Remnants of a royal palace in southern Mexico, dating to between around 2,300 and 2,100 years ago, come from what must have been one of the Americas’ earliest large, centralized governments, researchers say.

Excavations completed in 2014 at El Palenque uncovered a palace with separate areas where a ruler conducted affairs of state and lived with his family, say archaeologists Elsa Redmond and Charles Spencer, both of the American Museum of Natural History in New York City. Only a ruler of a bureaucratic state could have directed construction of this all-purpose seat of power, the investigators conclude the week of March 27 in Proceedings of the National Academy of Sciences.

The royal palace, the oldest such structure in the Valley of Oaxaca, covered as many as 2,790 square meters, roughly half the floor area of the White House. A central staircase connected to an inner courtyard that probably served as a place for the ruler and his advisors to reach decisions, hold feasts and — based on human skull fragments found there — perform ritual sacrifices, the scientists suggest. A system of paved surfaces, drains and other features for collecting rainwater runs throughout the palace, a sign that the entire royal structure was built according to a design, the researchers say.

El Palenque’s palace contains no tombs. Its ancient ruler was probably buried off-site, at a ritually significant location, Redmond and Spencer say.

A newly discovered glass frog from Ecuador’s Amazon lowlands is giving researchers a window into its heart.

Hyalinobatrachium yaku has a belly so transparent that the heart, kidneys and urine bladder are clearly visible, an international team of researchers reports May 12 in ZooKeys. Researchers identified H. yaku as a new species using field observations, recordings of its distinct call and DNA analyses of museum and university specimens.

Yaku means “water” in Kichwa, a language spoken in Ecuador and parts of Peru where H. yaku may also live. Glass frogs, like most amphibians, depend on streams. Egg clutches dangle on the underside of leaves, then hatch, and the tadpoles drop into the water below. But the frogs are threatened by pollution and habitat destruction, the researchers write. Oil extraction, which occurs in about 70 percent of Ecuador’s Amazon rainforest, and expanding mining activities are both concerns.

When faced with rushing floodwaters, fire ants are known to build two types of structures. A quickly formed raft lets the insects float to safety. And once they find a branch or tree to hold on to, the ants might form a tower up to 30 ants high, with eggs, brood and queen tucked safely inside. Neither structure requires a set of plans or a foreman ant leading the construction, though. Instead, both structures form by three simple rules:

If you have an ant or ants on top of you, don’t move.
If you’re standing on top of ants, keep moving a short distance in any direction.
If you find a space next to ants that aren’t moving, occupy that space and link up.
“When in water, these rules dictate [fire ants] to build rafts, and the same rules dictate them to build towers when they are around a stem [or] branch,” notes Sulisay Phonekeo of the Georgia Institute of Technology in Atlanta. He led the new study, published July 12 in Royal Society Open Science.

To study the fire ants’ construction capabilities, Phonekeo and his Georgia Tech colleagues collected ants from roadsides near Atlanta. While covered in protective gear, the researchers dug up ant mounds and placed them in buckets lined with talc powder so the insects couldn’t climb out. Being quick was a necessity because “once you start digging, they’ll … go on attack mode,” Phonekeo says. The researchers then slowly flooded the bucket until the ants floated out of the dirt and formed a raft that could be easily scooped out.

In the lab, the researchers placed ants in a dish with a central support, then filmed the insects as they formed a tower. The support had to be covered with Teflon, which the ants could grab onto but not climb without help. Over about 25 minutes, the ants would form a tower stretching up to 30 mm high. (The ants themselves are only 2 to 6 mm long.)
The towers looked like the Eiffel Tower or the end of a trombone, with a wide base and narrow top. And the towers weren’t static, like rafts of ants are. Instead, videos of the ant towers showed that the towers were constantly sinking and being rebuilt.

Peering into the transparent Petri dish from below revealed that the ants build tunnels in the base of a tower, which they use to exit the base before climbing back up the outside.

“The ants clear a path through the ants underneath much like clearing soil,” Phonekeo says. Ants may be using the tunnels to remove debris from inside the towers. And the constant sinking and rebuilding may give the ants a chance to rest without the weight of any compatriots on their backs, he says.

To find out what was happening inside the tower, the researchers fed half their ants a liquid laced with radioactive iodide and then filmed the insects using a camera that captured X-rays. In the film, radioactive ants appeared as dark dots, and the researchers could see that some of those dots didn’t move, but others did.

The team then turned to the three rules that fire ants follow when building a raft and realized that they also applied to towers. But there was also a fourth rule: A tower’s stability depends on the ants that have attached themselves to the rod. The top row of ants on the rod aren’t stable unless they form a complete ring. So to get a taller tower, there needs to be a full ring of ants gripping to the rod and each other.

That such simple rules could form two completely different structures is inspiring to Phonekeo. “It makes me wonder about the possibilities of living structures that these ants can build if we can design the right environment for them.”

Plate tectonics may have gotten a pretty early start in Earth’s history. Most estimates put the onset of when the large plates that make up the planet’s outer crust began shifting at around 3 billion years ago. But a new study in the Sept. 22 Science that analyzes titanium in continental rocks asserts that plate tectonics began 500 million years earlier.

Nicolas Greber, now at the University of Geneva, and colleagues suggest that previous studies got it wrong because researchers relied on chemical analyses of silicon dioxide in shales, sedimentary rocks that bear the detritus of a variety of continental rocks. These rocks’ silicon dioxide composition can give researchers an idea of when continental rocks began to diverge in makeup from oceanic rocks as a result of plate tectonics.

But weathering can wreak havoc on the chemical makeup of shales. To get around that problem, Greber’s team turned to a new tool: the ratios of two titanium isotopes, forms of the same element that have different masses. The proportion of titanium isotopes in the rocks is a useful stand-in for the difference in silicon dioxide concentration between continental and oceanic rocks, and isn’t so easily altered by weathering. Those data helped the team estimate that continental rocks — and therefore plate tectonics — were already going strong by 3.5 billion years ago.

How do you observe the invisible currents of the atmosphere? By studying the swirling, billowing loads of sand, sea salt and smoke that winds carry. A new simulation created by scientists at NASA’s Goddard Space Flight Center in Greenbelt, Md., reveals just how far around the globe such aerosol particles can fly on the wind.

The complex new simulation, powered by supercomputers, uses advanced physics and a state-of-the-art climate algorithm known as FV3 to represent in high resolution the physical interactions of aerosols with storms or other weather patterns on a global scale (SN Online: 9/21/17). Using data collected from NASA’s Earth-observing satellites, the simulation tracked how air currents swept aerosols around the planet from August 1, 2017, through November 1, 2017.
In the animation, sea salt (in blue) snagged by winds sweeping across the ocean’s surface becomes entrained in hurricanes Harvey, Irma, Jose and Maria, revealing their deadly paths. Wisps of smoke (in gray) from fires in the U.S. Pacific Northwest drift toward the eastern United States, while Saharan dust (in brown) billows westward across the Atlantic Ocean to the Gulf of Mexico. And the visualization shows how Hurricane Ophelia formed off the coast of Africa, pulling in both Saharan dust and smoke from Portugal’s wildfires and transporting the particles to Ireland and the United Kingdom.

When you lock eyes with a baby, it’s hard to look away. For one thing, babies are fun to look at. They’re so tiny and cute and interesting. For another, babies love to stare back. I remember my babies staring at me so hard, with their eyebrows raised and unblinking eyes wide open. They would have killed in a staring contest.

This mutual adoration of staring may be for a good reason. When a baby and an adult make eye contact, their brain waves fall in sync, too, a new study finds. And those shared patterns of brain activity may actually pave the way for better communication between baby and adult: Babies make more sweet, little sounds when their eyes are locked onto an adult who is looking back. The scientists report the results online November 28 in the Proceedings of the National Academy of Sciences.

Psychologist Victoria Leong of the University of Cambridge and Nanyang Technological University in Singapore and colleagues invited infants into the lab for two experiments. In the first, the team outfitted 17 8-month-old babies with EEG caps, headwear covered with electrodes that measure the collective behavior of nerve cells across the brain. The infants watched a video in which an experimenter, also outfitted in an EEG cap, sung a nursery rhyme while looking either straight ahead at the baby, at the baby but with her head turned at a 20-degree angle, or away from the baby and with her head turned at a 20-degree angle.
When the researcher looked at the baby (either facing the baby or with her head slightly turned), the babies’ brains responded, showing activity patterns that started to closely resemble those of the researcher.

The second experiment moved the test into real life. The same researcher from the video sat near 19 different babies. Again, both the babies and the researcher wore EEG caps to record their brain activity. The real-life eye contact prompted brain patterns similar to those seen in the video experiment: When eyes met, brain activity fell in sync; when eyes wandered, brain activity didn’t match as closely.

The baby’s and the adult’s brain activity appeared to get in sync by meeting in the middle. When gazes were shared, a baby’s brain waves became more like the researcher’s, and the researcher’s more like the baby’s. That finding is “giving new insights into infants’ amazing abilities to connect to, and tune in with, their adult caregivers,” Leong says.

What are simpatico brain waves actually good for, you might ask? Well, researchers don’t know exactly, but they have some ideas. When high school students’ brain waves were in sync with one another, the kids reported being more engaged in the classroom, a recent study found. And when two adults reach a mutual understanding, their brains synchronize, too, says another study. These findings hint that such synchronization lets signals flow easily between two brains, though Leong says that much more research needs to be done before scientists understand synchronization’s relevance to babies’ communication and learning.
That easy signal sending is something that happened between the babies and the adult, too. When the experimenter was looking at the babies, the babies made more vocalizations. And in turn, these sweet sounds seemed to have made the experimenter’s brain waves even more similar to those of the babies.

It’s a beautiful cycle, it seems, when eyes and brains meet. And that meeting spot is probably where some interesting learning happens, for both adult and baby.

NEW ORLEANS — Jupiter’s Great Red Spot has deep roots. Data from the first pass of NASA’s Juno spacecraft over the incessant storm show that its clouds stretch at least 350 kilometers down into the planet’s atmosphere. That means the storm is about as deep as the International Space Station is high above the Earth.

Juno has been orbiting Jupiter since July 4, 2016, and it made its first close flyby of the red spot about a year later (SN Online: 7/7/17). As the spacecraft swooped 9,000 kilometers above the giant storm, Juno’s microwave radiometer peered through the deep layers of cloud, measuring the atmosphere’s temperature down hundreds of kilometers.
“Juno is probing beneath these clouds, and finding the roots of the red spot,” Juno co-investigator Andrew Ingersoll of Caltech said December 11 at a news conference at the American Geophysical Union’s fall meeting. Cheng Li of Caltech presented the research at AGU on December 12.
The radiometer probes different layers of the atmosphere by measuring the gas in six different microwave wavelengths. Ingersoll and his colleagues found that the gas beneath the red spot’s surface gets warmer with depth, and a warm zone at the same location as the spot was visible down to 350 kilometers
The fact that the 16,000-kilometer-wide spot is warmer at the bottom than at the top could help explain the storm’s screaming wind speeds of about 120 meters per second. Warm air rises, so the internal heat could provide energy to churn the storm.

Juno principal investigator Scott Bolton of the Southwest Research Institute in San Antonio notes that the spot “goes as deep as we can see,” but it could go deeper. “I’m not sure we’ve established the true foot,” he says. On a future flyby, Juno will try to use gravity data to detect the storm at depths of thousands of kilometers. If the spot does go down that deep, theorists will struggle to explain why, Bolton says.

The only previous data on Jupiter’s interior came from the Galileo spacecraft, which ended its mission by entering Jupiter’s atmosphere at a single point in 1995. “I like to say that if aliens sent a probe to Earth and it landed in the Sahara, they would conclude the Earth is all desert,” says planetary scientist Michael Wong of Caltech, who was not involved in the new study. “Juno getting this global view gives us a new understanding of the inner workings … We have never really seen the interior of a giant planet in this way before.”

NEW ORLEANS — For the first time, scientists have definitively linked human-caused climate change to extreme weather events.

A handful of extreme events that occurred in 2016 — including a deadly heat wave that swept across Asia — simply could not have happened due to natural climate variability alone, three new studies find. The studies were part of a special issue of the Bulletin of the American Meteorological Society, also known as BAMS, released December 13.
These findings are a game changer — or should at least be a conversation changer, Jeff Rosenfeld, editor in chief of BAMS, said at a news conference that coincided with the studies’ release at the American Geophysical Union’s annual meeting. “We can no longer be shy about talking about the connection between human causes of climate change and weather,” he said.

For the last six years, BAMS has published a December issue containing research on extreme weather events from the previous year that seeks to disentangle the role of anthropogenic climate change from natural variability. The goal from the start has been to find ways to improve the science of such attribution, said Stephanie Herring of the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information in Boulder, Colo., who was lead editor of the latest issue.

To date, BAMS has published 137 attribution studies. But this is the first time that any study has found that a weather event was so extreme that it was outside the bounds of natural variability — let alone three such events, Herring said.

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In addition to the Asia heat wave, those events were the record global heat in 2016 and the growth and persistence of a large swath of high ocean temperatures, nicknamed “the Blob,” in the Bering Sea off the coast of Alaska. The unusually warm waters, which lingered for about a year and a half, have been linked to mass die-offs of birds, collapsed codfish populations in the Gulf of Alaska and altered weather patterns that brought drought to California.

Many of the other 24 studies in the new issue found a strong likelihood of human influence on extreme weather events, but stopped short of saying they were completely out of the realm of natural variability. One study found that an already strong El Niño in 2016 was probably enhanced by human influence, contributing to drought and famine conditions in southern Africa. Another reported that greenhouse gas–driven warming of sea surface temperatures in the Coral Sea was the main factor driving an increase in coral bleaching risk along the Great Barrier Reef. But not all of the studies linked 2016’s extreme events to human activity. Record-breaking rainfall in southeastern Australia between July and September, for example, was due to natural variability, one study found.

With hurricanes, wildfires and drought, 2017 is chock-full of extreme event candidates for next year’s crop of BAMS attribution studies. Already, the likelihood of human influence on the extreme rainfall from Hurricane Harvey is the subject of three independent studies, two of which were also presented at the American Geophysical Union meeting. The storm dropped about 1.3 meters of water on Houston and its surrounding areas in August. The three studies, discussed in a separate news conference December 13, found that human influence probably increased the hurricane’s total rainfall, by anywhere from at least 15 percent to at least 19 percent.

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“I think [the BAMS studies] speak to the profound nature of the impacts we’re now seeing,” says Michael Mann, a climate scientist at Penn State who was not involved in any of the studies. But Mann says he’s concerned that many researchers are too focused on quantifying how much human influence was responsible for a particular event, rather than how human influence affects various processes on the planet. One example, he notes, is the established link between rising temperatures and increased moisture in the atmosphere that is also implicated in Hurricane Harvey’s extreme rainfall.

Another possible issue with attribution science, he says, is that the current generation of simulations simply may not be capable of capturing some of the subtle changes in the climate and oceans — a particular danger when it comes to studies that find no link to human activities. It’s a point that climate scientist Andrew King of the University of Melbourne in Australia, who authored the paper on Australia’s rainfall, also noted at the news conference.

“When we find no clear signal for climate change, there might not have been a human influence on the event, or [it might be that] the particular factors of the event that were investigated were not influenced by climate change,” he said. “It’s also possible that the given tools we have today can’t find this climate change signal.”

Rosenfeld noted that people tend to talk about the long odds of an extreme weather event happening. But with studies now saying that climate change was a necessary condition for some extreme events, discussions about long odds no longer apply, he said. “These are new weather extremes made possible by a new climate.”

The neutron star collision heard and seen around the world has failed to fade. That lingering glow could mean that a jet of bright matter created in the crash has diffused into a glowing, billowy cocoon that surrounds the merged star, researchers report online December 20 in Nature.

Gravitational waves from the collision between two ultradense stellar corpses was picked up in August by the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, and its sister experiment in Italy, Advanced Virgo (SN: 11/11/17, p. 6). Using telescopes on the ground and in space, physicists raced to conduct follow-up observations, and found that the collision released light across the electromagnetic spectrum.
Right away, the event looked unusual, says astrophysicist Kunal Mooley, who conducted the research while at the University of Oxford. Physicists think that a jet of fast-moving, bright material blasts out of the center of neutron star collisions. If that jet is aimed directly at Earth, telescopes can see it as an ephemeral flash of light called a short gamma-ray burst, or GRB.
But the gamma-ray signals produced by the August collision were 10,000 times less bright than those seen in other detected short gamma-ray bursts. Even stranger, X-rays and radio waves from the event didn’t appear until about 16 days after the collision. Most short gamma-ray bursts are visible in X-rays and radio waves right away and fade over time.
Astronomers thought those oddities meant the jet was facing slightly away from Earth and expected the light to fade quickly. But Mooley and colleagues continued tracking the glow with three radio telescope arrays on three continents for more than 100 days after the collision. Radio wave emissions continued to brighten for at least 93 days, and are still visible now, the team found. (X-rays were temporarily blocked when the neutron star moved behind the sun from Earth’s perspective.)

“This thing continues to rise, instead of fading into oblivion as we expected,” says astrophysicist Wen-fai Fong of Northwestern University in Evanston, Ill., who was not involved in the new study.

The finding may mean that astronomers are seeing a new kind of gamma-ray burst. Mooley and colleagues suggest that the rise in radio wave emissions could be explained if the jet slammed into a shell of neutron-rich material kicked out in the neutron star crash, transferring most of its energy to that debris and smothering the jet. That extra energy could create a glowing cocoon that keeps radiating far longer than the original blast.

The new result is “really challenging our understanding of what physics is happening from this merger,” Fong says. But, she adds, “the jury is still out on whether this is the same as the short GRBs we’ve seen over the past decade, or whether it’s something completely different,” such as a luminescent cocoon. She and her colleagues also took radio wave observations of the merged stars in the first 100 days after the collision. The team is preparing a paper with a different interpretation that includes a jet emerging from the wreckage later, she says.

Other explanations for the lingering light are possible, Mooley acknowledges. Future detections “will give us an opportunity to really study … what fraction of neutron star mergers give rise to [short] GRBs and what fraction give rise to other phenomena and explosions that we haven’t seen so far in our universe,” he says.

2017 revealed some surprising biology of organisms large and small, from quick-dozing elephants to sex-changing lizards and carbon-dumping sea creatures.

Switch it up
Toasty temperatures trump genetics when it comes to the sex of a bearded dragon lizard. Now researchers have found how RNA editing helps turn overheated male embryos into females (SN Online: 6/14/17).

Homegrown
Giant larvaceans don’t have noses, but they sure know how to blow snot bubbles. The sea invertebrates live in disposable “mucus houses” that, based on recent observations, collect food fast. When these larvaceans ditch a dirty house and “sneeze” themselves a new one, they might send a lot of carbon to the deep sea (SN: 6/10/17, p. 13).

Blood and guts
Antarctic-dwelling sea spiders use their long legs for more than creepy-crawling below the ice. Stretches of digestive tract in the creatures’ legs do double duty — not only digesting meals, but also pumping an arthropod version of blood and oxygen through the rest of the body (SN: 2/4/17, p. 13).

Fluorescent fashion
South American polka dot tree frogs are the first amphibians known to naturally fluoresce. The frogs’ intense blue-green glow might play a role in complex courtship and fighting behaviors, biologists propose (SN: 4/15/17, p. 4).

Brainless beauty sleep
Upside-down jellyfish are the first brainless animals known to catch some z’s, lab experiments suggest (SN: 10/28/17, p. 10). The finding raises new questions about when and why sleep evolved.

Pachyderm power nap
For some wild elephants, a good night’s sleep ends soon after it starts. Electronic monitoring of two African elephants found that the animals snooze about two hours per day — the shortest sleep requirement recorded for mammals (SN: 4/1/17, p. 10).

Heads up
Chop off a hydra’s head, and two more grow in its place — or so the ancient Greek myth goes. By fiddling with the cytoskeletons of real-life hydras, researchers found that the pond polyps rely on mechanical forces as well as molecular cues to regenerate head and tentacles in the right places (SN: 3/4/17, p. 19).

Balancing act
Flamingos may be more stable standing on one leg than two, especially when asleep, researchers reported (SN: 6/24/17, p. 15). The blushing bird’s center of gravity is located near its tucked-in knee, which helps with stability. A one-legged stance requires little muscular effort, the scientists say, but others caution that it may not be an energy saver.

Ultimate survivor
Tardigrades are known for withstanding extreme temperatures, intense radiation and even the vacuum of space. Those adaptations could help this hardy lineage survive until Earth is engulfed by the sun in several billion years, researchers estimate (SN Online: 7/14/17). An analysis of the microscopic water bears’ genetic blueprints offers clues to their survival strategies, and challenges claims that tardigrades are extreme gene swappers (SN: 8/19/17, p. 13).

Paint it blue
Scientists borrowed a gene each from Canterbury bells and butterfly peas to breed the world’s first true blue chrysanthemums. The method could be used to give other flower species the blues (SN: 8/19/17, p. 12).