суббота, 8 июня 2019 г.

Tricking the Mind Any spy sneaking into enemy territory needs…


Tricking the Mind


Any spy sneaking into enemy territory needs a convincing disguise to blend in with the locals. The same is true of electrical devices implanted into the body. If the body recognises the gadget as an outsider, it will try to fight it off, interfering with its ability to monitor normal activity. For example, brain implants tend to be conspicuous in the natural surroundings, being large and more rigid, so the immune system steps in. A new version is smaller, more flexible, and mimics brain cells (neurons) much more closely (red, surrounded by neurons (green) and other brain material called astrocytes (blue) at two days, two weeks and three months after implantation, left to right). Once injected, the artificial neurons can settle in unnoticed, meaning they can report on natural activity, which could reveal important information about a range of neurological conditions, and could one day help enact new treatments directly to troublesome areas.


Written by Anthony Lewis



You can also follow BPoD on Instagram, Twitter and Facebook


Archive link


Roman Cavalry Saddle, Fittings and Ornaments, Vindolanda Roman Fort and Vicus,...







Roman Cavalry Saddle, Fittings and Ornaments, Vindolanda Roman Fort and Vicus, Hadrian’s Wall, Northumberland, 31.5.19.


Source link


Shattuckite with Quartz | #Geology #GeologyPage…


Shattuckite with Quartz | #Geology #GeologyPage #Mineral


Locality: Kandesei, Kaokoveld, Kunene Region, Namibia, Africa


Dimensions: 8.2 × 5.5 × 2.4 cm


Photo Copyright © Crystal Classics


Geology Page

www.geologypage.com

https://www.instagram.com/p/BydK-5OABGh/?igshid=1fiy5hnlv5vvr


Calcite | #Geology #GeologyPage #Mineral Locality: Iraí, Alto…


Calcite | #Geology #GeologyPage #Mineral


Locality: Iraí, Alto Uruguai region, Rio Grande do Sul, Brazil

Size: 7.1 x 6.7 x 4.7 cm


Photo Copyright © Anton Watzl Minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/BydL1oVAlpo/?igshid=1kjcl5sweetrd


2019 June 8 On the Beach with Mars Image Credit &…


2019 June 8


On the Beach with Mars
Image Credit & Copyright: Jack Fusco


Explanation: At the end of last year’s northern summer, after its dazzling opposition, Mars still shone brightly in the night. The celestial beacon easily attracted the attention of these two night skygazers who stood still for just a while, but long enough to be captured in the sea and night skyscape from Big Sur, planet Earth. Its central bulge near the southwestern horizon, the Milky Way runs through the scene too, while the long exposure also reveals a faint blue bioluminescence blooming in the waves along Pfeiffer Beach. Now much fainter, Mars can be spotted near the western horizon after sunset, but this month Jupiter is near its closest and brightest, reaching its own opposition on June 10. Night skygazers can spot brilliant Jupiter over southern horizons, glaring next to the stars toward the central Milky Way.


∞ Source: apod.nasa.gov/apod/ap190608.html


New genes out of nothing

One key question in evolutionary biology is how novel genes arise and develop. Swedish researchers now show how new genes and functions that are advantageous to bacteria can be selected from random DNA sequences. The results are presented in the scientific journal mBio.











New genes out of nothing
Credit: bigstock

How do new genes and functional proteins arise and develop? This is one of the most fundamental issues in evolutionary biology. Two different types of mechanism have been proposed: (1) new genes with novel functions arise from existing genes, and (2) new genes and proteins evolve from random DNA sequences with no similarity to existing genes and proteins. In the present study, the researchers explored the latter type of mechanism: evolution of new genes and proteins from randomised DNA sequences — de novo evolution, as it is called. It is fairly easy to understand that when a gene already exists, it can be modified and acquire a new function. But how does «nothing» turn into a function affording a small advantage that is favoured by natural selection?
The raw material for the experiment was an big library of some 500 million randomised gene sequences, from which peptide sequences with a biological function were identified. In the experiment, random gene sequences were placed on a plasmid and overexpressed. The scientists then investigated whether they could give bacteria a specific, defined property. Were they, for example, able to give the bacteria antibiotic resistance? They identified several short peptides (22-25 amino acids long) that could give the bacteria a high degree of resistance to aminoglycosides, an important class of antibiotics used for severe infections.


«When the project started, we had low expectations. We were amazed when we found peptides able to confer a resistance level 48 times higher,» says Dr Michael Knopp, the study’s lead author.


Through a combination of genetic and functional experiments, the scientists were able to demonstrate that the peptides cause resistance by attaching themselves to bacterial cell membranes and affecting the proton potential across the membrane. The disruption of the proton potential causes a decrease in antibiotic uptake, rendering the bacteria resistant.


«This study is important because it shows that completely random sequences of amino acids can give rise to new, advantageous functions, and that this process of de novo evolution can be studied experimentally in the laboratory,» says Dan I. Andersson, Professor of Medical Bacteriology, who is chiefly responsible for the study.


Source: Uppsala University [June 04, 2019]



TANN



Archive


Scientists crack origin of the Persian walnut

Prized worldwide for its high-quality wood and rich flavor of delicious nuts, the Persian walnut (Juglans regia) is an important economic crop. The Persian walnut is one of 22 species in the genus Juglans, which includes black and white walnuts and butternuts, grown across Europe, the Americas and Asia.











Scientists crack origin of the Persian walnut
Nut photos of three different walnut species, J. mandshurica (Manchurian), J. nigra (black) and J. regia (Persian),
 that were used in the study show clear differences among the outer shells of the species. The Persian walnut
(Juglans regia) is an important economic crop and one of 22 species in the genus Juglans, which includes
black and white walnuts and butternuts, grown across Europe, the Americas and Asia
[Credit: Department of Biology, Systematic Botany and Mycology,
University of Munich (LMU), Munich, Germany]

China leads world production, followed by California, Turkey and Iran. But until now, the evolution of walnuts has been unknown. Walnuts have a rich fossil record, which suggest an origin of walnuts and initial divergence into black walnuts and butternuts (white walnuts) in North America, some 35-45 million years ago. With this high age, both walnut lineages would have had ample opportunity to migrate into the Old World via the Bering and North Atlantic land bridges, yet only butternuts have been detected in the fossil records of Europe and Asia, and no ancient fossils of the Persian walnut are known.
Using genomic data analyzed with phylogenetic and population genetic approaches, researchers have now cracked this mystery, showing that the Persian walnut is the result of hybridization between two long-extinct species around 3.45 million years ago.


Past analyses by the team based on some 2900 single-copy nuclear genes from 19 species of walnuts were unable to sort out the relationships between North American, Asian, and Persian walnut species. However, they excluded incomplete lineage sorting as the cause of the phylogenetic uncertainty. «This led us to speculate that ancient hybridization might be involved in the origin of the Persian walnut and the American butternut,» said Da-Yong Zhang, a population geneticist who is one of the senior authors.











Scientists crack origin of the Persian walnut
An optimal species network inferred using the PhyloNet software for walnut evolution. The result is maximum
pseudo-likelihood tree with one reticulation. The γ value indicates the inheritance probability from the ancestor
 of sect. Cardiocaryon, while 1-γ indicates that from the ancestor of sect. Rhysocaryon. The genomic
mosaicism of both the Persian walnut (incl. J. sigillata) and the American butternut J. cinerea
 provides evidence for the importance of hybridization throughout the evolution of walnuts
[Credit: Department of Biology, Systematic Botany and Mycology,
University of Munich]

To test their hybridization hypothesis, rather than look at individual genes, this time, they used whole-genome sequencing from 80 individual trees that represented 19 of the 22 species of Juglans.


«We applied a battery of genome-wide methods for hybridization detection and to test speciation models to infer the time of origin of the Persian walnut,» said the Wei-Ning Bai, another senior author. «In the end, we characterized the genetic composition of the genomes of not only the Persian walnut, but also the Iron walnut, J. sigillata, and the American butternut, J. cinerea.» The authors paint a picture, based on walnut fruit fossils and their genomic evidence, that walnuts «by the late Oligocene must have expanded from America to Europe and then spread to Asia and further expanded into Europe, where the black walnut and butternut lineages came into contact and hybridized some 3.45 Ma ago. While walnuts diversified in Asia and the New World, they were lost from Europe during the Pleistocene climate oscillations, with eventually only the newly formed hybrid lineage that gave rise to J. regia surviving.»


«All of our genome-wide analyses converged to provide unambiguous evidence of hybridization at the roots of both the American butternut (J. cinerea) and the Persian walnut (J. regia/J. sigillata),» said the authors. «Our results further resolve the controversy concerning the origin of the American butternut, J. cinerea, which turns out to result from massive nuclear gene introgression involving an American black walnut through pollen swamping by an immigrating Asian butternut.»


«The genomic mosaicism of both the Persian walnut (incl. J. sigillata) and the American butternut J. cinerea provides evidence for the importance of hybridization throughout the evolution of walnuts,» said the authors.


The findings are published in Molecular Biology and Evolution.


Source: Oxford University Press [June 04, 2019]




TANN



Archive


Snout dated: Slow-evolving elephant shark offers new insights into survival of...

The mineralocortoid receptor (MR) regulates water and sodium transport throughout cells and tissues, which is critical for controlling blood pressure and so, not surprisingly, the MR is common to all vertebrate animals. Aldosterone, which is a physiological steroid for land vertebrate MRs, evolved in lungfish (forerunners of land vertebrates), suggesting that the evolution of aldosterone was important in the conquest of land by preventing dehydration in animals living out of water.











Snout dated: Slow-evolving elephant shark offers new insights into survival of vertebrates living on land
An elephant shark, characterized by its distinctive snout
[Credit: Susumu Hyodo, University of Tokyo]

And yet, aldosterone is absent in sharks and ray-finned fish, prompting the question of which steroids activate the MR in them, and the roles played by these steroids in humans.


In an unusual study, an international team of scientists from Japan, Singapore and the United States, led by Michael E. Baker, PhD, research professor at University of California San Diego School of Medicine, report that compared to humans, a different set of steroid hormones activate MR in elephant sharks, a species of cartilaginous fish that represents the oldest surviving group of jawed vertebrates.


The discovery, published in Science Signaling, not only highlights another evolutionary change as vertebrates transitioned from water to land, but suggests that MR may have other, critical roles in maintaining human health.


«Although the MR is traditionally thought of as a transcription factor that’s important in regulating electrolyte transport in kidneys, it is becoming clear that the MR has physiological actions in non-traditional organs, including the brain and heart,» said Baker.


«Our findings suggest that the activity of the MR in non-traditional organs is ancient and, indeed, evolved in a basal jawed vertebrate. Studies with elephant sharks support other research that shows the physiology of steroid hormones like aldosterone, cortisol and progesterone in other non-traditional tissues, such as ovary and testis, also may be important in human health.»


The elephant shark (Callorhinchus milii) is an uncommon animal model. Known by several names, such as ghost shark, elephant fish and silver trumpeter, the species is found in waters off southern Australia. The smooth-skinned fish grow to a maximum size of four feet and pose no threat to humans. Their distinctive hoe-shaped, proboscis-like snout is used to detect prey, primarily shellfish and bottom-dwelling invertebrates, through movement and weak electrical fields.


Elephant sharks possess another unusual feature: They have the slowest evolving genome of all known vertebrates, «which makes them ideal for providing insights into how MR evolved in bony vertebrates, including humans,» said the study’s first author Yoshinao Katsu, PhD, assistant professor of biological science at Hokkaido University in Japan.


Baker, Katsu and colleagues in Singapore, Japan and Minnesota found that elephant shark MR responds to the same physiological corticosteroids (aldosterone, cortisol, corticosterone and 11-deoxycorticosterone) that activate MR in humans and other mammals. But another major steroid hormone — progesterone — triggers shark MR but does nothing in humans, rats, frogs or alligators.


«Because the synthesis of progesterone synthesis is simpler than either aldosterone, cortisol, corticosterone or 11-deoxycorticosterone, we propose that progesterone was an ancestral, maybe the ancestral steroid for MR,» said Katsu.


As such, said the authors, the odd-looking elephant shark and its compact, slow-evolving genome provide a different, comparative way to look at and understand the evolution of humans and other vertebrates at the point when they became terrestrial creatures.


«Elephant shark proteins are a window into the past,» said Baker.


Author: Scott LaFee | Source: University of California — San Diego [June 04, 2019]



TANN



Archive


Pathogens may have facilitated the evolution of warm-blooded animals

Six hundred million years ago, fever appeared in animals as a response to infections: the higher body temperatures optimized their immune systems. At the time, virtually all animal species were cold-blooded. They had to sit in warm patches of habitat for extended periods of time to achieve fever-range body temperatures. For Michael Logan, a Tupper Fellow at the Smithsonian Tropical Research Institute in Panama (STRI), pathogens may be the reason why warm-blooded creatures first emerged.











Pathogens may have facilitated the evolution of warm-blooded animals
By keeping their bodies warm at all times, birds and mammals may be effectively priming their
 immune systems to withstand virulent pathogens [Credit: Michael Logan]

At first glance, cold-blooded creatures or ‘ectotherms’ seem to have it easy. Because they cannot regulate their body temperature internally, they spend 30 times less energy than warm-blooded creatures or ‘endotherms’ of the same size. So, while mammals and birds are constantly investing their calories in maintaining a high, stable body temperature, reptiles and amphibians can just search for a warm spot in their surrounding environment if they want to get cozy. But if ectothermy is so great, why did mammals and birds develop a different strategy that is so costly?
Over the years, scientists have proposed three different models for why endotherms evolved high, stable body temperatures. One claims that it aids physiological processes; another, that it helps animals maintain activity over longer periods of time; and the third, that it enables parents to take care of precocial offspring. However, none of these models have found strong support and the evolutionary history of endothermy remains somewhat of a mystery.


Although these various hypotheses may have some truth to them, for Logan, the trigger must have been something that profoundly impacted the ability of animals to survive and reproduce, otherwise endothermy would be too costly a strategy and would not be favored by natural selection. In a recent paper, published in the journal Ideas in Ecology and Evolution, he explains this theory.











Pathogens may have facilitated the evolution of warm-blooded animals
The ability to mount a rapid fever response to a pathogen means warm-blooded creatures
are not limited by the thermal variation in their habitats [Credit: Michael Logan]

«My hypothesis is that by keeping their bodies warm at nearly all times, mammals and birds effectively prime their immune systems to withstand virulent pathogens, and that this may be part of the reason the extremely costly strategy of endothermy evolved in the first place,» Logan said.
In this context, endothermy may offer critical advantages over ectothermy. The ability to mount a rapid fever response to a pathogen means endotherms are not limited by the thermal variation in their habitats. Meanwhile, cold-blooded creatures depend on external sources of heat to reach fever-like temperatures. They are subject to fluctuations in environmental conditions, and in searching for the ideal microclimate required to initiate fever, they may struggle to forage or mate and may be exposed to predators.


«This hypothesis has emerged from recent discoveries in the fields of immunology and animal physiology, but we still need to rigorously test it with data and experiments,» Logan said. «For example, my model predicts that species that maintain the warmest, most stable body temperatures (all else remaining equal) should also experience the highest frequency of disease outbreaks or the most virulent pathogens.»


Source: Smithsonian Tropical Research Institute [June 04, 2019]



TANN



Archive


Rare fossils provide more detailed picture of biodiversity during Middle Ordovician

A clutch of marine fossil specimens unearthed in northern Portugal that lived between 470 and 459 million years ago is filling a gap in understanding evolution during the Middle Ordovician period.











Rare fossils provide more detailed picture of biodiversity during Middle Ordovician
Maine fossils from Portugal are shedding light on Middle Ordovician, where there
had been a gap in the fossil record [Credit: Julien Kimmig/KU]

The discovery, explained in a new paper just published in The Science of Nature, details three fossils found in a new «Burgess Shale-type deposit.» (The Burgess Shale is a deposit in Canada renowned among evolutionary biologists for excellent preservation of soft-bodied organisms that don’t have a biomineralized exoskeleton.)


«The paper describes the first soft-body fossils preserved as carbonaceous films from Portugal,» said lead author Julien Kimmig, collections manager at the University of Kansas Biodiversity Institute and Natural History Museum. «But what makes this even more important is that it’s one of the few deposits that are actually from the Ordovician period — and even more importantly, they’re from the Middle Ordovician, a time were very few soft-bodied fossils are known.»


Kimmig and his KU Biodiversity Institute colleagues, undergraduate researcher Wade Leibach and senior curator Bruce Lieberman, along with Helena Couto of the University of Porto in Portugal (who discovered the fossils), describe three marine fossil specimens: a medusoid (jellyfish), possible wiwaxiid sclerites and an arthropod carapace.


«Before this, there had been nothing found on the Iberian Peninsula in the Ordovician that even resembled these,» Kimmig said. «They close a gap in time and space. And what’s very interesting is the kind of fossils. We find Medusozoa — a jellyfish — as well as animals which appear to be wiwaxiids, which are sluglike armored mollusks that have big spines. We found these lateral sclerites of animals which were actually thought to have gone extinct in the late Cambrian. There might have been some that survived into the Ordovician in a Morocco deposit, but nothing concrete has been ever published on those. And here we have evidence for the first ones actually in the middle of the Ordovician, so it extends the range of these animals incredibly.»


Kimmig said the discovery of uncommon wiwaxiids fossils in this time frame suggests the animals lived on Earth for a far greater span of time than previously understood.


«Especially with animals that are fairly rare that we don’t have nowadays like wiwaxiids, it’s quite nice to see they lived longer than we ever thought,» he said. «Closely after this deposit, in the Upper Ordovician, we actually get a big extinction event. So, it’s likely the wiwaxiids survived up to that big extinction event and didn’t go extinct earlier due to other circumstances. But it might have been whatever caused the big Ordovician extinction event killed them off, too.»











Rare fossils provide more detailed picture of biodiversity during Middle Ordovician
A disc-shaped fossil that once lived in today’s northern Portugal between
470 and 459 million years ago [Credit: Julien Kimmig]

According to the researchers, the soft-bodied specimens fill a gap in the fossil record for the Middle Ordovician and suggest «many soft-bodied fossils in the Ordovician remain to be discovered, and a new look at deep-water shales and slates of this time period is warranted.»


«It’s a very interesting thing with these discoveries — we’re actually getting a lot of information about the distribution of animals chronologically and geographically,» Kimmig said. «Also, this gives us a lot of information on how animals adapted to different environments and where they actually managed to live. With these soft-body deposits, we get a much better idea of how many animals there were and how their environment changed over time. It’s something that applies to modern days, with changing climate and changing water temperatures, because we can see how animals over longer periods of time in the geologic record have actually adapted to these things.»


Co-author Couto discovered the fossils in the Valongo Formation in northern Portugal, an area famed for containing trilobites. When the animals were alive, the Valongo Formation was part of a shallow sea on the margin of northern Gondwana, the primeval supercontinent.


«Based on the shelly fossils, the deposit looks like it was a fairly common Ordovician community,» Kimmig said. «And now we know that in addition to those common fossils jellyfish were floating around, we had sluglike mollusks roaming on the ground, too, and we had bigger arthropods, which might have been predatory animals. So, in that regard, we’re getting a far better image with these soft-bodied fossils of what these communities actually looked like.»


According to the KU researcher, scientists didn’t grasp until recently that deposits from this period could preserve soft-bodied specimens.


«For a long time, it was just not known that these kinds of deposits survived in to the Ordovician,» Kimmig said. «So, it is likely these deposits are more common in the Ordovician than we know of, it’s just that people were never looking for them.»


Kimmig led analysis of the fossils at KU’s Microscopy and Analytical Imaging Laboratory to ensure the fossils were made of organic material. Leibach, the KU undergraduate researcher, conducted much of the lab work.


«We analyzed the material and looked at the composition because sometimes you can get pseudo fossils — minerals that create something that looks like a fossil,» Kimmig said. «We had to make sure that these fossils actually had an organic origin. And what we found is that they contain carbon, which was the big indication they would actually be organic.»


Source: University of Kansas [June 04, 2019]



TANN



Archive


Paleontologists discover giant reptile in Antarctica

It is the largest elasmosaurid in the world, similar in appearance to the Loch Ness monster. With a body mass that exceeded 12 tons, it doubles in size the majority of reptiles of his family known until now. According to the researchers, they would have developed a form of feeding similar to that of whales.











Paleontologists discover giant reptile in Antarctica
Credit: Agencia CTyS-UNLaM

The paleontologist José O’Gorman of the Museum of La Plata (MLP) and CONICET assured the CTyS-UNLaM Agency that «a very important specimen was extracted in the Marambio Island; It is the largest elasmosaurid in the world. «


«Due to the large size of this specimen, its rescue was carried out during successive campaigns of the Argentine Antarctic Institute and its rescue culminated in 2017», explained the main author of this study published recently in the scientific journal Cretaceous Research.


In addition, this giant reptile stands out for being the elasmosaurid closest to the extinction of dinosaurs that has been discovered on the white continent. Dr. Marcelo Reguero, researcher of the Argentine Antarctic Institute and the MLP, said that «this fossil is very close to the end of the Cretaceous, when it is estimated that a large meteorite fell and caused the disappearance of many species.»


The remains of this giant reptile are in the Museum of La Plata. Part of his spine has been found, part of his anterior and posterior fins and some elements of the scapular waist. While his skull has not been found, researchers have analyzed what feeding strategy he might have had to develop such a large size.


It is estimated that the length of this reptile was between 11.2 and 12 meters. «It weighed between 10 and 13 tons, so it is well above those that were known until now, which had a mass of between five and six tons,» said Dr. O’Gorman.


The elasmosaurids are part of the great family of plesiosaurs, those extinct reptiles in what possibly inspired the collective imagination to create the monster of Loch Ness.











Paleontologists discover giant reptile in Antarctica
Credit: Agencia CTyS-UNLaM

Within the elasmosaurids, this giant reptile is part of the subfamily of aristonectinos, which had a slightly shorter neck, much more robust vertebrae and a much larger skull.


«The hypothesis that could explain the great size of this new specimen, and that seems to be progressively supported by the evidence, is that the aristonectinos had a way of capturing their prey different from the rest of the elasmosaurids; We believe that, instead of capturing their prey individually, these animals opened their mouth and captured a large number of small prey at the same time, such as small crustaceans, for example, «O’Gorman said.


This type of capture is similar to the one applied by the current whales. Dr. O’Gorman said that «the whales take advantage of a roughness they have on the palate to catch the microplankton, while we consider that the aristonectinos used the battery of teeth as a kind of trap».


«It seems that evolution repeated certain patterns of development between these two groups that have no relationship,» O’Gorman analyzed. And he differentiated: «Plesiosaurs are reptiles and have nothing to do with cetaceans that are mammals.»


Dr. Marcelo Reguero highlighted the logistics and work that made possible the rescue of this specimen as well as other fossils in Antarctica.


In this site located towards the center of the Marambio Island, sediments of an ancient shallow marine environment are found. «There we have also found very small vertebrae of baby plesiosaurs; at that moment, there was a fairly calm sea» Reguero said. to the Agency CTyS-UNLaM.



In these deposits, flying seabirds and dinosaurs of different groups have also been found. Reguero appreciated that «whenever international congresses are held where the results of the research in Antarctica are exposed, the studies in paleontology of vertebrates carried out by the Argentine scientists are in very well positioned».


This new giant reptile specimen was discovered in 1989 and was recently completed in 2017. «The collection was carried out over many years and many teams have participated; this evidences the need for a support of the scientific activity that the Argentine Antarctic Institute has maintained over time, «said Dr. O’Gorman.


In addition to José O’Gorman and Marcelo Reguero, the researcher of the Argentine Antarctic Institute Sergio Santillana and the paleontologist Rodrigo Otero of the Laboratory of Ontogenia and Phylogeny of the University of Chile participated in this study that unveiled the world’s largest elasmosaurid known so far.


Source: CTyS-UNLaM Agency [June 04, 2019]



TANN



Archive


Ancestral Puebloan pottery-making wasn’t ‘women’s work’

New research from Dr. John Kantner, a University of North Florida professor specializing in anthropological archaeology, suggests that pottery making wasn’t a primarily female activity in ancient Puebloan society, as had long been assumed based on historical evidence that women produced pottery for each household.











Ancestral Puebloan pottery-making wasn't 'women's work'
The sprawling 650-room complex of Pueblo Bonito in New Mexico was at the center of the Chaco Canyon
community between 800 and 1200 AD [Credit: Phil Schermeister/National Geographic]

Kanter, also associate vice president of research at UNF, is the principal investigator and lead author of this study published in the Proceedings of the National Academy of Sciences.
His research team and co-authors are comprised of Michele Pierson and Shaza Wester, former UNF undergraduates, and David McKinney, formerly a graduate student at Georgia State University.


«An understanding of the division of labor in different societies, and especially how it evolved in the human species, is fundamental to most analyses of social, political and economic systems,» said Kantner, a Southside Jacksonville resident.











Ancestral Puebloan pottery-making wasn't 'women's work'
Researchers analyzed the breadth of ridges in fingerprints left on the ceramics by potters; the ridges
on men’s fingerprints are generally wider than women’s [Credit: University of North Florida]

The findings, he notes, reconstruct the division of labor between men and women in an ancient society and indicate that labor wasn’t strictly divided upon gender lines, despite the conventional wisdom that men and women engaged in separate domestic tasks.
Instead, the researchers found that the proportion of males and females involved in pottery-making was seemingly unconstrained by considerations of gender, with, in some households, more males making pottery while in others, equal numbers of both sexes were involved.


Kantner’s team used an innovative method for identifying the sex of potters through the analysis of fingerprint impressions. They recorded fingerprints on pottery from around the 10th to 11th century CE, measuring the width of fingerprint ridges—the patterns on the tip of each finger—to distinguish between male and female prints.











Ancestral Puebloan pottery-making wasn't 'women's work'
The pottery was found during excavations of ancient households in Chaco Canyon
[Credit: University of North Florida]

Analysis of over 980 ceramic shards from a 1,000-year-old Ancestral Puebloan community in modern-day New Mexico’s Chaco Canyon revealed representation of both male and female prints.
The time frame of the pottery production was marked by the development of Chaco Canyon as a highly influential political and religious center. This development coincided with a shift toward gender equity in pottery-making, the authors write, suggesting that high demand for pottery in Chaco Canyon may have spurred more people of both genders to produce pottery.


«The results challenge previous assumptions about gendered divisions of labor in ancient societies and suggest a complex approach to gender roles throughout time,» noted Kantner.


Source: University of North Florida [June 04, 2019]



TANN



Archive


Neolithic pottery sherds from China reveal alcohol production techniques

Was it the lure of beer that encouraged prehistoric humans to begin farming? Archaeological evidence from China suggests it might have been as the region’s first farmers had worked out how to turn millet and other cereals into alcoholic drinks in two distinct ways, hinting at how important alcohol was at the time.











Neolithic pottery sherds from China reveal alcohol production techniques
A group of pottery vessels studied, with some analyzed for food traces, in the Baoji Museum
in Shaanxi province, China [Credit: Li Liu]

Li Liu at Stanford University and her colleagues analysed the residues left on 8000- to 7000-year-old pottery sherds unearthed at two early farming sites in north China. At both sites, some of the residues contained cereal starch granules with signs of physical damage similar to that caused by fermentation.


A key stumbling block when brewing beer from cereals is to break down the starches into fermentable sugars. Significantly, say Liu and her colleagues, the ancient brewers at the two sites appear to have used different techniques to do this.


At the site of Lingkou, tiny mineral particles from plants – phytoliths – in the residues suggest the brewers simply let the grains sprout, which frees up the sugars. But at the site of Guantaoyuan, 300 kilometres to the west, the mix of phytoliths and fungi suggests an alternative approach. Here, the archaeologists say the brewers triggered the breakdown of starches by using a ‘fermentation starter’ known as qū, which is made from grains that have been allowed to mould. Qū is still used today to produce cereal wines and spirits.


Collectively, says Liu, the evidence suggests the history of these two distinct fermentation techniques stretches back to the early days of farming in East Asia.











Neolithic pottery sherds from China reveal alcohol production techniques
A globular jar fitted with a funnel-steamer in the Baoji Museum
in Shaanxi province, China [Credit: Li Liu]

“That would be very exciting,” says Patrick McGovern at the University of Pennsylvania Museum of Archaeology and Anthropology. The origins of qū are hotly disputed, he says. Traditionally, its roots are traced back to the Shang Dynasty in China, which began about 3700 years ago. But even in that period its questionable when qū use started, he says.


However, McGovern would like to see stronger evidence that the brewers at Guantaoyuan really were using qū. In 2004, he and his colleagues described even earlier evidence of fermented drinks in the region, at a 9000-year-old site in central China. The brewers there used honey and fruit as well as rice. It’s an important distinction, says McGovern. Not only are honey and fruit rich in fermentable sugars, they also naturally carry the yeasts that perform fermentation – which cereals do not. If they used honey and fruit as well as cereals, early brewers at Guantaoyuan would not have needed to use qū to get fermentation started.


But there is agreement that the new study emphasises the important of alcoholic drinks in early farming cultures. Liu suspects the spread of domesticated rice might have been encouraged in part because of its use in such drinks. “Alcohol would be used in feasting which helps some individuals to gain high social status and to form alliances,” she says.


McGovern thinks alcoholic drinks might even have helped encourage humans to adopt farming. The large quantities of grain produced by farming could be stored and turned into beer or bread all year round. Beer might have been seen as the more desirable product. Bread doesn’t have the mind-altering effect of alcohol, which I think is so important for social and religious reasons,” he says.


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


Author: Colin Barras | Source: New Scientist [June 04, 2019]



TANN



Archive


How We’re Accelerating Our Missions to the Moon

image

Our Space Launch System isn’t your average rocket. It is the only rocket that can send our Orion spacecraft, astronauts and supplies to the Moon. To accomplish this mega-feat, it has to be the most powerful rocket ever built. SLS has already marked a series of milestones moving it closer to its first launch, Artemis.


Here are four highlights you need to know about — plus one more just on the horizon.


Counting Down


image

Earlier this month, Boeing technicians at our Michoud Assembly Facility in New Orleans successfully joined the top part to the core stage with the liquid hydrogen tank. The core stage will provide the most of the power to launch Artemis 1. Our 212-foot-tall core stage, the largest the we have ever built, has five major structural parts. With the addition of the liquid hydrogen tank to the forward join, four of the five parts have been bolted together. Technicians are finishing up the final part — the complex engine section — and plan to bolt it in place later this summer.  


Ready to Rumble


image

This August, to be exact. That’s when the engines for Artemis 1 will be added to the core stage. Earlier this year, all the engines for the first four SLS flights were updated with controllers, tested and officially cleared “go” for launch. We’ve saved time and money by modifying 16 RS-25 engines from the space shuttle and creating a more powerful version of the solid rocket boosters that launched the shuttle. In April, the last engine from the shuttle program finished up a four-year test series that included 32 tests at our Stennis Space Center near Bay St. Louis, Mississippi. These acceptance tests proved the engines could operate at a higher thrust level necessary for deep space travel and that new, modernized flight controllers —the “brains” of the engine — are ready to send astronauts to the Moon in 2024.


Getting a Boost


image

Our industry partners have completed the manufacture and checkout of 10 motor segments that will power two of the largest propellant boosters ever built. Just like the engines, these boosters are designed to be fast and powerful. Each booster burns 60 tons of propellant every second, generating a max thrust of 3.6 million pounds for two minutes of pure awesome. The boosters will finish assembly at our Kennedy Space Center in Florida and readied for the rocket’s first launch in 2020. In the meantime, we are well underway in completing the boosters for SLS and Orion’s second flight in 2022.


Come Together


image

Meanwhile, other parts of the rocket are finished and ready for the ride to the Moon. The final piece of the upper part of the rocket, the launch vehicle stage adapter, will soon head toward Kennedy Space Center in Florida. Two other pieces, including the interim cryogenic propulsion stage that will provide the power in space to send Orion on to the Moon, have already been delivered to Kennedy.


Looking to the Future


image

Our engineers evaluated thousands of designs before selecting the current SLS rocket design. Now, they are performing critical testing and using lessons learned from current assembly to ensure the initial and future designs are up to the tasks of launching exploration missions for years to come. This real-time evaluation means engineers and technicians are already cutting down on assembly time for future mission hardware, so that we and our partners can stay on target to return humans to the Moon by 2024 — to stay so we can travel on to Mars.


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


NASA Opens International Space Station to New Commercial Opportunities, Private...


ISS — International Space Station patch.


June 7, 2019


NASA is opening the International Space Station for commercial business so U.S. industry innovation and ingenuity can accelerate a thriving commercial economy in low-Earth orbit.



International Space Station (ISS). Image Credit: NASA/STS-132

This move comes as NASA focuses full speed ahead on its goal of landing the first woman and next man on the Moon by 2024, where American companies also will play an essential role in establishing a sustainable presence.


NASA officials, including the agency’s Chief Financial Officer Jeff DeWit, will discuss details of the five-part near-term plan in a news conference at 10 a.m. EDT today. The news conference will air live on NASA Television and the agency’s website: http://www.nasa.gov/live


NASA will continue research and testing in low-Earth orbit to inform its lunar exploration plans, while also working with the private sector to test technologies, train astronauts and strengthen the burgeoning space economy. Providing expanded opportunities at the International Space Station to manufacture, market and promote commercial products and services will help catalyze and expand space exploration markets for many businesses.


The agency’s ultimate goal in low-Earth orbit is to partner with industry to achieve a strong ecosystem in which NASA is one of many customers purchasing services and capabilities at lower cost.


NASA’s plan addresses both the supply-side and demand-side for a new economy, enabling use of government resources for commercial activities, creating the opportunity for private astronaut missions to the space station, enabling commercial destinations in low-Earth orbit, identifying and pursuing activities that foster new and emerging markets, and quantifying NASA’s long-term demand for activities in low-Earth orbit.


Commercial Activities Aboard the Space Station


More than 50 companies already are conducting commercial research and development on the space station via the International Space Station U.S. National Laboratory, and their results are yielding great promise. In addition, NASA has worked with 11 different companies to install 14 commercial facilities on the station that support research and development projects for NASA and the ISS National Lab.


This effort is intended to broaden the scope of commercial activity on the space station beyond the ISS National Lab mandate, which is limited to research and development. A new NASA directive will enable commercial manufacturing and production and allow both NASA and private astronauts to conduct new commercial activities aboard the orbiting laboratory. The directive also sets prices for industry use of U.S. government resources on the space station for commercial and marketing activities.


Pricing released Friday is specific to commercial and marketing activities enabled by the new directive, reflects a representative cost to NASA, and is designed to encourage the emergence of new markets. As NASA learns how these new markets respond, the agency will reassess the pricing and amount of available resources approximately every six months and make adjustments as necessary.


To qualify, commercial and marketing activities must either:


— Require the unique microgravity environment to enable manufacturing, production or development of a commercial application;


— Have a connection to NASA’s mission; or


— Support the development of a sustainable low-Earth orbit economy.


NASA’s directive enabling commercial and marketing activities aboard the space station addresses manufacturing, production, transportation, and marketing of commercial resources and goods, including products intended for commercial sale on Earth. NASA astronauts will be able to conduct coordinated, scheduled and reimbursable commercial and marketing activities consistent with government ethics requirements aboard the station.


To ensure a competitive market, NASA initially is making available five percent of the agency’s annual allocation of crew resources and cargo capability, including 90 hours of crew time and 175 kg of cargo launch capability, but will limit the amount provided to any one company.


Private Astronaut Missions


NASA also is enabling private astronaut missions of up to 30 days on the International Space Station to perform duties that fall into the approved commercial and marketing activities outlined in the directive released Friday, with the first mission as early as 2020. A new NASA Research Announcement focus area issued today outlines the path for those future private astronaut missions.


If supported by the market, the agency can accommodate up to two short-duration private astronaut missions per year to the International Space Station. These missions will be privately funded, dedicated commercial spaceflights.  Private astronaut missions will use a U.S. spacecraft developed under NASA’s Commercial Crew Program.


The commercial entity developing the mission will determine crew composition for each mission and ensure private astronauts meet NASA’s medical standards and the training and certification procedures for International Space Station crew members. Market studies identified private astronaut missions to low-Earth orbit as a key element to demonstrate demand and reduce risk for future commercial destinations in low-Earth orbit.


Commercial Destinations in Low-Earth Orbit


In the long-term, NASA’s goal is to become one of many customers purchasing services from independent, commercial and free-flying habitable destinations in low-Earth orbit. A robust low-Earth orbit economy will need multiple commercial destinations, and NASA is partnering with industry to pursue dual paths to that objective that either go through the space station or directly to a free-flying destination.


As a first step, NASA is making one space station port and utilities available for industry to attach a commercial module to support commercial activities, and today is releasing a synopsis as Appendix I in NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) 2 Broad Agency Announcement (BAA). NASA expects to release the solicitation June 14, with awards made by the end of the fiscal year. The forward port of the station’s Harmony module will be available to industry for a finite period of time.


NASA will follow up with a synopsis for NextSTEP 2 Appendix K in July to partner with industry in the development of future free-flying commercial stations in low-Earth orbit.


Stimulate Sustainable Demand


NASA continues to seek and pursue opportunities to stimulate sustainable commercial demand in low-Earth orbit and, to that end, has added two new focus areas to the NASA Research Announcement soliciting proposals for commercial concepts. these focus areas include in-space manufacturing, regenerative medicine, bioengineering, and other fields that may lead to a scalable, financially self-sustaining demand for low-Earth orbit capabilities.


In addition, NASA is seeking targeted studies to better understand real and perceived barriers of potential new market entrants and to address broad ideas which could help stimulate demand. Successful proposals will define the path to broadly foster market growth, provide data-driven rationale to support the defined path, and lead to recommendations on which NASA, industry or other organizations could act. More details are available in the synopsis for NextSTEP 2 BAA Appendix J. NASA expects to release the solicitation for Appendix J on June 14 with awards made by the end of the fiscal year.


NASA also is working to increase the research and development community’s understanding of the potential value of microgravity research and the path to conducting research in low-Earth orbit by coordinating across the microgravity community to lower barriers to entry and refinement of research via drop towers, parabolic, and suborbital flights.


Quantify NASA’s Long-term Demand


NASA is providing a forecast of its minimum long-term, low-Earth orbit requirements, representing the type and amount of services that NASA intends to purchase when those services become commercially available. The goal is to reduce uncertainty for commercial destination providers about NASA as a customer, and to help them make decisions about which NASA requirements they are interested in fulfilling.


NASA also is providing details and estimated quantities for NASA crew accommodation, human research, biological and physical science research, technology demonstrations, and hosted science instruments. In addition, NASA intends to continue purchasing services for a national laboratory capability in low-Earth orbit. For example, NASA’s strategy research in the areas of space biology, physical sciences, and fundamental physics is driven by recommendations from the National Academy of Sciences (NAS). Fundamental research and applied exploration research are not mutually exclusive, and advances in one area often enable advancements in the other. NASA’s Space Life and Physical Sciences Research Applications division has identified the highest research priorities for long-term use of low-Earth orbit: in life sciences, the priorities are studies of plants, model organisms, and of the microbiome of the built environment; and in physical sciences, the priorities are studies into combustion and phase change-associated energy transfer.


To improve the agency’s five-part plan and its effectiveness, NASA is seeking feedback from industry and others through a request for information, with responses due by July 3.


For more than 18 years, humans have lived and worked aboard the International Space Station, conducting thousands of experiments in areas such as human research, biology, and physical science, as well as advanced technology development. Many of these experiments, conducted via the ISS National Lab, have been research and development with commercial objectives.  New opportunities are needed to move beyond research and development, and the station will play an essential role in enabling those opportunities for new commercial markets needed to build a sustainable ecosystem in low-Earth orbit.


Learn more about opportunities for commercial activities aboard the International Space Station:


https://www.nasa.gov/leo-economy/low-earth-orbit-economy


Related links:


International Space Station U.S. National Laboratory: http://issnationallab.org/


NASA directive: https://www.nasa.gov/leo-economy/commercial-use/introduction-to-policy


NASA Research Announcement: https://nspires.nasaprs.com/external/solicitations/solicitationAmmendments.do?solId=%7B21E0270C-BC1F-EFC4-3D87-30713B5FF373%7D&path=&redirectURL=


Commercial Crew Program: http://www.nasa.gov/commercialcrew


Synopsis as Appendix: https://www.fbo.gov/index?s=opportunity&mode=form&tab=core&id=6c7008e1bf035d884057891a261e3b56


NextSTEP 2 BAA Appendix: https://www.fbo.gov/index?s=opportunity&mode=form&tab=core&id=ff01f1553bb5d81baf09db8739c37be5


Humans in Space: https://www.nasa.gov/topics/humans-in-space


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


Image (mentioned), Text, Credits: NASA/Karen Northon/Stephanie Schierholz/JSC/Gary Jordan.


Greetings, Orbiter.chArchive link


Countries share good practices to combat illicit trafficking of cultural property

Illicit trafficking of cultural objects is a problem affecting all countries, with stolen artefacts crossing borders and being offered to collectors, museums or auction houses. Efforts to combat the trafficking include awareness-raising and international cooperation, and use of permits, inventories, strong laws, and stolen art databases, among others.











Countries share good practices to combat illicit trafficking of cultural property
Credit: © Government of Canada

From 20 to 23 May 2019, UNESCO hosted two major meetings related to the fight against trafficking of cultural property and the restitution of stolen artefacts: the Fifth Meeting of States Parties, and the Seventh Session of the Subsidiary Committee, of the UNESCO Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property (1970).


Government authorities, representatives from international organizations as well as art markets and auction houses, joined police and customs officers, lawyers, museum directors and UNESCO experts to review challenges, identify actions and share good practices.


Participants highlighted the crucial importance of the 1970 Convention, which has 139 States Parties to date, in preventing and combating the illicit trafficking of cultural property, as well as the complementary 1995 UNIDROIT Convention on Stolen or Illegally Exported Objects. It was agreed that model provisions on the fight against the illicit trafficking of cultural property will be developed in order that countries can consider them to develop stronger national laws.


Countries such as Canada, China, Estonia, Greece, Guatemala, Italy, Lithuania, Mexico, Morocco, Nigeria, Pakistan, Republic of Korea, South Africa and Tunisia detailed their effective practices in combatting illicit trafficking of cultural property. Canada, for example, highlighted laws, import and export controls, inventories and work with trained police and customs officials, among measures that prevent trafficking and that facilitated the return of approximately 23,000 objects to 14 different countries, including to Jordan in 2018 and Iraq in 2019.


Nine new members were elected to the Subsidiary Committee of the Meeting of States Parties to the 1970 Convention: Algeria, Benin, China, Equator, Iran, Lebanon, Netherlands, Russian Federation and Slovakia.


Held on 22-23 May 2019, the Subsidiary Committee focused on due diligence, cooperation with the art market, sensitization of judiciary and awareness raising among the public and especially among youth. For instance, Mexico highlighted their introduction of training modules on illicit trafficking in university curricula, while Libya discussed the links they developed between schools and museums in their educational programmes.


The importance of international cooperation and sensitization among judiciary and law enforcement officials were especially stressed by representatives of international organizations such as INTERPOL, UNIDROIT, the International Council of Museums, and the World Customs Organization. Mr Corrado Catesi, from INTERPOL, highlighted that “Awareness among police and customs professionals constitute a priority to fight the illicit trafficking of cultural property.”  Members of the Committee agreed that specific training is of high importance, and that creating specialized professional units dedicated to the protection and the recovery of cultural property is recommended.


Regarding the return and restitution of stolen objects in the framework of the 1970 Convention, the Committee decided to feature it on the agenda of the next meeting of States Parties to the 1970 Convention. “These are matters of concern to the international community including the highest organs of international cooperation,” said George Okello Abungu, Director General, National Museums, Kenya.


Source: UNESCO [June 04, 2019]



TANN



Archive


Herd of dinosaurs discovered in underground opal mine

Scientists have revealed that fossils from an underground opal mine near Lightning Ridge, outback NSW (Australia), include remains from a herd of dinosaurs, among them a new dinosaur species and the world’s most complete opalized dinosaur.











Herd of dinosaurs discovered in underground opal mine
Artist’s reconstruction of Fostoria dhimbangunmal
[Credit: © James Kuether]

Dr. Phil Bell, lead researcher from the University of New England in Armidale, said he was stunned by the sheer number of bones found. «We initially assumed it was a single skeleton, but when I started looking at some of the bones, I realized that we had four scapulae (shoulder blades) all from different sized animals.» It is the first dinosaur «herd» to be discovered in Australia.
The new dinosaur has been named Fostoria dhimbangunmal in honor of opal miner Robert Foster, who discovered the fossils in the 1980s. The species name, dhimbangunmal (pronounced bim-baan goon-mal), means «sheep yard» in the local Yuwaalaraay and Yuwaalayaay languages, in recognition of the Sheepyard locality where the bones were found.


In total, parts of four Fostoria skeletons were unearthed, ranging from small juveniles to larger animals that might have been five meters in length, prompting speculation they were part of a small herd or family.











Herd of dinosaurs discovered in underground opal mine
A fossil vertebrae of the newly discovered dinosaur species Fostoria dhimbangunmal
discovered in opal [Credit: Robert A. Smith/Australian Opal Centre]

The bones, which are mostly grey potch opal, were found in the 1980s by opal miner Robert Foster at the Sheepyard opal field, near Lightning Ridge. Scientists from the Australian Museum in Sydney helped excavate the fossils, but the bones remained unstudied until donated to the Australian Opal Centre by Robert’s children Gregory and Joanne Foster in 2015, under the Federal Government’s Cultural Gift Program.
Jenni Brammall, paleontologist and special projects officer of the Australian Opal Centre, says, «Fostoria has given us the most complete opalized dinosaur skeleton in the world. Partial skeletons of extinct swimming reptiles have been found at other Australian opal fields, but for opalized dinosaurs we generally have only a single bone or tooth or in rare instances, a few bones. To recover dozens of bones from the one skeleton is a first.»











Herd of dinosaurs discovered in underground opal mine
A fossilized toe bone of Fostoria dhimbangunmal found in opal
[Credit: Robert A. Smith/Australian Opal Centre]

Fostoria was a two-legged plant-eating iguanodontian dinosaur closely related to the famous Muttaburrasaurus from central Queensland, which was discovered in 1980.


The discovery comes on the back of the new small plant-eating dinosaur also from Lightning Ridge, Weewarrasaurus pobeni, which was named by Dr. Bell and colleagues late last year.


«The rate of discovery is astounding. On average, there’s at least one new dinosaur discovered around the world every week,» Dr. Bell said. «With more palaeontologists and scientists looking further afield than ever before, it’s an exciting time for dinosaur lovers everywhere, especially in Australia.»


The new research was published in the Journal of Vertebrate Paleontology.


Source: University of New England [June 05, 2019]



TANN



Archive


Details of first historically recorded plague pandemic revealed by ancient genomes

An international team of researchers has analyzed human remains from 21 archaeological sites to learn more about the impact and evolution of the plague-causing bacterium Yersinia pestis during the first plague pandemic (541-750 AD). In a study published in Proceedings of the National Academy of Sciences, the researchers reconstructed 8 plague genomes from Britain, Germany, France and Spain and uncovered a previously unknown level of diversity in Y. pestis strains. Additionally, they found the first direct genetic evidence of the Justinianic Plague in the British Isles.











Details of first historically recorded plague pandemic revealed by ancient genomes
Lunel-Viel (Languedoc-Southern France). Victim of the plague thrown into a demolition
trench of a Gallo-Roman house; end of the 6th-early 7th century
[Credit: CNRS — Claude Raynaud]

The Justinianic Plague began in 541 in the Eastern Roman Empire, ruled at the time by the Emperor Justinian I, and recurrent outbreaks ravaged Europe and the Mediterranean basin for approximately 200 years.


Contemporaneous records describe the extent of the pandemic, estimated to have wiped out up to 25% of the population of the Roman world at the time. Recent genetic studies revealed that the bacterium Yersinia pestis was the cause of the disease, but how it had spread and how the strains that appeared over the course of the pandemic were related to each other was previously unknown.


In the current study, an international team of researchers led by the Max Planck Institute for the Science of Human History analyzed human remains from 21 sites with multiple burials in Austria, Britain, Germany, France and Spain. They were able to reconstruct 8 new Y. pestis genomes, allowing them to compare these strains to previously published ancient and modern genomes.


Additionally, the team found the earliest genetic evidence of plague in Britain, from the Anglo-Saxon site of Edix Hill. By using a combination of archaeological dating and the position of this strain of Y. pestis in its evolutionary tree, the researchers concluded that the genome is likely related to an ambiguously described pestilence in the British Isles in 544 AD.


High diversity of Y. pestis strains during the First Pandemic


The researchers found that there was a previously unknown diversity of strains of Y. pestis circulating in Europe between the 6th and 8th centuries AD. The 8 new genomes came from Britain, France, Germany and Spain.











Details of first historically recorded plague pandemic revealed by ancient genomes
Sampling of a tooth from a suspected plague burial
[Credit: Evelyn Guevara]

«The retrieval of genomes that span a wide geographic and temporal scope gives us the opportunity to assess Y. pestis’ microdiversity present in Europe during the First Pandemic,» explains co-first author Marcel Keller, PhD student at the Max Planck Institute for the Science of Human History, now working at the University of Tartu.


The newly discovered genomes revealed that there were multiple, closely related strains of Y. pestis circulating during the 200 years of the First Pandemic, some possibly at the same times and in the same regions.


Despite the greatly increased number of genomes now available, the researchers were not able to clarify the onset of the Justinianic Plague.


«The lineage likely emerged in Central Asia several hundred years before the First Pandemic, but we interpret the current data as insufficient to resolve the origin of the Justinianic Plague as a human epidemic, before it was first reported in Egypt in 541 AD. However, the fact that all genomes belong to the same lineage is indicative of a persistence of plague in Europe or the Mediterranean basin over this time period, instead of multiple reintroductions.»


Possible evidence of convergent evolution in strains from two independent historical pandemics


Another interesting finding of the study was that plague genomes appearing towards the end of the First Pandemic showed a big deletion in their genetic code that included two virulence factors. Plague genomes from the late stages of the Second Pandemic some 800-1000 years later show a similar deletion covering the same region of the genomes.











Details of first historically recorded plague pandemic revealed by ancient genomes
Map and phylogenetic tree showing the newly published (yellow) and previously published (turquoise) genomes.
Shaded areas and dots represent historically recorded outbreaks of the First Pandemic
[Credit: Marcel Keller]

«This is a possible example of convergent evolution, meaning that these Y. pestis strains independently evolved similar characteristics. Such changes may reflect an adaptation to a distinct ecological niche in Western Eurasia where the plague was circulating during both pandemics,» explains co-first author Maria Spyrou of the Max Planck Institute for the Science of Human History.
The current study offers new insights into the first historically documented plague pandemic, and provides additional clues alongside historical, archaeological, and palaeoepidemiological evidence, helping to answer outstanding questions.


«This study shows the potential of palaeogenomic research for understanding historical and modern pandemics by comparing genomes across millennia,» explains senior author Johannes Krause of the Max Planck Institute for the Science of Human History.


«With more extensive sampling of possible plague burials, we hope to contribute to the understanding of Y. pestis’ microevolution and its impact on humans during the course of past and present pandemics.»


Source: Max Planck Institute for the Science of Human History [June 05, 2019]



TANN



Archive


Featured

    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...

Popular