Some of the earliest settlers of the Americas curtailed their coastal migration to hunker down in what’s now northwestern Peru, new finds suggest. Although researchers have often assumed that shoreline colonizers of the New World kept heading south from Alaska in search of marine foods, staying put in some spots made sense: Hunter-gatherers needed only simple tools to exploit rich coastal and inland food sources for thousands of years.

Excavations at two seaside sites in Peru find that people intermittently camped there from about 15,000 to 8,000 years ago, say anthropologist Tom Dillehay of Vanderbilt University in Nashville and his colleagues. Ancient people along Peru’s Pacific coast didn’t leave behind fishhooks, harpoons, nets or boats that could have been used to capture fish, sharks and sea lions, the scientists report May 24 in Science Advances. Yet remains of those sea creatures turned up at coastal campsites now buried beneath a human-made, earthen mound called Huaca Prieta and an adjacent mound called Paredones. Fish and other marine animals probably washed up on beaches or were trapped in lagoons that formed near the shore, Dillehay’s group proposes. Hungry humans needed only nets or clubs to subdue these prey.
Other marine foods found at the ancient Peruvian campsites included snails, crabs, clams, sea gulls and pelicans. Fragments of material woven out of rush plants, the earliest dating to between 10,600 and 11,159 years ago, may have come from fish traps or baskets, the researchers say.
Radiocarbon dating of burned wood, animal bones and plant seeds provided age estimates for a series of buried campsites at Huaca Prieta and Paredones.

Present-day hunters on Peru’s coast eat fish and small sharks that get trapped on the beach or in shallow shoreline lagoons. Hunters also build blinds where they wait to net and club birds, a tactic probably also used by ancient Americans, the investigators suspect.

Deer bones indicate that ancient Huaca Prieta and Paredones visitors hunted on land as well. And remains of avocado, beans and possibly cultivated squash and chili peppers at the ancient campsites — foods known to have been gathered or grown at inland locations — suggest that people transported these foods to the coast, possibly via trading.
Evidence that early New World settlers trekked back and forth from coastal to interior parts of Peru coincides with similar human movements in southern Chile more than 14,000 years ago (SN Online: 5/8/08). A team led by Dillehay uncovered seaweed fragments in hearths and structures at Monte Verde II, located 30 kilometers from Chile’s coast. Edible rushes, reeds and stones from the coast also turned up at Monte Verde II.

“Just as there was some contact with the sea at Monte Verde II, there was some contact with the interior at Huaca Prieta,” Dillehay says.

Simple stone tools, sharpened on one side, dominate implements excavated at the Peruvian sites and at Monte Verde II. Basic tools suitable for all sorts of cutting and scraping tasks fit a lifestyle in which people sought food across varied landscapes, the researchers contend.
Similar conditions may have characterized some North American coastlines by around 15,000 years ago, Dillehay says. “The problem is that these areas are now underwater” due to a global sea level rise between 20,000 and 6,000 years ago (SN: 8/13/11, p. 22).

Accumulating evidence supports the idea that early Americans favored the coast over an inland lifestyle, says archaeologist Daniel Sandweiss of the University of Maine in Orono. An ice-free corridor into North America’s interior may not have formed before 12,600 years ago (SN Online: 8/10/16), after people had reached Peru and Chile.

The pace at which people moved south from Huaca Prieta is unknown, Sandweiss says. Monte Verde II dates to roughly 500 years after the first coastal campsites in Peru, raising the possibility that Huaca Prieta folk founded the Chilean site, he suggests.

Dillehay doubts it. Modern hunter-gatherer groups vary greatly in size but usually don’t exceed several hundred members, making it unlikely that ancient Huaca Prieta and Paredones people were numerous enough to encounter food shortages, he says. Even if food ran out, hunter-gatherers only had to move a few kilometers north or south to find abundant grub. “We really don’t know where these people were coming and going,” Dillehay cautions.

If the Milky Way exists in the biggest cosmic void ever observed, that could solve a puzzling mismatch between ways to measure how fast the universe is expanding.

Observations of 120,000 galaxies bolstering the Milky Way’s loner status were presented by Benjamin Hoscheit June 7 at a meeting of the American Astronomical Society in Austin, Texas. Building on earlier work by his adviser, University of Wisconsin‒Madison astronomer Amy Barger, Hoscheit and Barger measured how the density of galaxies changed with distance from the Milky Way.
In agreement with the earlier study, the pair found that the Milky Way has far fewer neighbors than it should. There was a rise in density about 1 billion light-years out, suggesting the Milky Way resides in an abyss about 2 billion light-years wide.

Simulations of how cosmic structures form suggest that most galaxies clump along dense filaments of dark matter, which are separated by vast cosmic voids.

If the Milky Way lives in such a void, it could help explain why the universe seems to be expanding at different rates depending on how it’s measured (SN: 8/6/16, p. 10). Measurements based on the cosmic microwave background, the earliest light in the universe, suggest one rate of expansion, while measurements of nearby supernovas suggest a faster one.

Those supernovas could be feeling an extra gravitational pull from all the matter at the edges of the void, Hoscheit says. The actual expansion rate is probably the slower one measured in the universe’s early light.

“If you don’t account for the void effects, you could mistake this relationship to indicate that there is too much expansion,” Hoscheit says.

Those who struggle to fit a vacation wardrobe into a carry-on might learn from ladybugs. The flying beetles neatly fold up their wings when they land, stashing the delicate appendages underneath their protective red and black forewings.

To learn how one species of ladybug (Coccinella septempunctata) achieves such efficient packing, scientists needed to see under the bug’s spotted exterior. So a team from Japan replaced part of a ladybug’s forewing with a transparent bit of resin, to get a first-of-its-kind glimpse of the folding.
Slow-motion video of the altered ladybug showed that the insect makes a complex, origami-like series of folds to stash its wings, the scientists report in the May 30 Proceedings of the National Academy of Sciences. CT scans helped explain how the wings can be both strong enough to hold the insects aloft and easily foldable into a tiny package. The shape of the wing veins allows them to flex like a metal tape measure, making the wings stiff but bendable. Lessons learned from the wings could be applied to new technologies, including foldable aircraft wings or solar panels that unfurl from a spacecraft.

The hunt for gravitational waves is moving upward. A space-based detector called the Laser Interferometer Space Antenna, or LISA, was selected as a mission in the European Space Agency’s science program, the agency announced June 20.

LISA will consist of three identical satellites arranged in a triangle that will cartwheel through space in orbit around the sun just behind Earth. The spacecraft will use lasers to detect changes in the distance between each satellite. Those changes would indicate the passage of gravitational waves, the ripples in spacetime that massive bodies such as black holes shake off when they move.

The spacecraft was originally planned as a joint mission between ESA and NASA, but NASA pulled out in 2011 citing budget issues. In December 2015, ESA launched a single satellite called LISA Pathfinder to test the concept — a test it passed with flying colors.

Interest in LISA increased in 2016 after researchers at the ground-based LIGO detectors announced that they had finally observed gravitational waves. LIGO is best suited for detecting the crash caused when dense objects such as neutron stars or solar-mass black holes collide.

LISA, on the other hand, will be sensitive to the collision of much more massive objects — such as the supermassive black holes that make up most galaxies’ cores.

The mission design and cost are still being completed. If all goes as planned, LISA will launch in 2034.

Climate change may make the rich richer and the poor poorer in the United States.

Counties in the South face a higher risk of economic downturn due to climate change than their northern counterparts, a new computer simulation predicts. Because southern counties generally host poorer populations, the new findings, reported in the June 30 Science, suggest that climate change will worsen existing wealth disparities.

“It’s the most detailed and comprehensive study of the effects of climate change in the United States,” says Don Fullerton, an economist at the University of Illinois at Urbana-Champaign who was not involved in the work. “Nobody has ever even considered the effects of climate change on inequality.”
Researchers created a computer program called SEAGLAS that combined several climate simulations to forecast U.S. climate until 2100, assuming greenhouse gas emissions keep ramping up. Then, using data from previous studies on how temperature and rainfall affect several economic factors — including crop yields, crime rates and energy expenditures — SEAGLAS predicted how the economy of each of the 3,143 counties in the United States would fare.

By the end of the century, some counties may see their gross domestic product decline by more than 20 percent, while others may actually experience more than a 10 percent increase in GDP. This could make for the biggest transfer of wealth in U.S. history, says study coauthor Solomon Hsiang, an economist at the University of California, Berkeley.

In general, SEAGLAS predicts that counties in the lower Midwest, the South and the Southwest — already home to some of the country’s poorest communities — will bear the brunt of climate-caused economic damages, while counties in New England, the Great Lakes region and the Pacific Northwest will suffer less or see gains. For many of the examined economic factors, such as the number of deaths per year, “getting a little bit hotter is much worse if you’re already very hot,” explains Hsiang. “Most of the south is the hottest part of the country, so those are the regions where costs tend to be really high.”
The economic gaps may get stretched even wider than SEAGLAS predicts, Fullerton says, because the simulation doesn’t account for wealth disparities within counties. For example, wealthier people in poor counties may have access to air conditioning while their less fortunate neighbors do not. So blisteringly hot weather is most likely to harm the poorest of the poor.

Not all researchers, however, think the future is as bleak as SEAGLAS suggests. The simulation doesn’t fully account for adaptation to climate change, says Delavane Diaz, an energy and environmental policy analyst at the Electric Power Research Institute in Washington, D.C., a nonprofit research organization. For example, people in coastal regions could mitigate the cost of sea level rise by flood-proofing structures or moving inland, she says.

And the economic factors examined in this study don’t account for some societal benefits that may arise from climate change, says Derek Lemoine, an economist at the University of Arizona in Tucson. For instance, although crime rates rise when it’s warmer because more people tend to be out and about, people being active outside could have a positive impact on health.

But SEAGLAS is designed to incorporate different societal variables as new data become available. “I really like the system,” Lemoine says. “It’s a super ambitious work and the kind of thing that needs to be done.”

How well, not how much, people sleep may affect Alzheimer’s disease risk.

Healthy adults built up Alzheimer’s-associated proteins in their cerebral spinal fluid when prevented from getting slow-wave sleep, the deepest stage of sleep, researchers report July 10 in Brain. Just one night of deep-sleep disruption was enough to increase the amount of amyloid-beta, a protein that clumps into brain cell‒killing plaques in people with Alzheimer’s. People in the study who slept poorly for a week also had more of a protein called tau in their spinal fluid than they did when well rested. Tau snarls itself into tangles inside brain cells of people with the disease.
These findings support a growing body of evidence that lack of Zs is linked to Alzheimer’s and other neurodegenerative diseases. Specifically, “this suggests that there’s something special about deep, slow-wave sleep,” says Kristine Yaffe, a neurologist and psychiatrist at the University of California, San Francisco who was not involved in the study.

People with Alzheimer’s are notoriously poor sleepers, but scientists aren’t sure if that is a cause or a consequence of the disease. Evidence from recent animal and human studies suggests the problem goes both ways, Yaffe says. Lack of sleep may make people more prone to brain disorders. And once a person has the disease, disruptions in the brain may make it hard to sleep. Still, it wasn’t clear why not getting enough shut-eye promotes Alzheimer’s disease.
Researchers led by neurologist David Holtzman of Washington University School of Medicine in St. Louis speculated that lower levels of brain cell activity during deep sleep would produce less A-beta, tau and other proteins than other stages of sleep or wakefulness. Holtzman, Washington University sleep medicine physician Yo-El Ju and colleagues recruited 17 volunteers, all healthy adults between ages 35 and 65, who had no sleep disorders. “These are good sleepers,” Ju says.
Volunteers wore activity monitors to track their sleep at home and visited the sleep lab at least twice. On one visit, the volunteers slept normally while wearing headphones. On the other visit, researchers played beeps through headphones whenever the volunteers were about to go into deep sleep. The sounds usually didn’t wake the people up but kept them from getting any slow-wave sleep. Volunteers slept just as much on the night when deep sleep was disrupted as they did on the night when no sound was played through the headphones.
Spinal taps showed that the more deep sleep people missed out on, the higher their levels of A-beta in the morning. Tau levels didn’t budge because of just one night of slow-wave sleep disruption, but people whose activity monitors indicated they had slept poorly the week before the test also had higher levels of that protein.

“This study in humans is really an elegant experimental demonstration” that bolsters Holtzman’s hypothesis that lack of rest for brain cells could be detrimental, says Adam Spira, a psychologist at Johns Hopkins Bloomberg School of Public Health. Without proper deep sleep, brain cells continue to churn out, producing more A-beta and tau than a well-rested brain.

Some research has suggested that toxic proteins get flushed out of the brain during sleep (SN: 11/16/13, p. 7). Messing with slow-wave sleep doesn’t seem to interfere with this wash cycle, Ju says. Levels of other proteins made by nerve cells didn’t vary with the lack of deep sleep, she says.

The tempo of a male elephant seal’s call broadcasts his identity to rival males, a new study finds.

Every male elephant seal has a distinct vocalization that sounds something like a sputtering lawnmower — pulses of sound in a pattern and at a pace that stays the same over time.

At a California state park where elephant seals breed each year, researchers played different variations of an alpha male’s threat call to subordinate males who knew him. The seals weren’t as responsive when the tempo of that call was modified substantially, suggesting they didn’t recognize it as a threat. Modifying the call’s timbre — the acoustic quality of the sound — had the same effect, researchers report August 7 in Current Biology. Unlike dolphins and songbirds, elephant seals don’t seem to vary pitch to communicate.
Those vocal name tags serve a purpose. During breeding season, male elephant seals spend three months on land without food or water, competing with rivals for social status and mating rights. Fights between two blubbery car-sized animals can be brutal.

“We’ve seen males lose their noses,” says Caroline Casey, a biologist at the University of California, Santa Cruz. For lower-ranking males, identifying an alpha male by his call and then backing off might prevent a beach brawl.

Mums are now a flower of a different color. Japanese researchers have added a hint of clear sky to the humble plant’s palette, genetically engineering the first-ever “true blue” chrysanthemum.

“Obtaining blue-colored flowers is the Holy Grail for plant breeders,” says Mark Bridgen, a plant breeder at Cornell University. The results are “very exciting.”

Compounds called delphinidin-based anthocyanin pigments are responsible for the natural blues in such flowers as pansies and larkspur. Mums lack those compounds. Instead, the flowers come in a variety of other colors, evoking fiery sunsets, new-fallen snow and all things chartreuse.
In previous attempts to engineer a blue hue in chrysanthemums — and roses and carnations — researchers inserted the gene for a key enzyme that controls production of these compounds, causing them to accumulate. But the resulting blooms skewed more violet-purple than blue.
True blue pigment remained elusive, scientists thought, because its origin was complex; multiple genes have been shown to be involved in its generation. But Naonobu Noda, of the National Agriculture and Food Research Organization in Tsukuba, Japan, and colleagues were surprised to find that inserting only two borrowed genes into chrysanthemums created blue flowers. One gene, from Canterbury bells, got the enzyme process started; the other, from butterfly peas, further tweaked the pigment molecules.

Together, the gene double-team transformed 19 of 32 mums, or 59 percent, of the Taihei variety from having pink or magenta blooms into blue beauties. Additional analyses revealed that the blue color arose because of molecular interactions between the tweaked pigment and certain colorless compounds naturally found in many plants, including chrysanthemums. The two-part method could possibly be used in the production of other blue flowers, the researchers report July 26 in Science Advances.

A molecule that could help build otherworldly life is present on Saturn’s moon Titan, researchers have discovered.

Vinyl cyanide, a compound predicted to form membranelike structures, is created in Titan’s upper atmosphere, scientists report July 28 in Science Advances. There’s enough vinyl cyanide (C2H3CN) in the moon’s liquid methane seas to make about 10 million cell-like balls per cubic centimeter of ocean, researchers calculate. On Earth, about a million bacteria are found in a cubic centimeter of ocean water near shore.
“It’s very positive news for putative-Titan-life studies,” says Jonathan Lunine, a planetary scientist at Cornell University who was not involved in the new study.

Titan has no water, usually considered a prerequisite for life. Instead of water, freezing-cold Titan has liquid methane. There’s even a methane cycle that mimics Earth’s water cycle (SN: 3/21/15, p. 32). But Titan is so cold — usually about –178° Celsius — that the smallest unit of life on Earth, the cell, would shatter in the moon’s subzero seas.
In 2015, Lunine and Cornell colleagues James Stevenson and Paulette Clancy proposed a way life might exist in methane. Computer simulations predicted that vinyl cyanide (also called acrylonitrile or propenenitrile) could make flexible bubbles called azotosomes that would be stable in liquid methane (SN: 4/30/16, p. 28). Those bubbles might act much as cell membranes do on Earth, sheltering genetic material and concentrating biochemical reactions needed for life.
When the Cornell researchers suggested the presence of azotosomes on Titan, carbon, hydrogen and nitrogen had already been detected in abundance in the moon’s atmosphere. But no one knew whether those atoms joined to make vinyl cyanide there. The Saturn probe Cassini had detected a molecule of the right mass to be vinyl cyanide, but couldn’t definitively identify the molecule’s chemical makeup.

But evidence for the chemical compound was buried in archived data from a large radio telescope, Maureen Palmer of Catholic University of America in Washington, D.C., and colleagues discovered. Palmer, an astrochemistry and astrobiology researcher, combed data collected by the Atacama Large Millimeter/submillimeter Array, or ALMA, in Chile between February 22 and May 27, 2014.

Astronomers point ALMA at Titan to calibrate the telescope because the moon has known brightness levels, says Palmer, who also works at NASA’s Goddard Space Flight Center in Greenbelt, Md. The team used that calibration data to detect the signature of vinyl cyanide at specific wavelengths of light and calculate its abundance.

“This is a pretty secure detection,” says Ralph Lorenz, a planetary scientist at the Johns Hopkins University Applied Physics Lab in Laurel, Md.

Even with confirmation of vinyl cyanide, researchers can’t say that azotosomes form on Titan. That’s probably not something telescopes can determine, Lunine says. A probe would need to sample Titan’s seas to detect the structures.

And even detecting azotosomes would not mean there’s life on Titan, says Lorenz. The moon’s extreme cold may hamper metabolism. What’s more, no one knows whether liquid methane can take the place of water for supporting life, he says. “If I were a betting man, I’d say Titan does not have life.”

Nearly 5 percent of U.S. adults misused prescription opioids in 2015, a new study shows.

Based on the National Survey on Drug Use and Health, an in-person survey of more than 50,000 people, researchers estimate that 91.8 million, or 37.8 percent, of adults used prescription opioids in 2015. Some 11.5 million people misused the painkillers, and 1.9 million people reported opioid dependence or abuse, Beth Han of the Substance Abuse and Mental Health Services Administration in Rockville, Md., and colleagues report online August 1 in Annals of Internal Medicine.
Relieving pain was the most commonly cited reason for people’s most recent episode of misuse — for 66 percent of those reporting misuse, such as using without a prescription, and nearly 49 percent of those with opioid dependence or abuse. (Respondents could report more than one reason for their last misuse.) These results underscore the need for improved pain management, the authors say.