пятница, 30 ноября 2018 г.

2018 November 30 A Cold River to Orion Image Credit &…


2018 November 30


A Cold River to Orion
Image Credit & Copyright: Juris Sennikovs


Explanation: Ice is forming on the river Lielupe as it flows through the landscape in this winter’s night scene. Even in motion the frigid water still reflects a starry sky, though. The well planned, Orion-centered panorama looks toward the south, taken in three exposures from a bridge near the village of Stalgene, Latvia, planet Earth. Drifting pancakes of ice leave streaks in the long exposures, while familiar stars of Orion and the northern winter night appear above and below the horizon. Village lights along the horizon include skyward beams from the local community church. This image was a first place winner in the 2018 StarSpace astrophotography competition.


∞ Source: apod.nasa.gov/apod/ap181130.html


Captioned Image Spotlight: Active Dunes in Wirtz CraterThese…


Captioned Image Spotlight: Active Dunes in Wirtz Crater


These gorgeous dunes are likely active, with ripples on their upwind slopes and dark streaks on their downwind slopes forming and changing due to wind-driven sand motion.


This motion will also keep the dune brink (the edge between the two slopes) and bottom edges sharply defined. The dark lines and squiggles on the dune slope are formed by passing dust devils.


NASA/JPL/University of Arizona


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

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.











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
[Credit: Wits University]

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.











Detective mission to characterize and trace the history of a new African meteorite
This is a close-up of the meteorite fragment showing the fusion crust
[Credit: Wits University]

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.


“The Benenitra meteorite is a new Space rock, but it is also a witnessed fall, which makes it part of special group of meteorites. It is part of our collective heritage as a species, planet and Solar System. It fell in a remote area that will henceforth be recognised internationally for the event on the evening of 27 July. Our project provides an opportunity to further strengthen scientific collaboration in the SADC region. Ultimately, one of our goals is to inform the people of Benenitra about the significance of what they witnessed and thus build greater awareness of science,” says Gibson.


Source: University of the Witwatersrand [November 27, 2018]



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The quest for galactic relics from the primordial universe

They are massive, they are very small, and they are extremely rare, but may hold the secrets of how galaxies form and evolve. A new study lifts the tip of the veil over the timid life of the massive ultra-compact galaxies. It was recently published in the journal Astronomy and Astrophysics and was carried out by an international team led by Fernando Buitrago, of Instituto de Astrofisica e Ciencias do Espaco (IA) and Faculdade de Ciencias da Universidade de Lisboa (FCUL).











The quest for galactic relics from the primordial universe
Massive ultracompact galaxies with stellar masses greater than 80 billion suns
[Credit: Buitrago et al., 2018]

Massive ultra-compact galaxies have several times more stars than our Milky Way, more than the equivalent to 80 billion suns, and thus are very bright, but their stars are densely packed within a size much smaller than our galaxy’s. The researchers identified a new set of 29 galaxies with these properties, at distances between two and five billion light-years from Earth.


Seven of these shy heavyweights are actually primordial galaxies that remained untouched by others since their formation, more than ten billion years ago. These so-called relic galaxies open windows onto how galaxies looked like and were in the early ages of the universe, although they are in our galactic neighborhood.


“When you study very small objects and you study them in the far away universe, it is very hard to tell anything about them,” says Fernando Buitrago. “As this sample of galaxies we studied is in the nearby universe and relatively close to us, even being truly small, we have a better chance of probing them.”


One of the advances of the paper now published is to present the density of these massive ultra-compact galaxies in the universe, relics and non-relics altogether. The researchers have found only 29 in the most complete survey of galaxies in the local universe.


“They are so rare that we need roughly a volume with nearly 500 million light-years across to find a single one of them,” says Ignacio Ferreras, the second author of the study.


Ferreras determined the ages of the stars in the galaxies, separating the redder and older relic galaxies from the bluer and younger. How could those relics be preserved untouched across cosmic time is something yet to be understood, says Fernando Buitrago.


According to the paradigm of galaxy formation and evolution, these relic ultra-compact galaxies could only be saved from merging with others and evolving by residing in overly populated clusters of galaxies. It may sound counter-intuitive as one would expect that in such crowded environments they would more easily interact and lose their original properties, but Buitrago explains: “In a place where there are many galaxies, there is also a lot of gravitational pull and the velocities of the galaxies are very high. Thus, the galaxies pass by each other without enough time to interact significantly.”


“The surprise came when we realized that not all the galaxies in our sample live in such systems,” Buitrago adds. “We found them in a range of environments, and for those that live in underdense neighborhoods, this is very hard to explain.”


In this study, the researchers tried to measure some of the properties of these objects, such as their sizes and ages, but they are requesting observing time with large ground-based telescopes to point directly at them. In order to understand their past history, they would like to study in greater detail the places where they live in, the other galaxies around them, and their relative positions in space.


“Massive galaxies evolve in an accelerated way when compared to other galaxies in the universe. By understanding the properties of the most massive galaxies, we could understand the eventual fate of all the other galaxies, including our own Milky Way,” Fernando Buitrago says.


Source: Instituto de Astrofísica e Ciências do Espaço [November 27, 2018]



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New evidence reveals how heavy elements were created after the Big Bang

The Big Bang theory and the question of how life on Earth began has fascinated scientists for decades, but now new research from The University of Western Australia suggests the conditions that resulted from the Big Bang are different to what we thought.











New evidence reveals how heavy elements were created after the Big Bang
Credit: Pasieka/Getty Images

The Big Bang theory, developed in 1927 is considered the most credible scientific explanation of how the universe was created. It suggests that through a process of expansion and explosion hydrogen gas was created which led to the formation of stars, and their death (supernova) led to the creation of life.


Researchers Professor Snezhana Abarzhi and Ms Annie Naveh from UWA’s School of Mathematical Sciences conducted a mathematical analysis of the conditions that were created from a supernova.


Professor Abarzhi said although the supernova explosion was violent it wasn’t as turbulent and quick as previously thought.


“It is traditionally considered that turbulence was the mechanism for energy transfer and accumulation which resulted in chemicals being formed in the supernova,” Professor Abarzhi said.


“However our research has revealed it wasn’t turbulent but actually a slow process where hot spots of energy were localised and trapped, resulting in the formation of, for example iron, gold and silver from atoms produced by the Big Bang.


“The findings are important because they challenge our understanding of the Big Bang theory and how life formed.”


Professor Abarzhi said it was fascinating to see the complexity of how the universe might have been formed.


“Human beings essentially started as hydrogen atoms and energy, swirling around to create other chemicals and these interactions resulted in life,” she said.


“The creation of life on Earth will always fascinate and challenge us, leaving more questions than answers, but this latest research brings us one step closer to understanding how we came to exist.”


The findings are published in Proceedings of the National Academy of Sciences.


Source: University of Western Australia [November 27, 2018]



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Brazil loses ‘one million football pitches’ worth of forest

Deforestation in Brazil has reached such epic proportions that an area equivalent to one million football pitches was lost in just one year, Greenpeace said.











Brazil loses 'one million football pitches' worth of forest
Deforestation in Brazil’s Amazon rainforest has been worsening with the loss of an area the size
of one million football pitches in one year [Credit: Carl De Souza/AFP]

Between August 2017 and July 2018, deforestation increased by almost 14 percent with an area of 7,900 square kilometers (3,050 square miles) of forest cleared, according to the governmental institution of special investigations.


“It’s more or less one million football fields of deforestation in just one year,” Marcio Astrini, the public policies coordinator for Greenpeace Brazil, told AFP.


“Every year we have this news that forest is being criminally deforested.”


Astrini said things could get even worse if president-elect Jair Bolsonaro carries out his threats to loosen environmental protection rules.


His appointment of Tereza Cristina as agriculture minister also caused concerns as she heads the agribusiness lobby in congress and is a supporter of clearing more forested area to make way for pasture land and agriculture.


The Amazon rainforest represents more than half of Earth’s remaining rainforest and covers an area of 5.5 billion km2, about 60 percent of which is in Brazil.


But it is under threat from illegal logging as well as farming, in particular from soybean plantations and pasture land for cattle.


Between 2004 and 2012, deforestation in Brazil was slowed through controls imposed at a government level as well as by the private sector.


But Bolsonaro has said he will “end protected areas, indigenous reserves, that he will reduce the power to inspect and punish environmental crimes,” according to Astrini.


“If he does all this, if he reduces the ability to punish crimes, Amazon deforestation could explode into an unimaginable situation,” added Astrini.


Source: AFP [November 27, 2018]



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Mosquitoes, other blood-sucking flies have been spreading malaria for up to 100 million...

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.











Mosquitoes, other blood-sucking flies have been spreading malaria for up to 100 million years
Fossilised black fly [Credit: Oregon State University]

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.











Mosquitoes, other blood-sucking flies have been spreading malaria for up to 100 million years
Fossilised flea [Credit: Oregon State University]

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.


“That topic has been and will continue to be under discussion for years to come,” he said.


The findings are published in Historical Biology.


Author: Steve Lundeberg | Source: Oregon State University [November 27, 2018]



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Fossil algae reveal 500 million years of climate change

Earth scientists are able to travel far back in time to reconstruct the geological past and paleoclimate to make better predictions about future climate conditions. Scientists at the Netherlands Institute for Sea Research (NIOZ) and Utrecht University succeeded in developing a new indicator (proxy) of ancient CO2-levels, using the organic molecule phytane, a debris product of chlorophyll. This new organic proxy not only provides the most continuous record of CO2-concentrations ever, it also breaks a record in its time span, covering half a billion years. The data show the present idea that rises in CO2-levels that used to take millions of years, are now happening in a century. These findings are published in Science Advances.











Fossil algae reveal 500 million years of climate change
Cells of coccolithophore genera Gephyrocapsa grown in laboratory culture
[Credit: ERC]

As CO2 increases today, it’s vital to understand what impact these changes will have. To better predict the future, we must understand long-term changes in CO2 over geologic history. Direct measurements of past CO2 are available, e.g. bubbles in ice cores containing ancient gases. However, ice cores have a limited time span of one million years. To go farther back in time, earth scientists have developed various indirect measurements of CO2 from proxies e.g. from algae, leaves, ancient soils and chemicals stored in ancient sediments to reconstruct past environmental conditions.
Phytane, a new way to travel in time


A new proxy, using a degradation product of chlorophyll, allows geochemists to infer a continuous record of historic CO2-levels in deep time. Scientists at NIOZ have recently developed phytane as a promising new organic proxy that uncovers half a billion years of CO2-levels in the oceans, from the Cambrian until recent times.


Using the new proxy, they were able to make the most continuous record of ancient carbon dioxide levels ever. “We developed and validated a new way to time travel — going farther back in time and to more places,” says NIOZ-scientist Caitlyn Witkowski. “With phytane, we now have the longest CO2-record with one single marine proxy. This new data is invaluable to modelers who can now more accurately make predictions of the future.”


Witkowski and colleagues selected more than 300 samples of marine sediments from deep sea cores and oils from all over the globe, reflecting the majority of geological periods in the last 500 million years.


Fossil molecules


Past chemical reactions can be ‘stored’ in fossil molecules, and so they may reflect various ancient environmental conditions. Geochemists are able to ‘read’ these conditions, such as seawater temperature, pH, salinity and CO2-levels. Organic matter, such as phytane, reflects the pressure of CO2 in ocean water or the atmosphere (pCO2).











Fossil algae reveal 500 million years of climate change
For her research Witkowski collected seawater with fresh, modern algae to test potential
indicators of the past [Credit: Caitlyn Witkowski]

Little green miracles


Although all organic matter has the potential to reflect CO2, phytane is special. Phytane is the pigment responsible for our green world. Anything that uses photosynthesis to absorb sunlight, including plants, algae, and some species of bacteria, has chlorophyll from which phytane comes. Plants and algae take in CO2 and produce oxygen. Without these little green miracles, our world just wouldn’t be the same.


Because chlorophyll is found all around the world, phytane is also everywhere and is a major constituent of decayed and fossilized biomass. “Phytane doesn’t chemically change over the course of time, even if it is millions of years old,” Witkowski says.


Carbon isotope fractionation


CO2 of the past is estimated from organic matter, such as phytane, through the phenomenon of carbon isotope fractionation during photosynthesis. When taking up CO2, plants and algae prefer the light carbon isotope (12C) over the heavy carbon isotope (13C). They only use the heavy carbon isotope when CO2-levels in the surrounding water or atmosphere are low. The proportion between these two isotopes therefore reflects the level of carbon dioxide in the environment at the moment of growth.


This also explains why Witkowski didn’t use terrestrial plants as a source for her research, exclusively using phytane from (fossilized) marine sources. The plant world is divided into so-called C3- and C4-plants, each with their own unique ratio of light-to-heavy carbon. Phytoplankton all have very similar ratios compared to their plant counterparts. Witkowski: “By choosing only marine sources, we could limit uncertainty of the phytane source in the dataset.”


“In our data, we see high levels of carbon dioxide, reaching 1000 ppm as opposed to today’s 410 ppm. In this respect, present day levels are not unique, but the speed of these changes have never been seen before. Changes that typically take millions of years are now happening in a century. This additional CO2-data may help us understand the future of our planet.” In future research, phytane can be used to go even further back in time than the Phanerozoic, the earliest found in two billion-year-old samples.


Source: Royal Netherlands Institute for Sea Research [November 28, 2018]



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Fires fueled spread of grasslands on ancient Earth

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.











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 [Credit: Anna K. Behrensmeyer]

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.


The new fire marker approach could be used to examine landscape-scale interactions between fire and vegetation for other geographic regions and climactic transitions, like glacial-interglacial transitions or catastrophic climate-change events, researchers said.


Author: Matthew James Carroll | Source: Pennsylvania State University [November 28, 2018]



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The ‘Chinese Pyramids’ and the pole star

The funerary complex of the first Chinese emperor of the Qin dynasty (3th century BC) is one of the most famous archaeological sites in the world. This is of course due to the discovery of the statues of the terracotta army, intended to accompany the emperor in the afterlife. Much less known than the statues is the fact that tomb proper (still not excavated) lies beneath a gigantic, artificial hill of rammed earth. This hill has a square shape, a base side of more than 350 meters and is over 40 meters high, so that it can easily be called a pyramid.











The 'Chinese Pyramids' and the pole star
This is the huge mole of the Maoling Mausoleum of Emperor Wu of Han
[Credit: Giulio Magli]

Even less known is the fact that also all the emperors of the subsequent dynasty, the Western Han, chose to be buried under similar pyramids. These mausoleums are visible still today within the rapidly developing landscape of the northwestern surroundings of Xian along the Wei River. Including also the tombs of the queens and other members of royal families, there are over 40 of such “Chinese pyramids”. Of these, only two have been (partly) excavated.
The new study is part of an extensive program of research on the role of astronomy and of the traditional doctrine of “feng shui” in the Chinese imperial necropolises and has just been published in the academic journal Archaeological Research in Asia.


In the work simple techniques based on satellite images are used, together with field surveys, to collect a large number of new data and, in particular, to study the orientation of the pyramid bases. It is in fact well known that, for example, the Egyptian pyramids are oriented with great precision to the cardinal points, by virtue of the very strong bonds of the funerary religion of the Egyptian pharaohs with the sky and in particular with the circumpolar stars.











The 'Chinese Pyramids' and the pole star
The Terracotta Warriors protecting the Qin Mausoleum’s east front
[Credit: Giulio Magli]

Although – of course – there is no connection with the Egyptian pyramids, also the Chinese emperors credited their power as a direct mandate of the heaven, identifying the circumpolar region as a celestial image of the imperial palace and its inhabitants. It was therefore natural to expect the Chinese pyramids, tombs of the emperors, to be oriented to the cardinal points. In this connection, the results of the new study are in part surprising.
It turns out that these monuments can be classified according to two “families”. One such families comprises monuments oriented with good precision to the cardinal points, as expected. In the other family there are significant deviations from the true north, all of comparable and all on the same “hand “(to the west of the north looking towards the monument).


It is out of the question that this second family may have been due to errors of the Chinese astronomers and architects. One could think of the use of the compass, which was invented in China in a somewhat rudimentary form at that time, but there is no correspondence with the paleomagnetic data. The explanation proposed in the article is thus astronomical: the emperors who built the pyramids of the “family 2” did not want to point to the north celestial pole, which at the time did not correspond to any star, but to the star to which the pole would be approached in the future: Polaris.


All this discourse may look strange at first sight, but it must be remembered that there is a phenomenon, the precession of the earth’s axis, which slowly but constantly moves the position in the sky in which the earth’s axis points, and therefore the celestial pole. The Chinese astronomers were almost certainly aware of this. Nowadays we are used to identify the north celestial pole with Polaris (although in reality the correspondence is not perfect) but at the time of the Han emperors the pole was still far from Polaris, and with a distance in degrees approximately equal to the deviation of the Chines pyramids from the geographic north.


Source: Politecnico di milano [November 28, 2018]



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Hubble Uncovers Thousands of Globular Star Clusters Scattered Among Galaxies



Coma Cluster Full Mosaic

This is a Hubble Space Telescope mosaic 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 observe


d 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.”


The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.





Credits:






Image: NASA, ESA, J. Mack (STScI), and J. Madrid (Australian Telescope National Facility)






Science: NASA, ESA, and J. Madrid (Australian Telescope National Facility)






Related Links






Contact

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland
410-338-4514
villard@stsci.edu


Juan Madrid
Australian Telescope National Facility, Sydney, Australia
jmadrid@astro.swin.edu.au






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Hubble Explores the Coma Cluster’s More Than 1,000 Galaxies


NASA – Hubble Space Telescope patch.


Nov. 29, 2018



This Hubble Space Telescope mosaic is 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 conduct 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.


The study, 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.



Hubble Space Telescope (HST)

For more information about Hubble, visit:


http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/


Image, Animation, Credits: NASA, Yvette Smith, ESA, J. Mack (STScI) and J. Madrid (Australian Telescope National Facility).


Greetings, Orbiter.chArchive link


Spacewalk Preps and Muscle Research Keep Crew Busy


ISS – Expedition 57 Mission patch.


November 29, 2018



International Space Station (ISS). Animation Credit: NASA

A Russian spacewalk is planned before three Expedition 57 crew members return to Earth aboard a Soyuz spacecraft just before Christmas. Meanwhile, in the middle of the spacewalk and departure preparations, the International Space Station residents today also explored how living in space impacts the human muscle system.


Flight Engineer Sergey Prokopyev will work outside the space station Dec. 11 to inspect the Soyuz MS-09 crew vessel. The first-time spacewalker will join veteran cosmonaut Oleg Kononenko for a scheduled 6-hour inspection on the outside of the spaceship that will return the Expedition 57 crew home Dec. 19 U.S. time.



Image above: Flight Engineer Serena Auñón-Chancellor researches the complex process of cement solidification in space. Results may impact possible construction processes and designs for space habitats on the surface of the Moon and Mars. Image Credit: NASA.


Prokopyev checked the Orlan spacesuits today that he and Kononenko will wear during the eighth spacewalk of the year. Expedition 57 Commander Alexander Gerst and Flight Engineer Serena Auñón-Chancellor assisted Prokopyev checking the Russian spacesuits for leaks.


Gerst and Auñón-Chancellor then moved on to a study that has been ongoing aboard the orbital lab since September of 2017 observing how muscles adapt to outer space. The duo set up the Columbus lab module for research operations and scanned their head and foot muscles with an ultrasound device. The data may help doctors improve fitness in space and develop treatments for muscle and aging problems on Earth.



Image above: Flying over South Indian Ocean, seen by EarthCam on ISS, speed: 27’564 Km/h, altitude: 421,18 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam’s from ISS on November 29, 2018 at 23:22 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.


Back on Earth, on opposite sides of the globe, a pair of rockets are getting ready to send a new crew and more science and supplies to the space station. Russia’s Soyuz MS-11 spacecraft will launch Kononenko and fellow crew members Anne McClain and David Saint-Jacques from Kazakhstan to the station on Monday at 6:31 a.m. EST. The following day at 1:38 p.m. in Florida, the SpaceX Dragon will blast off to the station to deliver more than 5,600 pounds of cargo to resupply the station residents.


Related links:


Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html


Columbus lab module: https://www.nasa.gov/mission_pages/station/structure/elements/europe-columbus-laboratory


SpaceX Dragon: https://www.nasa.gov/mission_pages/station/structure/launch/spacex.html


NASA TV: https://www.nasa.gov/multimedia/nasatv/index.html


Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Images (mentioned), Animation (mentioned), Text, Credits: NASA/Marck Garcia/Orbiter.ch Aerospace/Roland Berga.


Best regards, Orbiter.chArchive link


Climate change risks ‘extinction domino effect’

New research reveals the extinction of plant or animal species from extreme environmental change increases the risk of an ‘extinction domino effect’ that could annihilate all life on Earth.











Climate change risks 'extinction domino effect'
Virtual earths modelling shows an ‘extinction domino effect’ risk ten times higher than forecast, indicating rising
global temperatures due to climate change could wipeout entire species [Credit: Flinders University]

This would be the worst-case scenario of what scientists call ‘co-extinctions’, where an organism dies out because it depends on another doomed species, with the findings published in the journal Scientific Reports.


Think of a plant’s flower pollinated by only one species of bee — if the bee becomes extinct, so too will the plant eventually.


“Even the most resilient species will inevitably fall victim to the synergies among extinction drivers as extreme stresses drive ecosystems to collapse.” says lead author Dr Giovanni Strona of the European Commission’s Joint Research Centre based in Ispra in northern Italy.


Researchers from Italy and Australia simulated 2,000 ‘virtual earths’ linking animal and plant species. Using sophisticated modelling, they subjected the virtual earths to catastrophic environmental changes that ultimately annihilated all life.


Examples of the kinds of catastrophes they simulated included runaway global warming, scenarios of ‘nuclear winter’ following the detonation of multiple atomic bombs, and a large asteroid impact.


“What we were trying to test is whether the variable tolerances to extreme global heating or cooling by different species are enough to explain overall extinction rates,”



“But because all species are connected in the web of life, our paper demonstrates that even the most tolerant species ultimately succumb to extinction when the less-tolerant species on which they depend disappear.”


“Failing to take into account these co-extinctions therefore underestimates the rate and magnitude of the loss of entire species from events like climate change by up to 10 times,” says co-author Professor Bradshaw of Flinders University in South Australia


Professor Bradshaw and Dr Strona say that their virtual scenarios warn humanity not to underestimate the impact of co-extinctions.


“Not taking into account this domino effect gives an unrealistic and exceedingly optimistic perspective about the impact of future climate change”, warns Professor Bradshaw.


It can be hard to imagine how the demise of a small animal or plant matters so much, but the authors argue that tracking species up to total annihilation demonstrates how the loss of one can amplify the effects of environmental change on the remainder.


“Another really important discovery was that in the case of global warming in particular, the combination of intolerance to heat combined with co-extinctions mean that 5-6 degrees of average warming globally is enough to wipe out most life on the planet”, says Dr Strona.


Professor Bradshaw further warns that their work shows how climate warming creates extinction cascades in the worst possible way, when compared to random extinctions or even from the stresses arising from nuclear winter.


Source: Flinders University [November 29, 2018]



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New study reveals common table salt may have been crucial for the origins of life

One of the most fundamental unexplained questions in modern science is how life began. Scientists generally believe that simple molecules present in early planetary environments were converted to more complex ones that could have helped jumpstart life by the input of energy from the environment.











New study reveals common table salt may have been crucial for the origins of life
Starting from hydrogen cyanide, the one-pot synthesis of cyanamide and precursors to simple sugars in water — using
 gamma rays in the presence of ammonium and chloride salts — offers a way forward for engineering complex
 mixtures that can evolve important, potentially prebiological compounds [Credit: Chemistry Select]

Scientists consider the early Earth was suffused with many kinds of energy, from the high temperatures produced by volcanoes to the ultraviolet radiation beamed down by the sun. One of the most classic studies of how organic compounds could have been made on the early Earth is the Miller-Urey experiment, which showed you electrical discharges simulating lightning can help make a variety of organic compounds, including amino acids, which are basic building blocks of all life.


Another important source of energy in planetary environments is high-energy radiation, which has various sources including radioactive decay of naturally occurring chemical elements such as uranium and potassium. Research led by Yi Ruiqin and Albert Fahrenbach from the Earth-Life Science Institute (ELSI) at Tokyo Institute of Technology, Japan, has recently shown that a variety of compounds useful for the synthesis of RNA, are produced when simple compound, combined with sodium chloride, are exposed to gamma rays.


This work importantly brings us one step closer to understanding how RNA, which is widely thought to be a candidate molecule for helping start life, could have arisen abiotically on early Earth. Due to its complexity, making RNA “from scratch” under primitive solar system conditions is no easy task. Biology is great at it, because it has evolved over billions of years to do the job with amazing efficiency.


Before life emerged, there would have been little in the environment that would have assisted in making RNA. These researchers found that sodium chloride – or common table salt – can assist in making the necessary building blocks for RNA. Sodium chloride is the chemical compound that makes the sea salty, thus it is highly likely this process could occur on primitive planets, including Earth.


The most challenging aspect of this work was figuring out that salt, specifically the chloride component, played a crucial role in these reactions. Typically, chemists ignore chloride in their reactions. When chemists conduct reactions in water, it is highly likely at least some chloride is in there anyway, though most of the time it just sits idly by as a “spectator.” It often doesn’t play a significant role in the reactions chemists are interested in, it’s just part of the background a lot of the time.


These researchers found out though, that this was not the case in their experiments, and it took them some time to figure that out. What they eventually deduced was that the ionizing radiation they were using as the energy source to drive their reactions causes chloride to lose an electron and become what is known as a “radical”. As the name suggests, the chloride is then no longer so mild-mannered and becomes much more chemically reactive. Once the chloride is activated by gamma radiation, it is free to help construct other high energy compounds which finally can help build up complex RNA molecules.


While these researchers haven’t yet coaxed their reactions all the way to RNA, this work shows that there is now nothing in principle which should stop this from occurring. The question now is not so much how to make all the necessary building blocks to make RNA, but how to combine them in a “warm little pond” to make the first RNA polymers. One of the major challenges to this is understanding how other molecules, that is, other than those important for making RNA, might affect this process.


The authors think this could be pretty “messy” chemistry in the sense that a lot of other molecules, which could interfere with this process, would be made at the same time. Whether these other molecules will interfere with RNA synthesis, or even have a beneficial effect, is the future focus of these scholars’ research. Understanding very complex mixtures of chemicals is not only a challenge in origins of life research, but a major challenge for organic chemistry in general.


The findings are published in Chemistry Select.


Source: Tokyo Institute of Technology [November 29, 2018]



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

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.











Whales lost their teeth before evolving hair-like baleen in their mouths
Carlos Mauricio Peredo, National Museum of Natural History predoctoral fellow and lead author of the study, with the
33 million-year-old early baleen whale Maiabalaena nesbittae. The fossil is the first of its species to be described by
scientists and will now serve as the exemplar of this species for the scientific community. 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 [Credit: Smithsonian]

In the recent 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 lost their teeth before evolving hair-like baleen in their mouths
Baleen is the soft, hair-like structure on the upper mouth of whales, such as the humpback whale in this photo, which allows
 them to trap prey in their mouth. 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. 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 [Credit: Ari S. Friedlaender/University of California, Santa Cruz/NOAA]

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.











Whales lost their teeth before evolving hair-like baleen in their mouths
The upper jaw and skull of Maiabalaena nesbittae. 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. “When we
talk about whale evolution, textbooks tend to focus on the early stages, when whales went from land to sea,” said Nicholas
Pyenson, the National Museum of Natural History’s curator of 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” [Credit: Smithsonian]

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.











Whales lost their teeth before evolving hair-like baleen in their mouths
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 [Credit: Alex Boersma]

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.


“Given the scale and rate of changes in the ocean today, we don’t exactly know what that will mean for all of the different species of filter-feeding whales,” he said. “We know that they’ve changed in the past. It’s just a matter of whether they can keep up with whatever the oceans are doing–and we’re changing the oceans pretty quickly right now.”


Source: Smithsonian [November 29, 2018]



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

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.











Oldest-known ancestor of modern primates may have come from North America, not Asia
Teilhardina brandti likely resembled a modern tarsier, a small primate native to Southeast Asia. A lower jaw 
from a tarsier is pictured at top with a lower jaw from Teilhardina brandti for comparison 
[Credit: Florida Museum/Kristen Grace]

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 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.











Oldest-known ancestor of modern primates may have come from North America, not Asia
The unusual tooth sockets in UF specimen 333700 upended the hypothesis that Teilhardina brandti was a younger
 species in the genus. The sockets closely resemble those in Teilhardina asiatica, thought to be 
the most primitive Teilhardina species [Credit: Florida Museum/Paul Morse]

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.”











Oldest-known ancestor of modern primates may have come from North America, not Asia
Teilhardina americana, whose jaw is pictured here, has been reclassified as a new genus, Bownonomys, 
as a result of Morse’s analysis [Credit: Florida Museum/Zach Randall & Rose Roberts]

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, Bownomomys, 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.


“A changing planet has dramatic effects on biology, ecosystems and evolution. It’s part of the process that has produced the diversity of life we see today and mass extinctions of life that have happened periodically in Earth’s history,” Bloch said. “One of the unexpected results of global warming 56 million years ago is that it marks the origin of the group that ultimately led to us. How we will fare under future warming scenarios is less certain.”


The findings were published in the Journal of Human Evolution.


Source: Florida Museum of Natural History [November 29, 2018]



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