Humans first arrived in South America through a series of extraordinary migrations – and genetic studies now reveal more about how they settled and then split into four distinct groups on the continent
Briefing
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Meta's AI memorised books verbatim – that could cost it billions
Many AI models were trained on the text of books, but a new test found at least one model has directly memorised nearly the entirety of some books, including Harry Potter and the Philosopher’s Stone, which could complicate ongoing legal battles over copyright infringement
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Reduced investment in universities has multifaceted effects
Nature, Published online: 10 June 2025; doi:10.1038/d41586-025-01809-2
Reduced investment in universities has multifaceted effects
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When Letting Your Mind Wander Helps You Learn
Zoning out reveals hidden patterns in tasks
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Gorilla Gourmets Are Actually Truffle Hunting
Researchers followed gorillas for years to uncover truffle-hunting behavior—and it may be socially transmitted
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This mind-bending physics breakthrough could redefine timekeeping
By using a clever quantum approach that involves two “hands” on a clock one moving quickly and invisibly in the quantum world, the other more traditionally scientists have found a way to boost timekeeping precision dramatically. Even better, this trick doesn’t require a matching increase in energy use. The discovery not only challenges long-held beliefs about how clocks and physics work, but could also lead to powerful new tools in science, technology, and beyond.
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From the andes to the beginning of time: Telescopes detect 13-billion-year-old signal
Astronomers have pulled off an unprecedented feat: detecting ultra-faint light from the Big Bang using ground-based telescopes. This polarized light scattered by the universe’s very first stars over 13 billion years ago offers a new lens into the Cosmic Dawn. Overcoming extreme technical challenges, the CLASS team matched their data with satellite readings to isolate this ancient signal. These insights could reshape our understanding of the universe s early evolution, and what it reveals about mysterious components like dark matter and neutrinos.
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The Increase in Infant Milk Formulas and Why It Matters
The Increase in Infant Milk Formulas and Why It Matters
Breastfeeding can play an especially important role in early-life nutrition. It can benefit children’s future school performance and economic prospects in later life, as well as the mother’s health.
Health authorities across the world endorse the World Health Organization’s (WHO) recommendation that newborns should where possible exclusively breastfeed from the first hour of life until six months of age, and thereafter receive safe and nutritious foods with continued breastfeeding up to two years of age or beyond.
Despite this, our recent study shows that global commercial milk formula sales are booming. Between 2005 and 2019, world milk formula sales more than doubled from 3.5kg to 7.4kg per child. Total sales grew from 1 million tonnes to 2.1 million tonnes.
This growth in sales was seen in all types of formula, including “standard” formula for infants (0-6 months), “follow-up” formula (7-12 months), toddler milks (13-36 months), and so-called “specialised” formulas. So more children from a wider range of age groups are consuming formula.
Rapid growth has occurred in many highly-populated countries, including the Middle East, north Africa, eastern Europe, central Asia, and parts of Latin America. The most remarkable growth has been in east and south-east Asia. China, in particular, accounted for only 14% of global formula sales in 2005 – but now accounts for 33% of all sales.
In south Asia and west and central Africa, the amount sold to each customer remains low and show no signs of growth. In Europe and North America, although per customer sales volumes remain high, they plateaued or slightly decreased between 2005-2019.

Infant formula sales have doubled between 2005 and 2019. 279photo Studio/ Shutterstock
Behind the sales ‘boom’
There are medical reasons for using safe and adequate breastmilk substitutes. And some women find continuing breastfeeding difficult depending on their circumstances, and may use formula as an alternative or complement to breastfeeding. Our study also shows decisions and practices around formula use can be strongly shaped by wider societal forces, such as commercial marketing, rather than individual choice.
It’s known that milk formula sales increase as countries become richer and more urbanised, and as more mothers enter into formal employment. Asia’s formula sales boom may be partly explained by millions of women entering the paid workforce, especially in the region’s vast manufacturing zones.
Millions of women worldwide also lack adequate paid maternity leave and social protection. This means the decision to formula feed may only be done out of necessity, to avoid losing employment and income. We also know that many hospitals and healthcare settings aren’t equipped to help women establish breastfeeding, with few maternal and newborn care facilities worldwide meeting standards of care for breastfeeding mothers and newborns.
Commercial factors are also important. Just five companies control 57% of the global formula milk industry, worth US$56.6 billion (£42.5 billion) The industry spends an estimated US$5 billion on marketing every year, which powerfully shapes social norms about feeding babies and children.
Marketing messages can portray formula as modern, scientific and comparable or superior to breastmilk. The growth of social media enables companies to target mothers with personalised product offerings and ads.
Hospitals are a key marketing channel, too. Companies often engage health professionals to promote formula feeding. In many countries, health professionals are directly compensated to promote formula. But more commonly, companies influence health professionals indirectly by sponsoring their associations, conferences and education.

Companies cross-promote products by using the same packaging. ValeStock/ Shutterstock
Companies also cross-promote their entire product range of follow-up and toddler milks by using packing and labelling that resembles standard infant formula. This allows companies to get around the stricter prohibitions on infant formula marketing.
Marketing regulations are also important. The fact that formula sales are booming in China but have flat-lined at low levels in India partly reflects contrasting regulatory environments – with regulations on marketing being stricter and more comprehensive in India.
Despite an international code to stop aggressive and inappropriate marketing of breast-milk substitutes, most governments haven’t fully incorporated it into law. And even when laws exist, marketing violations by formula companies often go unpunished. The formula industry has also been able to lobby against any strengthening of regulation, partly by promoting their own – much weaker – corporate policies on marketing.
Health concerns
Breastmilk and breastfeeding where it is possible has numerous advantages over formula and bottle feeding – which is why the growth of formula sales is concerning.
Breastfeeding has been shown to reduce the likelihood of children developing infections, and reduces a child’s risk of developing chronic disease like obesity and diabetes later in life. Breastfeeding is also associated with lower risk of developing breast and cervical cancer, or diabetes among mothers.
Rising consumption of formula milk by toddlers and young children is also a worry, as these products are often ultra-processed, expensive, loaded with sugar and can introduce poor dietary habits. Their increased use could further contribute to increases of overweight and obese children globally.
Formula isn’t a sterile product and can be dangerous when prepared in unhygienic conditions, or when over-diluted or over-concentrated. It lacks the immune-boosting and other important elements of breastmilk, further increasing the risk of malnutrition and infectious illness. As a result, universal breastfeeding in place of formula use could prevent an estimated 823,000 child deaths every year (mainly in low- and middle-income countries), including 595,000 deaths from diarrhoea and pneumonia, and an estimated 20,000 maternal deaths from breast cancer (mainly in high income countries).
The global surge in formula sales is clearly a problem for global health. Given the power of the corporate milk formula industry to influence behaviour and understanding, more needs to be done to ensure that all mothers and children are protected from inappropriate promotion, and that they are enabled to breastfeed as long as they want to. This means strengthening laws that ban harmful marketing practices, expanding access to paid maternity leave, and ensuring that all healthcare facilities meet global standards.

David McCoy, Professor of Global Public Health, Queen Mary University of London; Julie P. Smith, Honorary Associate Professor, Australian National University, and Phillip Baker, Research Fellow, Institute for Physical Activity and Nutrition, Deakin University, Deakin University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Mon, 12/07/2020 – 18:21Categories -
Appreciating van Leeuwenhoek: The Cloth Merchant Who Discovered Microbes
Appreciating van Leeuwenhoek: The Cloth Merchant Who Discovered Microbes
Imagine trying to cope with a pandemic like COVID-19 in a world where microscopic life was unknown. Prior to the 17th century, people were limited by what they could see with their own two eyes. But then a Dutch cloth merchant changed everything.
His name was Antonie van Leeuwenhoek, and he lived from 1632 to 1723. Although untrained in science, Leeuwenhoek became the greatest lens-maker of his day, discovered microscopic life forms and is known today as the “father of microbiology.”
Visualizing ‘animalcules’ with a ‘small see-er’

Leeuwenhoek opened the door to a vast, previously unseen world. J. Verolje/Wellcome Collection, CC BY
Leeuwenhoek didn’t set out to identify microbes. Instead, he was trying to assess the quality of thread. He developed a method for making lenses by heating thin filaments of glass to make tiny spheres. His lenses were of such high quality he saw things no one else could.
This enabled him to train his microscope – literally, “small see-er” – on a new and largely unexpected realm: objects, including organisms, far too small to be seen by the naked eye. He was the first to visualize red blood cells, blood flow in capillaries and sperm.

Drawings from a Leeuwenhoek letter in 1683 illustrating human mouth bacteria. Huydang2910, CC BY-SA
Leeuwenhoek was also the first human being to see a bacterium – and the importance of this discovery for microbiology and medicine can hardly be overstated. Yet he was reluctant to publish his findings, due to his lack of formal education. Eventually, friends prevailed upon him to do so.
He wrote, “Whenever I found out anything remarkable, I thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.” He was guided by his curiosity and joy in discovery, asserting “I’ve taken no notice of those who have said why take so much trouble and what good is it?”
When he reported visualizing “animalcules” (tiny animals) swimming in a drop of pond water, members of the scientific community questioned his reliability. After his findings were corroborated by reliable religious and scientific authorities, they were published, and in 1680 he was invited to join the Royal Society in London, then the world’s premier scientific body.
Leeuwenhoek was not the world’s only microscopist. In England, his contemporary Robert Hooke coined the term “cell” to describe the basic unit of life and published his “Micrographia,” featuring incredibly detailed images of insects and the like, which became the first scientific best-seller. Hooke, however, did not identify bacteria.
Despite Leuwenhoek’s prowess as a lens-maker, even he could not see viruses. They are about 1/100th the size of bacteria, much too small to be visualized by light microscopes, which because of the physics of light can magnify only thousands of times. Viruses weren’t visualized until 1931 with the invention of electron microscopes, which could magnify by the millions.

An image of the hepatitis virus courtesy of the electron microscope. E.H. Cook, Jr./CDC via Associated Press
A vast, previously unseen world
Leeuwenhoek and his successors opened up, by far, the largest realm of life. For example, all the bacteria on Earth outweigh humans by more than 1,100 times and outnumber us by an unimaginable margin. There is fossil evidence that bacteria were among the first life forms on Earth, dating back over 3 billion years, and today it is thought the planet houses about 5 nonillion (1 followed by 30 zeroes) bacteria.
Some species of bacteria cause diseases, such as cholera, syphilis and strep throat; while others, known as extremophiles, can survive at temperatures beyond the boiling and freezing points of water, from the upper reaches of the atmosphere to the deepest points of the oceans. Also, the number of harmless bacterial cells on and in our bodies likely outnumber the human ones.
Viruses, which include the coronavirus SARS-CoV-2 that causes COVID-19, outnumber bacteria by a factor of 100, meaning there are more of them on Earth than stars in the universe. They, too, are found everywhere, from the upper atmosphere to the ocean depths.

A visualization of the human rhinovirus 14, one of many viruses that cause the common cold. Protein spikes are colored white for clarity. Thomas Splettstoesser, CC BY-SA
Strangely, viruses probably do not qualify as living organisms. They can replicate only by infecting other organisms’ cells, where they hijack cellular systems to make copies of themselves, sometimes causing the death of the infected cell.
It is important to remember that microbes such as bacteria and viruses do far more than cause disease, and many are vital to life. For example, bacteria synthesize vitamin B12, without which most living organisms would not be able to make DNA.
Likewise, viruses cause diseases such as the common cold, influenza and COVID-19, but they also play a vital role in transferring genes between species, which helps to increase genetic diversity and propel evolution. Today researchers use viruses to treat diseases such as cancer.
Scientists’ understanding of microbes has progressed a long way since Leeuwenhoek, including the development of antibiotics against bacteria and vaccines against viruses including SARS-CoV-2.
But it was Leeuwenhoek who first opened people’s eyes to life’s vast microscopic realm, a discovery that continues to transform the world.

By Richard Gunderman, Chancellor’s Professor of Medicine, Liberal Arts, and Philanthropy, Indiana University. This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Tue, 04/06/2021 – 10:49Categories -
Doomscrolling COVID-19 News Takes an Emotional Toll – Here is How to Prevent That
Doomscrolling COVID-19 News Takes an Emotional Toll – Here is How to Prevent That
Picture this: it’s April 2020, you’re between Zoom meetings, and scrolling through your social media newsfeed. Headlines like “Death toll continues to rise”, “COVID-19 may cause long-term health implications” and “Health-care systems overwhelmed” flash across your screen. Your mood takes a dive, but you can’t stop scrolling.
If this scenario rings true for you, you’re not alone. Research shows people have a tendency to seek out information during uncertain times – it’s a natural coping mechanism. But is persistent information-seeking on social media, sometimes called doomscrolling, helpful during a pandemic, or any time?
Research on the effects of bad news on mood more generally suggest exposure to negative COVID news is likely to be detrimental to our emotional wellbeing. And indeed, early evidence on the effects of COVID news consumption on mental distress reflected this. For instance, one study conducted in March 2020 involving more than 6,000 Americans found that the more time participants spent consuming COVID news in a day, the unhappier they felt.
These findings are striking but leave a few key questions unanswered. Does doomscrolling make people unhappy, or are unhappy people just more likely to doomscroll? How much time spent doomscrolling is a problem? And what would happen if, instead of doomscrolling, we were “kindness scrolling” – reading about humanity’s positive responses to a global crisis?
To find out, we conducted a study where we showed hundreds of people real-world content on either Twitter or YouTube for two to four minutes. The Twitter feeds and YouTube videos featured either general news about COVID, or news about kindness during COVID. We then measured these participants’ moods using a questionnaire, and compared their moods with participants who did not engage with any content at all.
People who were shown general COVID-related news experienced lower moods than people who were shown nothing at all. Meanwhile, people who were shown COVID news stories involving acts of kindness didn’t experience the same decline in mood, but also didn’t gain the boost in mood we’d predicted.
These findings suggest that spending as little as two to four minutes consuming negative news about COVID-19 can have a detrimental impact on our mood.
Although we didn’t see an improvement in mood among participants who were shown positive news stories involving acts of kindness, this may be because the stories were still related to COVID. In other research, positive news stories have been associated with improvements in mood.
Making your social media a more positive place
Our research was published earlier this month. Ironically, news coverage of our findings, with headlines such as “Just five minutes spent on social media is enough to make you miserable, study finds”, could be part of a person’s doomscrolling content.
But we didn’t find that all social media use makes people miserable. Rather, we found that consuming negative content about COVID via Twitter or YouTube in the midst of a pandemic does.
So what can we do to look after ourselves, and make our time on social media more pleasurable?

We found that just a few minutes consuming negative news about COVID-19 can have a detrimental impact on our mood. Nuchylee/Shutterstock
One option is to delete our social media accounts altogether. Figures show almost half of Facebook users in the UK and the US considered leaving the platform in 2020.
But how realistic is it to distance ourselves from platforms that connect nearly half of the world’s population, particularly when these platforms offer social interactions at a time when face-to-face interactions can be risky, or impossible?
Given that avoidance might not be practical, here are some other ways to make your experience on social media more positive.
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Be mindful of what you consume on social media. If you log on to connect with other people, focus on the personal news and photos shared instead of the latest headlines.
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Seek out content that makes you happy to balance out your newsfeed. This may be images of cute kittens, beautiful landscapes, drool-worthy food videos or something else. You could even follow a social media account dedicated to sharing only happy and positive news.
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Use social media to promote positivity and kindness. Sharing good things that are happening in your life can improve your mood, and your positive mood can spread to others. You may also like to compliment others on social media. While this might sound awkward, people will appreciate it more than you think.
Importantly, we’re not suggesting that you avoid all news and negative content. We need to know what’s happening in the world. However, we should also be mindful of our mental health.
As the pandemic continues to alter our lives and newsfeeds, our findings highlight the importance of being aware of the emotional toll negative news takes on us. But there are steps we can take to mitigate this toll and make our social media a happier place.
By Kathryn Buchanan, Lecturer, Psychology Department, University of Essex; Gillian Sandstrom, Senior Lecturer, Department of Psychology, University of Essex; Lara Aknin, Distinguished Associate Professor of Psychology, Simon Fraser University, and Shaaba Lotun, PhD candidate, Department of Psychology, University of Essex. This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Fri, 10/22/2021 – 18:03Categories -