четверг, 8 августа 2019 г.

Batted Away Occurring mainly in India and Bangladesh, the…


Batted Away


Occurring mainly in India and Bangladesh, the zoonotic Nipah virus (pictured, in orange, on the surface of a cell) can be transmitted from fruit bats to humans, and then between humans too. Symptoms include severe respiratory disease and inflammation of the brain, or encephalitis, often with fatal consequences, yet few treatments exist. Recent experiments found that remdesivir, a drug currently being tested as treatment for Ebola, could combat the effects of Nipah virus in monkeys. Twenty-four hours after receiving an otherwise lethal dose of Nipah virus, four African green monkeys were treated with remdesivir for twelve days; while some developed mild symptoms, all were eventually cleared of active virus, and survived to the end of the three month-long trial. How effective the drug would be if administered longer after infection remains to be tested, but these encouraging results suggest remdesivir could be a useful tool in fighting future outbreaks.


Written by Emmanuelle Briolat



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New Zealand’s biodiversity will take millions of years to recover

The arrival of humans in New Zealand, some 700 years ago, triggered a wave of extinction among native bird species. Many more species are currently under threat. Recent calculations by scientists from the University of Groningen in the Netherlands and Massey University in New Zealand show that it would take at least 50 million years of evolution to restore the biodiversity that has been lost. Their results were published on in the journal Current Biology.











New Zealand's biodiversity will take millions of years to recover
A Kakapo bird [Credit: Andrew Digby/Current Biology]

Alfred Russel Wallace (a 19th-century naturalist who independently formulated a theory of evolution around the same time as Darwin) described New Zealand’s biota as ‘wonderfully isolated’. Until the first Maori arrived on the islands (in around 1280 CE), the only native mammals were bats. However, the Maori and the Europeans (who reached the islands in 1642) set in motion a wave of extinction that wiped out over 70 bird species, including the iconic giant moa.


Genetic data


But how extensive is the damage to this country’s biodiversity? Dr. Luis Valente is an evolutionary biologist employed by the Naturalis Biodiversity Center (a museum of natural history) in Leiden, the Netherlands. He was recently appointed assistant professor at the University of Groningen.


Several years ago, together with Professor Rampal Etienne (also from the University of Groningen), Dr. Valente developed a mathematical model to explore this question. The model can be used to estimate how long it will take evolution to restore biodiversity to its original level on these islands.


The model is based on the premise that island biodiversity eventually reaches an equilibrium. However, this idea has been challenged in recent years. Its critics suggest that the dynamics of island environments prevent equilibrium from ever being reached.


In previous work, on a Caribbean island, Dr. Valente and Prof. Etienne used genetic data from extinct bat species to show that biodiversity levels had veered away from a state of equilibrium. They calculated that it would take the surviving bat population eight million years of evolution to recover.











New Zealand's biodiversity will take millions of years to recover
A Kaka bird [Credit: Juan Carlos Carcia/Current Biology]

Kakapo


The researchers have since performed similar calculations on bird species in New Zealand. ‘We have sequenced parts of the genome from nearly all these species, including many extinct ones’, explains Luis Valente. Computer simulations show that bird biodiversity will take around 50 million years to recover from the extinctions that followed the arrival of humans.


However, a number of bird species, like the kakapo and several species of kiwi, are now classified as ‘endangered’ or ‘critically endangered’. If they go extinct, this would add another six million years to the recovery time. And if species that are currently classified as ‘vulnerable’ were also to disappear, this would add a further 10 million years to that figure.


It should be noted that here, the term ‘recovery’ is used to mean the point at which evolution has returned the number of species to its original level. However, these newly evolved species will not be identical to those that have been lost.


As Dr. Valente points out, ‘I am also working on Mauritius, where the dodo used to live. While evolution will not bring the dodo back, it was related to pigeons, so a new bird species might eventually evolve from the island’s present-day pigeon population.’


Conservation


So what is the use of knowing the recovery time of an island ecosystem? ‘Well, one practical consideration is that it enables us to quantify the ecological damage that has been done. Given the limited resources available for conservation, these numbers could show us how to achieve the best cost-benefit ratio, in terms of investing in protecting endangered species’, says Luis Valente.


‘Using our model, we can determine the natural rates of change on islands. If two different islands each have an equal number of endangered species, then we might need to focus our conservation efforts on the one with the longer recovery time.’ He adds that recovery time is just one of the many factors that need to be considered when establishing conservation priorities


Dr. Valente and his co-workers are planning to extend their studies to other islands, to further their understanding of evolutionary dynamics. ‘This method would be useful for other isolated ecosystems as well, such as mountains or lakes.’


Source: Cell Press [August 05, 2019]



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Long-lasting effects of ironwork on mammal distributions over the last millennium in...

Awareness is growing among scientists about the significance of pre-modern anthropogenic impacts prior to the Industrial Revolution on present-day patterns of biodiversity. In particular, pre-modern energy-intensive industries, such as ironwork, of the sort depicted in the 1997 anime film Princess Mononoke directed by Hayao Miyazaki, were major drivers of ecosystem alteration and have had long-lasting impacts on the distributions of many species. However, the phenomenon remains insufficiently studied and the empirical evidence is quite limited.











Long-lasting effects of ironwork on mammal distributions over the last millennium in Japan
Flying squirrels are among the mammals estimated to be most highly impacted by ironwork.
[Credit: 
Hisashi Yanagawa, NIES]

Millennial-scale effects of past energy-intensive anthropogenic activities are the subject of a new study led by two Japanese researchers from the National Institute for Environmental Studies and Obihiro University of Agriculture and Veterinary Medicine, published in Scientific Reports.
The researchers used a statistical framework to estimate the impact of pre-modern ironwork during four historical periods in the last millennium on the current distributions of 29 mammalian genera native to Japan, taking into account other potential factors such as paleoclimate and modern-day land use. Past ironwork impacts were quantified using site records from a national archaeological database.











Long-lasting effects of ironwork on mammal distributions over the last millennium in Japan
Ancient painting of traditional ironwork (from ‘Mines in Paintings and Illustrated Scrolls Collection
Image Database’, from the collection of Engineering Bldg. 3 Library, Univ. of Tokyo)
[Credit: NIES]

The current distributions of 21 of 29 mammalian genera were significantly affected by the impacts of past ironwork activities. In particular, the impacts of ironwork in the Kofun period (about 1700-1300 years ago), when iron production originally began in Japan, were significant for 13 genera. Medium-to-large mammals, such as the fox and wild boar, showed positive responses to the impacts of ironwork, but small mammals, such as the flying squirrel and dormouse, were negatively impacted in many different historical periods. The difference in response between small and medium-to-large mammals could be explained by traits related to body size, such as dispersal ability and habitat generalism, which are important for survival in a disturbed, heterogeneous landscape.
«Ironwork brought long-term environmental change in multiple ways,» says lead author Keita Fukasawa of the National Institute for Environmental Studies. «It required large quantities of charcoal, and the mountains around ironworking sites were often stripped bare due to intensive logging. Moreover, mining of iron sand resulted in soil erosion, which sometimes led to irreversible habitat degradation for small mammals dwelling in old-growth forests. However, such habitat alterations also contributed to the development of the traditional rural landscape in Japan, called satoyama, which consists of patches of various types of habitats such as grassland and secondary forest, which are suitable for medium-to-large mammals.»











Long-lasting effects of ironwork on mammal distributions over the last millennium in Japan
Number of genera that respond negatively and positively to the impacts of ironwork. Results
for two historical periods, early modern (446-151 BP) and Kofun (c. 1700-1300 BP),
are shown [Credit: NIES]

«Today in Japan, iron production relies on imported iron ore and fossil fuels, so the exploitation of domestic resources for iron production has ended. On a global scale, however, over-exploitation of firewood and mining remain drivers of biodiversity loss. Studies examining the long-lasting effects of pre-industrial Anthropogenic activities on biodiversity will offer insights into the historical background to macro-ecological patterns and provide practical knowledge for the development of sustainable societies in the Anthropocene that mitigate impacts on ecosystems. For example, if we can identify species that may be negatively impacted over the long term by the exploitation of a specific resource, it will help us to establish appropriate zoning for conservation and resource use.»


Source: National Institute for Environmental Studies [August 05, 2019]



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Paradoxical Survival: Examining the Parrondo effect across biology

Inspired by the flashing Brownian ratchet, Parrondo’s paradox is a counter-intuitive phenomenon in which two losing games, when played in a specific order, can surprisingly end up winning. For example, slot machines are designed to ensure that players lose in the long run. «What the paradox says is that there might be slot machines which are subtly linked in such a way that playing either slot machine independently will lead to financial disaster, but switching in between them will eventually leave the player richer than before,» said senior author, Assistant Professor Kang Hao Cheong of the Singapore University of Technology and Design (SUTD).











Paradoxical Survival: Examining the Parrondo effect across biology
Probability space of Parrondo’s paradox [Credit: Shu & Wang, 2014]

To explore the plethora of exciting applications in biology, researchers from SUTD have examined a large range of recent developments of Parrondo’s paradox in biology, across ecology and evolution, genetics, social and behavioral systems, cellular processes, and disease.
Their study, appearing in a recent issue of BioEssays, has identified key connections between numerous seemingly disjointed works, culminating in an emergent pattern of nested recurrent mechanics that appear to span the entire biological gamut, from the smallest of spatial and temporal scales to the largest. The authors explained that the pivotal role the paradox plays in the shaping of living systems has become increasingly apparent, which points strongly towards its potential identity as a universal principle underlying biological diversity and persistence.


«Developments in Parrondo’s paradox to date have revealed a potential unifying fundamental characteristic of life itself, more valuable to our understanding of nature than its individual components,» said co-author Jin Ming Koh.


The picture that the authors paint of biological reality is a striking one. Their work suggests that the biosphere might be supported by countless layers of Parrondo?paradoxical effects, each ingesting inevitably losing strategies and producing enhanced outcomes at a slightly larger temporal or spatial scale for the layer above, in what may be visualized as a fractal?like recurrent pattern. Such an imagery offers a fresh perspective on our view of nature and of ourselves.


The trio is now attempting to analyze the detailed structure of these mechanisms, which might span from hugely macroscopic spatial scales of entire ecosystems to the molecular inner workings of cells, and from the million?year timescales of evolution to sub-microsecond genetic and molecular processes. «Every cell, organism and species, and species assemblage and ecosystem, is necessarily mortal, yet the biosphere persists,» said Assistant Professor Cheong.


Source: Singapore University of Technology and Design [August 05, 2019]



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Intense look at La Brea Tar Pits explains why we have coyotes, not saber-toothed cats

The most detailed study to date of ancient predators trapped in the La Brea Tar Pits is helping Americans understand why today we’re dealing with coyotes dumping over garbage cans and not saber-toothed cats ripping our arms off.











Intense look at La Brea Tar Pits explains why we have coyotes, not saber-toothed cats
Illustration by Mauricio Anton depicting the hunting behavior of La Brea carnivores,
including saber-toothed cats, dire wolves, and coyotes
[Credit: Mauricio Anton]

Larisa DeSantis, a Vanderbilt University paleontologist, grew up visiting the one-of-a-kind fossil site in Los Angeles, which contains fossils of predators that tried to eat horses, bison and camels stuck in the tar over the past 50,000 years and themselves became trapped, offering the best opportunity to understand Ice Age animals facing climate change. The Pleistocene Epoch spanned 2.6 million years ago to about 10,000 years ago, encompassing multiple glacial and interglacial periods and the arrival of humans, one or both of which forced predators to adapt their diets or die.
DeSantis spent the last decade visiting La Brea, studying the teeth of extinct species such as American lions, saber-toothed cats and dire wolves; and teeth from ancient animals whose offspring are still alive today, such as gray wolves, cougars and coyotes. Her work revealed that competition for prey among carnivores wasn’t a likely cause of the Pleistocene megafaunal extinction as formerly believed, because, like dogs and cats of today, one preferred running after herbivores in the open fields, while the other preferred stalking them in forested areas.


«Isotopes from the bones previously suggested that the diets of saber-toothed cats and dire wolves overlapped completely, but the isotopes from their teeth give a very different picture,» said DeSantis, an associate professor of biological sciences at Vanderbilt. «The cats, including saber-toothed cats, American lions and cougars, hunted prey that preferred forests, while it was the dire wolves that seemed to specialize on open-country feeders like bison and horses.  While there may have been some overlap in what the dominant predators fed on, cats and dogs largely hunted differently from one another.»



To study these ancient predators, she employs dentistry — taking molds of the teeth and shaving off tiny bits of enamel for chemical analysis. Information about everything the animal ate lies within the isotopes, she said. Further, the microscopic wear patterns on teeth can clarify who was eating flesh or scavenging on bones.


It’s likely that those giant predators went extinct due to climate change, the arrival of humans to their environment or a combination of the two, she said, and her team is working to clarify the cause of the extinction with multiple colleagues across six institutions as part of a separate on-going study.


What they know is predators alive today in the Americas were better able to adapt their diets. Instead of only feeding on large prey, they could effectively hunt small mammals, scavenge what they could from carcasses or do both.


«The other exciting thing about this research is we can actually look at the consequences of this extinction,» DeSantis said. «The animals around today that we think of as apex predators in North America — cougars and wolves — were measly during the Pleistocene. So when the big predators went extinct, as did the large prey, these smaller animals were able to take advantage of that extinction and become dominant apex-predators.»


An even more detailed picture of ancient life at La Brea is contained in the paper «Causes and consequences of Pleistocene megafaunal extinctions as revealed from Rancho La Brea mammals,» published in the journal Current Biology.


Author: Spencer Turney | Source: Vanderbilt University [August 05, 2019]



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New species of early dinosaur described from South Africa

A new dinosaur species has been discovered after laying misidentified in a museum collection for 30 years. Prof Paul Barrett, a dinosaur researcher at the Natural History Museum, is part of a team that reassessed the specimen, which is held at the University of Witwatersrand, Johannesburg. Along with his colleagues in South Africa, and led by Paul’s Ph.D. student Kimberley Chapelle, they recognised it not only as a new species of sauropodomorph, but an entirely new genus. The specimen has now been named Ngwevu intloko which means «grey skull» in the Xhosa language, chosen to honour South Africa’s heritage.











New species of early dinosaur described from South Africa
The skull has been in the collection for over 30 years, but was misidentified
[Credit: © Jonah Choiniere]

Prof Barrett explains, «This is a new dinosaur that has been hiding in plain sight. «The specimen has been in the collections in Johannesburg for about 30 years, and lots of other scientists have already looked at it. But they all thought that it was simply an odd example of Massospondylus.»
Massospondylus was one of the first dinosaurs to reign at the start of the Jurassic period. Regularly found throughout southern Africa, these animals belonged to a group called the sauropodomorphs and eventually gave rise to the sauropods, a group containing the Natural History Museum’s iconic dinosaur cast Dippy. Researchers are now starting to look closer at many of the supposed Massospondylus specimens, believing there to be much more variation than first thought.











New species of early dinosaur described from South Africa
Micro-CT scan of Ngwevu intloko skull 2 
[Credit: Kimberley Chapelle]

Kimberley Chapelle explains why the team were able to confirm that this specimen was a new species, «In order to be certain that a fossil belongs to a new species, it is crucial to rule out the possibility that it is a younger or older version of an already existing species. This is a difficult task to accomplish with fossils because it is rare to have a complete age series of fossils from a single species. Luckily, the most common South African dinosaur Massospondylus has specimens ranging from embryo to adult! Based on this, we were able to rule out age as a possible explanation for the differences we observed in the specimen now named Ngwevu intloko.»











New species of early dinosaur described from South Africa
A good deal of the rest of the animal’s skeleton also got fossilised
[Credit: © Kimberley Chapelle]

The new dinosaur has been described from a single fairly complete specimen with a remarkably well-preserved skull. The new dinosaur was bipedal with a fairly chunky body, a long slender neck and a small, boxy head. It would have measured three metres from the tip of its snout to the end of its tail and was likely an omnivore, feeding on both plants and small animals.
The findings will help scientists better understand the transition between the Triassic and Jurassic period, around 200 million years ago. Known as a time of mass extinction it now seems that more complex ecosystems were flourishing in the earliest Jurassic than previously thought.











New species of early dinosaur described from South Africa
By taking slices of the fossilised bones, the team could estimate the animal’s age
[Credit: © Kimberley Chapelle]

«This new species is interesting,» says Prof Barrett, ‘because we thought previously that there was really only one type of sauropodomorph living in South Africa at this time. We now know there were actually six or seven of these dinosaurs in this area, as well as variety of other dinosaurs from less common groups. It means that their ecology was much more complex than we used to think. Some of these other sauropodomorphs were like Massospondylus, but a few were close to the origins of true sauropods, if not true sauropods themselves.»











New species of early dinosaur described from South Africa
Ngwevu intloko would have looked similar to the Massospondylus
seen here, with a chonky body and a long, slender neck
[Credit: Nobu Tamura/WikiCommons]

This work shows the value of revisiting specimens in museum collections, as many news species are probably sitting unnoticed in cabinets around the world.


The new paper is published in the journal PeerJ.


Source: Natural History Museum [August 05, 2019]



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Meet ‘Hercules’—the giant parrot that dwarfs its modern cousins

Australasian palaeontologists have discovered the world’s largest parrot, standing up to 1m tall with a massive beak able to crack most food sources.











Meet 'Hercules'—the giant parrot that dwarfs its modern cousins
Reconstruction of the giant parrot Heracles, dwarfing a bevy of 8cm high Kuiornis — small New Zealand
wrens scuttling about on the forest floor [Credit: Dr Brian Choo, Flinders University]

The new bird has been named Heracles inexpectatus to reflect its Herculean myth-like size and strength — and the unexpected nature of the discovery.


«New Zealand is well known for its giant birds,» says Flinders University Associate Professor Trevor Worthy. «Not only moa dominated avifaunas, but giant geese and adzebills shared the forest floor, while a giant eagle ruled the skies.


«But until now, no-one has ever found an extinct giant parrot — anywhere.»


The NZ fossil is approximately the size of the giant ‘dodo’ pigeon of the Mascarenes and twice the size of the critically endangered flightless New Zealand kakapo, previously the largest known parrot.


Like the kakapo, it was a member of an ancient New Zealand group of parrots that appear to be more primitive than parrots that thrive today on Australia and other continents.


Experts from Flinders University, UNSW Sydney and Canterbury Museum in New Zealand estimate Heracles to be 1 m tall, weighing about 7 kg.


The new parrot was found in fossils up to 19 million years old from near St Bathans in Central Otago, New Zealand, in an area well known for a rich assemblage of fossil birds from the Miocene period.


«We have been excavating these fossil deposits for 20 years, and each year reveals new birds and other animals,» says Associate Professor Worthy, from the Flinders University Palaeontology Lab.


«While Heracles is one of the most spectacular birds we have found, no doubt there are many more unexpected species yet to be discovered in this most interesting deposit.»











Meet 'Hercules'—the giant parrot that dwarfs its modern cousins
Graphic showing the Heracles inexpectatus silhouette next to an average height person
and common magpie [Credit: Professor Paul Scofield, Canterbury Museum]

«Heracles, as the largest parrot ever, no doubt with a massive parrot beak that could crack wide open anything it fancied, may well have dined on more than conventional parrot foods, perhaps even other parrots,» says Professor Mike Archer, from the UNSW Sydney Palaeontology, Geobiology and Earth Archives (PANGEA) Research Centre.


«Its rarity in the deposit is something we might expect if it was feeding higher up in the food chain,» he says, adding parrots «in general are very resourceful birds in terms of culinary interests».


«New Zealand keas, for example, have even developed a taste for sheep since these were introduced by European settlers in 1773.»


Birds have repeatedly evolved giant species on islands. As well as the dodo, there has been another giant pigeon found on Fiji, a giant stork on Flores, giant ducks in Hawaii, giant megapodes in New Caledonia and Fiji, giant owls and other raptors in the Caribbean.


Heracles lived in a diverse subtropical forest where many species of laurels and palms grew with podocarp trees.


«Undoubtedly, these provided a rich harvest of fruit important in the diet of Heracles and the parrots and pigeons it lived with. But on the forest floor Heracles competed with adzebills and the forerunners of moa,» says Professor Suzanne Hand, also from UNSW Sydney.


«The St Bathans fauna provides the only insight into the terrestrial birds and other animals that lived in New Zealand since dinosaurs roamed the land more than 66 million years ago,» says Paul Scofield, Senior Curator at Canterbury Museum, Christchurch.


Canterbury Museum research curator Vanesa De Pietri says the fossil deposit reveals a highly diverse fauna typical of subtropical climates with crocodilians, turtles, many bats and other mammals, and over 40 bird species.


«This was a very different place with a fauna very unlike that which survived into recent times,» she says.


The study is published in The Royal Society: Biology Letters.


Source: Flinders University [August 06, 2019]



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2019 August 8 Curiosity at Teal Ridge Image Credit: NASA,…


2019 August 8


Curiosity at Teal Ridge
Image Credit: NASA, JPL-Caltech, MSSS, Curiosity Mars Rover


Explanation: Part of a 360 degree panorama, this view looks out from the Mars rover Curiosity’s current location on the Red Planet dubbed Teal Ridge. The mosaicked scene was captured by the rover’s Mastcam on Earth calendar date June 18, 2019. That corresponds to Curiosity’s sol 2440, or 2,440th martian day on the surface. Since landing seven years ago on August 6, 2012 in Gale Crater, Curiosity has traveled some 21 kilometers (13 miles). On the right, the rover’s tracks lead back toward Vera Rubin Ridge with the Gale Crater rim visible in the distance. The robotic rover leaves wheel tracks about 3 meters (10 feet) apart. During its mission, Curiosity has had great successes exploring the history of water in the martian environment. In fact, NASA’s Mars 2020 rover is largely based on the Mars Curiosity rover design.


∞ Source: apod.nasa.gov/apod/ap190808.html


Ancient shipwrecks discovered off Greek island of Levitha

Five major ancient shipwrecks that carried amphorae and an anchor pole pointing to a large sea vessel are among the amazing finds found by archaeologists during underwater searches at the bottom of Levitha, a small island in the Aegean Sea, between Amorgos and Leros.











Ancient shipwrecks discovered off Greek island of Evitha
Credit: Ephorate of Underwater Antiquities/Hellenic Ministry of Culture and Sports/Anastasis Agathos

It is the most impressive discovery in 2019 and included a mixed shipload of amphorae from the Aegean (Knidos, Kos, and Rhodes), Phoenicia and Carthage, dated just before the middle of the 3rd century BC, during the maritime domination of the Ptolemaic and Antigonides empires in the Aegean.











Ancient shipwrecks discovered off Greek island of Evitha
Credit: Ephorate of Underwater Antiquities/Hellenic Ministry of Culture and Sports/Anastasis Agathos

The shipwreck at Knidos had a trove including amphorae, dating back to the same period, while three more shipwrecks with cargoes of Cone or pseudo-Cone amphorae were found (2nd and 1st centuries BC) and the 2nd century AD), a shipwreck with amphorae cargo from the North Aegean of the 1st century BC, a shipwreck with cargo of amphorae of the 1st century BC. and finally, a shipwreck with amphorae dating back to the early Christian period.











Ancient shipwrecks discovered off Greek island of Evitha
Credit: Ephorate of Underwater Antiquities/Hellenic Ministry of Culture and Sports/Anastasis Agathos

Of particular interest is a granite anchor pole, lifted from a depth of 45 meters, weighing 400 kg. It is probably dated to the 6th century BC. and is the largest stone pillar of the Archaic period, which has been found to this day in the Aegean. It was most likely used by a colossal sized ship.











Ancient shipwrecks discovered off Greek island of Evitha
Credit: Ephorate of Underwater Antiquities/Hellenic Ministry of Culture and Sports/
Anastasis Agathos

The discoveries are the fruits of the first mission of the underwater archaeological research overseen by the Ephorate of Underwater Antiquities on the island of Levitha, which took place from 15 to 29 June under the direction of archaeologist Dr. George Koutsouflakis.











Ancient shipwrecks discovered off Greek island of Evitha
Credit: Ephorate of Underwater Antiquities/Hellenic Ministry of Culture and Sports/Anastasis Agathos

The underwater archaeological research is being conducted over a three-year period (2019-2021), with the aim of identifying and documenting ancient shipwrecks in the coastal zone in the cluster of four isolated islands (Levitha, Mavria, Glaros and Chinaros), which appears to have played a key role in ancient and modern navigation.


The research was funded by the Ministry of Culture and Sport and the British Academy of Humanities and Social Sciences and was supported by Patmos residents Alexander Schwarzenberg, Michalis Vagenas, Dionysios Cleoudis, Theologos Giannaros and the Dimitrios Kambosos family from Levithas.

Source: Protothema [August 06, 2019]



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Five Record-Setting Gamma-ray Bursts!

For 10 years, our Fermi Gamma-ray Space Telescope has scanned the sky for gamma-ray bursts (GRBs), the universe’s most luminous explosions!


image

Most GRBs occur when some types of massive stars run out of fuel and collapse to create new black holes. Others happen when two neutron stars, superdense remnants of stellar explosions, merge. Both kinds of cataclysmic events create jets of particles that move near the speed of light.


A new catalog of the highest-energy blasts provides scientists with fresh insights into how they work. Below are five record-setting events from the catalog that have helped scientists learn more about GRBs:


1. Super-short burst in Boötes!


image

The short burst 081102B, which occurred in the constellation Boötes on Nov. 2, 2008, is the briefest LAT-detected GRB, lasting just one-tenth of a second!


2. Long-lived burst!


image

Long-lived burst 160623A, spotted on June 23, 2016, in the constellation Cygnus, kept shining for almost 10 hours at LAT energies — the longest burst in the catalog.


For both long and short bursts, the high-energy gamma-ray emission lasts longer than the low-energy emission and happens later.


3. Highest energy gamma-rays!


image

The highest-energy individual gamma ray detected by Fermi’s LAT reached 94 billion electron volts (GeV) and traveled 3.8 billion light-years from the constellation Leo. It was emitted by 130427A, which also holds the record for the most gamma rays — 17 — with energies above 10 GeV.


4. In a constellation far, far away!


image

The farthest known GRB occurred 12.2 billion light-years away in the constellation Carina. Called 080916C, researchers calculate the explosion contained the power of 9,000 supernovae.


5. Probing the physics of our cosmos!


image

The known distance to 090510 helped test Einstein’s theory that the fabric of space-time is smooth and continuous. Fermi detected both a high-energy and a low-energy gamma ray at nearly the same instant. Having traveled the same distance in the same amount of time, they showed that all light, no matter its energy, moves at the same speed through the vacuum of space.


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ALMA Dives into Black Hole’s ‘Sphere of Influence’


ALMA has made the most precise measurements of cold gas swirling around a supermassive black hole — the cosmic behemoth at the center of the giant elliptical galaxy NGC 3258. The multi-color ellipse reflects the motion of the gas orbiting the black hole, with blue indicating motion toward us and red motion away from us. The inset box represents how the orbital velocity changes with distance from the black hole. The material was found to rotate faster the closer in the astronomers observed to the black hole, enabling them to accurately calculate its mass: a whopping 2.25 billion times the mass of our Sun. Credit: ALMA (ESO/NAOJ/NRAO), B. Boizelle; NRAO/AUI/NSF, S. Dagnello; Hubble Space Telescope (NASA/ESA); Carnegie-Irvine Galaxy Survey. Hi-Res File



Artist impression of disk of material rotating around a supermassive black hole

Credit: NRAO/AUI/NSF





Capturing Orbital Motion around a Black Hole in Unprecedented Clarity


What happens inside a black hole stays inside a black hole, but what happens inside a black hole’s “sphere of influence” – the innermost region of a galaxy where a black hole’s gravity is the dominant force – is of intense interest to astronomers and can help determine the mass of a black hole as well as its impact on its galactic neighborhood.


New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide an unprecedented close-up view of a swirling disk of cold interstellar gas rotating around a supermassive black hole. This disk lies at the center of NGC 3258, a massive elliptical galaxy


about 100 million light-years from Earth. Based on these observations, a team led by astronomers from Texas A&M University and the University of California, Irvine, have determined that this black hole weighs a staggering 2.25 billion solar masses, the most massive black hole measured with ALMA to date.


Though supermassive black holes can have masses that are millions to billions of times that of the Sun, they account for just a small fraction of the mass of an entire galaxy. Isolating the influence of a black hole’s gravity from the stars, interstellar gas, and dark matter in the galactic center is challenging and requires highly sensitive observations on phenomenally small scales.


“Observing the orbital motion of material as close as possible to a black hole is vitally important when accurately determining the black hole’s mass.” said Benjamin Boizelle, a postdoctoral researcher at Texas A&M University and lead author on the study appearing in the Astrophysical Journal. “These new observations of NGC 3258 demonstrate ALMA’s amazing power to map the rotation of gaseous disks around supermassive black holes in stunning detail.”


Astronomers use a variety of methods to measure black hole masses. In giant elliptical galaxies, most measurements come from observations of the orbital motion of stars around the black hole, taken in visible or infrared light. Another technique, using naturally occurring water masers (radio-wavelength lasers) in gas clouds orbiting around black holes, provides higher precision, but these masers are very rare and are associated almost exclusively with spiral galaxies having smaller black holes.


During the past few years, ALMA has pioneered a new method to study black holes in giant elliptical galaxies. About 10 percent of elliptical galaxies contain regularly rotating disks of cold, dense gas at their centers. These disks contain carbon monoxide (CO) gas, which can be observed with millimeter-wavelength radio telescopes.


By using the Doppler shift of the emission from CO molecules, astronomers can measure the velocities of orbiting gas clouds, and ALMA makes it possible to resolve the very centers of galaxies where the orbital speeds are highest.


“Our team has been surveying nearby elliptical galaxies with ALMA for several years to find and study disks of molecular gas rotating around giant black holes,” said Aaron Barth of UC Irvine, a co-author on the study. “NGC 3258 is the


best target we’ve found, because we’re able to trace the disk’s rotation closer to the black hole than in any other galaxy.” Just as the Earth orbits around the Sun faster than Pluto does because it experiences a stronger gravitational force, the inner regions of the NGC 3258 disk orbit faster than the outer parts due to the black hole’s gravity. The ALMA data show that the disk’s rotation speed rises from 1 million kilometers per hour at its outer edge, about 500 light-years from the black hole, to well over 3 million kilometers per hour near the disk’s center at a distance of just 65 light-years from the black hole.


The researchers determined the black hole’s mass by modeling the disk’s rotation, accounting for the additional mass of the stars in the galaxy’s central region and other details such as the slightly warped shape of the gaseous disk. The clear detection of rapid rotation enabled the researchers to determine the black hole’s mass with a precision better than one percent, although they estimate an additional systematic 12 percent uncertainty in the measurement because the distance to NGC 3258 is not known very precisely. Even accounting for the uncertain distance, this is one of the most highly precise mass measurements for any black hole outside of the Milky Way galaxy.


“The next challenge is to find more examples of near-perfect rotating disks like this one so that we can apply this method to measure black hole masses in a larger sample of galaxies,” concluded Boizelle. “Additional ALMA observations that reach this level of precision will help us better understand the growth of both galaxies and black holes across the age of the universe.”


The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.





Contact:


Suzy Gurton
sgurton@nrao.edu



Reference:


“A Precision Measurement of the Mass of the Black Hole in NGC 3258 from High-Resolution ALMA Observations of its Circumnuclear Disk,” B. Boizelle, et al., the Astrophysical Journal: apj.aas.org; Preprint: https://arxiv.org/abs/1906.06267


The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).


ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.



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Distant ‘heavy metal’ gas planet is shaped like a football

The scorching hot exoplanet WASP-121b may not be shredding any heavy metal guitar riffs, but it is sending heavy metals such as iron and magnesium into space. The distant planet’s atmosphere is so hot that metal is vaporizing and escaping the planet’s gravitational pull. The intense gravity of the planet’s host star has also deformed the sizzling planet into a football shape.











Distant 'heavy metal' gas planet is shaped like a football
This artist’s illustration shows WASP-121b, a distant world that is losing magnesium and iron gas from its atmosphere.
The observations represent the first time that heavy metals have been detected escaping from a «hot Jupiter,»
which is a large, gaseous exoplanet that orbits very close to its host star. WASP-121b’s orbit is so close
that the star’s gravity is nearly ripping the planet apart, giving the planet an oblique football shape
 [Credit: NASA, ESA, and J. Olmsted (STScI)]

The new observations, made by an international team of astronomers using NASA’s Hubble Space Telescope, describe the first known instance of heavy metal gas streaming away from a «hot Jupiter,» which is a nickname for large, gaseous exoplanets that orbit very close to their host stars. A research paper describing the results, co-authored by University of Maryland Astronomy Professor Drake Deming, was published in the Astronomical Journal.


«This planet is a prototype for ultra-hot Jupiters. These planets are so heavily irradiated by their host stars, they’re almost like stars themselves,» Deming said. «The planet is being evaporated by its host star to the point that we can see metal atoms escaping the upper atmosphere where they can interact with the planet’s magnetic field. This presents an opportunity to observe and understand some very interesting physics.»


Normally, hot Jupiter planets are still cool enough inside to condense heavier elements such as magnesium and iron into clouds that remain in the planet’s atmosphere. But that’s not the case with WASP-121b, which is orbiting so close to its host star that the planet’s upper atmosphere reaches a blazing 4,600 degrees Fahrenheit. The planet is so close, in fact, that it is being ripped apart by the star’s gravity, giving the planet an oblique football shape. The WASP-121 star system resides about 900 light-years from Earth.


«Heavy metals have been seen in other hot Jupiters before, but only in the lower atmosphere,» explained lead researcher David Sing of Johns Hopkins University. «With WASP-121b, we see magnesium and iron gas so far away from the planet that they’re not gravitationally bound. The heavy metals are escaping partly because the planet is so big and puffy that its gravity is relatively weak. This is a planet being actively stripped of its atmosphere.»


The researchers used Hubble’s Space Telescope Imaging Spectrograph to search for ultraviolet light signatures of magnesium and iron. These signatures can be observed in starlight filtering through WASP-121b’s atmosphere, as the planet passes in front of its host star.


The observations of WASP-121b add to the developing story of how planets lose their primordial atmospheres. When planets form, they gather an atmosphere made of gas from the disk that gave rise to both the planet and its host star. These young atmospheres consist mostly of hydrogen and helium, the most plentiful elements in the universe. As the planet moves closer to its star, much of this early atmosphere burns off and escapes to space.


«The hot Jupiters are mostly made of hydrogen, and Hubble is very sensitive to hydrogen, so we know these planets can lose the gas relatively easily,» Sing said. «But in the case of WASP-121b, the hydrogen and helium gas is outflowing, almost like a river, and is dragging these metals with them. It’s a very efficient mechanism for mass loss.»


According to the researchers, WASP-121b will be a perfect target for NASA’s James Webb Space Telescope, scheduled for launch in 2021. The Webb telescope will enable researchers to search for water and carbon dioxide, which can be detected at longer, redder wavelengths of infrared light. The combination of Hubble and Webb observations should give astronomers a more complete inventory of the chemical elements that make up the planet’s atmosphere.


«Hot Jupiters this close to their host star are very rare. Ones that are this hot are even rarer still,» Deming added. «Although they’re rare, they really stand out once you’ve found them. We look forward to learning even more about this strange planet.»


Source: University of Maryland [August 01, 2019]




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Anaemic star carries the mark of its ancient ancestor

A newly discovered ancient star containing a record-low amount of iron carries evidence of a class of even older stars, long hypothesised but assumed to have vanished.











Anaemic star carries the mark of its ancient ancestor
A visualisation of the formation of the first stars [Credit: Wise, Abel, Kaehler (KIPAC/SLAC)]

In a paper published in the journal Monthly Notices of the Royal Astronomical Society: Letters, researchers led by Dr Thomas Nordlander of the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) confirm the existence of an ultra-metal-poor red giant star, located in the halo of the Milky Way, on the other side of the Galaxy about 35,000 light-years from Earth.


Dr Nordlander, from the Australian National University (ANU) node of ASTRO 3D, together with colleagues from Australia, the US and Europe, located the star using the university’s dedicated SkyMapper Telescope at the Siding Spring Observatory in NSW.


Spectroscopic analysis indicated that the star had an iron content of just one part per 50 billion.


«That’s like one drop of water in an Olympic swimming pool,» explains Dr Nordlander. «This incredibly anaemic star, which likely formed just a few hundred million years after the Big Bang, has iron levels 1.5 million times lower than that of the Sun.»


Its diminutive iron content is enough to place the star — formally dubbed SMSS J160540.18-144323.1 — into the record books, but it is what that low level implies about its origin that has the astronomers really excited.


The very first stars in the Universe are thought to have consisted of only hydrogen and helium, along with traces of lithium. These elements were created in the immediate aftermath of the Big Bang, while all heavier elements have emerged from the heat and pressure of cataclysmic supernovae — titanic explosions of stars. Stars like the Sun that are rich in heavy element therefore contain material from many generations of stars exploding as supernovae.


As none of the first stars have yet been found, their properties remain hypothetical. They were long expected to have been incredibly massive, perhaps hundreds of times more massive than the Sun, and to have exploded in incredibly energetic supernovae known as hypernovae.


The confirmation of the anaemic SMSS J160540.18-144323.1, although itself not one of the first stars, adds a powerful bit of evidence.


Dr Nordlander and colleagues suggest that the star was formed after one of the first stars exploded. That exploding star is found to have been rather unimpressive, just ten times more massive than the Sun, and to have exploded only feebly (by astronomical scales) so that most of the heavy elements created in the supernova fell back into the remnant neutron star left behind.


Only a small amount of newly forged iron escaped the remnant’s gravitational pull and went on, in concert with far larger amounts of lighter elements, to form a new star — one of the very first second generation stars, that has now been discovered.


Co-researcher Professor Martin Asplund, a chief investigator of ASTRO 3D at ANU, said it was unlikely that any true first stars have survived to the present day.


«The good news is that we can study the first stars through their children — the stars that came after them like the one we’ve discovered,» he says.


Source: The ARC Centre of Excellence for All Sky Astrophysics in 3D [August 01, 2019]




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Mechanism for gamma-ray bursts from space decoded

Gamma-ray bursts, short and intense flashes of energetic radiation coming from outer space, are the brightest explosions in the universe. As gamma rays are blocked by the atmosphere, the bursts were discovered accidentally in the late sixties by the Vela satellites, defense satellites sent to monitor manmade nuclear explosions in space.











Mechanism for gamma-ray bursts from space decoded
Gamma-ray bursts [Credit: WikiCommons]

Since their discovery the bursts have been at the focus of attention with several dedicated satellites launched to explore their origin. In the late nineties it was realized that long bursts (lasting more than a few seconds) arise during the death and collapse of massive stars, while in the first decade of this century it was found that shorter bursts (lasting less than a few seconds) arise in neutron star mergers. This last realization was confirmed dramatically two years ago with simultaneous observations of gravitational waves by the gravitational wave detectors LIGO and Virgo and a short burst by two satellites, NASA’s Fermi and ESA’s Integral.
Still many mysteries involving these bursts remained. Particularly puzzling was the question how the high energy radiation is produced. Last January a gamma-ray detector aboard NASA’s Neil Gehrels Swift satellite detected GRB 190114C, a bright burst that took place 4.5 billion years ago in a distant galaxy. Following a trigger from Swift, the MAGIC telescope, a Cherenkov detector at the Roque de los Muchachos Observatory in La Palma, Spain, slewed toward the burst’s location and detected extremely high energy photons (at TeV energies) coming from it. The ultra-high energy TeV photons, which were observed about 50 seconds after the prompt emission, in the so-called afterglow phase, were at least 10 times more energetic than the highest energy photons detected previously from any burst.


By now only preliminary data of the MAGIC observations have been posted. Still, Prof. Evgeny Derishev from the Institute for Applied Physics in Nizhny Novogorod and Prof. Tsvi Piran from the Hebrew University of Jerusalem combined these data with observations of lower energy (X-ray) photons carried out by the Neil Gehrels Swift and have shown that they reveal the details of the emission mechanism.


In a paper published in the Astrophysical Journal Letters, the authors show that the observed radiation must have originated in a jet moving at 0.9999 the speed of light toward us. The high energy radiation observed by MAGIC was emitted by electrons accelerated to TeV energies within the jet. The emission process can also be identified: it is the so-called «inverse Compton mechanism» in which ultra-high energy electrons collide with low-energy photons and boost their energy. Remarkably the same relativistic electrons are also producing the low-energy «seed» photons via synchrotron radiation.


«MAGIC has found the Rosetta stone of gamma-ray bursts,» says Prof. Piran. «This unique detection enables us for the first time to discriminate between different emission models and discover what are the exact conditions in the explosion. We can also understand now why such radiation wasn’t observed in the past.» Future Cherenkov telescopes such as the planned Cherenkov Telescope Array, a multinational project under construction, will be much more sensitive than MAGIC. The current detection suggests that many other such events will be detected in the future and will continue to shed light on this cosmic mystery.


Source: Hebrew University of Jerusalem [August 01, 2019]



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Pre-life building blocks spontaneously align in evolutionary experiment

When Earth was a lifeless planet about 4 billion years ago, chemical components came together in tiny molecular chains that would later evolve into proteins, crucial life building blocks. A new study has shown how fortuitously some early predecessors of protein may have fallen into line.











Pre-life building blocks spontaneously align in evolutionary experiment
Late in the Hadean Eon, Earth’s earliest period, some 4 billion years ago, first life chemicals are believed to have
 come together. Earth’s surface seethed with vulcanic activity close to Earth’s first lakes, and meteors crashed
down regularly importing new chemicals from space. New experiments about the chemical evolution of
prebiotic amino acid linkages mimic mild conditions during the late Hadean Eon. Artist’s depiction
[Credit: Getty Images]

In the laboratory, under conditions mimicking those on pre-life Earth, a small selection of amino acids linked up spontaneously into neat segments in a way that surprised researchers at the Georgia Institute of Technology. They had given these amino acids found in proteins today some stiff competition by adding amino acids not found in proteins, thinking these non-protein, or non-biological, amino acids would probably not allow predominantly biological segments to come together.
The non-biological amino acids had the potential to chemically react equally well or better than the biological ones and frequently become part of the tiny chains, perhaps serving as an in-between step in the greater evolution toward proteins. The experiment dashed those expectations — but to the researchers’ delight. The reactions resulted mostly in strings that were closer to today’s actual proteins and less in chains that included non-biological amino acids.


«The non-biological amino acids were being excluded to some extent,» said Nick Hud, one of the study’s principal investigators and a Regents Professor in Georgia Tech’s School of Chemistry and Biochemistry.


Doorway to evolution


In particular, the researchers had thought the non-biological amino acids would outcompete the biological amino acid lysine, but it was not the case. They also thought lysine would often not fit neatly into the chains the way it does in proteins. The reaction surprised them again.


«Lysine went into the chains predominantly in the way that it is connected in proteins today,» said Hud, who is also director of the National Science Foundation/NASA Center for Chemical Evolution (CCE), which is headquartered at Georgia Tech and explores the chemistry that may have paved the way to first life.


The research team, which included collaborators from The Scripps Research Institute, published their results in the journal Proceedings of the National Academy of Sciences. The research was funded by the NSF and NASA.


The study’s experiment points to chemical evolution having prefabricated some amino acid chains useful in living systems before life had evolved a way to make proteins. The preference for the incorporation of the biological amino acids over non-biological counterparts also adds to possible explanations for why life selected for just 20 amino acids when 500 occurred naturally on the Hadean Earth.


«Our idea is that life started with the many building blocks that were there and selected a subset of them, but we don’t know how much was selected on the basis of pure chemistry or how much biological processes did the selecting. Looking at this study, it appears today’s biology may reflect these early prebiotic chemical reactions more than we had thought,» Loren Williams, another principal investigator in the study and a professor in Georgia Tech’s School of Chemistry and Biochemistry.


Mono, oligo, poly


To help understand the study’s significance, let’s look at how proteins form, then at the study’s core experiment, which revealed an unexpectedly high preference for bonds between sites called alpha-amines (α-amines) on the biological amino acids. Those bonds gave resulting molecular segments a protein-like shape in the lab.











Pre-life building blocks spontaneously align in evolutionary experiment
An outtake from a mural on the origin of life celebrates famous experimental milestones in the science that tries to
explain how chemicals evolved into the first building blocks of life on an Earth before life existed. The NSF
Center for Chemical Evolution headquartered at Georgia Tech has adopted this banner as a symbol
[Credit: Christine He & David Fialho for Georgia Tech]

In a protein, one amino acid is a single chemical unit, or monomer. A few of them linked together is called an oligomer, and really long chains are polymers. In proteins, the polymer is called a polypeptide — named after the peptide bonds that link its monomers together.


Polypeptides are long chains that often form helices, like old phone cords, or flat sheets. They kink and fold up into specific, mostly functional wads, sheets, and other shapes, which are called proteins. The study looked at how amino acid monomers linked up to make interesting oligomers that look like small pieces of proteins.


Hadean Eon experiment


Late in the Hadean Eon, Earth’s earliest phase, when prebiotic chemistry was taking shape, the planet’s surface was awash in vulcanism and rain, and large meteors pummeled it with new chemicals. The researchers’ experimental lab setup reflected relatively mild conditions for those times and feasibly present ingredients.


First author Moran Frenkel-Pinter placed the biological amino acids lysine, arginine, and histidine together with three non-biological competitors in water containing hydroxy acids. Hydroxy acids are known to facilitate amino acid reactions and would have been common on prebiotic Earth.


The mixture was heated to 85 degrees Celsius, pushing the reaction and evaporating the water, and the researchers analyzed the products formed.


«We found this high preference for the inclusion of these biological amino acids and the linkage via the α-amine,» said Frenkel-Pinter, a NASA postdoctoral researcher in the CCE.


Amine groups are made of nitrogen and hydrogen and are quite reactive, but the α-amine is part of the core of an amino acid, and other amines in this experiment were at the end of a sidechain extending off the core. The latter is often more reactive.


«It surprised us that this chemistry favored the α-amine connection found in proteins, even though chemical principles might have led us to believe that the non-protein connection would be favored,» Frenkel-Pinter said. «The preference for the protein-like linkage over non-protein was about seven to one.»


Easy chemical evolution


Most resulting oligomers had evenly placed links in the chain, which are used in life, as opposed to non-α-amine bonded oligomers, which built more irregular chains.


The finished products were mostly depsipeptides, which the CCE previously established as stepping stone products in an easy, reliable pathway to peptides.


In another reflection of life chemistry, the abiotic depsipeptide transition to peptides is the same basic reaction (ester-amide) carried out by ribosomes, the cellular machines that make proteins today.


Surprise reactions, in which potential pre-life chemistry casually falls into place, have happened often in the CCE’s research. They have shored up the center’s core hypothesis that most biological polymers formed in wet and dry cycles, perhaps on rain-swept dirt flats or lakeshore rocks regularly baked by the sun’s heat.


Despite its grounded simplicity, the premise of everyday wet-dry cycles being key to the origin of life is unconventional, challenging a more established narrative that improbable concurrences of cataclysms and multiple ingredients were necessary to produce life’s early materials in rare and volatile events.


Author: Ben Brumfield | Source: Georgia Institute of Technology [August 01, 2019]



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The purpose of life: why the textbook needs an update

New research from Australia and Finland could help explain one of nature’s strangest quirks—why some animals forego mating to help other animals procreate. The study challenges decades-old ideas about evolution, and why animals behave as they do.











The purpose of life: why the textbook needs an update

Credit: Steven & Courtney Johnson & Horwitz/Flickr



Co-author Professor Michael Jennions from The Australian National University (ANU) says it was traditionally thought that animals evolved to maximise their reproductive success—sometimes called ‘Darwinian fitness’.


«It is logical. Any new traits which happen to result in more offspring will eventually spread throughout the population,» Professor Jennions said. «It is why cheetahs run so fast and dolphins swim so well.»


But why would some animals—like worker bees and meerkats—give up their own chances of reproducing to help others? British zoologist William Hamilton offered a solution back in 1964.


«Hamilton put forward the idea that animals can enhance the number of genes they pass on not only by producing offspring, but by helping relatives,» Professor Jennions said.


«He suggested that animals should strive for high ‘inclusive fitness’ — which takes into account not only an individual’s own offspring, but any impact on its relatives’ reproduction.»


However, a stumbling block in Hamilton’s theory was its claim that an individual’s inclusive fitness should exclude any offspring produced with help from others.


Credit: The Australian National University     


Professor Jennions and his co-author Dr. Lutz Fromhage from the University of Jyvaskyla in Finland say this is unfeasible in most real-world situations.


«For example, the evolution of the behaviour and morphology of a queen bee cannot be understood in isolation from the help given by workers,» Professor Jennions said.


According to Dr. Fromhage, the researchers’ computer simulations show that, to justify inclusive fitness as the thing which individuals evolve to maximise, all offspring—including those produced with help from others—must be taken into account.


«None of the effects of received help should be disregarded or stripped away when measuring inclusive fitness,» Dr. Fromhage said.


«Our paper is technical, but the outcome is highly practical. Field studies of social evolution, be they on bacteria in hospitals, or hyaena in the wild, are inspired by the idea of inclusive fitness.»


The research has been published online in the journal Proceedings of the Royal Society B.


Source: The Australian National University [August 01, 2019]



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