четверг, 30 мая 2019 г.

Ancient marble head of Dionysus discovered near Roman Forum

Archaeologists in Rome have uncovered a large marble head from Rome’s imperial age that is believed to show Dionysus, also known as Bacchus, the Greek god of wine, music and dance.











Ancient marble head of Dionysus discovered near Roman Forum
Credit: Municipality of Rome

The white marble bust, believed to be 2,000 years old, was discoved in the heart of the city, near the Roman Forum, during excavations last week.


The head had been reused to form part of a medieval wall but experts say it is in excellent condition.


The head, with hollow eyes probably once filled with glass or precious stones, would have belonged to a large statue of the god created in the imperial age.


“The archaeologists were excavating a late medieval wall when they saw, hidden in the earth, a white marble head,” said a statement from the Archaeological Park of the Colosseum, which encompasses the Roman Forum.











Ancient marble head of Dionysus discovered near Roman Forum
Credit: Municipality of Rome

“It was built into the wall, and had been recycled as a building material, as often happened in the medieval era. Extracted from the ground, it revealed itself in all its beauty.”


“The face is refined and gracious, young and feminine. All of which makes us think this could be a depiction of Dionysos.”


The marble head will be cleaned and eventually put on display.


“Rome continues to surprise us every day,” said Virginia Raggi, the mayor of the capital. The head of the statue… is in excellent condition. It’s a marvel.”



Dionysus was the son of Zeus and Semele, the mortal daughter of the king of Thebes.


He was known as the god of wine, winemaking and grape cultivation, as well as of fertility, theatre and religious ecstasy.


He was worshiped by the ancient Greeks as one of the 12 Olympians before being incorporated into the Roman pantheon of gods as Bacchus.


Source: The Local [May 28, 2019]



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7000-year-old skeleton found in Bulgaria

Archaeologists from the Bulgarian Academy of Sciences (BAS) have found an early Neolithic grave at the Slatina site in capital city Sofia, according to an announcement on the BAS website.











7000-year-old skeleton found in Bulgaria
The recently discovered skeleton of a woman [Credit: BAS]

Archaeologists have been working on the current project examining the Slatina site for more than five years, uncovering details of an early Neolithic settlement that dated back to the period 6100 to 5500 BCE. The site was first examined and studied in the 1950s.
Slatina is believed to be the site of the oldest human settlement in what would later become Sofia.











7000-year-old skeleton found in Bulgaria
Furnace discovered during the excavations [Credit: BAS]

BAS said that many buildings had been found during the digs, including two large houses, of 117 and 147 m2, and one of close to 300 m2.
The settlement was surrounded by concentric ditches, which had protective and magical functions, sacrifices were made in them, BAS said.











7000-year-old skeleton found in Bulgaria
Stone implements and animal bones discovered at the site [Credit: BAS]

Among the newly discovered finds in the village of Slatina are various household and cult objects, such as a a bone spoon and ceramic vessels, and parts of cult sacrificial tables.
Bulgarian media reported Vassil Nikolov, deputy head of BAS and head of the dig team, as saying that the Neolithic grave find was extremely rare.











7000-year-old skeleton found in Bulgaria
Fragments of a sacrifical table found at the site [Credit: BAS]

The newly-discovered skeleton most likely was that of a woman buried with a child in the immediate vicinity of the remnants of a house on the outskirts of the village.
The archaeological excavations by Nikolov’s team are to continue in the central part of the settlement. They are financed by Sofia municipality, with the support of the Sofia Inspectorate.











7000-year-old skeleton found in Bulgaria
Pottery fragments found at the site [Credit: BAS]

Those who settled in Slatina in the Neolithic Age are believed to have come from central Asia, introducing agriculture to the area that would later become Bulgaria. They produced pottery, painted with white paint before being baked, and many ornaments painted in shades of red.


Source: The Sofia Globe [May 28, 2019]



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Research reveals the link between primate knuckles and hand use

Research carried out by the University of Kent has found differences between the knuckle joints of primates that will enable a better understanding of ancient human hand use.











Research reveals the link between primate knuckles and hand use
Credit: University of Kent

Using samples from the Powell-Cotton Museum in Birchington-on-Sea (UK), as well as samples from Germany, Belgium and the USA, a team led by School of Anthropology and Conservation (SAC) Ph.D. student Christopher Dunmore examined the internal bone structure, called trabeculae or cancellous bone, of great apes.


Trabecular bone is a honeycomb structure that is found within most bones and changes depending on what that bone is used for during a lifetime. When it is preserved in fossils, researchers can learn more about how ancient apes as well as humans moved and interacted with their environment.


The study compared the internal bone structure of the knuckle joints in chimpanzee, bonobo, orang-utan and gorilla hands, to assess whether this bone structure records how these apes moved when knuckle-walking on the ground or hanging from trees.


The researchers found the knuckle joints of orang-utans were consistent with flexing the knuckles while grasping branches, while the joints of chimpanzees, bonobos and gorillas were consistent with knuckle-walking—the most frequent ways in which these animals move around in their respective environments.


The information will now enable scientists studying fossils to better understand whether ancient humans were swinging from trees or walking on the ground.


Mr Dunmore said: ‘For the first time we see interesting internal bone patterns differentiating subtle differences between chimpanzee and gorilla knuckle-walking, as well as arboreal grasping in orang-utans. This matters because when we find ancient human hand fossils that preserve their internal structure, we can work out if they were probably swinging from trees during their lifetime or if they were walking on the ground more like humans today.’


The study was published in the Journal of Anatomy.


Source: University of Kent [May 29, 2019]



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Early humans deliberately recycled flint to create tiny, sharp tools

A new Tel Aviv University study finds that prehistoric humans «recycled» discarded or broken flint tools 400,000 years ago to create small, sharp utensils with specific functions. These recycled tools were then used with great precision and accuracy to perform specific tasks involved in the processing of animal products and vegetal materials.











Early humans deliberately recycled flint to create tiny, sharp tools
Experimental activity of cutting tubers with a small recycled flake and a close-up
of its prehension (inset) [Credit: Flavia Venditti/AFTAU]

The site of Qesem Cave, located just outside Tel Aviv, was discovered during a road construction project in 2000. It has since offered up countless insights into life in the region hundreds of thousands of years ago.


In collaboration with Prof. Cristina Lemorini of Sapienza University of Rome, the research was led jointly by postdoctoral fellow Dr. Flavia Venditti in collaboration with Profs. Ran Barkai and Avi Gopher. All three are members of TAU’s Department of Archaeology and Ancient Near Eastern Cultures.


In recent years, archaeologists working in caves in Spain and North Africa and digs in Italy and Israel have unearthed evidence that prehistoric people recycled objects they used in daily life. Just as we recycle materials such as paper and plastic to manufacture new items today, early hominids collected discarded or broken tools made of flint to create new utensils for specific purposes hundreds of thousands of years ago.


«Recycling was a way of life for these people,» Prof. Barkai says. «It has long been a part of human evolution and culture. Now, for the first time, we are discovering the specific uses of the recycled ‘tool kit’ at Qesem Cave.»


Exceptional conditions in the cave allowed for the immaculate preservation of the materials, including micro residue on the surface of the flint tools.


«We used microscopic and chemical analyses to discover that these small and sharp recycled tools were specifically produced to process animal resources like meat, hide, fat and bones,» Venditti explains. «We also found evidence of plant and tuber processing, which demonstrated that they were also part of the hominids’ diet and subsistence strategies.»


According to the study, signs of use were found on the outer edges of the tiny objects, indicating targeted cutting activities related to the consumption of food: butchery activities and tuber, hide and bone processing. The researchers used two different and independent spectroscopic chemical techniques: Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX).


«The meticulous analysis we conducted allowed us to demonstrate that the small recycled flakes were used in tandem with other types of utensils. They therefore constituted a larger, more diversified tool kit in which each tool was designed for specific objectives,» Venditti says.


She adds, «The research also demonstrates that the Qesem inhabitants practiced various activities in different parts of the cave: The fireplace and the area surrounding it were eventually a central area of activity devoted to the consumption of the hunted animal and collected vegetal resources, while the so-called ‘shelf area’ was used to process animal and vegetal materials to obtain different by-products.»


«This research highlights two debated topics in the field of Paleolithic archaeology: the meaning of recycling and the functional role of small tools,» Prof. Barkai observes. «The data from the unique, well-preserved and investigated Qesem Cave serve to enrich the discussion of these phenomena in the scientific community.»


«Our data shows that lithic recycling at Qesem Cave was not occasional and not provoked by the scarcity of flint,» Venditti concludes. «On the contrary, it was a conscious behavior which allowed early humans to quickly obtain tiny sharp tools to be used in tasks where precision and accuracy were essential.»


The researchers are continuing to investigate prehistoric recycling by applying their analysis to other sites in Africa, Europe and Asia.


The study was published in the Journal of Human Evolution.


Source: Tel Aviv University [May 29, 2019]



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Humans used northern migration routes to reach eastern Asia

Northern and Central Asia have been neglected in studies of early human migration, with deserts and mountains being considered uncompromising barriers. However, a new study by an international team argues that humans may have moved through these extreme settings in the past under wetter conditions. We must now reconsider where we look for the earliest traces of our species in northern Asia, as well as the zones of potential interaction with other hominins such as Neanderthals and Denisovans.











Humans used northern migration routes to reach eastern Asia
The sand dunes of Mongol Els jutting out of the steppe in Mongolia. Many of these desert
barriers only appeared after the Last Glacial Maximum (~20,000 years ago)
[Credit: Nils Vanwezer]

Archaeologists and palaeoanthropologists are increasingly interested in discovering the environments facing the earliest members of our species, Homo sapiens, as it moved into new parts of Eurasia in the Late Pleistocene (125,000-12,000 years ago). Much attention has focused on a ‘southern’ route around the Indian Ocean, with Northern and Central Asia being somewhat neglected.


However, in a paper published in PLOS ONE, scientists of the Max Planck Institute for the History of Human Science in Jena, Germany, and colleagues at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, argue that climate change may have made this a particularly dynamic region of hominin dispersal, interaction, and adaptation, and a crucial corridor for movement.


‘Heading North’ Out of Africa and into Asia


«Archaeological discussions of the migration routes of Pleistocene Homo sapiens have often focused on a ‘coastal’ route from Africa to Australia, skirting around India and Southeast Asia,» says Professor Michael Petraglia of the Max Planck Institute for the Science of Human History, a co-author of the new study. «In the context of northern Asia, a route into Siberia has been preferred, avoiding deserts such as the Gobi.»


Yet over the past ten years, a variety of evidence has emerged that has suggested that areas considered inhospitable today might not have always been so in the past. «Our previous work in Saudi Arabia, and work in the Thar Desert of India, has been key in highlighting that survey work in previously neglected regions can yield new insights into human routes and adaptations,» says Petraglia.











Humans used northern migration routes to reach eastern Asia
Ancient lake landforms around Biger Nuur, Mongolia, which is evidence
of larger lake sizes in the past [Credit: Nils Vanwezer]

Indeed, if Homo sapiens could cross what is now the Arabian Deserts then what would have stopped it crossing other currently arid regions such as the Gobi Desert, the Junggar Basin, and the Taklamakan Desert at different points in the past? Similarly, the Altai Mountains, the Tien Shan and the Tibetan Plateau represent a potentially new high altitude window into human evolution, especially given the recent Denisovan findings from Denisova Cave in Russia and at the Baishiya Karst Cave in China.


Nevertheless, traditional research areas, a density of archaeological sites, and assumptions about the persistence of environmental ‘extremes’ in the past has led to a focus on Siberia, rather than the potential for interior routes of human movement across northern Asia.


A «Green Gobi»?


Indeed, palaeoclimatic research in Central Asia has increasingly accumulated evidence of past lake extents, past records of changing precipitation amounts, and changing glacial extents in mountain regions, which suggest that environments could have varied dramatically in this part of the world over the course of the Pleistocene. However, the dating of many of these environmental transitions has remained broad in scale, and these records have not yet been incorporated into archaeological discussions of human arrival in northern and Central Asia.











Humans used northern migration routes to reach eastern Asia
Illustrated dispersal routes from the results of the Least Cost Path analysis. The three routes
 from the «wet» simulations and the single route from the «dry» simulation are presented
together in conjunction with palaeoclimatic extents (glaciers and palaeolakes)
[Credit: Nils Vanwezer and Hans Sell]

«We factored in climate records and geographical features into GIS models for glacials (periods during which the polar ice caps were at their greatest extent) and interstadials (periods during the retreat of these ice caps) to test whether the direction of past human movement would vary, based on the presence of these environmental barriers,» says Nils Vanwezer, PhD student at the Max Planck Institute for the Science of Human History and a joint lead-author of the study.


«We found that while during ‘glacial’ conditions humans would indeed likely have been forced to travel via a northern arc through southern Siberia, during wetter conditions a number of alternative pathways would have been possible, including across a ‘green’ Gobi Desert,» he continues. Comparisons with the available palaeoenvironmental records confirm that local and regional conditions would have been very different in these parts of Asia in the past, making these ‘route’ models a definite possibility for human movement.


Where did you come from, where did you go?


«We should emphasize that these routes are not ‘real’, definite pathways of Pleistocene human movement. However, they do suggest that we should look for human presence, migration, and interaction with other hominins in new parts of Asia that have been neglected as static voids of archaeology,» says Dr. Patrick Roberts also of the Max Planck Institute for the Science of Human History, co-author of the study. «Given what we are increasingly discovering about the flexibility of our species, it would be of no surprise if we were to find early Homo sapiens in the middle of modern deserts or mountainous glacial sheets.»


«These models will stimulate new survey and fieldwork in previously forgotten regions of northern and Central Asia,» says Professor Nicole Boivin, Director of the Department of Archaeology at the Max Planck Institute for the Science of Human History, and co-author of the study. «Our next task is to undertake this work, which we will be doing in the next few years with an aim to test these new potential models of human arrival in these parts of Asia.»


Source: Max Planck Society [May 29, 2019]



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Declining fertility rates may explain Neanderthal extinction, suggests new model

A new hypothesis for Neanderthal extinction supported by population modelling is put forward in a new study by Anna Degioanni from Aix Marseille Université, France and colleagues, published in the open-access journal PLOS ONE.











Declining fertility rates may explain Neanderthal extinction, suggests new model
Credit: Jose A Astor/Alamy

The lack of empirical data allowing testing of hypotheses is one of the biggest challenges for researchers studying Neanderthal extinction. Many hypotheses involve catastrophic events such as disease or climate change.


In order to test alternative hypothetical extinction scenarios, Degioanni and colleagues created a Neanderthal population model allowing them to explore demographic factors which might have resulted in declining populations and population extinction over a period of 4,000-10,000 years (a time frame compatible with known Neanderthal history).


The researchers created baseline demographic parameters for their Neanderthal extinction model (e.g. survival, migration, and fertility rates) based on observational data on modern hunter-gatherer groups and extant large apes, as well as available Neanderthal paleo-genetic and empirical data from earlier studies. The authors defined populations as extinct when they fell below 5,000 individuals.


The authors saw that in their model, extinction would have been possible within 10,000 years with a decrease in fertility rates of young (<20 year-old) Neanderthal women of just 2.7 percent; if the fertility rate decreased by 8 percent, extinction occurred within 4,000 years. If this decrease in fertility was amplified by a reduction in survival of infants (children less than one year old), a decrease in survival of just 0.4 percent could have led to extinction in 10,000 years.


The authors intended to explore possible Neanderthal extinction scenarios rather than to posit any definitive explanation. However, the researchers note that this study is the first to use empirical data to suggest that relatively minor demographic changes, such as a reduction in fertility or an increase in infant mortality, might have led to Neanderthal extinction. The authors note that modelling can be a useful tool in studying Neanderthals.


The authors add: «This study of the disappearance of the Neanderthals does not attempt to explain «why» the Neanderthals disappeared, but to identify «how» their demise may have taken place. This original approach is made on the basis of demographic modeling.


The results suggest that a very small reduction in fertility may account for the disappearance of the Neanderthal population. According to this research, this decrease did not concern all female Neanderthals, but only the youngest (less than 20 years old).»


Source: Public Library of Science [May 30, 2019]



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Lligwy Prehistoric Burial Chamber, Anglesey, North Wales, 28.5.19.


Lligwy Prehistoric Burial Chamber, Anglesey, North Wales, 28.5.19.











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2019 May 30 Sunrise at Copernicus Crater Image Credit &…


2019 May 30


Sunrise at Copernicus Crater
Image Credit & Copyright: Sage Gray


Explanation: A prominent impact site anchored in the lunar Oceanus Procellarum, Copernicus crater is at the center of this telescopic portrait in light and shadow. Caught in stacked and sharpened video frames recorded on April 14 at 3:30am UTC, the lunar terminator, or boundary between night and day, cuts across the middle of the 93 kilometer diameter crater. Sunlight is just beginning to strike its tall western walls but doesn’t yet shine on lower terrain nearby, briefly extending the crater’s outline into the lunar nightside. At that moment standing at Copernicus crater you could watch the sunrise, an event that happens at Copernicus every 29.5 days. Of course that corresponds to a lunar month or a lunation, the time between consecutive Full Moons, as seen from planet Earth.


∞ Source: apod.nasa.gov/apod/ap190530.html


Domino effect of species extinctions also damages biodiversity

The mutual dependencies of many plant species and their pollinators mean that the negative effects of climate change are exacerbated. As UZH researchers show, the total number of species threatened with extinction is therefore considerably higher than predicted in previous models.











Domino effect of species extinctions also damages biodiversity
Part of a giant network of mutual dependencies: Plants need insects to disperse their pollen and,
in turn, insects depend on plants for food [Credit: istock.com/KenanOlgun]

Global climate change is threatening biodiversity. To predict the fate of species, ecologists use climatic models that consider individual species in isolation. This type of model, however, overlooks the fact that species are part of a giant network of mutual dependencies: For example, plants need insects to disperse their pollen and, in turn, insects depend on plants for food.


Seven pollination networks in Europe investigated


These types of mutually beneficial interactions have been very important in generating the diversity of life on Earth. But the interaction also has a negative knock-on effect when the extinction of one species causes other species that are dependent on it to also die out, an effect that is called co-extinction.


Evolutionary biologists at the University of Zurich, together with ecologists from Spain, Great Britain and Chile, have now quantified how much more of an impact climate change has on biodiversity when these mutual dependencies between the species are taken into account. To this end, the researcher team analyzed the networks between flowering plants and their insect pollinators in seven different regions of Europe.


Extinction of the rock rose means the myrtle is also under threat


First author Jordi Bascompte gives a specific example to illustrate the results of the study: «In one of the networks situated in southern Spain, the sage-leaved rock rose has a 52 percent predicted probability of extinction caused by climate change in 2080. Should this happen, one of its pollinators, the small carpenter bee, would face a risk of co-extinction as a consequence of losing one of the resources it depends upon. Because the small carpenter bee also pollinates the myrtle, the latter is also under threat of extinction.»


Thus while the predicted extinction risk of the myrtle considered in isolation is 38 percent, the risk rises to around 62 percent when taking into account the network of interactions.


«If the interactions of individual species are also considered, the total number of species threatened with extinction rises,» summarizes Bascompte. «Some species with a very low likelihood of climate-related extinction according to the traditional model are at high risk of extinction due to their dependencies.»


Particular threat to biodiversity in Mediterranean regions


The authors also observed that the role of co-extinctions in increasing the pool of species being eradicated could be particularly high in Mediterranean communities. As an example, in a community in Greece, the total number of plant species predicted to disappear locally by 2080 could be as high as between two and three times the amount expected when considering species in isolation.


The researchers point to two reasons for this: First, Mediterranean regions have been more strongly affected by climate change than central and northern Europe. Second, the southern European regions are home to species with narrower distribution ranges, which makes them more susceptible to extinction than those broadly distributed. With such a high fraction of species and their interactions being driven extinct, the remaining network is more fragile and therefore prone to coextinction cascades.


The findings are published in Science Advances.


Source: University of Zurich [May 28, 2019]



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Fossil zooplankton indicate that marine ecosystems have entered the Anthropocene

It can be said that marine plankton has now entered the Anthropocene epoch. The researchers compared the compositions of fossil plankton (foraminifera) assemblages in sediments of the pre-industrial era with those of more recent times. The team has published their results in the journal Nature.











Fossil zooplankton indicate that marine ecosystems have entered the Anthropocene
The species composition of planktonic foraminifera from the past is stored in the sediments
[Credit: MARUM — Center for Marine Environmental Sciences,
University of Bremen; M. Kucera]

Planktonic foraminifera are microscopic organisms that live in the surface waters of the oceans. When they die their calcareous shells are deposited in the seafloor sediments. These fossil foraminifera document the species communities before humans began to alter the Earth’s climate. In turn, information on the present-day state of planktonic foraminifera is revealed by samples collected in sediment traps over the past 50 years. By comparing the fossil and modern communities of foraminifera, researchers can determine to what extent the plankton assemblages have changed since the beginning of industrialization.
For their study, Dr. Lukas Jonkers and Prof. Michal Kucera of MARUM at the University of Bremen, and Prof. Helmut Hillebrand of the Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg, compared over 3,700 samples from pre-industrial sediments with samples from sediment traps that reflect the plankton status from 1978 to 2013. The scientists have concluded that the present-day species communities are systematically different from pre-industrial times. «The exciting result was that this difference is not accidental, rather it reflects a signal of global warming. Modern communities in areas that are becoming warmer are similar to pre-industrial communities from warmer regions, indicating that species communities have shifted their distribution in a direction consistent with temperature change,» explains Lukas Jonkers.











Fossil zooplankton indicate that marine ecosystems have entered the Anthropocene
A sediment trap is retrieved from the sea. In these traps, particles are collected from the water column over
an extended period of time, usually for one year. From the samples, scientists can learn when and where
the various species live today [Credit: MARUM — Center for Marine Environmental Sciences,
University of Bremen; C. Schmidt]

«We have known for a long time that species associations are changing, but for many biological communities there were no reliable benchmarks, particularly on a global scale, due to the short time duration of observations,» says Jonkers. This has now changed with the data analyzed by these workers. «The data set is very large and also globally representative.» The disturbing aspect of the observation is that in many regions of the ocean the plankton communities have evidently migrated «into alien waters». There they must adapt to new conditions and, in some cases, rebuild their food webs. «The question is whether they can do this rapidly enough, or whether climate change will progress faster than the communities can adapt,» says Michal Kucera.
«Our cooperation illustrates how important it is for paleoecology and modern biodiversity research to work together,» adds Helmut Hillebrand. He is the head of the planktology working group of the ICBM and of the Helmholz Institute for Functional Marine Biodiversity at the University of Oldenburg. «Our study helps to understand how climate change impacts biodiversity. This is one of the prominent questions in the latest global report by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).


The reaction of marine ecosystems to climate change is an ongoing topic of research by scientists in Oldenburg and Bremen within the Cluster of Excellence «The Ocean Floor — Earth’s Uncharted Interface.»


Source: Marum — Center for Marine Environmental Sciences, University of Bremen [May 28, 2019]



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Africa’s elephant poaching rates in decline, but iconic animal still under threat

Elephant poaching rates in Africa have started to decline after reaching a peak in 2011, an international team of scientists have concluded.











Africa's elephant poaching rates in decline, but iconic animal still under threat
Despite the decline in poaching, Africa’s elephants are still at risk
[Credit: Colin Beale, University of York]

However, the team say the continent’s elephant population remains threatened without continuing action to tackle poverty, reduce corruption and decrease demand of ivory.


The research, which included scientists from the universities of Freiburg, York and the Convention for the International Trade in Endangered Species (CITES), reveals a decline in annual poaching mortality rate from an estimated peak of over 10 % in 2011 to less than 4 % in 2017.


It is estimated there are around 350,000 elephants left in Africa, but approximately 10-15,000 are killed each year by poachers.


At current poaching rates, elephants are in danger of being virtually wiped from the continent, surviving only in small, heavily protected pockets.


One of the authors of the study, Dr Colin Beale, from the University of York’s Department of Biology said: «We are seeing a downturn in poaching, which is obviously positive news, but it is still above what we think is sustainable so the elephant populations are declining.»


«The poaching rates seem to respond primarily to ivory prices in South- East Asia and we can’t hope to succeed without tackling demand in that region.»


The research team say it is impossible to say if the ivory trade ban introduced in China 2017 is having an impact on the figures as ivory prices started to fall before the ban and may reflect a wider downturn in the Chinese economy.


«We need to reduce demand in Asia and improve the livelihoods of people who are living with elephants in Africa; these are the two biggest targets to ensure the long-term survival of elephants», Dr Beale added.


«While we can’t forget about anti-poaching and law enforcement, improving this alone will not solve the poaching problem,» Dr Beale added.


The scientists looked at data from the MIKE (Monitoring the Illegal Killing of Elephants) programme, which records carcass data provided by park rangers at 53 protected sites across Africa.


Dr Beale added: «Elephants are the very definition of charismatic megafauna, but they are also important engineers of African savannah and forest ecosystems and play a vital role in attracting ecotourism so their conservation is a real concern.»


Lisa Rolls Hagelberg, Head of Wildlife Communication & Ambassador Relations, UN Environment, said: «Ensuring a future with wild elephants, and myriad other species, will require stronger laws and enforcement efforts and genuine community engagement; however, as long as demand exists supply will find a way to quench it.


«Only about 6% of the current funding going towards tackling illegal trade in wildlife is directed to communication.


For long-term success, governments need to prioritize comprehensive social and behavioural change interventions to both prevent and reduce demand. We have the know how, now we need to invest to truly influence environmental consciousness.»


Severin Hauenstein, from the University of Freiburg, added: «This is a positive trend, but we should not see this as an end to the poaching crisis.


«After some changes in the political environment, the total number of illegally killed elephants in Africa seems to be falling, but to assess possible protection measures, we need to understand the local and global processes driving illegal elephant hunting.»


The study is published in Nature Communications.


Source: University of York [May 28, 2019]



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All ears: Genetic bases of mammalian inner ear evolution

Mammals have adapted to live in the darkest of caves and the deepest oceans, and from the highest mountains to the plains. Along the way, mammals have also adapted a remarkable capacity in their sense of hearing, from the high-frequency echolocation calls of bats to low frequency whale songs. Even our best friend companion animals, dogs, have developed a hearing range twice as wide as people.











All ears: Genetic bases of mammalian inner ear evolution
A bat-eared fox peeks from the grass in Hwange National Park, Zimbabwe
[Credit: Roy Toft, National Geographic Image Collection]

Assuming that these adaptations have a root genetic cause, a team of scientists led by Lucia Franchini of the National Council of Scientific and Technological Research (CONICET), in Buenos Aires, Argentina, have made it their goal to identify the genetic bases underlying the evolution of the inner ear in mammals. Their latest findings underscored the promise of their approach, which identified two new genes involved in hearing. The study was published in the advanced online edition of Molecular Biology and Evolution.


«This paper builds on the premise that the evolution of mammalian inner ear hearing related novelties should leave a discoverable trace of adaptive molecular signature,» said Franchini. «This work highlights the usefulness of evolutionary studies to pinpoint novel key functional genes.»


The basic processes of hearing in different mammalian species is the same. The auditory system of mammals is characterized by a middle ear composed of three ossicles (the incus (anvil), malleus (hammer) and stapes (stirrup), which funnels sound to the inner ear.


Franchini’s group focused on the inner ear, which turns changes in sound intensity into electrical signals that the brain can process. Within the inner ear is the snail-shaped cochlea that transforms sound waves into nerve impulses, including an auditory organ of Corti that possesses two types of specialized sensory hair cells (HCs), inner (IHCs) and outer hair cells (OHCs).


«In the mammalian cochlea, IHCs and OHCs display a clear division of labor,» explains Franchini. «The IHCs receive and relay sound information behaving as the true sensory cells, while OHCs amplify sound information. Thus, IHCs which are the primary transducers, release glutamate to excite the sensory fibers of the cochlear nerve and OHCs act as biological motors to amplify the motion of the sensory epithelium.»


In their study, they used a two-pronged approach, complementing in silico gene comparisons with follow-up experimental studies, to gain a more complete understanding of the genetic circuitry behind mammalian inner ear adaptations.


«These functional and morphological innovations in the mammalian inner ear contribute to its unique hearing capacities,» said lead author Lucia Franchini. However, the genetic bases underlying the evolution of this mammalian landmark are poorly understood. We propose that the emergence of morphological and functional innovations in the mammalian inner ear could have been driven by adaptive molecular evolution.»


First, they took advantage of extensive gene expression databases to perform software-based, or, in silico comparative studies of 1,300 genes to identify genes that may have been positively selected to help mammals adapt over evolutionary time. In total, they found 13%, or 165 inner ear genes that may have been selected for adaptation.


«This analysis indicated that both IHCs and OHCs went through similar levels of gene adaptive evolution probably underlying the morphological and functional remodelling that both cellular types underwent in the mammalian lineage,» said Franchini.


«Notably we found that analysing functional categories of positively selected genes the most enriched functional term were ‘cytoskeletal protein binding’ and ‘structural constituent of the cytoskeleton’. These findings indicate that the OHC genes that underwent positive selection could have contributed to the acquisition of the highly specialized cytoskeleton present in these cells that underlies its distinctive functional properties, including somatic electromotility.»


Next, they experimentally tested hearing gene functions in a series of mouse studies. Among these, they focused on two previously unknown inner ear genes: STRIP2 (from Striatin Interacting Protein 2) and ABLIM2 (Actin Binding LIM domain 2), which were functionally characterized by generating novel strains of mutant mice by using CRISPR/Cas9 technology. In each case, they used CRISPR to turn off part of the normal gene function to see how it affected the hearing genetic circuitry.


«We performed auditory functional studies of Strip2 and Ablim2 newly generated mutant mice by means of two complementary techniques that allow differential diagnosis of OHC versus IHC/neuronal dysfunction throughout the cochlea,» said Franchini. «To evaluate the integrity of the hearing system we recorded ABRs (Auditory Brainstem Responses) that are sound-evoked potentials generated by neuronal circuits in the ascending auditory pathways. We also evaluated the OHCs function through distortion product otoacoustic emissions (DPOAE) testing.»


They discovered that Strip2 likely plays a functional role in the first synapse between IHCs and nerve fibers. Moreover, when they at the cochlear sensory epithelium, they found a significant reduction in auditory-nerve synapses. In contrast, the mutant studies of Ablim2 suggest that the absence of Ablim2 does not affect either cochlear amplification or auditory nerve function.


«In summary, through this evolutionary approach we discovered that STRIP2 underwent strong positive selection in the mammalian lineage and plays an important role in the physiology of the inner ear,» said Franchini. «Moreover, our combined evolutionary and functional studies allow us to speculate that the extensive evolutionary remodeling that this gene underwent in the mammalian lineage provided an adaptive value. Thus, our study is a proof of concept that evolutionary approaches paired with functional studies could be a useful tool to uncover new key players in the function of organs and tissues.»


Credit: Oxford University Press [May 28, 2019]



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Continent drift and plateau uplift drive evolutions of Asia-Africa-Australia monsoon and...

Monsoon and arid climates are two climate types commonly seen in mid- and low-latitudes of the Earth. These climate types have sculpted the corresponding landforms, ecosystems and the living environments of human society. The present-day most well-known monsoon and arid regions are found in Africa, Asia and Australia. When did they originate? How have they evolved over time? What were the factors that determined their formations and evolutions? Have there been regional differences in their evolutions? These questions have been the subjects of research for the scientific community, but there is currently no consensus on them yet. A new study may shed some light on the answers to these questions.











Continent drift and plateau uplift drive evolutions of Asia-Africa-Australia monsoon and arid regions
Distribution patterns of the Asian-African-Australian monsoon regions (green) and arid regions (yellow)
in five geological periods during the Cenozoic. (a) mid-Paleocene (~60Ma); (b) late-Eocene (~40Ma);
(c) late-Oligocene (~25Ma); (d) late-Miocene (~10Ma); (e) present-day (0Ma). The blue shade
represents oceans or lakes, and the grey outlines indicate the 1500m elevation contour
of the Tibetan Plateau and its vicinity [Credit: ©Science China Press]

In an article entitled «Continental drift, plateau uplift, and the evolutions of monsoon and arid regions in Asia, Africa, and Australia during the Cenozoic», just published in Science China Earth Sciences, the formation and evolution of the Asia-Africa-Australia monsoon and arid regions and their controlling factors are investigated by an international team of scholars from China, the UK and the USA.


Geological evidence has shown that major changes have occurred to the monsoon and arid environments in the Asia-Africa-Australia realm, accompanying continental drift, uplift of the Tibetan Plateau, and changes in the atmospheric CO2 concentration since the beginning of the Cenozoic (about 65 million years ago abbreviated as Ma).


Based on reconstructed boundary conditions for 5 typical geological periods during the Cenozoic, including the mid-Paleocene (~60 Ma), late-Eocene (~40 Ma), late-Oligocene (~25 Ma), late-Miocene (~10 Ma), and the present-day (~0 Ma), the researchers performed a series of well-designed climate simulation experiments using a coupled ocean-atmosphere model by changing the land-sea distribution, topography, and CO2 concentration over time. The above diagrams shows the simulated distribution patterns of the Asian-African-Australian monsoon and arid regions in the five geological periods during the Cenozoic.


«Results of our numerical experiments indicate that the timings and causes of the formations of monsoon and arid regions in Asia, Africa and Australia were very different,» according to Dr. Xiaodong Liu, the lead author from the Institute of Earth Environment, Chinese Academy of Sciences.


Specifically, the northern and southern African monsoons existed during the mid-Paleocene, while the South Asian monsoon appeared in the Eocene after the Indian Subcontinent moved into the tropical Northern Hemisphere.


The probable South Asian monsoon during the mid-Paleocene (~56Ma), previously inferred from plant fossils, and originally thought to cover the region from India to the most southern coast of China, was actually two different geographic regions, located in the Southern Hemisphere and Northern Hemisphere tropical latitudes separated by the equator at ~60Ma. In contrast, the East Asian monsoon and northern Australian monsoon were established much later in the Miocene.


«The main controlling factors of different monsoon regions during the geological periods are also different,» he stated. For example, the establishments of the tropical monsoons in northern and southern Africa, South Asia, and Australia were determined by both continental drift and the seasonal migration of the Inter-Tropical Convergence Zone, while the position and height of the Tibetan Plateau were the key factors for the establishment of the East Asian monsoon.


«The evolutionary mechanisms of arid regions also varied from place to place,» he further explained. The presence of the subtropical arid regions in northern and southern Africa, Asia, and Australia depended on the positions of the continents and the control of the planetary scale subtropical high pressure zones, while the arid regions in the Arabian Peninsula and West Asia were closely related to the retreat of the Paratethys Sea. The formation of the mid-latitude arid region in the Asian interior, on the other hand, was the consequence of the uplift of the Tibetan Plateau.


«Although we used a low-resolution model, it still performed well in describing the distribution of monsoon and arid regions,» added Dr. Robin Smith, a co-author from the National Centre for Atmospheric Science, University of Reading. «This study reveals for the first time the regional differences and the importance of tectonic boundary conditions or geographical patterns in the formation and evolution of the Asia-Africa-Australia monsoon and arid regions during the Cenozoic.»


Dr. Zhi-Yong Yin, another coauthor from the Department of Environmental and Ocean Sciences, University of San Diego, stated that «although our simulations are consistent with certain paleoclimate proxies available, more geological evidence is needed to further verify these modeling results, due to the limitations of time and spatial scales of geological records.»


Source: Science China Press [May 28, 2019]



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Mysterious ancient burial mound in southwest France used for 2,000 years

Researchers have found evidence that an unremarkable prehistoric burial mound near Bordeaux, in southwest France, was re-used by locals for around 2,000 years. The researchers say what drew people to the mound for two millennia remains a mystery.











Mysterious ancient burial mound in southwest France used for 2,000 years
Credit: Patrice Courtaud, Universite de Bordeaux

The Le Tumulus des Sables site was discovered by chance in 2006, when school children stumbled across human remains in their kindergarten playground.


Hannah James, a PhD candidate at The Australian National University (ANU), says it was initially assumed the site was used solely by the Bell Beakers, one of the first cultures to spread out across Europe.


«We now know people were actually coming back to this site and burying their bodies in there again and again, from the Neolithic to the Iron Age,» Ms James said.


«We’re looking at remains from around 3600 BCE, all the way through to around 1250 BCE. It’s unusual because it’s not a really obvious or prestigious. It’s a mound about 50 cm deep. It’s not on a hill or an obvious location, so there’s something else about this site which caused people to come back and use it.»











Mysterious ancient burial mound in southwest France used for 2,000 years
Credit: Patrice Courtaud, Universite de Bordeaux

By using radiocarbon dating and analysis of four different isotopes, the team was able to gather more information about the people buried there.


«Carbon and nitrogen tell us about what kind of food they were eating. They were eating food from the land. Strangely it doesn’t look like they were hunting and gathering from the nearby river, or the ocean, which is 10 kilometres away. That doesn’t change over time.»


The evidence shows one individual was born in a much colder climate, like the Pyrenees Mountains to the south. It’s unclear whether this person migrated to the Le Tumulus des Sables region, or whether their whole skeleton, or single tooth, was brought back and dumped there.


According to Ms James, everyone else has «a very local signature… We found a lot of baby teeth, as well as teeth without full roots, which means the person died in childhood, while the tooth was still forming.»











Mysterious ancient burial mound in southwest France used for 2,000 years
Credit: Patrice Courtaud, Universite de Bordeaux

Archaeologists also found a jumble of metal, pottery and animal bones at the site, which made it difficult to identify the human remains.


«All the skeletal remains are really mixed up, and we’re dealing with tiny fragments of bones,» Ms James said. «We analysed the same tooth each time, to make sure we were looking at different individuals — but the actual number of people buried there could be much higher.»


The research is published in the Journal of Archaeological Science: Reports.


Author: Jessica Fagan | Source: Australian National University [May 28, 2019]



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Clay, Clouds and Curiosity

image

Our Curiosity Mars rover recently drilled into the Martian bedrock on Mount Sharp and uncovered the highest amounts of clay minerals ever seen during the mission. The two pieces of rock that the rover targeted are nicknamed “Aberlady” and “Kilmarie” and they appear in a new selfie taken by the rover on May 12, 2019, the 2,405th Martian day, or sol, of the mission.


image

On April 6, 2019, Curiosity drilled the first piece of bedrock called Aberlady, revealing the clay cache. So, what’s so interesting about clay? Clay minerals usually form in water, an ingredient essential to life. All along its 7-year journey, Curiosity has discovered clay minerals in mudstones that formed as river sediment settled within ancient lakes nearly 3.5 billion years ago. As with all water on Mars, the lakes eventually dried up.


image

But Curiosity does more than just look at the ground. Even with all the drilling and analyzing, Curiosity took time on May 7, 2019 and May 12, 2019 to gaze at the clouds drifting over the Martian surface. Observing clouds can help scientists calculate wind speeds on the Red Planet.


For more on Curiosity and our other Mars missions like InSight, visit: https://mars.nasa.gov.


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.


Subaru Telescope Captures 1800 Exploding Stars


Figure 1: Some supernovae discovered in this study. There are three images for each supernova for before it exploded (left), after it exploded (middle), and supernovae itself (difference of the first two images). (Credit: N. Yasuda et al.)  All images of supernovae discovered in this paper can be viewed here (Cooperated by Dr. Michitaro Koike of NAOJ).


Astronomers using the Subaru Telescope identified about 1800 new supernovae in the distant Universe, including 58 Type Ia supernovae over 8 billion light-years away. These findings will help elucidate the expansion of the Universe.


A supernova is the name given to an exploding star that has reached the end of its life. The star often becomes as bright as its host galaxy, shining one billion times brighter than the Sun for anytime between a month to six months before dimming down. Supernova classed as Type Ia are useful because their constant maximum brightness allows researchers to calculate how far the star is from Earth. This is particularly useful for researchers who want to measure the expansion of the Universe.


In recent years, researchers began reporting a new type of supernovae five to ten times brighter than Type Ia supernovae. Named Super Luminous Supernovae, many have been trying to learn more about these stars. Their unusual brightness enables researchers to spot stars in the farthest parts of the Universe usually too faint to observe. Since distant Universe means the early Universe, studying this kind of star could reveal characteristics about the first, massive stars created after the Big Bang.


But supernovae are rare events, and there are only a handful of telescopes in the world capable of capturing sharp images of distant stars. In order to maximize the chances of observing a supernova, a team led by Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Professor Naoki Yasuda, and researchers from Tohoku University, Konan University, the National Astronomical Observatory of Japan, School of Science, the University of Tokyo, and Kyoto University, used the Subaru Telescope.


This telescope is capable of generating shape stellar images, and the Hyper Suprime-Cam, an 870 mega-pixel digital camera attached at its top, captures a very wide area of the night sky in one shot.


By taking repeated images of the same area of night sky over a six month period, the researchers could identify new supernovae by looking for stars that suddenly appeared brighter before gradually fading out.


As a result, the team identified 5 super luminous supernovae, and about 400 Type Ia supernovae. Fifty-eight of these Type Ia supernovae were located more than 8 billion light years away from Earth. In comparison, it took researchers using the Hubble Space Telescope about 10 years to discover a total of 50 supernovae located more than 8 billion light years away from Earth.




Figure 2: A map showing all of the supernovae (in red) discovered in this study. The blue circles indicate the areas Hyper Suprime-Cam was able to capture in one shot. The background is an image taken by the Sloan Digital Sky Survey. An image of the moon has been added to understand the area of night sky Hyper Suprime-Cam can capture. (Credit: Kavli IPMU, Partial data supplied by: SDSS)



«The Subaru Telescope and Hyper Suprime-Cam have already helped researchers create a 3D map of dark matter, and observation of primordial black holes, but now this result proves that this instrument has a very high capability finding supernovae very, very far away from Earth. I want to thank all of my collaborators for their time and effort, and look forward to analyzing our data to see what kind of picture of the Universe it holds,» said Yasuda.


The next step will be to use the data to calculate a more accurate expansion of the Universe, and to study how dark energy has changed over time.



These results were published in Publications of the Astronomical Society of Japan (Yasuda et al., «The Hyper Suprime-Cam SSP Transient Survey in COSMOS: Overview»). A preprint is available here.



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