Genetic testing suggests horse domestication did not begin in Anatolia

by Bob Yirka , Phys.org

Genetic diversity and coat color of horses in Anatolia and Transcaucasia before and after 2000 calBCE. Credit: Eva-Maria Geigl, CNRS, and Institut du cheval et de l'équitation ifce, France

An international team of researchers has found via genetic testing that horse domestication very likely did not begin in Anatolia as has been thought. Instead, it appears more likely that horses were first domesticated in the Eurasian Steppe and were subsequently imported to both the Caucasus and Anatolia. In their paper published in the journal Science Advances, the group describes their exhaustive study of ancient horse remains from a host of locations in eastern parts of Asia, the Caucasus and Anatolia.


For many years, scientists have believed that the horse was first domesticated in Anatolia approximately 5,500 years ago. Anatolia is the peninsula also known as Asia Minor; today it makes up most of Turkey. In this new effort, the researchers have found evidence that suggests that horses were actually first domesticated in the Eurasian Steppe and were exported to Anatolia approximately 4,000 years ago, during the Bronze Age.

The work involved obtaining and genetically analyzing 100 equid remains that had been found at eight sites in Anatolia and six in the Caucasus (a region between the Black Sea and the Caspian Sea that is today mainly occupied by Armenia) dating back 2,500 to 11,000 years ago. Some of the remains were from domesticated horses, while others were from those that had remained wild. To learn more about their origins, the researchers conducted paleogenetic and morphological studies that included analysis of Y chromosome DNA, mitochondrial DNA and DNA markers that have previously been associated with coat color. Over time, domestication has led to changes in the coat color of horses. They found lineages present in modern domestic horses that appeared suddenly in 2,000 BCE horses (as opposed to showing up over time) which suggested that domestication had occurred elsewhere. A sharp change in coat colors also suggested horses had been brought to the region from somewhere else. The researchers suggest that the other location was likely north and west of the Caucasus, closer to the Black Sea—the exact site is still unknown.

Bone of Middle Bronze Age domestic horse. Credit: Benjamin S. Arbuckle, University Chapel Hill

The researchers also found evidence of imported domesticated horses being bred with wild Anatolian horses, and also donkeys. They found evidence of the earliest known mule in southwest Asia.

Wild Anatolian horse tooth. Credit: Benjamin S. Arbuckle, University Chapel Hill


Explore further  After 100 years in captivity, a look at the world's last truly wild horses

More information: Silvia Guimaraes et al. Ancient DNA shows domestic horses were introduced in the southern Caucasus and Anatolia during the Bronze Age, Science Advances (2020). DOI: 10.1126/sciadv.abb0030

Journal information: Science Advances


© 2020 Science X Network
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New high-speed test shows how antibiotics combine to kill bacteria

by Uppsala University

With the modified agar plate CombiANT it is possible to do high-speed tests in order to see how bacteria react to different combinations of antibiotics. Credit: Nikos Fatsis-Kavalopoulos

Researchers at Uppsala University have developed a new method to determine—rapidly, easily and cheaply—how effective two antibiotics combined can be in stopping bacterial growth. The new method is simple for laboratories to use and can provide greater scope for customizing treatment of bacterial infections. The study is published in PLOS Biology.


Combinations of antimicrobial agents are invariably prescribed for certain infectious diseases, such as tuberculosis, HIV and malaria. Bacterial infections that are not readily treatable, such as those affecting cardiac valves and prostheses, and lung infections in cystic fibrosis, are also usually subjected to a combination of antibiotics. The effect sought, "synergism", means that the joint action of the combined agents is more effective than could in fact have been expected, based on the efficacy of the separate agents. In contrast, the opposite phenomenon—that is, two antibiotics counteracting each other's effects ("antagonism")—is undesirable. However, knowing what the combined effect will be is not always easy.

With the newly developed method known as CombiANT (combinations of antibiotics), interactions between various antibiotics can be tested on agar plates and results obtained in 24 hours. The lead author of the study, Nikos Fatsis-Kavalopoulos, developed the method at Uppsala University. It is based on creating a "concentration gradient" of antibiotics that have been cast into an agar plate, using a 3-D-printed plastic disc.

On the agar plate, bacteria that have been isolated from an individual patient are then cultured to see how they react to different combinations of antibiotics.

In their study, the researchers investigated E. coli bacteria isolated from urinary tract infections. Different cultures of E. coli proved not to react in the same way to specific antibiotic combinations. A combination of antibiotics that had synergistic effects on most cultures brought about antagonism in some, with the result that the treatment for the latter group was inferior.

"This result may be of great clinical importance. Consequently, instead of assuming that synergistic and antagonistic interactions are equal for all bacterial isolates, we test individually every isolate taken from an infected patient," says Dan I. Andersson, Professor of Medical Bacteriology at Uppsala University, who is primarily responsible for the study.

Customizing the drug combo in this way may be crucially important in achieving high efficacy in the treatment of infections. Being a simple, low-cost method, it is also easy to introduce and use in health care.


Explore further How antibiotics interact with each other

More information: Nikos Fatsis-Kavalopoulos et al, CombiANT: Antibiotic interaction testing made easy, PLOS Biology (2020). DOI: 10.1371/journal.pbio.3000856

Journal information: PLoS Biology

Ecologists sound alarm on plastic pollution

by University of Toronto

Ascension Island in the South Atlantic Ocean is yet another remote island littered in plastic waste. Credit: Marcus Eriksen

Ecologists studying the prevalence of plastic pollution in aquatic ecosystems around the world are concerned after measuring the scale of human response needed to reduce future emissions and manage what's already floating around out there.

"Unless growth in plastic production and use is halted, a fundamental transformation of the plastic economy to a framework based on recycling is essential, where end-of-life plastic products are valued rather than becoming waste," says Chelsea Rochman, assistant professor in the Department of Ecology & Evolutionary Biology at the University of Toronto (U of T), and senior author of a study published in Science outlining the accelerating pace with which plastic emissions enter Earth's waterways annually.

"Even if governments around the world meet their ambitious global commitments, and other countries join those efforts to curb plastic pollution, worldwide annual emissions to rivers, lakes and oceans could be as much as 53 million metric tonnes by the year 2030," says Stephanie Borrelle, Smith Postdoctoral Fellow at U of T and lead author on the study. "That's far beyond the 8 million metric tonnes amount that was declared unacceptable in 2015."

The research by an international group of experts led by Rochman and Borrelle, consisted of an evaluation of the level of effort needed to achieve a global reduction target for plastic pollution of less than 8 million metric tonnes (MT).

New research led by ecologists at the University of Toronto examining annual plastic pollution entering oceans, rivers and lakes around the world, outlines potential impacts of various mitigation strategies over the coming decade. Credit: CreativeCause.com.au

The group first estimated that 24-34 million MT of plastic emissions currently enter aquatic ecosystems every year. They then modelled future scenarios using existing mitigation strategies: reducing production of plastic waste (which includes bans), improving management of plastic waste that is produced, and continuous recovery (i.e., cleanup) from the environment.

The researchers found that even with parallel efforts in all three solutions, the level of effort required within each is enormous: (1) a 25—40% reduction in the production of plastic across all economies; (2) increasing the level of waste collection and management to at least 60% across all economies—with a change from 6—60% in low-income economies; and (3) recovery of 40% of annual plastic emissions through cleanup efforts.

"To put that last number into people power, the cleanup alone would require at least 1 billion people participating in Ocean Conservancy's annual International Coastal Cleanup," says Borrelle. "This would be a Herculean task given this is 660 times the effort of the 2019 cleanup."

"Recyclable" plastic chairs are piled high in every space available,

 Dhravi Slum, Mumbai, India. Credit: Marcus Eriksen

The researchers note, however, that even if the prescribed effort is realized, the world remains locked into an unacceptable plastic future.

"The global community must coordinate a fundamental transformation of the plastics economy, one that reduces the amount of virgin plastic production, and reimagines how we make use and dispose of plastic materials," says Rochman.


Explore further Surface clean-up technology won't solve ocean plastic problem

More information: S.B. Borrelle el al., "Predicted growth in plastic waste exceeds efforts to mitigate plastic pollution," Science (2020). science.sciencemag.org/cgi/doi … 1126/science.aba3656

Journal information: Science


Provided by University of Toronto

Supercooled water is a stable liquid, scientists show for the first time

by Pacific Northwest National Laboratory

Scientists have captured reversible changes in the structure of supercooled water for the first time, using pulsed laser heating and infrared spectroscopy. Credit: Timothy Holland, Pacific Northwest National Laboratory

Supercooled water is really two liquids in one. That's the conclusion reached by a research team at the U.S. Department of Energy's Pacific Northwest National Laboratory after making the first-ever measurements of liquid water at temperatures much colder than its typical freezing point.

The finding, published today in the journal Science, provides long-sought experimental data to explain some of the bizarre behavior water exhibits at extremely cold temperatures found in outer space and at the far reaches of Earth's own atmosphere. Until now, liquid water at the most extreme possible temperatures has been the subject of competing theories and conjecture. Some scientists have asked whether it is even possible for water to truly exist as a liquid at temperatures as low as -117.7 F (190 K) or whether the odd behavior is just water rearranging on its inevitable path to a solid.

The argument matters because understanding water, which covers 71 percent of the Earth's surface, is critical to understanding how it regulates our environment, our bodies and life itself.

"We showed that liquid water at extremely cold temperatures is not only relatively stable, it exists in two structural motifs," said Greg Kimmel, a chemical physicist at PNNL. "The findings explain a long-standing controversy over whether or not deeply supercooled water always crystallizes before it can equilibrate. The answer is: no."

Supercooled water: A tale of two liquids

You'd think we understand water by now. It's one of the most abundant and most studied substances on the planet. But despite its seeming simplicity—two atoms of hydrogen and one atom of oxygen per molecule—H2O is deceptively complicated.

It is surprisingly difficult for water to freeze just below its melting point: water resists freezing unless it has something to get it started, like dust or some other solid to cling to. In pure water, it takes an energetic nudge to jostle the molecules into the special arrangement needed to freeze. And it expands when it freezes, which is weird behavior compared with other liquids. But that weirdness is what sustains life on Earth. If ice cubes sank or water vapor in the atmosphere didn't retain warmth, life on Earth as we know it wouldn't exist.


Water's weird behavior has kept chemical physicists Bruce Kay and Greg Kimmel occupied for more than 25 years. Now, they and postdoctoral scientists Loni Kringle and Wyatt Thornley have accomplished a milestone that they hope will expand our understanding of the contortions liquid water molecules can make.

Various models have been proposed to explain water's unusual properties. The new data obtained using a sort of stop-motion "snapshot" of supercooled water shows that it can condense into a high-density, liquid-like structure. This higher density form co-exists with a lower-density structure that is more in line with the typical bonding expected for water. The proportion of high-density liquid decreases rapidly as the temperature goes from -18.7 F (245 K) to -117.7 F (190 K), supporting predictions of "mixture" models for supercooled water.

Kringle and Thornley used infrared spectroscopy to spy on the water molecules trapped in a kind of stop motion when a thin film of ice got zapped with a laser, creating a supercooled liquid water for a few fleeting nanoseconds.

"A key observation is that all of the structural changes were reversible and reproducible," said Kringle, who performed many of the experiments.

Graupel: it's supercooled water!

This research may help explain graupel, the fluffy pellets that sometimes fall during cool- weather storms. Graupel forms when a snowflake interacts with supercooled liquid water in the upper atmosphere.

"Liquid water in the upper atmosphere is deeply cooled," says Kay, a PNNL lab fellow and expert in the physics of water. "When it encounters a snowflake it rapidly freezes and then in the right conditions, falls to Earth. It's really the only time most people will experience the effects of supercooled water."

These studies may also help understand how liquid water can exist on very cold planets—Jupiter, Saturn, Uranus and Neptune—in our solar system, and beyond. Supercooled water vapor also creates the beautiful tails that trail behind comets.

Water molecule gymnastics

Here on Earth, a better understanding of the contortions water can perform when placed in a tight situation, such as a single water molecule wedged into a protein, could help scientists design new medicines.

"There isn't a lot of space for the water molecules that surround individual proteins," said Kringle. "This research could shed light on how liquid water behaves in closely packed environments."

Thornley noted that "in future studies, we can use this new technique to follow the molecular rearrangements underlying a broad range of chemical reactions."

There is still much to be learned, and these measurements will help lead the way to a better understanding of the most abundant life-giving liquid on Earth.


Explore further

New study provides evidence for decades-old theory to explain the odd behaviors of water

More information: "Reversible structural transformations in supercooled liquid water from 135 to 245 K" Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abb7542

Journal information: Science


Provided by Pacific Northwest National Laboratory

UPDATED

Everything you need to know about signs of life discovered on Venus

Astronomers have detected a gas in Venus' atmosphere that suggests that the planet might be home to microbial life – one of the most exciting discoveries in recent years


By MATT REYNOLDS
Tuesday 15 September 2020


NASA/JPL-Caltech

Although Venus is the closest planet to Earth, it’s also one of the Solar System’s most under-loved residents. While Mars is inundated with orbiting problems and visits from rovers, at the moment Venus only has one spacecraft keeping it company – the Japanese probe Akatsuki.

That might all be about to change. On September 14 an international team of scientists announced that they had found what might be a sign of life floating in the atmosphere above Venus. After decades of searching fruitlessly for life on Mars, our next door neighbour has surprised us with one of the most promising indicators of life anywhere in the Solar System.

Here’s everything you need to know about one of the most exciting discoveries in the hunt for extraterrestrial life so far.

What’s all the fuss about?

Astronomers have detected a gas called phosphine in the clouds 50 kilometres above the surface of Venus. This is intriguing because we don’t know any non-biological way that phosphine could be made on Venus, which leaves open the possibility that tiny alien microbes in the planet’s atmosphere could be farting out the gas.

So it’s just a gas? I was hoping for something a little more tangible. A photo or something

Sorry about that. In scientific terms, this is a pretty promising signal though. On Earth phosphine is only made in the lab or by microorganisms and can be found in swamps as well as animal intestines. It’s present in large amounts on Jupiter and Saturn, but that’s because those planets have violent storms ideal for producing the gas and these conditions aren’t replicated anywhere else in the Solar System, as far as we know.

There are two other things that make the biological origin of phosphine a credible hypothesis. First, there’s quite a lot of it up there – about five to 20 parts per billion. That might sound tiny, but it’s thousands of times more than what you’d find in Earth’s atmosphere. Second, we know that phosphine is constantly being broken down by light so in order to detect it now it means that some process is constantly replenishing the phosphine in the atmosphere.

Does that mean it’s definitely being produced by life?

No – not by a long shot. What it does mean is that we don’t know any chemical or physical process that could be generating this gas on Venus, which leaves biological origins as a plausible answer. It could be all down to some chemical process that we just don’t understand yet.
Venus is a pretty niche choice for life. I thought Mars was where all the action is?

For decades, scientists have argued that Venus might be able to support life, but we haven’t tried very hard to check it out as attention has focused on Mars and the icy moons of Jupiter and Saturn. It’s easy to see why – the planet’s surface temperature averages more than 420 degrees Celsius and its dense atmosphere exerts a surface press more than 90 times experienced at sea level on Earth. Its clouds, meanwhile, are more than 80 per cent sulphuric acid. This inhospitable environment is partly why we haven’t been able to study Venus as well as we’d like. The planet has a nasty habit of melting and crushing any spacecraft that we send there.

But conditions in Venus’ atmosphere might not be so dreadful. The clouds about 31 kilometres above the rocky surface of the planet might reach temperatures of 30 degrees Celsius and have a pressure similar to that of Earth. We already know that microbes live in the atmosphere on Earth, so it’s plausible that life that once lived on the surface of Venus – back when it was a more hospitable place – could have made its way into the atmosphere and stayed there while conditions on the surface deteriorated.

How do we find out for sure what’s really going on up there?

The phosphine measurements were made using two telescopes, the James Clerk Maxwell Telescope in Hawaii and the Atacama Large Millimeter/submillimeter Array in Chile and the team behind the discovery are working to confirm these observations with even more detailed measurements. But what we really need is a sample from the atmosphere so we can take a proper look at what’s going on.


A private company called Rocket Lab has a mission to Venus planned for 2023. Nasa also has shortlisted two possible Venus probes that could eventually head to our rocky next door neighbour while this discovery is likely to prompt a flurry of new proposed journeys. Any mission is likely to take a long time to be planned and carried out though, so we’ve got a wait on our hands until we have the next piece of evidence.

Matt Reynolds is WIRED's science editor. He tweets from @mattsreynolds1

Life on Venus? Astronomers discover evidence of microbial life

A new study reveals the presence of phosphine on Venus: 

a molecule that could be an indicator of microbial life in the planet's clouds.



By Iain Todd
September 14, 2020 

Astronomers have discovered a rare molecule in the clouds of Venus that could indicate the presence of microbial life.

Venus is a scorching planet surrounded by thick, poisonous clouds, and might seem like an unlikely place to discover life beyond Earth, but a new study has found a rare molecule known as phosphine in the planet’s clouds.

On Earth, this molecule is only made either industrially or by microbes that survive in oxygen-free environments.

Astronomers have considered the possibility of microbial life high in the clouds around Venus for decades. Such microbes could avoid the scorching temperatures below, but would still need to withstand high levels of acidity.

While there is still much analysis to carry out, the detection of phosphine molecules could be a sign that there is extra-terrestrial life on Venus.

The discovery was made by a team of astronomers led by Professor Jane Greaves of Cardiff University and is described in a new paper in Nature Astronomy.

An artist’s impression of Venus, inset showing a representation of phosphine molecules. Credit: ESO / M. Kornmesser / L. Calçada & NASA / JPL / Caltech

The astronomers used the James Clerk Maxwell Telescope (JCMT) in Hawaii to detect phosphine around Venus, then turned to the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile for follow-up observations.

In both cases they observed Venus at a wavelength of about 1 millimetre, enabling them to see beyond the visible spectrum detectable by the human eye.

While the results look promising for the search for life elsewhere in the Solar System, the team say there is still some information lacking, and the presence of life cannot yet be confirmed.

One team member, Dr William Bains of the Massachusetts Institute of Technology, has been looking into ways that phosphine can be produced naturally.

Examples include sunlight, minerals being blown upwards from the surface of Venus, volcanoes and lighting, but, say the team, none of these sources could produce enough to explain the amount detected in the study.

Left: the James Clerk Maxwell Telescope. Right: ALMA. Credit: A. Woodcraft (AdamW at en.wikipedia) / ESO/José Francisco Salgado (josefrancisco.org)

Contrary to that, in order to create the amount of phosphine observed, terrestrial organisms would only need to operate at around 10% of their maximum productivity, according to Dr Paul Rimmer of the University of Cambridge.

Microbes on Venus would be very different to similar microbes on Earth in order to survive in Venus’s extreme conditions.

Many alternative ways of producing phosphine can be ruled out by this new study, but the team say that confirmation of the presence of life on Venus is still a long way away.

An image of Venus, observed in the 365nm waveband by the Venus Ultraviolet Imager (UVI) on board the Akatsuki probe. The observations were made on 6 May 2016, when the spacecraft saw the whole planet illuminated. Credit: J. Greaves / Cardiff University
Looking for life beyond Earth

The study is the latest in the search for life beyond Earth, whether it be methane on Mars or plumes erupting from subsurface oceans of icy moons like Enceladus at Saturn and Europa at Jupiter.

On Venus, dark streaks where ultraviolet light is absorbed could be explained by colonies of microbes, for example. The Japanese Akatsuki spacecraft is currently mapping these streaks to gather more information.

NASA’s Discovery Program is currently considering a proposed mission to send an orbiter to study Venus’s atmosphere, named DAVINCI+. If selected, it could launch in 2026.

If there is indeed microbial life on Venus, scientists appear to be getting closer and closer to confirming it.

Streaks in the clouds of Venus, as seen by JAXA’s Akatsuki orbiter (left) and reconstructed by simulations with the AFES-Venus computer programme (right). Credit: JAXA

“This was an experiment made out of pure curiosity, really, taking advantage of JCMT’s powerful technology, and thinking about future instruments,” says Professor Greaves.

“I thought we’d just be able to rule out extreme scenarios, like the clouds being stuffed full of organisms. When we got the first hints of phosphine in Venus’ spectrum, it was a shock!

“In the end, we found that both observatories had seen the same thing: faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below.”

A view of Enceladus’s south pole, captured by the Cassini spacecraft, 21 November 2009. On the limb can be seen plumes of water vapour erupting from the subsurface ocean below the moon’s icy crust. Could Enceladus’s ocean host microbial life? Credit: NASA/JPL/Space Science Institute

MIT’s Dr Clara Sousa Silva has been considering the search for phosphine as a so-called ‘biosignature’ gas of non-oxygen-using life on exoplanets.

“Finding phosphine on Venus was an unexpected bonus!” she says.

“The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment, but the clouds of Venus are almost entirely made of acid.”

Professor Emma Bunce, President of the Royal Astronomical Society, said of the discovery:

“A key question in science is whether life exists beyond Earth, and the discovery by Professor Jane Greaves and her team is a key step forward in that quest.


“I’m particularly delighted to see UK scientists leading such an important breakthrough: something that makes a strong case for a return space mission to Venus.”

For more information, view the study by visiting the Nature website.


Iain Todd is BBC Sky at Night Magazine’s staff writer.

Venus' ancient layered, folded rocks point to volcanic origin

by Tracey Peake, North Carolina State University

A simulated view from above Tellus Tessera, one of the regions on Venus where Byrne et al. identify the presence of layering. Image generated from NASA's Magellan mission data. Credit: North Carolina State University

An international team of researchers has found that some of the oldest terrain on Venus, known as tesserae, have layering that seems consistent with volcanic activity. The finding could provide insights into the enigmatic planet's geological history.

Tesserae are tectonically deformed regions on the surface of Venus that are often more elevated than the surrounding landscape. They comprise about 7% of the planet's surface, and are always the oldest feature in their immediate surroundings, dating to about 750 million years old. In a new study appearing in Geology, the researchers show that a significant portion of the tesserae have striations consistent with layering.

"There are generally two explanations for tesserae—either they are made of volcanic rocks, or they are counterparts of Earth's continental crust," says Paul Byrne, associate professor of planetary science at North Carolina State University and lead author of the study. "But the layering we find on some of the tessera isn't consistent with the continental crust explanation."

The team analyzed images of Venus' surface from NASA's 1989 Magellan mission, which used radar to image 98% of the planet through its dense atmosphere. While researchers have studied the tesserae for decades, prior to this work the layering of the tesserae hasn't been recognized as widespread. And according to Byrne, that layering would not be possible if the tesserae were portions of continental crust.

"Continental crust is composed mainly of granite, an igneous rock formed when tectonic plates move and water is subducted from the surface," Byrne says. "But granite doesn't form layers. If there's continental crust on Venus, then it's below the layered rocks we see.

"Aside from volcanic activity, the other way to make layered rock is through sedimentary deposits, like sandstone or limestone. There isn't a single place today on Venus where these kinds of rocks could form. The surface of Venus is as hot as a self-cleaning oven and the pressure is equivalent to being 900 meters (about 985 yards) underwater. So the evidence right now points to some portions of the tesserae being made up of layered volcanic rock, similar to that found on Earth."

Byrne hopes that the work will help to shed light on more of Venus' complicated geological history.

"While the data we have now point to volcanic origins for the tesserae, if we were one day able to sample them and find that they are sedimentary rocks, then they would have had to have formed when the climate was very different—perhaps even Earth-like," Byrne says.

"Venus today is hellish, but we don't know if it was always like this. Was it once like Earth but suffered catastrophic volcanic eruptions that ruined the planet? Right now we cannot say for certain, but the fact of the layering in the tesserae narrows down the potential origins of this rock."

The research team included scientists from the U.S., the U.K, Turkey, Canada and Russia. Images came from NASA's Planetary Data System and Astrophysics Data System.

Explore further

Mercury's volcanic activity—or lack of it—could help astronomers find other Earth-like worlds
More information: Paul K. Byrne et al, Venus tesserae feature layered, folded, and eroded rocks, Geology (2020). DOI: 10.1130/G47940.1

Journal information: Geology

Provided by North Carolina State University

Human footprints dating back 120,000 years found in Saudi Arabia

by Issam Ahmed

This handout photo shows a view of the edge of the Alathar ancient lake deposit and surrounding landscape

Around 120,000 years ago in what is now northern Saudi Arabia, a small band of homo sapiens stopped to drink and forage at a shallow lake that was also frequented by camels, buffalo and elephants bigger than any species seen today.

The humans may have hunted the big mammals but they did not stay long, using the watering hole as a waypoint on a longer journey.

This detailed scene was reconstructed by researchers in a new study published in Science Advances on Wednesday, following the discovery of ancient human and animal footprints in the Nefud Desert that shed new light on the routes our ancient ancestors took as they spread out of Africa.

Today, the Arabian Peninsula is characterized by vast, arid deserts that would have been inhospitable to early people and the animals they hunted down.

But research over the last decade has shown this wasn't always the case—due to natural climate variation it experienced much greener and more humid conditions in a period known as the last interglacial.

Arabia at the time was more akin to the semi-arid grasslands of the modern African savanna.

The paper's first author Mathew Stewart of the Max Planck Institute for Chemical Ecology, Germany, told AFP the footprints were discovered during his PhD field work in 2017 following the erosion of overlying sediments at an ancient lake dubbed 'Alathar' (meaning "the trace" in Arabic).

Elephant (left) and camel (right) trackways. Credit: Stewart et al., 2020

The first human footprint discovered at Alathar and its corresponding digital elevation model (DEM). Credit: Stewart et al., 2020

Elephant (left) and camel (right) trackways. Credit: Stewart et al., 2020

The first human footprint discovered at Alathar and its corresponding digital elevation model (DEM). Credit: Stewart et al., 2020


"Footprints are a unique form of fossil evidence in that they provide snapshots in time, typically representing a few hours or days, a resolution we tend not to get from other records," he said.

The prints were dated using a technique called optical stimulated luminescence—blasting light at quartz grains and measuring the amount of energy emitted from them.

A Green Arabia

In total, seven out of the hundreds of prints discovered were confidently identified as hominin, including four that, given their similar orientation, distances from one another and differences in size, were interpreted as two or three individuals traveling together.

The researchers argue these belonged to anatomically modern humans, as opposed to Neanderthals, on the basis that our extinct cousins aren't known to have been present in the wider Middle East region at the time, and based on stature and mass estimates inferred from the prints.

This handout photo shows animal fossils eroding out of the surface of the Alathar ancient lake deposit

This handout photo shows elephant trackway

"We know that humans were visiting this lake at the same time these animals were, and, unusually for the area, there's no stone tools," said Stewart, which would indicate the humans made a longer term settlement there.

"It appears that these people were visiting the lake for water resources and just to forage at the same time as the animals," and probably to also hunt them.

The elephants, which had gone extinct in the nearby Levant region some 400,000 years ago, would have been particularly attractive prey, and their presence also suggests other plentiful freshwater resources and greenery.

In addition to the footprints, some 233 fossils were recovered, and it's likely that carnivores were attracted to the herbivores at Alathar, similar to what is seen in African savannas today.

It was previously known that early humans spread to Eurasia via southern Greece and the Levant, exploiting coastal resources along the way, but the new research shows that "inland routes, following lakes and rivers, may have been particularly important" too, said Stewart.

"The presence of large animals such as elephants and hippos, together with open grasslands and large water resources, may have made northern Arabia a particularly attractive place to humans moving between Africa and Eurasia," added the study's senior author Michael Petraglia of the Max Planck Institute for the Science of Human History.


Explore further  First human migration out of Africa more geographically widespread than previously thought

More information: M. Stewart el al., "Human footprints provide snapshot of last interglacial ecology in the Arabian interior," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.aba8940

Journal information: Science Advances



© 2020 AFP

BC
Invasive shrimp-sucking parasite continues northward Pacific expansion

by Josh Silberg and Natalie Van Hoose, Florida Museum of Natural History

The cough drop-sized parasite Orthione griffenis, native to Asia and Russia, has decimated mud shrimp populations along the West Coast. The parasite on the right is a female with the much smaller male attached. Credit: Amanda Bemis and Gustav Paulay/Florida Museum

Researchers have identified an invasive blood-sucking parasite on mud shrimp in the waters of British Columbia's Calvert Island. The discovery represents the northern-most record of the parasite on the West Coast and is likely an indication of its ability to spread without human transport.

Orthione griffenis, a cough drop-sized crustacean native to Asia and Russia, has decimated mud shrimp populations in California and Washington over the past 30 years, causing the collapse of delicate mudflat ecosystems anchored by the shrimp. By the 2000s, it had reached as far as Vancouver Island. The discovery of O. griffenis at Calvert Island, described in a new study, represents a northward leap of more than 180 miles.

Scientists found the parasite during a 2017 bioblitz, organized by the Hakai Institute and the Smithsonian Institution's Marine Global Earth Observatory, in which they intensely surveyed and documented marine life.

"I was on the lookout for things that seemed out of place," said study lead author Matt Whalen, a Hakai postdoctoral researcher at the University of British Columbia who studies coastal biodiversity. "But this particular parasite wasn't initially on my radar."

Most scientists believed the parasites' expansion was exclusively mediated by human transport—O. griffenisis thought to have first arrived in North America by traveling in ships' ballast water. Their appearance at Calvert Island, 150 miles from the nearest city of more than 5,000 people, shows "clearly, they can do it on their own," said study co-author Gustav Paulay, curator of invertebrate zoology at the Florida Museum of Natural History.

The parasite Orthione griffenis attaches to the gills of its host - here, a mud shrimp, Upogebia pugettensis. Credit: Amanda Bemis and Gustav Paulay/Florida Museum

"This is such an astonishingly spectacular part of the planet," he said. "During the bioblitz, one of the things we talked about was that there were no invasive species at all. And then we found this thing."

Whalen described the find as "a bit depressing."

"We tended to associate this parasite with places that have a lot of marine traffic and aquaculture, like California and Oregon," he said in a statement. "Finding them on Calvert Island really suggests that there's very little preventing the spread because of the parasite's life cycle."

The parasite is a bizarre crustacean called a bopyrid isopod. In the pre-adult part of its life, it hitches a ride on planktonic copepods—an intermediate host that allows the isopods to travel to new and far-flung mudflats in search of shrimp blood. As adults, the parasites attach to the gills of another crustacean host, in this case a mud shrimp, Upogebia pugettensis, and proceed to sap the life from it. Infected mud shrimp are so hard done by that they lack the required energy to reproduce.

"They're essentially castrated," Paulay said.

The parasite was found at Calvert Island in a 2017 survey of marine life. The record represents a northward leap of more than 180 miles from its last known northern boundary. Credit: Whalen et al. in Bioinvasions Records

Mud shrimp may not be much to look at—much like crayfish with stumpier claws—but these homely crustaceans play an outsized role as environmental engineers in the mudflats of the Pacific Coast. They cycle nutrients when they filter food, pumping oxygenated water into an expansive network of tunnel dwellings, which provide housing for a suite of creatures, including gobies, worms, clams and other shrimp species. The shrimp's presence affects how the entire mudflat ecosystem functions—or doesn't.

When a parasite coevolves in the same place as its host, they often reach a sort of détente, Paulay said. After all, the parasite needs a host to survive, and killing it off at once would not make a great long-term strategy. But when a parasite is introduced from elsewhere, that armistice may never arrive.

"The infection rates on Calvert Island were higher than I would've anticipated," Whalen said. "About one in four hosts were parasitized. That's a pretty good chunk of the population."

For now, scientists are tracking the northward spread of the parasite. The parasite's prevalence on Calvert Island shows that it may only be a matter of time before it reaches the North Coast of British Columbia and moves onward to Alaska, the upper edge of the mud shrimp's range.

For Paulay, the discovery of O. griffenis also underscores how marine bioblitzes can function as early warning systems for invasions.

"Every bioblitz we do, we find invasive species," he said. "If you catch them early enough, you have a chance to do something about it."


Explore further Researchers find instance of parasites fueling cannibalism

More information: Matthew Whalen et al, Poleward range expansion of invasive bopyrid isopod, Orthione griffenis Markham, 2004, confirmed by establishment in Central British Columbia, Canada, BioInvasions Records (2020). DOI: 10.3391/bir.2020.9.3.09

Provided by Florida Museum of Natural History

 Amazon taps Quebec firm to add to electric vehicle fleet

Amazon could use them to transport products between distribution centres

Financial Post Staff Sep 16, 2020   

Amazon.com Inc. is tapping a Quebec-based electric bus and truck manufacturer to provide it with 10 battery-powered delivery vehicles as part of the e-commerce giant’s climate pledge to eliminate CO2 emissions by 2049

Amazon announced in a short tweet on Wednesday that it would be rolling out vehicles produced by The Lion Electric Company. No other details were released and neither Lion Electric nor Amazon replied to multiple requests to comment.

Lion lectric is predominately known for manufacturing electric school buses. It currently lists three online — the LionA, the LionC and the LionD. The company also lists a minibus and a truck, the Lion8, for sale. A company presentation also shows plans for the Lion6, another tractor truck scheduled for the fourth quarter of 2020 and a boom truck and ambulance scheduled for 2021.

The company, which was founded in 2008, has 250 employees.

Lion Electric chief executive officer Marc Bedard told Quebec City newspaper Le Soleil that Amazon’s order was for 10 Lion6 trucks. Each one, he said, is made for heavy duty deliveries of up to 26,000 pounds. Bedard explained that Amazon intends to primarily use them to transport products from one distribution centre to another.

“Our goal is that this is a first order that will be followed by others,” he told Le Soleil.

Bedard said Amazon had been testing Lion Electric’s vehicles for over a year. In January, the Quebec press reported that Amazon executives visited Lion Electric’s facilities. Amazon has been looking to aggressively reduce its emission footprint, and recently purchased 100,000 electric delivery trucks from Michigan-based startup Rivian.

The Amazon news comes on the heels of Lion Electric announcing that it had secured its largest ever order at the end of August. The company will be producing 50 electric trucks for Canadian National Railway for intermodal use between its terminals in urban zones, according to a press release. CN has its own strategy to reduce emissions and said the trucks will allow it to remove 100 tons of greenhouse emissions from the road on an annual basis.

IT CAME FROM CANADA***
McMaster professor embroiled in White House controversy over reports he attempted to muzzle scientists
DR ALEXANDER I PRESUME

ADRIAN MORROW

U.S. CORRESPONDENT
WASHINGTON
PUBLISHED SEPTEMBER 17, 2020

A McMaster University professor is at the centre of a White House controversy over reports he tried to muzzle government scientists, demanded the power to edit COVID-19 documents from the Centers for Disease Control and Prevention and accused CDC staff of attempting to “hurt” U.S. President Donald Trump.

Paul Elias Alexander, an assistant professor of health-research methods at the Hamilton university, joined the U.S. Department of Health and Human Services earlier this year. He was brought in as a scientific adviser to Michael Caputo, a former Trump campaign staffer with no scientific or medical background installed as HHS’s assistant secretary of public affairs in April.

On Wednesday, HHS announced Dr. Alexander is “leaving the department” permanently and Mr. Caputo will take a 60-day medical absence. The development comes after Politico and the Washington Post published a string of e-mails from Dr. Alexander and Mr. Caputo attempting to silence scientists working on COVID-19 or make them change their reports to downplay the pandemic’s severity and support Mr. Trump’s messaging.

Michael Caputo, the top communications official at the U.S. Department of Health and Human Services (HHS), will take a two-month-long leave of absence, the agency said on Wednesday, after a social media tirade drew widespread attention.REUTERS

In a lengthy e-mail to The Globe and Mail on Wednesday and a subsequent interview, Dr. Alexander accused the CDC of “generating pseudo scientific reports” and said he was more qualified to analyze COVID-19 data than the 1,700 scientists at the agency.

“None of those people have my skills,” Dr. Alexander said. “I make the judgment whether this is crap.”

Dr. Alexander would not discuss his relationship with Mr. Caputo. Two months ago, Mr. Caputo told The Hamilton Spectator that he and Dr. Alexander became friends after he made appearances on a radio show Mr. Caputo hosted in Buffalo, N.Y. Dr. Alexander told The Globe that he started advising HHS as a “volunteer” in March and only joined the staff in July.

Dr. Alexander said that he is originally from the Caribbean and has legal status in the U.S., but “Canada is my home” and “the greatest nation in the world.” He received his PhD in health research methodologies from McMaster in 2015, and a master’s degree from the University of Oxford. He also worked for the Infectious Diseases Society of America in Washington from January, 2017, to December, 2019.

McMaster distanced itself from Dr. Alexander on Wednesday.

“He is not currently teaching, and he is not paid by the university for his contract role as a part-time assistant professor. As a consultant, he is not speaking on behalf of McMaster University or the Department of Health Research Methods, Evidence and Impact,” spokeswoman Susan Emigh wrote in an e-mail.

McMaster professor Gordon Guyatt, who supervised Dr. Alexander’s PhD work, said he had been asked to direct all questions about his former student to the university’s public-relations department. . Dr. Guyatt is known for coining the term “evidence-based medicine,” which describes the idea that healthcare decisions should be guided by scientific methods.

The CDC issues Morbidity and Mortality Weekly Reports that inform doctors about how the pandemic is progressing. These publications are written by apolitical researchers. But after Mr. Caputo joined HHS, his office began demanding the ability to make changes to the documents.

In one e-mail reported by Politico, Dr. Alexander told officials at CDC such reports should not be published “unless I read and agree" and can “tweak” the documents. In another, he blasted the agency for reporting on COVID-19 risks to children, contrary to Mr. Trump’s call for schools to reopen.

“CDC to me appears to be writing hit pieces on the administration,” he wrote. "Very misleading by CDC and shame on them.”

Dr. Alexander also took umbrage with a CDC report about coronavirus’s threat to pregnant women. He wrote that the agency was “undermining the President,” the Washington Post reported, because the document made it seem “as if the President and his administration can’t fix this.”

In e-mails to the National Institutes of Health, Dr. Alexander also tried to give orders on what Dr. Anthony Fauci, the U.S.'s top infectious diseases expert, would say publicly. In these messages, Dr. Alexander said he “vehemently” disagreed with Dr. Fauci on widespread testing for university students, and asked that he tell the public masks for schoolchildren are not necessary, Politico reported. Dr. Alexander claimed “there is no data, none, zero, across the entire world” that showed COVID-19 transmission in children. He also ordered the NIH to stop adhering to randomized controlled trials, generally considered the best way to test new drugs.

Dr. Alexander’s positions in these e-mails largely contradict scientific consensus and back Mr. Trump. The President has often played down the seriousness of the pandemic, which has killed more than 200,000 Americans. And his allies have called for new COVID-19 treatments to be approved using lower-quality studies than randomized control trials.

Dr. Alexander told The Globe and Mail that he was pushing the CDC to make their reports more upbeat so people would feel more confident going out and spending money.

“Your restaurant will be able to keep their store open and have their livelihood and not go bankrupt, hang themselves because of no money. The employee could keep a job and not go into depths of despair and drink and commit suicide,” he said. “Don’t just put in negative things. People want to hear the good news too."

Dr. Alexander said “there might have been one or two times” that the CDC changed its reports because of him, but he said he “can’t remember exactly” what the changes were. Dr. Alexander said that “nobody at HHS manipulated any data” in the reports, and that his changes were about messaging and presentation.

He praised Dr. Guyatt as his “mentor,” and also lauded Scott Atlas, a radiologist and White House adviser who has advocated herd immunity and less testing in the pandemic, both contrary to most scientific opinion. “This is someone who truly cares about the well-being of people and politics,” Dr. Alexander said.

Asked about his accusations that government scientists were undermining Mr. Trump, Dr. Alexander said he did not think agencies should contradict any president’s policy. But he expressed some regret at his word choice.

“I did things with good intentions,” he said. “Sometimes you make a mess, you are a bumbling idiot and you make a fool of yourself.”

 DAVID LYNCH'S EVIL NORTH