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.

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.

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.”

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.

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.

In a pitch-black rainforest with fluttering moths and crawling centipedes, Christina Warinner dug up her first skeleton. Well, technically it was a full skeleton plus two headless ones, all seated and draped in ornate jewelry. To deter looters, she excavated through the night while one teammate held up a light and another killed as many bugs as possible.

As Warinner worked, unanswerable questions about the people whose skeletons she was excavating flew through her mind. “There’s only so much you can learn by looking with your own eyes at a skeleton,” she says. “I became increasingly interested in all the things that I could not see — all the stories that these skeletons had to tell that weren’t immediately accessible, but could be accessible through science.”

At age 21, Warinner cut her teeth on that incredibly complex sacrificial burial left behind by the Maya in a Belize rainforest. Today, at age 37, the molecular anthropologist scrapes at not-so-pearly whites to investigate similar questions, splitting her time between the University of Oklahoma in Norman and the Max Planck Institute for the Science of Human History in Jena, Germany.
In 2014, she and colleagues reported a finding that generated enough buzz to renew interest in an archaeological resource many had written off decades ago: fossilized dental plaque, or calculus. Ancient DNA and proteins in the plaque belong to microbes that could spill the secrets of the humans they once inhabited — what the people ate, what ailed them, perhaps even what they did for a living.

Bacteria form plaque that mineralizes into calculus throughout a person’s life. “It’s the only part of your body that fossilizes while you’re still alive,” notes Warinner. “It’s also the last thing to decay.”

Though plaque is prolific in the archaeological record, most researchers viewed calculus as “the crap you scraped off your tooth in order to study it,” says Amanda Henry, an archaeologist at Leiden University in the Netherlands. With some exceptions, molecular biologists saw calculus as a shoddy source of ancient DNA.

But a few researchers, including Henry, had been looking at calculus for remnants of foods as potential clues to ancient diets. Inspired by some of Henry’s images of starch grains preserved in calculus, Warinner wondered if the plaque might yield dead bacterial structures, perhaps even bacteria’s genetic blueprints.

Her timing couldn’t have been better. Warinner began her graduate studies at Harvard in 2004, just after the sequencing of the human genome was completed and by the time she left in 2010, efforts to survey the human microbiome were in full swing. As a postdoc at the University of Zurich, Warinner decided to attempt to extract DNA from the underappreciated dental grime preserved on the teeth of four medieval skeletons from Germany.
At first, the results were dismal. But she kept at it. “Tina has a very interested, curious and driven personality,” Henry notes. Warinner turned to a new instrument that could measure DNA concentrations in skimpy samples, a Qubit fluorometer. A surprising error message appeared: DNA too high. Dental calculus, it turned out, was chock-full of genetic material. “While people were struggling to pull out human DNA from the skeleton itself, there’s 100 to 1,000 times more DNA in the calculus,” Warinner says. “It was sitting there in almost every skeletal collection untouched, unanalyzed.”
To help her interpret the data, Warinner mustered an army of collaborators from fields ranging from immunology to metagenomics. She and her colleagues found a slew of proteins and DNA snippets from bacteria, viruses and fungi, including dozens of oral pathogens, as well as the full genetic blueprint of an ancient strain of Tannerella forsythia, which still infects people’s gums today. In 2014, Warinner’s team revealed a detailed map of a miniature microbial world on the decaying teeth of those German skeletons in Nature Genetics.

Later in 2014, her group found the first direct protein-based evidence of milk consumption in the plaque of Bronze Age skeletons from 3000 B.C. That same study linked milk proteins preserved in the calculus of other ancient human skeletons to specific animals — providing a peek into long-ago lifestyles.

“The fact that you can tell the difference between, say, goat milk and cow milk, that’s kind of mind-blowing,” says Laura Weyrich, a microbiologist at the University of Adelaide in Australia, who also studies calculus.
Since then, Warinner has found all sorts of odds and ends lurking on archaic chompers from poppy seeds to paint pigments. Warinner’s team is still looking at the origins of dairying and its microbial players, but she’s also branching out to the other end of the digestive spectrum. The researchers are looking at ancient DNA in paleofeces, which is exactly what it sounds like — desiccated or semifossilized poop. It doesn’t stay as fresh as plaque in the archaeological record. But she’s managed to find some sites with well-preserved samples. By examining the array of microbes that lived in the excrement and plaque of past humans and their relatives, Warinner hopes to characterize how our microbial communities have changed through time — and how they’ve changed us.

The research has implications for understanding chronic, complex human diseases over time. Warinner’s ancient DNA work “opens up a window on past health,” says Clark Larsen, an anthropologist at Ohio State University.

It’s all part of what Warinner calls “the archaeology of the unseen.”

Editor’s note: This story was corrected on October 4, 2017, to note that the 2014 report on milk consumption was based on protein evidence, not DNA.

A founding father of behavioral economics — a research school that has popularized the practice of “nudging” people into making decisions that authorities deem to be in their best interests — has won the 2017 Nobel Memorial Prize in Economic Sciences.

Richard Thaler, of the University of Chicago Booth School of Business, received the award October 9 for being the leader of a discipline that has championed the idea of humans not as purely rational and selfish — as long posited by economists. Instead, he argues, we are driven by simple, often emotionally fueled assumptions that can lead us astray.

“Richard Thaler has pioneered the analysis of ways in which human decisions systematically deviate from traditional economic models,” says cognitive scientist Peter Gӓrdenfors of Lund University, Sweden, a member of the Economic Sciences Prize Committee.

Thaler argues that, even if people try to make good economic choices, our thinking abilities are limited. In dealing with personal finances, for instance, he finds that most people mentally earmark money into different accounts, say for housing, food, vacations and entertainment. That can lead to questionable decisions, such as saving for a vacation in a low-interest savings account while buying household goods with a high-interest credit card.

At an October 9 news conference at the University of Chicago, Thaler referenced mental accounting in describing what he would do with the roughly $1.1 million award. “Every time I spend any money on something fun, I’ll say it came from the Nobel Prize.”

Thaler’s research has also focused on how judgments about fairness, such as sudden jumps in the prices of consumer items, affect people’s willingness to buy those items. A third area of his research finds that people’s short-term desires often override long-term plans. A classic example consists of putting off saving for retirement until later in life.

That research in particular inspired his 2008 book Nudge: Improving Decisions about Health, Wealth and Happiness, coauthored by Cass Sunstein, now at Harvard Law School. Nudging, also known as libertarian paternalism, is a way for public and private institutions to prod people to make certain decisions (SN: 3/18/17, p. 18). For instance, employees more often start saving for retirement early in their careers when offered savings plans that they must opt out of.
Many governments, including those of the United Kingdom and the United States, have funded teams of behavioral economists, called nudge units, to develop ways to nudge people to, say, apply for government benefits or comply with tax laws. A total of 75 nudge units now exist worldwide, Thaler said at the news conference.

Nudging has its roots in a line of research, dubbed heuristics and biases, launched in the 1970s by two psychologists — 2002 economics Nobel laureate Daniel Kahneman of Princeton University and the late Amos Tversky of Stanford University. Investigators in heuristics and biases contend that people can’t help but make many types of systematic thinking errors, such as being overconfident in their decisions.

Thaler, like Kahneman, views the mind as consisting of one system for making rapid, intuitive decisions that are often misleading and a second system for deliberating slowly and considering as much relevant information as possible.

Despite the influence of Thaler’s ideas on research and social policy, they are controversial among decision researchers (SN: 6/4/11, p. 26). Some argue that nudging overlooks the power of simple rules-of-thumb for making decisions that people can learn to wield on their own.

“I don’t think I’ve changed everybody’s minds,” Thaler said. “But many young economists embrace behavioral economics.”

In the United States, cartoon characters are a no-no in cigarette ads, and candy- or fruit-flavored cigarettes can’t be sold. But that’s not the case for e-cigarettes, and these youth-appealing tactics are luring teens who have never used tobacco products to give e-cigs and even cigarettes a try, a new study suggests.

Researchers analyzed surveys of nearly 7,000 kids ages 12 to 17 who had never used a tobacco product as of 2013 to 2014. Teens who recalled seeing or liking e-cigarette ads were 1.6 times as likely to be open to trying e-cigs or to actually try them the next year as kids who didn’t remember the ads, researchers report online March 26 in JAMA Pediatrics. E-cig ads often feature celebrities, cartoons (one product shows a unicorn vomiting a rainbow) or references to sweet flavors, such as Skittles.
Past research has shown a link between traditional cigarette advertisements and receptive nonsmoking adolescents going on to light up. Nearly nine out of 10 smokers tried their first cigarette by age 18. Gearing traditional cigarette ads toward teens has been restricted since 1998.

In 2016, more than 2.1 million U.S. middle and high school students reported using e-cigarettes. That same year, an estimated 20.5 million — or four in five — were exposed to e-cigarette ads.

But e-cigarette ads are doing more than hyping vaping, the study suggests. The ads also appeared to nudge some teens and young adults to take up cigarette smoking. Of a larger group of about 10,500 kids ages 12 to 21 who had never used tobacco products, 18 percent recalled seeing or liking e-cigarette ads but not cigarette ads. Five percent of those teens had started to smoke by the next year.

Extrapolating to the U.S. population, “105,000 12- to 21- year olds appear to have smoked their first cigarette because of the influence of e-cigarette advertising,” says John Pierce, a behavioral epidemiologist at the University of California, San Diego.
Previous research has found that teens who use e-cigarettes are more likely to smoke traditional cigarettes (SN: 9/19/15, p. 14). The fact that e-cigarette ads may up the risk of smoking “raises an unprecedented concern for adolescent tobacco control,” addiction psychologist Adam Leventhal and epidemiologist Jessica L. Barrington-Trimis, both of the University of Southern California’s Keck School of Medicine in Los Angeles, write in an accompanying editorial in the journal.

In an interview, Leventhal adds that restricting such advertising is an important target for public health campaigns and policies to limit youth use of tobacco products.

Birds can sense Earth’s magnetic field, and this uncanny ability may help them fly home from unfamiliar places or navigate migrations that span tens of thousands of kilometers.

For decades, researchers thought iron-rich cells in birds’ beaks acted as microscopic compasses (SN: 5/19/12, p. 8). But in recent years, scientists have found increasing evidence that certain proteins in birds’ eyes might be what allows them to see magnetic fields (SN: 10/28/09, p. 12).

Scientists have now pinpointed a possible protein behind this “sixth sense.” Two new studies — one examining zebra finches published March 28 in Journal of the Royal Society Interface, the other looking at European robins published January 22 in Current Biology — both single out Cry4, a light-sensitive protein found in the retina. If the researchers are correct, this would be the first time a specific molecule responsible for the detection of magnetic fields has been identified in animals.
“This is an exciting advance — we need more papers like these,” says Peter Hore, a chemist at the University of Oxford who has studied chemical reactions involved in bird navigation.

Cry4 is part of a class of proteins called cryptochromes, which are known to be involved in circadian rhythms, or biological sleep cycles (SN: 10/02/17, p. 6). But at least some of these proteins are also thought to react to Earth’s magnetic field thanks to the weirdness of quantum mechanics (SN: 7/23/16, p. 8). The protein’s quantum interactions could help birds sense this field, says Atticus Pinzon-Rodriguez, a biologist at the University of Lund in Sweden who was involved with the zebra finch study.

To figure out which of three cryptochromes is responsible for this quantum compass, Pinzon-Rodriguez and his colleagues examined the retinas, muscles and brains of 39 zebra finches for the presence of the three proteins Cry1, Cry2 and Cry4.
The team found that while levels of Cry1 and Cry2 followed a rhythmic pattern that rose and fell over the day, Cry4 levels remained constant, indicating the protein was being produced steadily.

“We assume that birds use magnetic compasses any time of day or night,” says Lund biologist Rachel Muheim, a coauthor on the zebra finch study.

European robins also showed constant levels of Cry4 during a 24-hour cycle, and higher levels during their migratory season. And the researchers in that study found Cry4 in an area of the robin’s retina that receives a lot of light — a position that would help it work as a compass, the study says.

“We have quite a lot of evidence, but [Cry4] is not proven,” says Henrik Mouritsen, an animal navigation expert at the Institute of Biology and Environmental Sciences in Oldenburg, Germany, who participated in the robin study. More definitive evidence might come from observing birds without a functioning Cry4 protein, to see if they still seem to have an internal compass.

Even then, Hore says, we still may not understand how birds actually perceive magnetic fields. To know, you’d have to be a bird.

There’s a fine line between immersive and unnerving when it comes to touch sensation in virtual reality.

More realistic tactile feedback in VR can ruin a user’s feeling of immersion, researchers report online April 18 in Science Robotics. The finding suggests that the “uncanny valley” — a term that describes how humanoid robots that look almost but not quite human are creepier than their more cartoonish counterparts — also applies to virtual touch (SN Online: 11/22/13).
Experiment participants wearing VR headsets and gripping a controller in each hand embodied a virtual avatar holding the two ends of a stick. At first, users felt no touch sensation. Then, the hand controllers gave equally strong vibrations every half-second. Finally, the vibrations were finely tuned to create the illusion that the virtual stick was being touched in different spots. For instance, stronger vibrations in the right controller gave the impression that the stick was nudged on that side.

Compared with scenarios in which users received either no touch or even buzzing sensations, participants reported feeling far less immersed in the virtual environment when they received the realistic, localized touch. This result demonstrates the existence of a tactile uncanny valley, says study coauthor Mar Gonzalez-Franco, a human-computer interaction researcher at Microsoft Research in Redmond, Washington.

But when users were shown a marble touching the virtual stick wherever they felt the localized touch, the participants found this realistic tactile feedback highly immersive rather than bothersome. The finding indicates that rich tactile feedback in VR may need to be paired with other sensory cues that explain the source of the sensation to avoid spooking users, Gonzalez-Franco says.

Better understanding how realistic touch sensations can break the VR illusion may help developers create more engaging virtual environments for games and virtual reality therapy, says Sean Follmer, a human-computer interaction researcher at Stanford University not involved in the study.