signatures sharply increased.

Modern fire ecology can explain the process. Grasses grow faster than trees after a fire and they also help create conditions ripe for subsequent fires, promoting open landscapes. In the late Miocene, wet seasons brought on by monsoon conditions encouraged plant growth, which in turn created more fuel for fires during hot, dry seasons in Pakistan.

"The role fire played in the expansion and evolution of grassland systems in deep time is important because understanding how fire has maintained systems in the past can help us predict what may happen to these important systems in the future as climate continues to change," Karp said.

Read more at Science Daily

Newly discovered supernova complicates origin story theories

Six images showing the host galaxy of the newly discovered supernova ASASSN-18bt. The top row shows three images from before the explosion taken by Pan-STARRS, ASAS-SN, and Kepler. The bottom row shows images from ASAS-SN and Kepler after the supernova was visible. The discovery image from the ASAS-SN team is in the bottom middle. To its left is a version with all the surrounding stars eliminated, showing only the new supernova's light output. On the bottom right is a Kepler image from after the supernova was detected. Kepler's precision was crucial to understanding the light from ASASSN_18bt in the early hours after the explosion.

A supernova discovered by an international group of astronomers including Carnegie's Tom Holoien and Maria Drout, and led by University of Hawaii's Ben Shappee, provides an unprecedented look at the first moments of a violent stellar explosion. The light from the explosion's first hours showed an unexpected pattern, which Carnegie's Anthony Piro analyzed to reveal that the genesis of these phenomena is even more mysterious than previously thought.

Their findings are published in a trio of papers in The Astrophysical Journal and The Astrophysical Journal Letters.

Type Ia supernovae are fundamental to our understanding of the cosmos. Their nuclear furnaces are crucial for generating many of the elements around us, and they are used as cosmic rulers to measure distances across the universe. Despite their importance, the actual mechanism that triggers a Type Ia supernova explosion has remained elusive for decades.

That's why catching them in the act is crucial.

Astronomers have long tried to get detailed data at the initial moments of these explosions, with the hope of figuring out how these phenomena are triggered. This finally happened in February of this year with the discovery of a Type Ia supernova called ASASSN-18bt (also known as SN 2018oh).

ASASSN-18bt was discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN), an international network of telescopes headquartered at the Ohio State University that routinely scans the sky for supernovae and other cosmic explosions. NASA's Kepler space telescope was simultaneously able to take complementary data of this event. Kepler was designed to be incredibly sensitive to small changes in light for its mission of detecting extrasolar planets, so it was able to obtain especially detailed information about the explosion's genesis.

"ASASSN-18bt is the nearest and brightest supernova yet observed by Kepler, so it offered an excellent opportunity to test the predominant theories of supernova formation," said Shappee, who is lead author on the on the discovery and early time light curve paperand one of our Carnegie alumni.

Combining data from ASAS-SN, Kepler, and telescopes around the world, the astronomers realized that ASASSN-18bt looked unusual during its first couple of days.

"Many supernovae show a gradual increase in the light they put out," said Drout, who is jointly appointed at the University of Toronto. "But for this event, you could clearly see there's something unusual and exciting happening in the early times -- an unexpected additional emission."

Type Ia supernovae originate from the thermonuclear explosion of a white dwarf star -- the dead core left over by a Sun-like star after it exhausts its nuclear fuel. Material must be added to the white dwarf from a companion star to trigger the explosion, but the nature of the companion star and how the fuel is transferred has long been debated.

One possibility is that this additional light seen during the supernova's early times could be from the exploding white dwarf colliding with the companion star. Although this was the initial hypothesis, detailed comparisons with Piro's theoretical modeling work demonstrated that this additional light may have a different, unexplained origin.

"While the steep increase in ASASSN-18bt's early brightness could indicate that the explosion collides with another star, our follow-up data don't fit predictions for how this should look," Holoien said. "Other possibilities, such as an unusual distribution of radioactive material in the exploded star, are a better explanation for what we saw. More observations of ASASSN-18bt and more early discoveries like this one will hopefully help us differentiate between different models and better understand the origins of these explosions."

"Nature is always finding new ways to surprise us, and unique observations like this are great for motivating creative new approaches to how we think about these explosions, "added Piro. "As a theorist at the Carnegie Observatories, it's so helpful and inspiring to be right near the observers who are making these key measurements."

This supports a hypothesis put forward in recent work from the Carnegie Supernova Project, led by Maximilian Stritzinger ofAarhus University and co-led by Shappee and Piro, that there may be two distinct populations of Type Ia supernovae -- those that show early emission and those that do not.

Thanks to ASAS-SN and the next generation of surveys that are now monitoring the sky every night, astronomers will find even more new supernovae and catch them at the moment of explosion. As more of these events are found and studied, they will hopefully home in on the solution to the longstanding mystery of how these stellar explosions originate.

Read more at Science Daily

All of the starlight ever produced by the observable universe measured

This map of the entire sky shows the location of 739 blazars used in the Fermi Gamma-ray Space Telescope’s measurement of the extragalactic background light (EBL). The background shows the sky as it appears in gamma rays with energies above 10 billion electron volts, constructed from nine years of observations by Fermi’s Large Area Telescope. The plane of our Milky Way galaxy runs along the middle of the plot.

From their laboratories on a rocky planet dwarfed by the vastness of space, Clemson University scientists have managed to measure all of the starlight ever produced throughout the history of the observable universe.

Astrophysicists believe that our universe, which is about 13.7 billion years old, began forming the first stars when it was a few hundred million years old. Since then, the universe has become a star-making tour de force. There are now about two trillion galaxies and a trillion-trillion stars. Using new methods of starlight measurement, Clemson College of Science astrophysicist Marco Ajello and his team analyzed data from NASA's Fermi Gamma-ray Space Telescope to determine the history of star formation over most of the universe's lifetime.

A collaborative paper titled "A gamma-ray determination of the Universe's star-formation history" was published Nov. 30 in the journal Science and describes the results and ramifications of the team's new measurement process.

"From data collected by the Fermi telescope, we were able to measure the entire amount of starlight ever emitted. This has never been done before," said Ajello, who is lead author of the paper. "Most of this light is emitted by stars that live in galaxies. And so, this has allowed us to better understand the stellar-evolution process and gain captivating insights into how the universe produced its luminous content."

Putting a number on the amount of starlight ever produced has several variables that make it difficult to quantify in simple terms. But according to the new measurement, the number of photons (particles of visible light) that escaped into space after being emitted by stars translates to 4x10^84.

Or put another way: 4,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 photons.

Despite this stupendously large number, it is interesting to note that with the exception of the light that comes from our own sun and galaxy, the rest of the starlight that reaches Earth is exceedingly dim -- equivalent to a 60-watt light bulb viewed in complete darkness from about 2.5 miles away. This is because the universe is almost incomprehensibly huge. This is also why the sky is dark at night, other than light from the moon, visible stars and the faint glow of the Milky Way.

The Fermi Gamma-ray Space Telescope was launched into low orbit on June 11, 2008, and recently marked its 10-year anniversary. It is a powerful observatory that has provided enormous amounts of data on gamma rays (the most energetic form of light) and their interaction with the extragalactic background light (EBL), which is a cosmic fog composed of all the ultraviolet, visible and infrared light emitted by stars or from dust in their vicinity. Ajello and postdoctoral fellow Vaidehi Paliya analyzed almost nine years of data pertaining to gamma-ray signals from 739 blazars.

Blazars are galaxies containing supermassive black holes that are able to release narrowly collimated jets of energetic particles that leap out of their galaxies and streak across the cosmos at nearly the speed of light. When one of these jets happens to be pointed directly at Earth, it is detectable even when originating from extremely far away. Gamma ray photons produced within the jets eventually collide with the cosmic fog, leaving an observable imprint. This enabled Ajello's team to measure the density of the fog not just at a given place but also at a given time in the history of the universe.

"Gamma-ray photons traveling through a fog of starlight have a large probability of being absorbed," said Ajello, an assistant professor in the department of physics and astronomy. "By measuring how many photons have been absorbed, we were able to measure how thick the fog was and also measure, as a function of time, how much light there was in the entire range of wavelengths."

Using galaxy surveys, the star-formation history of the universe has been studied for decades. But one obstacle faced by previous research was that some galaxies were too far away, or too faint, for any present-day telescopes to detect. This forced scientists to estimate the starlight produced by these distant galaxies rather than directly record it.

Ajello's team was able to circumvent this by using Fermi's Large Area Telescope data to analyze the extragalactic background light. Starlight that escapes galaxies, including the most distant ones, eventually becomes part of the EBL. Therefore, accurate measurements of this cosmic fog, which have only recently become possible, eliminated the need to estimate light emissions from ultra-distant galaxies.

Paliya performed the gamma ray analysis of all 739 blazars, whose black holes are millions to billions of times more massive than our sun.

"By using blazars at different distances from us, we measured the total starlight at different time periods," said Paliya of the department of physics and astronomy. "We measured the total starlight of each epoch -- one billion years ago, two billion years ago, six billion years ago, etc. -- all the way back to when stars were first formed. This allowed us to reconstruct the EBL and determine the star-formation history of the universe in a more effective manner than had been achieved before."

When high-energy gamma rays collide with low-energy visible light, they transform into pairs of electrons and positrons. According to NASA, Fermi's ability to detect gamma rays across a wide range of energies makes it uniquely suited for mapping the cosmic fog. These particle interactions occur over immense cosmic distances, which enabled Ajello's group to probe deeper than ever into the universe's star-forming productivity.

"Scientists have tried to measure the EBL for a long time. However, very bright foregrounds like the zodiacal light (which is light scattered by dust in the solar system) rendered this measurement very challenging," said co-author Abhishek Desai, a graduate research assistant in the department of physics and astronomy. "Our technique is insensitive to any foreground and thus overcame these difficulties all at once."

Star formation, which occurs when dense regions of molecular clouds collapse and form stars, peaked around 11 billion years ago. But though the birthing of new stars has since slowed down, it has never stopped. For instance, about seven new stars are created in our Milky Way galaxy every year.

Establishing not only the present-day EBL, but revealing its evolution in cosmic history is a major breakthrough in this field, according to team member Dieter Hartmann, a professor in the department of physics and astronomy.

"Star formation is a great cosmic cycling and recycling of energy, matter and metals. It's the motor of the universe," Hartmann said. "Without the evolution of stars, we wouldn't have the fundamental elements necessary for the existence of life."

Understanding star formation also has ramifications for other areas of astronomical study, including research regarding cosmic dust, galaxy evolution and dark matter. The team's analysis will provide future missions with a guideline to explore the earliest days of stellar evolution -- such as the upcoming James Webb Space Telescope, which will be launched in 2021 and will enable scientists to hunt for the formation of primordial galaxies.

Read more at Science Daily

Whales lost their teeth before evolving hair-like baleen in their mouths

This is an artistic reconstruction of a mother and calf of Maiabalaena nesbittae nursing offshore of Oregon during the Oligocene, about 33 million years ago. While Maiabalaena would not have been able to chew or filter feed, muscle attachments on the bones of its throat indicate it likely had strong cheeks and a retractable tongue. These traits would have enabled it to suck water into its mouth, taking up fish and small squid in the process. The ability to suction feed would have rendered teeth, whose development requires a lot of energy to grow, unnecessary. The loss of teeth, then, appears to have set the evolutionary stage for the baleen, which the scientists estimate arose about 5 to 7 million years later.

Rivaling the evolution of feathers in dinosaurs, one of the most extraordinary transformations in the history of life was the evolution of baleen -- rows of flexible hair-like plates that blue whales, humpbacks and other marine mammals use to filter relatively tiny prey from gulps of ocean water. The unusual structure enables the world's largest creatures to consume several tons of food each day, without ever chewing or biting. Now, Smithsonian scientists have discovered an important intermediary link in the evolution of this innovative feeding strategy: an ancient whale that had neither teeth nor baleen.

In the Nov. 29 issue of the journal Current Biology, scientists at the Smithsonian's National Museum of Natural History and colleagues describe for the first time Maiabalaena nesbittae, a whale that lived about 33 million years ago. Using new methods to analyze long-ago discovered fossils housed in the Smithsonian's national collection, the team, which includes scientists at George Mason University, Texas A&M University and the Burke Museum of Natural History and Culture in Seattle, have determined that this toothless, 15-foot whale likely had no baleen, showing a surprising intermediary step between the baleen whales that live today and their toothed ancestors.

"When we talk about whale evolution, textbooks tend to focus on the early stages, when whales went from land to sea," said National Museum of Natural History's curator of fossil marine mammals. "Maiabalaena shows that the second phase of whale evolution is just as important for evolution over big scales. For the first time, we can now pin down the origin of filter-feeding, which is one of the major innovations in whale history."

When whales first evolved, they used teeth to chew their food, just like their land-dwelling ancestors. As time went on, many descendants of these early whales continued to chew their food, inheriting this trait from their predecessors. But as the oceans around them changed and animals evolved, entirely new feeding strategies arose, including baleen filter feeding, says National Museum of Natural History predoctoral fellow Carlos Mauricio Peredo, the lead author of the study who analyzed the Maiabalaena fossils.

Whales were the first mammals to evolve baleen, and no other mammal uses any anatomical structure even remotely similar to it to consume its prey. But frustratingly, baleen, whose chemical composition is more like that of hair or fingernails than bone, does not preserve well. It is rarely found in the fossil record, leaving paleontologists without direct evidence of its past or origins. Instead, scientists have had to rely on inferences from fossils and studies of fetal-whale development in the womb to piece together clues about how baleen evolved.

As a result, it has not been clear whether, as they evolved, early baleen whales retained the teeth of their ancestors until a filter-feeding system had been established. An early initial assumption, Peredo said, was that ocean-dwelling mammals must have needed teeth or baleen to eat -- but several living whales contradict that idea. Sperm whales have teeth in their bottom jaw, but none on the top, so they cannot bite or chew. Narwhals' only teeth are their long tusks, which they do not use for feeding. And some species of beaked whales, despite being classified as toothed whales, have no teeth at all.

Because of its age, Peredo said, paleontologists suspected Maiabalaena might hold important clues about baleen's evolution. The fossil comes from a period of massive geological change during the second major phase of whale evolution, around the time the Eocene epoch was transitioning to the Oligocene. With continents shifting and separating, ocean currents were swirling around Antarctica for the first time, cooling the waters significantly. The fossil record indicates that whales' feeding styles diverged rapidly during this timeframe, with one group leading to today's filter-feeding whales and the other leading to echolocating ones.

Consequently, Maiabalaena had received plenty of scrutiny since its discovery in Oregon in the 1970s, but the rock matrix and material that the fossil was collected in still obscured many of its features. It was not until Peredo finally cleaned the fossil and then examined it with state-of-the-art CT scanning technology that its most striking features became clear. Maiabalaena's lack of teeth was readily apparent from the preserved bone, but the CT scans, which revealed the fossil's internal anatomy, told the scientists something new: Maiabalaena's upper jaw was thin and narrow, making it an inadequate surface from which to suspend baleen.

"A living baleen whale has a big, broad roof in its mouth, and it's also thickened to create attachment sites for the baleen," Peredo said. "Maiabalaena does not. We can pretty conclusively tell you this fossil species didn't have teeth, and it is more likely than not that it didn't have baleen either."

While Maiabalaena would not have been able to chew or to filter feed, muscle attachments on the bones of its throat indicate it likely had strong cheeks and a retractable tongue. These traits would have enabled it to suck water into its mouth, taking up fish and small squid in the process. The ability to suction feed would have rendered teeth, whose development requires a lot of energy to grow, unnecessary. The loss of teeth, then, appears to have set the evolutionary stage for the baleen, which the scientists estimate arose about 5 to 7 million years later.

Peredo and Pyenson see studying whale evolution as key to understanding their survival in today's rapidly changing oceans. Like the emergence of baleen, tooth loss in whales is evidence of adaptability, suggesting that whales might be able to adapt to challenges posed in the ocean today. Still, Peredo cautions, evolutionary change may be slow for the largest whales, which have long life spans and take a long time to reproduce.

Read more at Science Daily

Stone tools linked to ancient human ancestors in Arabia have surprisingly recent date

These are handaxes from the site of Saffaqah, Saudi Arabia.

Beginning more than 1.5 million years ago, early humans made stone handaxes in a style known as the Acheulean -- the longest lasting tool-making tradition in prehistory. New research led by the Max Planck Institute for the Science of Human History and the Saudi Commission for Tourism and National Heritage has documented an Acheulean presence in the Arabian Peninsula dating to less than 190,000 years ago, revealing that the Arabian Acheulean ended just before or at the same time as the earliest Homo sapiens dispersals into the region.

Much attention has been given to understanding the spread of our own species, Homo sapiens, first within Africa and then beyond. However, less attention has been given to where diverse groups of close evolutionary cousins lived in Eurasia immediately prior to the arrival of Homo sapiens. Understanding this is critical because the spatial and temporal characteristics of such groups reveal the human and cultural landscape first encountered by our species on leaving Africa.

The youngest Acheulean site in Southwest Asia

In a paper published in Scientific Reports, an international team of researchers led by the Max Planck Institute for the Science of Human History and the Saudi Commission for Tourism and National Heritage reports the first ever dates obtained from an Acheulean site in Arabia, the site of Saffaqah, situated in Central Saudi Arabia. Saffaqah is the first stratified Acheulean site to be reported in the Arabian Peninsula and the dates reveal that early humans occupied the site until at least 190,000 years ago. These dates are surprisingly recent for a region known to feature among the oldest examples of such technology outside Africa. For example, dates from the Levant document an ancient Acheulean presence from 1.5 million years ago. Conversely the site of Saffaqah features the youngest Acheulean tools yet found in southwest Asia.

Over 500 stone tools, including handaxes and other artefacts known as cleavers, were recovered from the occupation levels. Some of the stone flakes used to make handaxes were in such fresh condition that they were recovered still resting on the stone nodules from which they had been detached. These and other artefacts show that the early humans responsible for making them were manufacturing stone tools at this site.

"It is not surprising that early humans came here to make stone tools," says Dr. Eleanor Scerri of the Max Planck Institute for the Science of Human History, the lead author of the study. "The site is located on a prominent andesite dyke that rises above the surrounding plain. The spot was both a source of raw material as well as a prime location to survey a landscape that, back then, sat between two major river systems." This choice location also seems to have continued to be attractive to early humans at an even later date than those recorded by the researchers in this study. Layers containing identical stone handaxes are also found above the dense occupation layers that were dated, raising the possibility that Saffaqah is among the youngest Acheulean sites documented anywhere.

Hominins living at the edge

The new dating results both record the late persistence of the Acheulean in the Peninsula and also show that as yet unidentified hominin populations were using networks of now extinct rivers to disperse into the heart of Arabia during a time of increased rainfall in the region. This suggests that these hominins were able to live on the margins of habitable zones and take advantage of relatively brief "greening" episodes in a generally arid area. The dispersal of these hominins into the heart of Arabia may also help to explain the surprisingly late persistence of the Acheulean, as it suggests a degree of isolation.

"These hominins were resourceful and intelligent," adds Dr. Scerri, "They dispersed across a challenging landscape using technology commonly seen as reflecting a lack of inventiveness and creativity. Instead of perceiving the Acheulean this way, we should really be struck by how flexible, versatile and successful this technology was."

Cutting edge science

To date the sediments from the site of Saffaqah, the researchers used a combination of dating techniques known as luminescence methods, including a newly developed infrared-radiofluorescence (IR-RF) dating protocol for potassium rich feldspars. The method relies on the ability of such minerals to store energy induced by natural radioactivity and to release this energy in the form of light. "The application of IR-RF dating allowed us to obtain age estimates from sediments that were previously difficult to reliably date," explains Marine Frouin of the University of Oxford, one of the researchers involved in the dating program.

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Oldest-known ancestor of modern primates may have come from North America, not Asia

Teilhardina brandti, a 56-million year-old primate found in Wyoming, may be older than its Asian cousin, previously thought to be the earliest ancestor of modern primates. Unusual tooth sockets in this lower jaw of Teilhardina brandti helped make the determination.

About 56 million years ago, on an Earth so warm that palm trees graced the Arctic Circle, a mouse-sized primate known as Teilhardina first curled its fingers around a branch.

The earliest-known ancestor of modern primates, Teilhardina's close relatives would eventually give rise to today's monkeys, apes and humans. But one of the persistent mysteries about this distant cousin of ours is where it originated.

Teilhardina (ty-hahr-DEE'-nuh) species quickly spread across the forests of Asia, Europe and North America, a range unparalleled by all other primates except humans. But where did its journey begin?

New research shows that Teilhardina brandti, a species found in Wyoming, is as old or older than its Asian and European relatives, upending the prevailing hypothesis that Teilhardina first appeared in China.

Teilhardina's origins, however, remain a riddle.

"The scientific conclusion is 'We just don't know,'" said Paul Morse, the study's lead author and a recent University of Florida doctoral graduate. "While the fossils we've found potentially overturn past hypotheses of where Teilhardina came from and where it migrated, they definitely don't offer a clearer scenario."

What is clear, Morse said, is that T. brandti had a wide variety of features, some of which are as primitive as those found in Teilhardina asiatica, its Asian cousin, previously thought to be the oldest species in the genus.

To make this determination, Morse studied 163 teeth and jaws in the most comprehensive analysis of T. brandti to date.

Teeth contain a treasure-trove of information and often preserve better than bone, thanks to their tough enamel. They can reveal clues about an animal's evolutionary past, its size, diet and age as an individual and in geological time.

Primate teeth have particularly distinct structures that are immediately recognizable to the trained eye, said Jonathan Bloch, study co-author and curator of vertebrate paleontology at the Florida Museum of Natural History.

"Identifying differences between primate teeth is not so different from a biker recognizing that a Harley is different from a scooter or an art critic evaluating whether an image was created by Picasso or Banksy," he said. "In detail, they are very different from each other in specific, predictable ways."

While Teilhardina bones are very rare in the fossil record, its teeth are more plentiful -- if you know how to find them. Bloch's team of paleontologists, Morse included, have spent years combing the surface of Wyoming's Bighorn Basin on hands and knees and then packing out 50-pound bags of soil to a river to screen wash. The remaining bits of bones and teeth -- which can be smaller than a flea -- are examined under a microscope back at the museum.

This painstaking search has built up the dental record of T. brandti from a single molar -- used to first describe the species in 1993 -- to hundreds of teeth, providing a broad look at the primate's population-level variation.

Still, Morse and Bloch were unprepared for the peculiar variation exhibited by specimen UF 333700, a jagged piece of jaw with T. brandti teeth.

"Jon and I started arguing about the alveoli" -- empty tooth sockets -- "and how they didn't look right at all," said Morse, now a postdoctoral researcher at Duke University. "By the end of the day, we realized that specimen completely overturned both the species definition of T. asiatica and part of the rationale for why it is the oldest Teilhardina species."

Studies based on a small number of teeth simply missed the diversity in Teilhardina's physical characteristics, Morse said.

"There's likely a tremendous amount of variation in the fossil record, but it's extremely difficult to capture and measure when you have a small sample size," he said. "That's one of the reasons collecting additional fossils is so important."

The analysis also reshuffled the Teilhardina family tree, reducing the number of described species from nine to six and reclassifying two species as members of a new genus, Bownonomys, named for prominent vertebrate paleontologist Thomas Bown.

But the precise ages of Teilhardina species are still impossible to pinpoint and may remain that way.

Teilhardina appeared during the geological equivalent of a flash in the pan, a brief 200,000-year period known as the Paleocene-Eocene Thermal Maximum, or PETM. This era was characterized by a massive injection of carbon into the Earth's atmosphere, which sent global temperatures soaring. Sea levels surged by 220 feet, ecosystems were overhauled and the waters at the North Pole warmed to 74 degrees.

Scientists can use the distinct carbon signature of the PETM to locate this period in the rock record, and carbon isotopes in teeth can also be used to identify fossil animals from the era.

But among Teilhardina fossil sites across the globe, only Wyoming has the uninterrupted, neatly demarcated layers of rock that allow paleontologists to hone in on more precise dates.

"The humblest statement would be to say that these species are essentially equivalent in age," Bloch said. "Determining which came earlier in the PETM probably surpasses the level of resolution we have in the rock record. But what we can say is that the only place where you can really establish where Teilhardina appears in this climate event with confidence is in the Bighorn Basin."

As the Earth warmed, plants and animals expanded their ranges northward, returning south as temperatures cooled at the end of the PETM.

"This dance of plants and animals with climate change happened over vast landscapes, with forests moving from the Gulf Coast to the Rocky Mountains in just a few thousand years," Bloch said.

Teilhardina likely tracked the shifts in its forest habitats across the land bridges that then connected North America, Greenland and Eurasia, he said.

"Teilhardina is not throwing its bag over its shoulder and walking," he said. "Its range is shifting from one generation to the next. Over 1,000 years, you get a lot of movement, and over 2,000-3,000 years, you could easily cover continental distances."

While it was well-suited to Earth's hothouse environment, Teilhardina disappeared with the PETM, replaced by new and physically distinct primates. It's a sobering reminder of what can happen to species -- including humans -- during periods of swift climatic changes, Bloch said.

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Gas clouds whirling around black hole form heart of distant astronomical object

Optical image of the quasar 3C 273 (the bright stellar-like object in the center) obtained with the Hubble Space Telescope. It was the first quasar ever to be identified.

In 1963, astronomer Maarten Schmidt identified the first quasi-stellar object or "quasar," an extremely bright but distant object. He found the single quasar, the active nucleus of a far-away galaxy known to astronomers as 3C 273, to be 100 times more luminous than all the stars in our Milky Way combined.

Now, the GRAVITY international team of astronomers, including Prof. Hagai Netzer of Tel Aviv University's School of Physics and Astronomy, have concluded that gas clouds rapidly moving around a central black hole form the very heart of this quasar. The results of the new research were published in Nature on November 29.

The first measurement of the mass of the black hole inside 3C 273, using an older method, was conducted at the TAU's Florence and George Wise Observatory in 2000, as part of PhD research conducted by TAU's Dr. Shai Kaspi, then a student in Prof. Netzer's group. This result has now been corroborated by GRAVITY's observations.

The research is the first detailed observation outside of our galaxy of gas clouds whirling around a central black hole. According to the researchers, GRAVITY's measurements will become the benchmark for measuring black hole masses in thousands of other quasars.

Taking a closer look at a black hole

The GRAVITY instrument, situated in Paranal, Chile, has unprecedented capabilities. It combines the collective area of four telescopes to form a virtual telescope, called an interferometer, 130 meters across. The instrument can detect distant astronomical objects at an extremely high resolution.

"Quasars are among the most distant astronomical objects that can be observed," Prof. Netzer says. "They also play a fundamental role in the history of the universe, as their evolution is intricately tied to galaxy growth. While almost all large galaxies harbor a massive black hole at their centers, so far only one in our Milky Way has been accessible for such detailed studies."

"GRAVITY allowed us to resolve, for the first time ever, the motion of gas clouds around a central black hole," says Eckhard Sturm of Max Planck Institute for Extraterrestrial Physics (MPE), who co-led the research for the study. "Our observations can follow the motion of the gas and reveal that the clouds do whirl around the central black hole."

So far, such observations had not been possible due to the small angular size of a quasar's inner region -- roughly the size of our solar system, but some 2.5 billion light years distant from us.

"Broad emission lines created by gas in the vicinity of the black hole are observational hallmarks of quasars. Until now, the distance of the gas from the black hole, and occasionally the pattern of the motion, could only be measured by an older method that made use of light variations in the quasars," Prof. Netzer says. "With the GRAVITY instrument, we can distinguish structures at the level of 10 micro-arc seconds, which corresponds to observing, for example, a 1-Euro coin on the Moon."

"Information about the motion and distance of the gas immediately around the black hole is crucial to measuring the mass of the black hole," explains Jason Dexter, also of MPE, who co-led the research. "For the first time, the old method was tested experimentally and passed its test with flying colors, confirming previous estimates of about 300 million solar masses for the black hole."

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Hubble uncovers thousands of globular star clusters scattered among galaxies

This is a Hubble Space Telescope mosaic of a portion of the immense Coma cluster of over 1,000 galaxies, located 300 million light-years from Earth. Hubble's incredible sharpness was used to do a comprehensive census of the cluster's most diminutive members: a whopping 22,426 globular star clusters. Among the earliest homesteaders of the universe, globular star clusters are snow-globe-shaped islands of several hundred thousand ancient stars. The survey found the globular clusters scattered in the space between the galaxies. They have been orphaned from their home galaxies through galaxy tidal interactions within the bustling cluster. Astronomers will use the globular cluster field for mapping the distribution of matter and dark matter in the Coma galaxy cluster.

Gazing across 300 million light-years into a monstrous city of galaxies, astronomers have used NASA's Hubble Space Telescope to do a comprehensive census of some of its most diminutive members: a whopping 22,426 globular star clusters found to date.

The survey, published in the November 9, 2018, issue of the Astrophysical Journal, will allow for astronomers to use the globular cluster field to map the distribution of matter and dark matter in the Coma galaxy cluster, which holds over 1,000 galaxies that are packed together.

Because globular clusters are much smaller than entire galaxies -- and much more abundant -- they are a much better tracer of how the fabric of space is distorted by the Coma cluster's gravity. In fact, the Coma cluster is one of the first places where observed gravitational anomalies were considered to be indicative of a lot of unseen mass in the universe -- later to be called "dark matter."

Among the earliest homesteaders of the universe, globular star clusters are snow-globe-shaped islands of several hundred thousand ancient stars. They are integral to the birth and growth of a galaxy. About 150 globular clusters zip around our Milky Way galaxy, and, because they contain the oldest known stars in the universe, were present in the early formative years of our galaxy.

Some of the Milky Way's globular clusters are visible to the naked eye as fuzzy-looking "stars." But at the distance of the Coma cluster, its globulars appear as dots of light even to Hubble's super-sharp vision. The survey found the globular clusters scattered in the space between the galaxies. They have been orphaned from their home galaxy due to galaxy near-collisions inside the traffic-jammed cluster. Hubble revealed that some globular clusters line up along bridge-like patterns. This is telltale evidence for interactions between galaxies where they gravitationally tug on each other like pulling taffy.

Astronomer Juan Madrid of the Australian Telescope National Facility in Sydney, Australia first thought about the distribution of globular clusters in Coma when he was examining Hubble images that show the globular clusters extending all the way to the edge of any given photograph of galaxies in the Coma cluster.

He was looking forward to more data from one of the legacy surveys of Hubble that was designed to obtain data of the entire Coma cluster, called the Coma Cluster Treasury Survey. However, halfway through the program, in 2006, Hubble's powerful Advanced Camera for Surveys (ACS) had an electronics failure. (The ACS was later repaired by astronauts during a 2009 Hubble servicing mission.)

To fill in the survey gaps, Madrid and his team painstakingly pulled numerous Hubble images of the galaxy cluster taken from different Hubble observing programs. These are stored in the Space Telescope Science Institute's Mikulski Archive for Space Telescopes in Baltimore, Maryland. He assembled a mosaic of the central region of the cluster, working with students from the National Science Foundation's Research Experience for Undergraduates program. "This program gives an opportunity to students enrolled in universities with little or no astronomy to gain experience in the field," Madrid said.

The team developed algorithms to sift through the Coma mosaic images that contain at least 100,000 potential sources. The program used globular clusters' color (dominated by the glow of aging red stars) and spherical shape to eliminate extraneous objects -- mostly background galaxies unassociated with the Coma cluster.

Though Hubble has superb detectors with unmatched sensitivity and resolution, their main drawback is that they have tiny fields of view. "One of the cool aspects of our research is that it showcases the amazing science that will be possible with NASA's planned Wide Field Infrared Survey Telescope (WFIRST) that will have a much larger field of view than Hubble," said Madrid. "We will be able to image entire galaxy clusters at once."

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Atomic clocks now keep time well enough to improve models of Earth

NIST physicist Andrew Ludlow and colleagues achieved new atomic clock performance records in a comparison of two ytterbium optical lattice clocks. Laser systems used in both clocks are visible in the foreground, and the main apparatus for one of the clocks is located behind Ludlow.

Experimental atomic clocks at the National Institute of Standards and Technology (NIST) have achieved three new performance records, now ticking precisely enough to not only improve timekeeping and navigation, but also detect faint signals from gravity, the early universe and perhaps even dark matter.

The clocks each trap a thousand ytterbium atoms in optical lattices, grids made of laser beams. The atoms tick by vibrating or switching between two energy levels. By comparing two independent clocks, NIST physicists achieved record performance in three important measures: systematic uncertainty, stability and reproducibility.

Published online Nov. 28 in the journal Nature, the new NIST clock records are:

    Systematic uncertainty: How well the clock represents natural vibrations, or frequency, of the atoms. NIST researchers found that each clock ticked at a rate matching the natural frequency to within a possible error of just 1.4 parts in 1018 -- about one billionth of a billionth.
    Stability: How much the clock's frequency changes over a specified time interval, measured to a level of 3.2 parts in 1019 (or 0.00000000000000000032) over a day.
    Reproducibility: How closely the two clocks tick at the same frequency, shown by 10 comparisons of the clock pair, yielding a frequency difference below the 10-18 level (again, less than one billionth of a billionth).

"Systematic uncertainty, stability, and reproducibility can be considered the 'royal flush' of performance for these clocks," project leader Andrew Ludlow said. "The agreement of the two clocks at this unprecedented level, which we call reproducibility, is perhaps the single most important result, because it essentially requires and substantiates the other two results."

"This is especially true because the demonstrated reproducibility shows that the clocks' total error drops below our general ability to account for gravity's effect on time here on Earth. Hence, as we envision clocks like these being used around the country or world, their relative performance would be, for the first time, limited by Earth's gravitational effects."

Einstein's theory of relativity predicts that an atomic clock's ticking, that is, the frequency of the atoms' vibrations, is reduced -- shifted toward the red end of the electromagnetic spectrum -- when operated in stronger gravity. That is, time passes more slowly at lower elevations.

While these so-called redshifts degrade a clock's timekeeping, this same sensitivity can be turned on its head to exquisitely measure gravity. Super-sensitive clocks can map the gravitational distortion of space-time more precisely than ever. Applications include relativistic geodesy, which measures the Earth's gravitational shape, and detecting signals from the early universe such as gravitational waves and perhaps even as-yet-unexplained "dark matter."

NIST's ytterbium clocks now exceed the conventional capability to measure the geoid, or the shape of the Earth based on tidal gauge surveys of sea level. Comparisons of such clocks located far apart such as on different continents could resolve geodetic measurements to within 1 centimeter, better than the current state of the art of several centimeters.

In the past decade of new clock performance records announced by NIST and other labs around the world, this latest paper showcases reproducibility at a high level, the researchers say. Furthermore, the comparison of two clocks is the traditional method of evaluating performance.

Among the improvements in NIST's latest ytterbium clocks was the inclusion of thermal and electric shielding, which surround the atoms to protect them from stray electric fields and enable researchers to better characterize and correct for frequency shifts caused by heat radiation.

The ytterbium atom is among potential candidates for the future redefinition of the second -- the international unit of time -- in terms of optical frequencies. NIST's new clock records meet one of the international redefinition roadmap's requirements, a 100-fold improvement in validated accuracy over the best clocks based on the current standard, the cesium atom, which vibrates at lower microwave frequencies.

NIST is building a portable ytterbium lattice clock with state-of-the-art performance that could be transported to other labs around the world for clock comparisons and to other locations to explore relativistic geodesy techniques.

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Predators drive Nemo's relationship with an unlikely friend

Clownfish in anemone

Predators have been identified as the shaping force behind mutually beneficial relationships between species such as clownfish and anemones.

The finding results from a University of Queensland and Deakin University-led study.

UQ School of Biological Sciences researcher and Australian-American Fulbright Scholar Dr William Feeney said the research aimed to understand the origin of such relationships, known as interspecies mutualisms, which are extremely common in nature.

"Clownfish -- like Nemo from Finding Nemo -- and anemones are a great example of this type of relationship," he said.

"Clownfish live in and around anemones, helping drive off the anemone's predators and providing it with food, while in exchange the anemone provides protection with its stinging tentacles.

"Clownfish have evolved to resist the stings of the anemone, so it ends up being a very beneficial relationship for both species."

The researchers said the study helped explain how natural selection had shaped global patterns of biological diversity.

"We tested and confirmed a very basic and intuitive -- but logistically difficult -- idea in evolutionary ecology," Dr Feeney said.

"In a nutshell, we were looking to find out whether external pressures, such as predators, can explain the repeated evolution of these kinds of mutually beneficial partnerships.

The research combined genetic analysis with field experiments in French Polynesia to build a better understanding of fish-anemone mutualism dynamics.

Deakin University Centre for Integrative Ecology Research Fellow Dr Rohan Brooker said the team found that fish-anemone mutualisms had evolved at least 55 times across 16 fish families over the past 60 million years.

"This is much more common that previously thought. Over a quarter of coral reef-associated fish families have at least one species that associates with anemones," Dr Brooker said.

"Our results suggest that the risk of predation has selected these relationships, and that partnerships with anemones primarily benefit smaller fishes.

"Overall, this study suggests that predation can explain the independent evolution of cooperative behaviours between species, and that this evolutionary pattern could apply globally.

"If you can't find Nemo, it might be a good idea to go rummaging through the tentacles of his anemone friends."

The study is published in Ecology Letters.

From Science Daily

Climate change poses significant threat to nutritional benefits of oysters

Dr. Anaelle Lemasson with some of the oysters used in the research.

The nutritional qualities of shellfish could be significantly reduced by future ocean acidification and warming, a new study suggests.

Research has previously shown that climate change could threaten future production, safety and quality by negatively impacting the fitness of marine species.

Now scientists from the University of Plymouth, in a study published in Marine Environmental Research, have demonstrated the potential for negative nutritional effects within economically and commercially valuable species.

The research focussed on the Pacific oyster (Magallana gigas) and the native flat oyster (Ostrea edulis), with results showing that increased temperatures and CO2 levels could significantly reduce the former's levels of proteins, lipids and carbohydrates.

With seafood being the source of more than 15% of animal protein consumed globally, scientists say the aquaculture industry may wish to consider a shift in focus toward species that are most robust to climate change and less prone to deterioration in quality.

Dr Anaëlle Lemasson, a former PhD student at the University, led the research having previously shown that although the physiology of the Pacific oyster can be negatively impacted by future climate change, its taste might not be adversely affected.

She said: "Identifying changes in nutritional quality, as well as species most at risk, is crucial if societies are to secure food production. Our previous research had suggested there could be negative effects in the conditions predicted to occur in 2050 and 2100. However the fact that Pacific oysters, which currently accounts for around 90% of UK oyster production, can be affected could be a cause for concern."

The research was conducted by scientists linked to the University's Marine Biology and Ecology Research Centre (MBERC) and the Food, Health and Nutrition research group.

MBERC is one of the world's leading research centres examining the impact of multiple stressors on marine organisms and environments, and undergraduate and postgraduate students are regularly involved in that research.

The oysters were subjected to six different sets of ocean conditions over a 12-week period, from current temperatures and CO2 levels to the increased measurements predicted for both the middle and end of the century.

As well as changes in nutrient levels, researchers also observed important changes to essential mineral composition, adding that the enhanced accumulation of copper in Pacific oysters may be of future concern in terms of consumption safety.

Dr Victor Kuri, Lecturer in Food Quality at the University, said: "With a low environmental impact, shellfish are a promising highly nutritious alternative to fish and other animal products, but their sustainability depends on their quality attributes including palatability, nutrition and safety. This work confirms the need to understand the science behind the risks and mechanisms of shellfish production, as this knowledge is needed to build adequate resilience in harvesting and aquaculture industries"

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Detective mission to characterize and trace the history of a new African meteorite

A fragment of the meteorite showing the black fusion crust and thumbprint-like depressions (called regmaglypts) formed by melting during its entry into the atmosphere. The small bumps on the surface are grains of nickel-iron alloy.

Researchers from Wits and colleagues from the University of Antananarivo in Madagascar are on a "detective mission" to describe, classify and trace the history of a meteorite that landed in and around the small town of Benenitra in southwestern Madagascar shortly before the lunar eclipse on 27 July 2018.

News of the event in this remote area was brought to the attention of a Wits Geosciences graduate, Tim Marais, who was travelling in the area a few days after the meteorite fall. He collected some preliminary eyewitness accounts that reported a bright meteor fireball, a loud explosion and a rain of rock fragments that fell in and around Benenitra that, fortuitously, appear to have missed all people and buildings, and he was able to acquire several small fragments that residents had managed to locate. He delivered these to Professors Roger Gibson and Lewis Ashwal in the School of Geosciences at Wits and asked them to verify their extra-terrestrial origin. The signs of a dark fusion crust and small spheres in the rock matrix that were visible on broken surfaces appeared promising and the School's Senior Technician, Caiphas Majola, was immediately commissioned to prepare a thin section of one of the fragments for microscopic analysis.

Tracing the history

Assessment of the thin section confirmed that it was, indeed, a meteorite and, more specifically, a relatively common type called a chondrite, referring to the small spherical chondrules that it contains. This established that the meteorite dates from the formation of our Solar System about 4.56 billion years ago.

At the same time, a news report appeared in the local Triatra Gazette newspaper on 4 August regarding the eyewitness reports and showing a large specimen with a similar black fusion crust. To corroborate the event scientifically, the team approached Dr Andry Ramanantsoa of the Laboratory of Seismology and Infrasound at the Institute and Observatory of Geophysics at the University of Antananarivo to investigate if there was any evidence that a significant explosion occurred in the atmosphere above Madagascar sometime in the evening of 27 July. Ramanantsoa was able to confirm, using infrasound data from the international Comprehensive Nuclear Test Ban Treaty Infrasound Station IS33 outside Antananarivo, that there had, indeed, been an "upper atmosphere energy release event" at 5.16 p.m. GMT (7.16 p.m. local time). Furthermore, he was able to identify that it occurred in a direction south-southwest of Antananarivo -- the exact bearing of Benenitra.

The next step was to see if the blast wave from the atmospheric detonation was sufficiently large to have caused a ground vibration that could be detected by geophysical seismometers. For this the team turned to Dr Andriamiranto (Ranto) Raveloson, a Postdoctoral Fellow and Technical Manager of the Africa Array Seismic Network that is co-ordinated from Wits. He was able to confirm a very faint seismic tremor at 5.17 p.m. GMT on the same night. The final confirmation that the fragment was related to a fall on 27 July was obtained from Dr Matthias Laubenstein from the Laboratori Nazionali del Gran Sasso at the Istituto Nazionale di Fisica Nucleare in Italy, who measured the meteorite for rare cosmogenic nuclides that are created when an asteroid in Space is bombarded by high-energy cosmic rays. His measurements showed high levels of cosmogenic nuclides, consistent with the meteorite having entered Earth's protective atmosphere only within the past few months.

Based on these findings, the team has submitted a request to the international Meteoritical Society to officially name and register Africa's newest meteorite -- Benenitra -- on its database.

Classifying Africa's newest meteorite

Ashwal and Gibson have refined the meteorite classification as an L6 chondrite. The name refers to the fact that it contains a low amount of iron (the "L"), and that it contains recognizable chondrules. Chondrules are the original building blocks of rocky bodies -- such as asteroids and the Inner Planets -- in Space. As these bodies grew larger, heat built up inside them -- partly through gravitational collapse and partly because of radioactive elements -- which caused the metals and chondrules to recrystallise and maybe even melt. Where temperatures were sufficiently high to melt the body, the denser metals were then able to settle towards the core of the body, with the less dense silicate melts rising towards the surface. Eventually the body would have cooled down sufficiently to solidify. The Benenitra meteorite appears to have got quite hot (the number "6" refers to the high amount of recrystallisation that occurred within the chondrules owing to this heating process) but only melted partially, allowing some of the chondrules to survive.

Poor Man's Space Probe

The meteorite also has a thin shock-melt vein that is most likely related to a collision with another asteroid that shattered the original body and sent the fragment spinning off on its eventual collision course with Earth.

"Meteorites are commonly called The Poor Man's Space Probe, because they deliver rocks from Outer Space to our door for free, where we can study the birth and history of other parts of our Solar System" says Gibson. The Benenitra meteorite fragment is being subjected to a range of other tests to establish properties such as its density and magnetism, and the team plans to write the results up soon in a scientific paper.

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NASA Hears MarCO CubeSats Loud and Clear from Mars

MarCO-B, one of the experimental Mars Cube One (MarCO) CubeSats, took this image of Mars from about 4,700 miles (6,000 kilometers) away during its flyby of the Red Planet on Nov. 26, 2018. MarCO-B was flying by Mars with its twin, MarCO-A, to attempt to serve as communications relays for NASA's InSight spacecraft as it landed on Mars.

NASA's MarCO mission was built to see whether two experimental, briefcase-sized spacecraft could survive the trip to deep space, and the two CubeSats proved more than able. After cruising along behind NASA's InSight for seven months, they successfully relayed data back down to Earth from the lander during its descent to the Martian surface on Monday, Nov. 26.

Nicknamed "EVE" and "WALL-E" after the stars of the 2008 Pixar film, MarCO-A and MarCO-B used experimental radios and antennas, providing an alternate way for engineers to monitor the landing. The CubeSats provided information to InSight's landing team in just 8 minutes -- the time it took for radio signals to travel from Mars to Earth. That was much faster than waiting on NASA's Mars orbiters, which weren't positioned to be able to observe the entire event and send data back to Earth immediately.

"WALL-E and EVE performed just as we expected them to," said MarCO chief engineer Andy Klesh of NASA's Jet Propulsion Laboratory in Pasadena, California, which built the CubeSats. "They were an excellent test of how CubeSats can serve as 'tag-alongs' on future missions, giving engineers up-to-the-minute feedback during a landing."

Landing on Mars is exceptionally difficult: Before InSight, only about 40 percent of all attempts by various nations had succeeded. Even if a spacecraft doesn't survive landing, having a "black box" -- or a pair of them, as with MarCO -- to record the event can help engineers design better landing technology.

Neither of the MarCO CubeSats carry science instruments, but that didn't stop the team from testing whether future CubeSats could perform useful science at Mars. As MarCO-A flew by, it conducted some impromptu radio science, transmitting signals through the edge of Mars' atmosphere. Interference from the Martian atmosphere changes the signal when received on Earth, allowing scientists to determine how much atmosphere is present and, to some degree, what it's made of.

"CubeSats have incredible potential to carry cameras and science instruments out to deep space," said John Baker, JPL's program manager for small spacecraft. "They'll never replace the more capable spacecraft NASA is best known for developing. But they're low-cost ride-alongs that can allow us to explore in new ways."

As a bonus, some consumer-grade cameras aboard MarCO provided "drive-by" images as the CubeSats sailed past Mars. MarCO-B was programmed to turn so that it could image the planet in a sequence of shots as it approached Mars (before launch, MarCO-A's cameras were found to be either non-functioning or too blurry to use).

After the landing, MarCO-B turned backward to take a farewell shot of the Red Planet. It also attempted to snap some photos of Mars' moons, Phobos and Deimos.

"WALL-E sent some great postcards from Mars!" said Cody Colley of JPL, MarCO's mission manager, who led the work to program each CubeSat to take images. "It's been exciting to see the view from almost 1,000 miles (1,600 kilometers) above the surface."

With the mission's objectives reached, the MarCO team will spend the next couple of weeks collecting additional data on each CubeSat. Of interest will be how much fuel is left in each CubeSat and detailed analyses of how their relay capability performed.

There's also sure to be more celebrating among the team.

Read more at Science Dialy

InSight Is catching rays on Mars

The Instrument Deployment Camera (IDC), located on the robotic arm of NASA's InSight lander, took this picture of the Martian surface on Nov. 26, 2018, the same day the spacecraft touched down on the Red Planet. The camera's transparent dust cover is still on in this image, to prevent particulates kicked up during landing from settling on the camera's lens. This image was relayed from InSight to Earth via NASA's Odyssey spacecraft, currently orbiting Mars.

NASA's InSight has sent signals to Earth indicating that its solar panels are open and collecting sunlight on the Martian surface. NASA's Mars Odyssey orbiter relayed the signals, which were received on Earth [Nov. 26] at about 5:30 p.m. PST (8:30 p.m. EST). Solar array deployment ensures the spacecraft can recharge its batteries each day. Odyssey also relayed a pair of images showing InSight's landing site.

"The InSight team can rest a little easier tonight now that we know the spacecraft solar arrays are deployed and recharging the batteries," said Tom Hoffman, InSight's project manager at NASA's Jet Propulsion Laboratory in Pasadena, California, which leads the mission. "It's been a long day for the team. But tomorrow begins an exciting new chapter for InSight: surface operations and the beginning of the instrument deployment phase."

InSight's twin solar arrays are each 7 feet (2.2 meters) wide; when they're open, the entire lander is about the size of a big 1960s convertible. Mars has weaker sunlight than Earth because it's much farther away from the Sun. But the lander doesn't need much to operate: The panels provide 600 to 700 watts on a clear day, enough to power a household blender and plenty to keep its instruments conducting science on the Red Planet. Even when dust covers the panels -- what is likely to be a common occurrence on Mars -- they should be able to provide at least 200 to 300 watts.

The panels are modeled on those used with NASA's Phoenix Mars Lander, though InSight's are slightly larger in order to provide more power output and to increase their structural strength. These changes were necessary to support operations for one full Mars year (two Earth years).

In the coming days, the mission team will unstow InSight's robotic arm and use the attached camera to snap photos of the ground so that engineers can decide where to place the spacecraft's scientific instruments. It will take two to three months before those instruments are fully deployed and sending back data.

In the meantime, InSight will use its weather sensors and magnetometer to take readings from its landing site at Elysium Planitia -- its new home on Mars.

About InSight

JPL manages InSight for NASA's Science Mission Directorate. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including France's Centre National d'Études Spatiales (CNES), the Institut de Physique du Globe de Paris (IPGP) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and IPGP provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain's Centro de Astrobiología (CAB) supplied the wind sensors.

Read more at Science Daily

Blood-sucking flies have been spreading malaria for 100 million years

Mosquitoes in the amber.

The microorganisms that cause malaria, leishmaniasis and a variety of other illnesses today can be traced back at least to the time of dinosaurs, a study of amber-preserved blood-sucking insects and ticks show.

In addition to demonstrating the antiquity of vectors and their long-term association with parasitic microorganisms, the findings are remarkable for several reasons.

First, bloodsuckers like mosquitoes, fleas, sand flies, ticks and biting midges aren't frequently found in amber, and rarer yet is evidence of any microorganisms they might have been carrying.

But a review by entomologist George Poinar of Oregon State University showed that amber from five regions around the world contained hematophagous arthropods carrying preserved, identifiable pathogens and parasites.

"Feeding on vertebrate blood evolved as an efficient way for certain insects and acarines to get protein for growth and reproduction," said Poinar, professor emeritus in the College of Science and an international expert on plant and animal life forms found preserved in amber. "It's likely that primitive mosquitoes and other arthropod vectors were present back in the Jurassic and were even transmitting pathogens at that period. This would have resulted in widely dispersed diseases, many of which were probably fatal to vertebrates when they first appeared."

Poinar looked at bloodsucking insects and ticks encased in Dominican, Mexican, Baltic, Canadian and Burmese amber dating back from 15 million to 100 million years.

Among the vectors were mosquitoes, sand flies, biting midges, bat flies, black flies, fleas, kissing bugs and ticks. They carry a cornucopia of microorganisms that today cause diseases such as filariasis, sleeping sickness, river blindness, typhus, Lyme disease and, perhaps most significantly, malaria.

Malaria remains a relentless public health concern, with multiple nations reporting increases in infections for 2018. In Venezuela alone, Poinar notes, more than 650,000 new cases of malaria have been reported this year.

"Numerous malaria species parasitize vertebrates today, and we now know that over the past 100 million years, malaria was being vectored by mosquitoes, biting midges, bat flies and ticks," Poinar said. "Obtaining fossil records of pathogens carried by biting arthropods establishes a timeline when and where various diseases appeared and how they could have affected the survival, extinction and distribution of vertebrates over time."

Poinar stresses, however, that while his research shows what parasites and pathogens specific bloodsuckers were transmitting at particular periods and locations in the past, "these fossils are not old enough to tell us when and how associations between vectors, pathogens and vertebrates originated."

Poinar believes that the microorganisms first infected blood-sucking arthropods and only after equilibria had been reached between them were the microorganisms then vectored to vertebrates.

Read more at Science Daily

Prehistoric cave art suggests ancient use of complex astronomy

Some of the world's oldest cave paintings have revealed how ancient people had relatively advanced knowledge of astronomy. Animal symbols represent star constellations in the night sky, and are used to mark dates and events such as comet strikes, analysis from the University of Edinburgh suggests.

Some of the world's oldest cave paintings have revealed how ancient people had relatively advanced knowledge of astronomy.

The artworks, at sites across Europe, are not simply depictions of wild animals, as was previously thought. Instead, the animal symbols represent star constellations in the night sky, and are used to represent dates and mark events such as comet strikes, analysis suggests.

They reveal that, perhaps as far back as 40,000 years ago, humans kept track of time using knowledge of how the position of the stars slowly changes over thousands of years.

The findings suggest that ancient people understood an effect caused by the gradual shift of Earth's rotational axis. Discovery of this phenomenon, called precession of the equinoxes, was previously credited to the ancient Greeks.

Around the time that Neanderthals became extinct, and perhaps before humankind settled in Western Europe, people could define dates to within 250 years, the study shows.

The findings indicate that the astronomical insights of ancient people were far greater than previously believed. Their knowledge may have aided navigation of the open seas, with implications for our understanding of prehistoric human migration.

Researchers from the Universities of Edinburgh and Kent studied details of Palaeolithic and Neolithic art featuring animal symbols at sites in Turkey, Spain, France and Germany.

They found all the sites used the same method of date-keeping based on sophisticated astronomy, even though the art was separated in time by tens of thousands of years.

Researchers clarified earlier findings from a study of stone carvings at one of these sites -- Gobekli Tepe in modern-day Turkey -- which is interpreted as a memorial to a devastating comet strike around 11,000 BC. This strike was thought to have initiated a mini ice-age known as the Younger Dryas period.

They also decoded what is probably the best known ancient artwork -- the Lascaux Shaft Scene in France. The work, which features a dying man and several animals, may commemorate another comet strike around 15,200 BC, researchers suggest.

The team confirmed their findings by comparing the age of many examples of cave art -- known from chemically dating the paints used -- with the positions of stars in ancient times as predicted by sophisticated software.

The world's oldest sculpture, the Lion-Man of Hohlenstein-Stadel Cave, from 38,000 BC, was also found to conform to this ancient time-keeping system.

This study was published in Athens Journal of History.

Dr Martin Sweatman, of the University of Edinburgh's School of Engineering, who led the study, said: "Early cave art shows that people had advanced knowledge of the night sky within the last ice age. Intellectually, they were hardly any different to us today.

Read more at Science Daily