A form of multicellular life visible to the naked eye may have emerged nearly a billion years earlier than scientists once thought.

At 1.56 billion years old, fossils discovered in north China represent the best evidence yet for the early existence of large eukaryotes, paleobiologist Maoyan Zhu of the Chinese Academy of Sciences in Nanjing and colleagues report May 17 in Nature Communications.

Eukaryotes, which have cells containing nuclei and other membrane-wrapped machinery, include everything from plants to people. The new find could mark when single-celled eukaryotes became multicellular organisms capable of drawing energy from the sun, says geobiologist Shuhai Xiao of Virginia Tech in Blacksburg, who was not involved in the research. “That’s why it’s important,” he says. “The fossils represent one of the major transitions in evolution.”
Remains of early life on Earth are scarce and sometimes hard to interpret (SN: 2/8/14, p. 16). Some scientists point to evidence of life from as early as 3.8 billion years ago; rocks in Greenland, for example, contain traces of carbon that could be cellular remnants. Harder evidence for microbes comes from what appear to be fossils of actual cells speckling 3.4-billion-year-old sandstone in Australia.

Signs of multicellular life crop up later in the fossil record, roughly 1.2 billion years ago, Zhu says. But until now, clear evidence for large-scale multicellular organisms, like the ones Zhu’s team reports, date back just 635 million years. The team’s new find — consisting of 167 fossils, some up to 30 centimeters long and 8 centimeters wide (roughly the size of a man’s footprint) — places these life-forms much further back in time, when Earth was hot and oxygen was scarce.

The fossils are compressions: cells squashed flat into ribbons — like a garden hose crushed beneath a car’s tire, or like kelp. In fact, the organisms may have looked “very similar to some algae living in the shallow sea today,” Zhu says.

After stretching ropy bodies along the shore, the ancient sea life was preserved in layers of mudstone. Inside the stone, the researchers found closely packed cells and organic carbon, evidence of cellular remains. Zhu can’t explain why such a large time gap exists between his find and similar large-scale fossils, but he suspects the problem may be with preservation of such old material.

Scientists once considered the time period when these organisms lived to be the “boring billion,” though that view seems to be shifting (SN: 11/14/15, p. 18). People thought that “there was very little evolutionary change, and not much going on geochemically,” Xiao says. The new work “tells us a different story.”

Two more of the ingredients for life as we know it have turned up in space, this time from a comet orbiting the sun. While hints of both have been seen in comets before, this is the clearest evidence to date.

Glycine, the smallest of the 20 amino acids that build proteins, is floating in the tenuous atmosphere of comet 67P/Churyumov-Gerasimenko, researchers report online May 27 in Science Advances. Comet 67P’s atmosphere also holds phosphorus, which is essential to DNA and RNA. Both detections support the idea that comets are at least partly responsible for seeding early Earth with material needed for life.
The phosphorus, glycine and a handful of other organic molecules were detected by the European Space Agency’s Rosetta spacecraft, which has been in orbit around 67P since August 2014 (SN: 9/6/14, p. 8). Kathrin Altwegg, a planetary scientist at the University of Bern in Switzerland, led the study.

Previous searches for glycine in comets Hale-Bopp and C/1996 B2 (Hyakutake) turned up nothing. Glycine was seen in samples from the Stardust mission, which flew through the tail of comet Wild 2 in 2004 and brought comet dust back to Earth, but those measurements were complicated by lab contamination. Scientists have detected hints of phosphorus in comet Halley.

Life’s ingredients keep turning up in cosmic environments. Meteorites carry amino acids and simple sugars have been seen in interstellar clouds(SN: 10/9/04, p. 237). And several of the essential molecules for DNA and RNA, such as ribose, have been created in laboratory experiments that simulate ice grains exposed to ultraviolet radiation from young stars (SN: 4/30/16, p. 18).

From California to China, desert moss (Syntrichia caninervis) braves life in hot deserts and still stays hydrated. What’s its secret? The moss gathers water via a topsy-turvy collection system in its leaves.

Moss leaves have tiny hairlike points at their ends called awns. Previous evidence pointed to a potential role for the awns in water collection and prompted Tadd Truscott of Utah State University and his colleagues to zero in on the structures.

Imaging exposed a system of barbs that line the awns and catch tiny airborne water droplets, the team reports June 6 in Nature Plants. When the air is misty, foggy or the least bit humid, trapped dewdrops move up grooves in the moss leaves by capillary action. The tiny drops form a bigger drop to be absorbed and stored by the plant. When it rains, moss awns reduce splash and capture raindrops by the same mechanism.

Most desert plants, especially cacti, get their water from roots, but moss may not be the only plant that uses unique leaf structures to stock up on water, the team argues.

For the second time, scientists have glimpsed elusive ripples that vibrate the fabric of space. A new observation of gravitational waves, announced by scientists with the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, follows their first detection, reported earlier this year (SN: 3/5/16, p. 6). The second detection further opens a new window through which to observe the universe.

“The era of gravitational wave astronomy is upon us,” says astronomer Scott Ransom of the National Radio Astronomy Observatory in Charlottesville, Va., who is not involved with LIGO. “Now that there’s two, you can’t get around that anymore.”

Both sets of cosmic quivers were wrought in cataclysmic collisions of black holes. But the latest observation indicates that such merging pairs of black holes are a varied bunch — the newly detected black holes were much smaller than the first pair. And this time, scientists concluded that one in the pair was spinning like a top.
“The most important thing is that it’s a second one,” says LIGO spokesperson Gabriela González of Louisiana State University in Baton Rouge. “But it’s important that it’s different, because it shows that there’s a spectrum of black hole systems out there.”

The two black holes in the most recent detection were about eight and 14 times the mass of the sun and were located roughly 1.4 billion light-years from Earth, the scientists estimate. When the pair fused, they formed one bloated black hole with a mass 21 times that of the sun. One sun’s worth of mass was converted into energy and carried away by the gravitational waves, LIGO scientists announced June 15 in San Diego during a meeting of the American Astronomical Society.
“Gravitational astronomy is real,” LIGO laboratory executive director David Reitze said in a news conference. “The future is going to be full of binary black hole mergers for LIGO.”

A paper describing the finding was published online June 15 in Physical Review Letters.

As the two black holes spiraled around each other and slammed together, they churned up cosmic undulations that stretched and squeezed space — as predicted by Einstein’s general theory of relativity. These waves careened across the universe, reaching LIGO’s twin detectors in Hanford, Wash., and Livingston, La., on December 26, 2015.

Each L-shaped LIGO detector senses the minuscule stretching and squeezing of space across its two 4-kilometer arms. As a gravitational wave passes through, one arm lengthens while the other shortens. Laser light bouncing back and forth in the arms serves as an ultrasensitive measuring stick that can pick up those subtle length changes (SN: 3/5/16, p. 22). As the gravitational waves rumbled past Earth in December, they stretched and squeezed the arms by less than a thousandth the width of a proton. “That’s very, very small,” González said. “That’s like changing the distance between Earth and the sun by a fraction of an atomic diameter.” This tiny deviation, appearing in both detectors nearly simultaneously, was enough to pick out the telltale ripples.

Compared with LIGO’s previously detected black hole merger, this one was a more minor dustup. These black holes were less than half the size of those in the first merger (30 and 35 solar masses according to a recently revised estimate). And the signal of their coalescence was more subtle, hiding under the messy wiggles in the data that result from random fluctuations or unwanted signals from the environment.
The first detection stunned scientists, due to the surprisingly large masses of the black holes and the whopping signals their gravitational waves left in the data. But the new black hole merger is more in line with expectations.
“This is comfort food,” says physicist Emanuele Berti of the University of Mississippi in Oxford, who is not involved with LIGO. “If you had asked me before the first detection, I would have bet that this would have been the first kind of binary black hole to be observed, not the monster we saw.”

There’s little question about whether the signal is real — a false alarm of this magnitude should occur only once in 200,000 years. “It’s very, very exciting,” says physicist Clifford Will of the University of Florida in Gainesville. It “looks like a very solid discovery.”

In a new twist, the scientists found that one of the two merging black holes was spinning. It was rotating at a speed at least 20 percent of its maximum possible speed. Using gravitational waves to study how pairs of black holes twirl could help scientists understand how they form.

The scientists used their data to put general relativity through its paces, looking for deviations from the theory’s predictions. But the black holes’ behavior was as expected.

LIGO also saw hints of a third black hole collision on October 12. The evidence was not strong enough to claim a definitive detection, though.

LIGO is currently offline, undergoing improvements that will allow the detectors to peer even further out into space. Scientists expect it to be back up and running this fall, churning out new detections of gravitational waves. “Now we know for sure that we’ll see more in the future,” González says.

AUSTIN, TEXAS — Success of an indoor spraying campaign to combat malaria on an African island may have started a worrisome trend in local mosquito evolution.

Since 2004, using pesticides inside homes has eradicated two of four malaria-spreading Anopheles mosquitoes on Bioko Island in Equatorial Guinea, vector biologist Jacob I. Meyers of Texas A&M University in College Station reported June 19 at the Evolution 2016 meeting. Numbers of the remaining two species have dropped. Yet the dregs of these supposedly homebody species are showing a rising tendency to fly outdoors looking for a blood meal, Meyers and colleagues cautioned. The results were also reported April 26 in Malaria Journal.

If the mosquitoes continue to shift toward outside bloodsucking, the campaign could lose some of its bite. Repeated treatments of indoor walls with pesticides that kill mosquitoes clinging to them may not be so effective if the pests venture from home.

What’s changing about these mosquitoes remains to be seen, but this looks like more than simple opportunism, Meyers said. Bed nets are not common, so Meyers doubts that the mosquitoes fly outdoors because no one is available to bite indoors. Nor does their reaction look like escape from repellent pesticides: Outdoor biting didn’t consistently rise after a spraying. The next step is to check for a genetic basis for the shift. Lots of research has explored physiology that lets insects resist pesticides, Meyers said, but the onset of possible resistant behavior has barely been explored.

Bottoms up, from the distant past. Thanks to a new method of analyzing the chemicals in liquids absorbed by clay containers, researchers have uncorked the oldest solid evidence of grape-based wine making in Europe, and possibly the world, at a site in northern Greece.

Chemical markers of red wine were embedded in two pieces of a smashed jar and in an intact jug discovered in 2010 in the ruins of a house destroyed by fire around 6,300 years ago at the ancient farming village of Dikili Tash.
After successfully testing the new technique on replicas of clay vessels filled with wine, then emptied, the scientists identified chemical markers of grape juice and fermentation in clay powder scraped off the inner surfaces of the Dikili Tash finds. None of the vessels contained visible stains or residue, researchers report online May 24 in the Journal of Archaeological Science.

Remains of crushed grapes found near the ancient jar shards and jug had already indicated that Dikili Tash farmers made wine or grape juice, say chemist Nicolas Garnier of École Normale Supérieure in Paris and archaeobotanist Soultana Maria Valamoti of Aristotle University of Thessaloniki in Greece.

Previous reports of ancient wine have largely relied on chemical markers of grapes but not the fermentation necessary to turn them into wine, leaving open the possibility that containers held grape juice. The “juice versus wine” conundrum applies to roughly 7,400-year-old jars from Iran (SN: 12/11/04, p. 371), Garnier says.

Physicists have snagged a bounty of five new particles in one go.

Members of the LHCb experiment, located at the Large Hadron Collider near Geneva, reported the prolific particle procurement in a paper posted online March 14 at arXiv.org. The five particles are each composed of three quarks — a class of particle that makes up larger particles such as protons and neutrons. Each of the new particles comprises two “strange” quarks and one “charm” quark.

The five particles are in various excited, or high-energy, states — giving each particle a different mass and a different arrangement of quarks within. Such particles are expected to exist according to the theory of the strong nuclear force, which bundles quarks together into larger particles.

The five excited particles are named after their low-energy relative, Ωc0 or omega-c-zero. Their rather uninspiring monikers are Ωc(3000)0, Ωc(3050) 0, Ωc(3066) 0, Ωc(3090) 0 and Ωc(3119) 0. Each number in parentheses indicates the mass of the particle in millions of electron volts.

Nomadic warriors and herders known as the Huns are described in historical accounts as having instigated the fifth century fall of the Roman Empire under Attila’s leadership. But the invaders weren’t always so fierce. Sometimes they shared rather than fought with the Romans, new evidence suggests.

Huns and farmers living around the Roman Empire’s eastern border, where the Danube River runs through present-day Hungary, borrowed ways of life from each other during the fifth century, say archaeologist Susanne Hakenbeck of the University of Cambridge and colleagues. Nomadic Huns on the Roman frontier raised relatively small numbers of animals and grew some crops, while border-zone farmers incorporated more meat into what had been a wheat- and vegetable-heavy diet, the scientists report March 22 in PLOS ONE.
“Our data show that the dietary strategies of the people on both sides of the Roman frontier were not fundamentally different,” Hakenbeck says.

Their findings challenge a traditional view of the Huns as marauders who roamed hundreds of kilometers from Central Asia to Europe. There’s no evidence of major social upheavals or a geographically distinctive group of newcomers at the frontier sites, so at least some Huns may have been homegrown, Hakenbeck suggests. Rapidly forming groups of Hun warriors and herders on horseback could have emerged in southeastern Europe not far from the Roman Empire’s border, perhaps supplemented by nomadic newcomers from farther east near the Black Sea, she proposes.

Still, geographic origins of the Huns are tough to pin down, says archaeologist Ursula Brosseder of the University of Bonn in Germany. The Huns developed as a political movement that picked up members from various ethnic groups as it spread, she explains. Brosseder suspects the “Hun phenomenon” formed on the grasslands of Western Eurasia, a territory that includes regions cited by Hakenbeck. The earliest evidence of Huns in that region dates to about 2,400 years ago.
The new study supports the idea that herding communities adapted flexibly to new environments, sometimes relying only on their livestock and at other times farming to varying extents, Brosseder says. Nomadic herders in Asia probably cultivated millet, a fast-growing cereal that can be used to feed people and horses, Hakenbeck says.
Her group studied skeletons of 234 people buried at five previously excavated sites on or near the Roman frontier. Each site contained evidence of contact with Huns, including bronze artifacts and adult skulls with elongated braincases created by binding the head during childhood. Reasons for this practice are poorly understood. It may have signified affiliation with the Huns or social status of some kind.

Graves at a Roman fort and a nearby cemetery lay on Roman land, about 150 kilometers from the frontier. Another two cemeteries were situated on the banks of the Danube River, directly on the Roman frontier. A final graveyard fell outside Roman territory. It was located about 150 kilometers east of the border.

Measurements of ratios of specific forms of carbon, nitrogen and oxygen in teeth and ribs enabled the scientists to identify what types of plants and how much meat or milk individuals ate during childhood, early adulthood and toward the end of their lives.

Results pointed to considerable consumption of cultivated plants, most likely millet, as well as meat or milk at all five sites. Variations on this general pattern occurred across sites and among individuals at each site, suggesting that groups and individuals rapidly adjusted how much they farmed or herded as circumstances dictated. “This mixing and matching was likely a kind of economic insurance policy in violent and unstable times,” Hakenbeck says.

Hakenbeck’s group also measured another tooth element, strontium, to determine whether individuals at four of the sites had grown up drinking water and eating food in the locales where they were buried. Between 30 and 50 percent of individuals studied at those sites weren’t locals, and the birthplaces of these people remain a mystery, Hakenbeck says.

In many cases, both newcomers and natives to the Roman frontier substantially changed their eating habits over the course of their lives, the researchers find. That fits Hakenbeck’s “mix and match” scenario, in which a fluctuating diet aided survival on the empire’s edge.

A common and usually harmless virus may trigger celiac disease. Infection with the suspected culprit, a reovirus, could cause the immune system to react to gluten as if it was a dangerous pathogen instead of a harmless food protein, an international team of researchers reports April 7 in Science.

In a study in mice, the researchers found that the reovirus, T1L, tricks the immune system into mounting an attack against innocent food molecules. The virus first blocks the immune system’s regulatory response that usually gives non-native substances, like food proteins, the OK, Terence Dermody, a virologist at the University of Pittsburgh, and colleagues found. Then the virus prompts a harmful inflammatory response.
“Viruses have been suspected as potential triggers of autoimmune or food allergy–related diseases for decades,” says Herbert Virgin, a viral immunologist at Washington University School of Medicine in St. Louis. This study provides new data on how a viral infection can change the immune system’s response to food, says Virgin, who wasn’t involved in the study.

Reoviruses aren’t deadly. Almost everyone has been infected with a reovirus, and almost no one gets sick, Dermody says. But if the first exposure to a food with gluten occurs during infection, the virus may turn the immune system against the food protein, the researchers found.

The immune system can either allow foreign substances, such as food proteins, to pass through the body peacefully, or it can go on the attack. In people with celiac disease, gluten is treated like a harmful pathogen; the immune system response damages the lining of the small intestine, causing symptoms like bloody diarrhea.

Celiac disease has been associated with two genetic features. Though 30 to 40 percent of people in the United States have one or both of these features, only 1 percent of the population has been diagnosed with the disease. This disparity suggests that some environmental factor triggers it.

Dermody and colleagues found that the T1L reovirus may be a trigger. In mice engineered to have one of those genetic features, the virus appeared to trick the immune system into seeing gluten as an enemy.
The key interaction occurs in the mesenteric lymph nodes, where gluten meets up with dendritic cells, which are like the “orchestra conductors” of the immune system, Dermody says. These cells dictate whether the immune system ignores a substance or mounts a defense against it.

But the virus engages with the dendritic cells as well, fooling the cells into thinking that gluten, like the virus, is in some way dangerous. And then the immune system attacks the gluten.

Dermody and colleagues also found that the reovirus stimulated activity of an enzyme called tissue transglutaminase. In people with celiac disease, the enzyme makes gluten more able to trigger a harmful immune system response.

Celiac patients also had higher levels of reovirus antibodies than those found in people without the disease.

Dermody doesn’t think that the T1L reovirus is the only virus that can stimulate celiac disease. Future research will analyze the potential of other viruses and also determine whether T1L is a true trigger of the disease in humans. If it is, then a reovirus vaccine could be developed for at-risk children, which could potentially block the development of celiac disease, “and that would be pretty amazing,” Dermody says.

On astrophysicists’ charts of star stuff, there’s a substance that still merits the label “here be dragons.” That poorly understood material is found inside neutron stars — the collapsed remnants of once-mighty stars — and is now being mapped out, as scientists better characterize the weird matter.

The detection of two colliding neutron stars, announced in October (SN: 11/11/17, p. 6), has accelerated the pace of discovery. Since the event, which scientists spied with gravitational waves and various wavelengths of light, several studies have placed new limits on the sizes and masses possible for such stellar husks and on how squishy or stiff they are.
“The properties of neutron star matter are not very well known,” says physicist Andreas Bauswein of the Heidelberg Institute for Theoretical Studies in Germany. Part of the problem is that the matter inside a neutron star is so dense that a teaspoonful would weigh a billion tons, so the substance can’t be reproduced in any laboratory on Earth.

In the collision, the two neutron stars merged into a single behemoth. This remnant may have immediately collapsed into a black hole. Or it may have formed a bigger, spinning neutron star that, propped up by its own rapid rotation, existed for a few milliseconds — or potentially much longer — before collapsing. The speed of the object’s demise is helping scientists figure out whether neutron stars are made of material that is relatively soft, compressing when squeezed like a pillow, or whether the neutron star stuff is stiff, standing up to pressure. This property, known as the equation of state, determines the radius of a neutron star of a particular mass.

An immediate collapse seems unlikely, two teams of researchers say. Telescopes spotted a bright glow of light after the collision. That glow could only appear if there were a delay before the merged neutron star collapsed into a black hole, says physicist David Radice of Princeton University because when the remnant collapses, “all the material around falls inside of the black hole immediately.” Instead, the neutron star stuck around for at least several milliseconds, the scientists propose.

Simulations indicate that if neutron stars are soft, they will collapse more quickly because they will be smaller than stiff neutron stars of the same mass. So the inferred delay allows Radice and colleagues to rule out theories that predict neutron stars are extremely squishy, the researchers report in a paper published November 13 at arXiv.org.
Using similar logic, Bauswein and colleagues rule out some of the smallest sizes that neutron stars of a particular mass might be. For example, a neutron star 60 percent more massive than the sun can’t have a radius smaller than 10.7 kilometers, they determine. These results appear in a paper published November 29 in the Astrophysical Journal Letters.

Other researchers set a limit on the maximum mass a neutron star can have. Above a certain heft, neutron stars can no longer support their own weight and collapse into a black hole. If this maximum possible mass were particularly large, theories predict that the newly formed behemoth neutron star would have lasted hours or days before collapsing. But, in a third study, two physicists determined that the collapse came much more quickly than that, on the scale of milliseconds rather than hours. A long-lasting, spinning neutron star would dissipate its rotational energy into the material ejected from the collision, making the stream of glowing matter more energetic than what was seen, physicists Ben Margalit and Brian Metzger of Columbia University report. In a paper published November 21 in the Astrophysical Journal Letters, the pair concludes that the maximum possible mass is smaller than about 2.2 times that of the sun.

“We didn’t have many constraints on that prior to this discovery,” Metzger says. The result also rules out some of the stiffer equations of state because stiffer matter tends to support larger masses without collapsing.

Some theories predict that bizarre forms of matter are created deep inside neutron stars. Neutron stars might contain a sea of free-floating quarks — particles that are normally confined within larger particles like protons or neutrons. Other physicists suggest that neutron stars may contain hyperons, particles made with heavier quarks known as strange quarks, not found in normal matter. Such unusual matter would tend to make neutron stars softer, so pinning down the equation of state with additional neutron star crashes could eventually resolve whether these exotic beasts of physics indeed lurk in this unexplored territory.