Tina Lasisi wants to untangle the evolution of human hair

Though humans’ nearly hairless bodies stick out like a cowlick among other primates, our nakedness isn’t unique in the world of mammals. Dolphins and whales are naked, says biological anthropologist Tina Lasisi of the University of Southern California in Los Angeles. There are naked mole-rats. “Elephants, depending on how you look at them, are kind of naked,” she says. “But we’re the only weirdos that are naked except for our head.”

Our species traded off much of our body hair for more sweat glands, an evolutionary adaptation that helps us regulate body heat more efficiently. But what about another uniquely human feature? We’re the only animals known to express tightly curled hair, like that seen in many people of African descent. Lasisi wants to know why and how it came to be.

For decades, traits that have been associated with racial categories, such as skin pigmentation and hair texture, have gone understudied or ignored among anthropologists, Lasisi says. Much of the study of human biological variation was deserted after the post–World War II backlash against eugenics, a racist field birthed from the idea that humankind could be improved if those deemed to have desirable traits were selectively allowed to reproduce. Since then, research on human variation has largely focused instead on traits that are not overtly racialized, such as lactose intolerance and adaptations to high altitudes.

But studying all forms of human variation is crucial to understanding our species’s evolution, Lasisi says. Studying variation in a way that normalizes rather than dampens or paints differences in a bad light is key not only to righting anthropology’s harmful legacy, but also ethical, socially responsible and sound science, she says.
Lasisi discovered biological anthropology as an undergraduate student at the University of Cambridge. As a Black person who spent many of her formative years among white people in the Netherlands, she was always aware of skin color. She vividly remembers learning that human skin pigmentation evolved as an adaptation to ultraviolet radiation — research pioneered by anthropologist Nina Jablonski of Penn State, who would later become Lasisi’s primary adviser. “It’s like a lightbulb went off in my head,” Lasisi says, and it made her wonder, “What else out there can be explained by evolution?”

Her interest in the origins of curly hair grew in part as an effort to understand her own locks. “Research is me-search,” Lasisi says. But when she first began, there wasn’t much science to comb through, and methodologies for measuring hair texture were either unreliable or inefficient.
Standout research
As part of her Ph.D. research, Lasisi worked with a team of anthropologists, thermal engineers and physiologists to study how curly hair might have given our bipedal ancestors a leg up in the hot and dry African savanna.

The team placed a variety of wigs made of human hair onto heat-sensing models and measured heat transfer in different environments. In dry settings, curly hair, especially tightly curled hair, protected the scalp from solar radiation while releasing more heat from the head than straight hair. Lasisi speculates that the larger amount of air space within curly hair is what does the trick.

To underpin her efforts and support future hair research, Lasisi developed an improved and standardized way of measuring hair curvature and cross-sectional shape. The technique involves segmenting, washing and taking pictures of hair strands and then running the images through an open-source computer program that she created.

Measuring these characteristics on a continuous spectrum (much like we do height, for instance), she argues, is a better way of studying hair texture than the long-standing practice of classifying hair into discrete categories, such as straight, wavy or curly. Such discrete categories are not standardized among experts and can become subjective, she says. They also obscure the immense variation that exists, even on a single person’s head, and especially among curly hair.
Lasisi is doing highly technical work that hasn’t been part of the conversation, says Robin Nelson, a biological anthropologist at Arizona State University in Tempe. “Before Tina, very few people were working on hair texture in the same way.”

Lasisi will bring this experience to the University of Michigan in Ann Arbor as an assistant professor in 2023, where she’ll continue her studies on human variation.

Reaching out
Lasisi wants everyone to be included in conversations about what makes humans human. She has appeared on the podcast Getting Curious with Jonathan Van Ness (of Queer Eye fame). She also hosts a PBS digital show on human evolutionary biology called Why Am I Like This?, which she helps conceptualize and write.

What’s more, Lasisi has cultivated a community of curious science seekers on Twitter, Instagram and TikTok. Through short-form videos marked by her signature wit and humor, such as her “Melanin March” series or “Darwin’s greatest hits against white supremacy,” Lasisi educates thousands of followers on human variation, how to talk about race and ethnicity from an anthropological perspective, and much more. She even gives prospective anthropologists career tips and behind-the-scenes glimpses of life in academia. Two-way discussions let her learn from her audience, which she calls her “little focus groups.”
Lasisi hopes her research and outreach will inspire and provide a helpful framework for more nuanced discussions about race, ethnicity, ancestry and human diversity — and that her visibility as a Black anthropologist will encourage other people of color to ask questions that are important to them. “I want to put enough information out there in the world, and [have] enough people out there in the world who have a grasp of that information,” she says, “so that we can see human variation for the beautiful, magnificent, complex thing that it is.”

The pandemic may be stunting young adults’ personality development

The psychological development of young adults may have taken a hit, thanks to the COVID-19 pandemic.

In typical times, people tend to become more conscientious and agreeable and less neurotic with age, a process known as psychological maturation. But in the United States, the pandemic seems to have reversed that personality trajectory, especially among adults under 30, researchers report September 28 in PLOS ONE. If those patterns persist, that could spell long-term trouble for this cohort, the researchers say.

“You get better as you go through life at being responsible, at coping with emotions and getting along with others,” says personality psychologist Rodica Damian of the University of Houston, who was not involved with this study. “The fact that in these young adults you see the opposite pattern does show stunted development.”
Personalities shape how people think, feel and behave. Researchers often assess a person’s personality profile along five core traits: neuroticism, conscientiousness, agreeableness, extraversion and openness to experience (SN: 9/1/21). Over time, these traits change slightly in individuals; neuroticism tends to decrease, for example, while agreeableness typically improves.

The pandemic, though, may be upending those typical trend lines. Even after factoring out expected changes, researchers in the new study observed about a decade’s worth of personality change, averaged across all study participants, in just three years — but going in the opposite of the expected direction. Young adults showed the greatest change in certain traits. Middle-aged adults — 30 to 64 years old — showed more change across all traits. The personalities of older adults, meanwhile, stayed largely unchanged.

Such age differences make intuitive sense to personality psychologist Wiebke Bleidorn of the University of Zurich. “The density of experiences in adolescence and young adulthood is so much higher” than in later life, says Bleidorn, who was not involved with the study. “If you miss out on your senior year of high school, you can’t get that back.”
To look at personality change in the United States before and during the pandemic, personality psychologist Angelina Sutin and colleagues analyzed data from the Understanding America Study.
This survey looks at how attitudes and behaviors in the country change in response to major events, such as the 2020 presidential election and the ongoing pandemic. Among those surveyed, roughly 7,000 people — ranging in age from 18 to 109 — took a personality inventory at least once in the six years prior to the pandemic and once during the pandemic.

Based on those responses, neuroticism overall in the United States dropped slightly in 2020, during the first year of the pandemic. That finding mirrors what the researchers found with a different dataset two years ago, when they reported that neuroticism declined in adults during the first six weeks of the pandemic. But the new findings include data from 2021 and 2022, which show that the dip was fleeting.

That initial dip was probably due to the sense of solidarity that emerged in the health crisis’s earlier months, along with people attributing their worries to the crisis rather than their own internal state, says Sutin, of Florida State University in Tallahassee. “In the second year, all that support fell apart.”
Average neuroticism scores have since rebounded to pre-pandemic levels. But the picture is nuanced, the researchers found. The 2020 dip was driven almost entirely by middle-aged participants and older adults. For those two groups, neuroticism scores continued to fall over the following years, albeit more slowly than before the pandemic. Neuroticism scores among young adults in 2021 and beyond, however, surpassed pre-pandemic levels.

Similarly, conscientiousness and agreeableness scores also declined among middle-aged adults in 2021 and early 2022, but the drop wasn’t nearly as steep as the one observed among young adults.

The findings are troubling, Sutin says. “We know these traits predict all sorts of long-term outcomes.”

For instance, high neuroticism links to mental health issues, such as anxiety, depression and feelings of loneliness. And low conscientiousness is linked to poor educational, work, health and relationship outcomes.

Still, whether these personality changes persist remains to be seen. It could be that young adults “missed the train” during a critical development period, Damian says. Maybe they would have gotten a college degree or pursued a more lucrative career without the pandemic. Or maybe these people can still reach their designated stop, just behind schedule.

“There are critical developmental periods and then there is plasticity,” Damian says. “We don’t know how it’s going to play out.”

Emily Jacobs wants to know how sex hormones sculpt the brain

When Emily Jacobs embarked on a career studying the brain in the early 2000s, a technique called functional magnetic resonance imaging, or fMRI, was having a moment. “Just like we have super powerful telescopes that can let us quantify the farthest reaches of the known universe, here we have this tool that could allow us to see the entire human brain and as a pulsing, living organ,” says Jacobs, a cognitive neuroscientist at the University of California, Santa Barbara.

By measuring changes in blood flow that serve as a proxy for brain activity, neuroscientists were getting new views of how different situations spur conversations between brain regions, and how the intensity of the conversations changes over time. “I was riding that wave of excitement,” Jacobs says.

But she soon realized there were big questions that weren’t being asked — questions important to half the world’s population. Do the natural hormonal changes that come with menstruation, pregnancy and menopause affect communication across the brain? What about hormonal contraceptives, such as the birth control pill, which are used by hundreds of millions of people globally? And what does it all mean for brain health and behavior?
Big goal
The rise and fall of hormones is a big reason women have historically been excluded from biomedical research, even though hormones in men fluctuate too. The resulting gap in knowledge of female biology has led to inadequate mental, physical and reproductive health care. “Science, and especially neuroscience, has not served the sexes equally,” Jacobs says.

With a range of tools — fMRI, other types of MRI and brain imaging, blood testing, neuropsychological testing, virtual reality and more — Jacobs’ lab is trying to fill in gaps in our basic understanding of how hormones act in the human brain. And she is studying the hormones as a lens for bigger questions about brain changes.

“What’s really special about Emily’s work is that she does it at so many different levels. It’s so multifaceted,” says cognitive neuroscientist Caterina Gratton of Northwestern University in Evanston, Ill. “She has multiple different types of brain measures, from the molecular all the way up to brain systems.”

Standout research
In a series of studies dubbed 28 and Me — for the 28 days of a typical menstrual cycle — Jacobs and colleagues closely monitored the brain of one woman for the duration of her natural menstrual cycle. Every 24 hours over 30 days, this 20-something woman’s brain was scanned, blood hormone levels checked and mood assessed.

As the woman’s estrogen levels peaked during ovulation, regions throughout the brain synced up. And regions in an important hub called the default mode network became tight conversationalists. What’s more, one part of this network rearranged itself to create a new and transient communication clique. After ovulation, when estrogen levels dropped and progesterone levels spiked, gray matter temporarily expanded in a brain structure tied to learning and memory.

When the same woman was examined a year later while on the pill, which quells progesterone, the changes weren’t observed.

The findings, described in 2021 in Current Opinion in Behavioral Sciences, provide strong evidence that the ebb and flow of sex hormones drives changes in the brain on a day-to-day basis, Jacobs and colleagues say. They also saw links between hormone fluctuations and brain changes in a male participant.
What’s next
The observations led cognitive neuroscientist Caitlin Taylor, a postdoc in Jacobs’ lab, to wonder how the brain responds to chronic hormone suppression from oral contraceptive use. The team is launching a large-scale study to attempt to find out.

Initially, Jacobs hesitated to green-light the research. She worried it could be twisted to erode access to contraception. Eventually, she relented, because women “deserve to have science that can serve us,” she says.

Another effort, which Jacobs and Taylor are building, will make data for such large-scale studies widely available. Called the University of California Women’s Brain Initiative, it aims to funnel records from the university system’s eight brain-imaging research centers into an open-access database. When a woman gets her brain scanned at one of the centers, her de-identified brain-imaging data, medical data and information about hormonal contraceptive use will be entered into the database. Once all eight centers are on board, there could be about 10,000 participants annually — way more than a single lab could recruit.

The expected mountain of data should be a boon to researchers asking big and small questions about brain health, Jacobs says. And she hopes it will improve women’s health care.

Christopher Barnes is on a quest for a universal coronavirus vaccine

In January 2020, Caltech biochemist Pamela Bjorkman asked for volunteers to help work out the structures of immune proteins that attack a newly discovered coronavirus. The pathogen had emerged in China and was causing severe pneumonia-like symptoms in the people it infected. Knowing the molecular arrangements of these antibodies would be an important step toward developing drugs to fight the virus.

Christopher Barnes, a postdoc working in Bjorkman’s lab on the structure of HIV and the antibodies that target it, jumped at the chance to solve a new puzzle. “I was like, ‘Oh, I’ll do it!’” Barnes says. At the time he wasn’t aware how urgent the research would become.

Now, we are all too familiar with SARS-CoV-2, which causes COVID-19 and has killed more than 6 million people globally. Studies of the structure of the virus and the antibodies that target it have helped scientists quickly develop vaccines and treatments that have saved tens of millions of lives. But the virus continues to adapt, making changes to the spike protein that it uses to break into cells. That has left researchers scrambling for new drugs and updated vaccines.

Using high-resolution imaging techniques, Barnes is probing coronavirus spike proteins and the antibodies that attack them. His goal: Find a persistent weak spot and exploit it to create a vaccine that works against all coronaviruses.

Standout research
Barnes’ team used cryo-electron microscopy to reveal the structures of eight antibodies that stop the original version of SARS-CoV-2. The technique catches cells, viruses and proteins going about their business by flash freezing them. In this case, the team isolated coronavirus particles entwined with immune system proteins from people with COVID-19.

The antibodies had attached to four spots on the spike protein’s receptor binding domain, or RBD, the team reported in Nature in 2020. This fingerlike region anchors the virus to the cell it will infect. When antibodies bind to the RBD, the virus can no longer connect to the cell.
Barnes’ team also created an antibody classification system based on the RBD location where the immune system proteins tend to latch on. “That’s been really helpful for understanding the types of antibody responses that are elicited by natural infection,” says structural biologist Jason McLellan, who wasn’t involved in the work, and for identifying prime candidates for drug development.

“A major strength of Chris is that he does not limit himself or his research to one technique,” says McLellan, of the University of Texas at Austin. “He quickly adapts and incorporates new technologies to answer important questions in the field.”

Since launching his own lab at Stanford, Barnes and colleagues have determined the structures of six antibodies that attack the original SARS-CoV-2 virus and delta and omicron variants. Those variants are skilled at evading antibodies, including lab-made ones given to patients to treat COVID-19.

The newly identified antibodies, described in the June 14 Immunity, target the spike protein’s N-terminal domain. The structures of the sites where the proteins attach are the same in delta and omicron, hinting that the sites might remain unchanged even in future variants, the team says. Eventually, scientists may be able to mass-produce antibodies that target these sites for use in new therapies.

What’s next
Barnes has now turned his attention to antibodies that can fend off all coronaviruses — from ones that cause the common cold to ones found in livestock and other animals that have the potential to spill over into people.

Barnes and immunologist Davide Robbiani of the University of Lugano in Switzerland identified classes of antibodies that target variants from all four coronavirus families, blocking the viruses’ ability to fuse with cells.

What’s more, the structure of one of the binding sites on the spike protein is the same across the coronavirus family tree, Barnes says. “This is something you wouldn’t want to mutate as you diversify your viral family because this is a critical component of how you enter the cell.”

Two independent teams have identified similarly broad action in the same antibody classes. Taken together, the findings suggest that a universal coronavirus vaccine is possible, Barnes says.

“We’ve all kind of discovered this at the same time,” he says. The teams are now thinking, “Wow, this exists. So let’s try to make a real, true pan-coronavirus vaccine.”

The pandemic shows us how crises derail young adults’ lives for decades

Ninna Ragasa was 24 years old when doctors discovered a mass on the left hemisphere of her brain. Further imaging revealed that Ragasa had an arteriovenous malformation, a tangle of blood vessels that disrupt the flow of oxygen to the brain.

Doctors suggested removing the mass to avoid the possibility of it rupturing, a potentially fatal outcome. Ragasa, a graduate student in interior design at the Pratt Institute in New York City, worried that the brain surgery would hurt her mobility and her career aspirations.

“Being a designer came easily to me,” says Ragasa, who is a friend of mine.

But the procedure went smoothly, and Ragasa returned to her life at Pratt. Then a year or so after the surgery, Ragasa started falling. At first, she blamed her hard-work, hard-party lifestyle and cut back on drinks. But she kept falling. So she switched from spike heels to chunky boots and then to flip flops. Nothing helped. One day Ragasa fell getting off the subway and had to crawl to her mother’s house.

Scans revealed that Ragasa’s brain had swelled after the procedure, causing her to gradually lose mobility along the right side of her body. Ragasa could no longer handle the physical demands of being an art student, such as building models and drawing. So she dropped out of school and found a job that came with medical insurance to pay for her physical therapy treatments. She felt, she says, totally lost.

Many of us get derailed at some point in our lives. We may get sick like Ragasa, divorced, laid off or lose a loved one. Our age when calamity strikes can profoundly influence our response to the event, research suggests, with young adults particularly vulnerable to getting thrown off course. That’s partially because when the rites of passage that mark the transition from childhood to adulthood are delayed or lost, young adults can feel unmoored and increasingly uncertain about the future — a point driven home by this cohort’s plummeting well-being during the ongoing pandemic.
Researchers have not always treated young adulthood as markedly different from other adult years. But it’s now well established that the human brain matures well into one’s 20s (SN: 5/22/19). And social and economic changes in recent generations mean that the once linear path from living in one’s parents’ home to moving out and starting one’s own family has elongated and become considerably more jagged. And for years, climate change has added mounting uncertainty to the already fraught mix (SN: 8/18/21). The pandemic, in other words, did not cause the mental health crisis among young adults, but merely accelerated existing trends.

Ages 18 to 25 constitute an intense time of exploration in love, work and worldview. This age band should be treated as a unique developmental period, distinct from either being a child or a full-fledged adult, psychologist Jeffrey Arnett of Clark University in Worcester, Ma., wrote in a seminal 2000 paper in American Psychologist. “Emerging adulthood is a time of life when many different directions remain possible, when little about the future has been decided for certain, when the scope of independent exploration of life’s possibilities is greater for most people than it will be at any other period of the life course.”

The pandemic has forced us to ask: What happens when that “scope of independent exploration of life’s possibilities” gets stalled or even curtailed?

The evidence so far suggests that the fallout for young adults could be dire. Instead of maturing, this group’s personalities have become more juvenile, I reported last month (SN: 9/28/22). In general, those under age 30 have become less conscientious, less agreeable and more neurotic. Compared with older adults, young adults have also reported higher levels of anxiety, depression and feelings of loneliness during the pandemic.
A survey of roughly 2,600 U.S. adults taken in January 2022, showed that members of this group have distorted the U-curve. This somewhat controversial theory holds that well-being, including happiness and health, are high in early and later life but low in middle age. In this view, despair, once reserved for middle age, has, it seems, become the badge of youth.

“The left part of the ‘U’ has essentially completely flattened,” wrote study coauthor and Harvard University epidemiologist Tyler VanderWeele in Psychology Today. “Young people … report being less happy and less healthy; having less meaning, greater struggles with character, and poor relationships; and [being] less financially stable compared to their older counterparts.”

Decisions made during young adulthood can also have profound knock-on effects. Temporarily delaying going to college at the pandemic’s onset, for instance, could become a permanent decision, thereby radically shifting the trajectory of one’s life.

Some young adults will recover from this event without much trouble, but others may struggle, says personality psychologist Rodica Damian of the University of Houston. “Sometimes when something happens during a critical development period, there is a snowball effect.”

Damian’s comment reminded me of a conversation I had more than a year ago with developmental psychologist Anthony Burrow of Cornell University. Rather presciently, shortly before the pandemic hit, Burrow had begun characterizing a phenomenon he referred to as “derailment.” Derailment, Burrow told me, refers to people’s feeling that their life has been thrown off course. That feeling can lead people to lose their sense of identity, to struggle to answer the question: Who am I?

“Derailment is a subjective sense that who you were cannot be reconciled with who you are,” Burrow says. “That train was heading in one direction on those tracks, but can no longer advance on that track.”

One way to gauge derailment during the pandemic is to ask ourselves: “Am I still the same person as I was pre-pandemic?” Burrow says. “It’s a basic question with profound implications.”

People in the United States who feel derailed struggle with anxiety, depression and reduced feelings of well-being, Burrow and his team reported in 2020 in the Journal of Personality and Social Psychology. Moreover, those feelings of derailment are associated with depressive symptoms a year or more down the road.

But Burrow’s work also points to ways to get our metaphorical trains back on track. In that same study, he found that journaling — having people write a narrative that stitches together their past and present selves — can help them regain that sense of continuity and reestablish goals for the future.

Other research suggests that adopting a more flexible East Asian mindset could help people cope with a life that veers off course. Derailed Japanese individuals, that is, do not show the same drop in well-being observed as Westerners, researchers reported in 2021 in the Journal of Happiness Studies. The researchers suspect that the difference lies in thinking styles. While Westerners tend to believe life should follow a linear course, Japanese people tend to believe life is dialectic, or full of contradictions and in constant flux. Derailments, as such, are to be expected.

Ragasa, who moved to the United States from the Philippines as a child, understands that flux. But losing her identity in her 20s, at a time when she felt physically and emotionally invincible, left her reeling. She eventually moved to Vermont and had a son.

Still, she took years to accept that the old art track she was on was gone forever. “I had to mourn it and let it go,” she says. Now, she says, she has begun the arduous process of finding a new track. “I still feel lost,” she says. “I have to figure out who I am now.”

For the first time, astronomers saw dust in space being pushed by starlight

A pair of stars in our galaxy is revealing how light pushes around matter. It’s the first time anyone has directly seen how the pressure of light from stars changes the flow of dust in space.

Such radiation pressure influences how dust clears from the regions near young stars and guides the formation of gas clouds around dying stars (SN: 9/22/20). The dust pattern surrounding a stellar pair 5,600 light-years away in the Cygnus constellation is providing a rare laboratory to observe the effect in action, astronomer Yinuo Han and colleagues report in the Oct. 13 Nature.

Astronomers have long known that the dust emerging from the star WR 140 and its companion is formed by gas from these two stars colliding and condensing into soot. But images of the pair taken over the course of 16 years show that the dust is accelerating as it travels away from the stars.

Dust initially departs the stars at about 6.5 million kilometers per hour, the researchers report, and over the course of a year accelerates to nearly 10 million km/h. At that speed, the dust could make the trip from our sun to Earth in a mere 15 hours.

The revelation came from comparing the positions of concentric dust shells year to year and deducing a speed. The researchers’ calculations show that the force accelerating the dust is the pressure exerted by light radiated from the stars, says Han, of the University of Cambridge. “Radiation pressure [becomes apparent] only when we put all the images next to each other.”

Not only are those layers of dust feeling light’s push, they also extend out farther than any telescope could see — until this year. Images from the James Webb Space Telescope, or JWST, depict more of the dusty layers around WR 140 and its companion than ever seen before, Han and another team report October 12 in Nature Astronomy.

At first glance, the intricate patterns surrounding the stars resemble a gigantic spider web. But the researchers’ analysis reveals that they are actually enormous, expanding, cone-shaped dust shells. They’re nested inside each other, with a new one forming every eight years as the stars complete another journey around their orbits. In the new images, the shells look like sections of rings because we observe them from the side, Han says.
The patterns don’t completely surround the stars because the distance between the stars changes as they orbit one another. When the stars are far apart, the density of the colliding gas is too low to condense to dust — an effect the researchers expected.

What surprised them is that the gas doesn’t condense well when the stars are closest together either. That suggests there’s a “Goldilocks zone” for dust formation: Dust forms only when the separation between the stars is just right, creating a series of concentric dust shells rippling away from the duo.

“Their Goldilocks zone is a new idea,” says astrophysicist Andy Pollock of the University of Sheffield in England, who was not part of either study. “A similar sort of thing happens in my field of X-rays.”

In his work, Pollock has observed that WR 140 and its partner emit more X-rays as the stars approach each other, but then fewer as they get very close together, suggesting there’s a Goldilocks zone for X-rays coming from the stars as well. “It would be interesting to see if there’s any connection” between the two types of Goldilocks zones, he says. “All of this must somehow fit together.”

Ancient DNA unveils Siberian Neandertals’ small-scale social lives

DNA from a group of Neandertals who lived together and a couple of others who lived not far away has yielded the best genetic peek to date into the social worlds of these ancient hominids.

As early as around 59,000 years ago, Neandertal communities in a mountainous part of Central Asia consisted of small groups of close relatives and adult female newcomers, researchers report October 19 in Nature.

That social scenario comes courtesy of DNA extracted from the teeth and bones of 13 Neandertals found at two caves in the foothills of southern Siberia’s Altai Mountains. Estimates of overall genetic similarity among these Stone Age folks indicate that they formed communities of about 20 individuals, with females often migrating from their home groups to those of their mates, say evolutionary geneticist Laurits Skov of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues.

It’s unknown whether Altai Neandertals’ small-scale lifestyle was unusual, perhaps due to living in a sparsely populated area, or mirrored Neandertal practices elsewhere in Asia and Europe. Large numbers of Neandertals in Central Europe transformed a forest into grassland around 125,000 years, suggesting they could scale up communities when needed (SN: 12/15/21).

Skov’s group studied the DNA of 11 Neandertals from Chagyrskaya Cave and two Neandertals from Okladnikov Cave (SN: 1/27/20). The Chagyrskaya individuals included a father and his teenage daughter as well as an adult female and an 8- to 12-year-old boy, who was possibly her nephew or grandson.

In the Chagyrskaya group, mitochondrial DNA, typically inherited from the mother, displayed greater diversity than DNA from the Y chromosome, which is inherited only by males. The enhanced mitochondrial DNA variety suggests that adult females frequently moved into that community while the males stayed put, the researchers suspect.

Mixing gold ions into whiskey can reveal its flavor

A new kind of “gold standard” could soon permeate the whiskey industry.

Whiskey distillers typically age spirits in charred, wooden casks for years, allowing the liquor to gradually absorb flavorful chemicals released from the wood (SN: 10/31/19). Now, researchers have demonstrated that swirling gold ions into a whiskey can reveal how much flavor the liquor has taken in — a quality called agedness. The method could provide master blenders with a quick and inexpensive test for whiskey agedness, researchers report October 6 in ACS Applied Nano Materials.
“A tiny amount of gold gives you this really bright, strong, red or blue or purple color,” says William Peveler, a chemist at the University of Glasgow in Scotland. The stronger the color, and the quicker that color arises, the more aged the whiskey, he says.

Master blenders sometimes conduct tasting sessions to gauge agedness, but this process can be labor intensive. Alternatively, laboratory assays can measure agedness by checking whiskeys for flavorful chemicals called congeners, absorbed from wood casks, but such analyses can be expensive.

Past research has shown that various chemicals, from neurotransmitters to poor-tasting compounds in maple syrup, could trigger gold ions in a solution to coalesce into ultra-tiny gold nuggets, or nanoparticles. So Peveler and colleagues mixed solutions containing less than a penny’s worth of gold ions into different whiskey blends and a vodka. While no nanoparticles formed in the vodka, the ions reacted with whiskey congeners to form nanoparticles in minutes. The size and shape of the nanoparticles varied between whiskeys, causing the spirits to flourish with different colors.

The researchers plan to further investigate how gold nanoparticles grow alongside alcohols and sugars in whiskeys to develop an even more comprehensive test for agedness.

A new treatment for debilitating nightmares offers sweeter dreams

For people haunted by recurring nightmares, untroubled sleep would be a dream come true. Now in a small experiment, neuroscientists have demonstrated a technique that, for some, may chase the bad dreams away.

Enhancing the standard treatment for nightmare disorder with a memory-boosting technique cut down average weekly nightmares among a few dozen people from three to near zero, researchers report online October 27 in Current Biology.

“The fact that they could actually make a big difference in the frequency of those nightmares is huge,” says Gina Poe, a neuroscientist at UCLA who wasn’t involved in the study.
People with nightmare disorder fear the night not for the monsters under the bed, but the monsters in their dreams. Frequent, terrifying dreams disturb sleep and even affect well-being in waking life. The go-to nightmare disorder treatment is imagery rehearsal therapy, or IRT. In this treatment, patients reimagine nightmares with a positive spin, mentally rehearsing the new story line while awake. It reduces nightmares for most but fails for nearly a third of people.

To boost IRT’s power, neuroscientist Sophie Schwartz of the University of Geneva and her colleagues leveraged a learning technique called targeted memory reactivation, or TMR. In this technique, a person focuses on learning something while a sound plays, and that same cue plays again during sleep. Experiencing the cue during sleep, which is important for memory storage, may reactivate and strengthen the associated memory (SN: 10/3/19).

In the new study, the researchers gave 36 people with nightmare disorder training in IRT, randomly assigning half of them to rehearse their revised nightmares in silence. The other half rehearsed while a short piano chord, the TMR cue, played every 10 seconds for five minutes.

For two weeks, participants practiced IRT daily and kept a dream diary. While they slept, a headband outfitted with sensors recorded their brains’ electrical activity and tracked their sleep stages. The piano chord served as a dream soundtrack, with the headband sounding off every 10 seconds during rapid eye movement, the sleep stage associated with dreaming. The headband played the sound for all participants, but only half had come to associate the sound with their new scenario during the IRT training.

For those trained on the chord, TMR nearly vanquished the nightmares, bringing the weekly average down from three to 0.2, and even encouraged happier dreams. The group that received only IRT improved too, but still averaged one weekly nightmare.

The TMR-IRT combination also had more staying power after three months, with that group’s average rising only slightly from about 0.2 to 0.3 nightmares a week, while the IRT-only group’s jumped to 1.5.

Larger studies will need to test how generalizable this treatment combination is. This study featured a small number of people, all young adults ages 20 to 35 who had nightmare disorder and no other psychiatric conditions. The study also didn’t compare IRT and TMR to no treatment, although the researchers write that previous studies have already shown how effective IRT can be.

If a TMR-IRT combo proves as strong in future research, it still has a way to go before it’s widely accessible. Commercially available sleep trackers in watches and rings have yet to distinguish between sleep stages as accurately as brain-monitoring tools.

Even with these caveats, the results are encouraging, Poe says. She suggests that future studies could test whether the TMR-IRT combination can help people with post-traumatic stress disorder, or PTSD, where nightmares rehash traumatic events (SN 9/12/14).

That’s something Schwartz wants to try. “I’m not sure we’ll succeed with these particular patients,” she says. “But if we do, this would be a really important addition to the methods we have for treating PTSD.”

Meet the BOAT, the brightest gamma-ray burst of all time

The brightest gamma-ray burst ever recorded recently lit up a distant galaxy — and astronomers have nicknamed it the BOAT, for Brightest of All Time.

“We use the boat emoji a lot when we’re talking about it” on the messaging app Slack, says astronomer Jillian Rastinejad of Northwestern University in Evanston, Ill.

Gamma-ray bursts are energetic explosions that go off when a massive star dies and leaves behind a black hole or neutron star (SN: 11/20/19; SN: 8/2/21). The collapse sets off jets of gamma rays zipping away from the poles of the former star. If those jets happen to be pointed right at Earth, astronomers can see them as a gamma-ray burst.
This new burst, officially named GRB 221009A, was probably triggered by a supernova giving birth to a black hole in a galaxy about 2 billion light-years from Earth, researchers announced October 13. Astronomers think it released as much energy as roughly three suns converting all of their mass to pure energy.

NASA’s Neil Gehrels Swift Observatory, a gamma-ray telescope in space, automatically detected the blast October 9 around 10:15 a.m. EDT, and promptly alerted astronomers that something strange was happening.

“At the time, when it went off, it looked kind of weird to us,” says Penn State astrophysicist Jamie Kennea, who is the head of science operations for Swift. The blast’s position in the sky seemed to line up with the plane of the Milky Way. So at first Kennea and colleagues thought it was within our own galaxy, and so unlikely to be something as dramatically energetic as a gamma-ray burst. If a burst like this went off inside the Milky Way, it would be visible to the naked eye, which wasn’t the case.

But soon Kennea learned that NASA’s Fermi Gamma-ray Space Telescope had also seen the flash — and it was one of the brightest things the telescope had ever seen. A fresh look at the Swift data convinced Kennea and colleagues that the flash was the brightest gamma-ray burst seen in the 50 years of observing these rare explosions.

“It’s quite exceptional,” Kennea says. “It stands head and shoulders above the rest.”
After confirmation of the burst’s BOAT bonafides — a term coined by Rastinejad’s adviser, Northwestern astronomer Wen-fai Fong — other astronomers rushed to get a look. Within days, scientists around the world got a glimpse of the blast with telescopes in space and on the ground, in nearly every type of light. Even some radio telescopes typically used as lightning detectors saw a sudden disturbance associated with GRB 221009A, suggesting that the burst stripped electrons from atoms in Earth’s atmosphere.

In the hours and days after the initial explosion, the burst subsided and gave way to a still relatively bright afterglow. Eventually, astronomers expect to see it fade even more, replaced by glowing ripples of material in the supernova remnant.

The extreme brightness was probably at least partially due to GRB 221009A’s relative proximity, Kennea says. A couple billion light-years might seem far, but the average gamma-ray burst is more like 10 billion light-years away. It probably was also just intrinsically bright, though there hasn’t been time to figure out why.

Studying the blast as it changes is “probably going to challenge some of our assumptions of how gamma-ray bursts work,” Kennea says. “I think people who are gamma-ray burst theorists are going to be inundated with so much data that this is going to change theories that they thought were pretty solid.”

GRB 221009A will move behind the sun from Earth’s perspective starting in late November, shielding it temporarily from view. But because its glow is still so bright now, astronomers are hopeful that they’ll still be able to see it when it becomes visible again in February.

“I’m so excited for a few months from now when we have all the beautiful data,” Rastinejad says.