Humans

Morfydd Clark (Galadriel)Amazon Studios
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The Rings of Power takes us back to J. R. R. Tolkien’s Middle-earth, where Morfydd Clark (above) plays a younger (but still ancient) Galadriel in Amazon’s bid to tell Sauron’s origin story. On Prime Video from 2am BST on 2 September.
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Taxi from Another Planet records the unlikely conversations between astrobiologist Charles Cockell and taxi drivers about aliens and space exploration. So is Mars our plan B? Will we understand aliens? And what if we are alone? On sale from 30 August.

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Matthew Cobb’s latest book is a disturbing history of genetic engineering, which asks whether it is worth the money – or the risk

Humans

24 August 2022

By Michael Marshall
Gene editing, exemplified by CRISPR technology, has elicited both hopes and fearsELLA MARU STUDIO/SCIENCE PHOTO LIBRARY
The Genetic Age
Matthew Cobb
Profile Books
FOR more than 50 years, biologists have been genetically engineering organisms in increasingly precise ways. From the early, crude methods of the 1960s and 1970s, to the modern “gene editing” exemplified by CRISPR technology, genetic engineering has elicited great hopes and terrifying fears.
In his disturbing and readable new book The Genetic Age: Our perilous quest to edit life, biologist and science historian Matthew Cobb tells the story of this field. … More

The idea of plant consciousness may be wild, but finding objective ways to probe their inner lives could bring benefits to us all

Humans

| Leader

24 August 2022

HelloRF Zcool/Shutterstock
TAKE a look at that plant sitting on the windowsill or tree in the local park. What might it be feeling? Could it be thinking? Experiments are probing the idea of plant cognition, even going so far as to suggest they possess some form of consciousness.
As wild as it sounds, it isn’t a new idea. The field of “plant neurobiology” began in 2006, aimed at understanding how plants process information from their environment.
It is now clear that plants are capable of complex communication and can intricately sense their surroundings, ideas that were originally dismissed. But proponents of plant … More

An analysis of thigh and forearm bones from Sahelanthropus tchadensis suggests the early hominin was mainly bipedal, but the claim is controversial

Humans

24 August 2022

By Clare Wilson
3D models of the femur and ulnae of Sahelanthropus tchadensisFranck Guy / PALEVOPRIM / CNRS – University of Poitiers
The ancestors of humans may have been walking on two legs by about 7 million years ago – a million years earlier than had been thought. But the finding, which comes from analysing a damaged thigh bone and two forearm bones, is controversial.
Estimates vary for when the ancestors of humans and chimpanzees split from each other but broadly converge on about 6 million years ago. This is also the age of the earliest fossil of a bipedal hominid, called Orrorin tugenensis.
The thigh bone, or femur, analysed in the latest study was discovered in the Lake Chad Basin in Chad. It was among thousands of bone pieces initially uncovered in 2001, almost all of which weren’t from primates.Advertisement
The first hominin fossils identified among the bone pieces were fragments of skull and a few teeth. These were identified as a new and very early hominin species named Sahelanthropus tchadensis, dating from about 6 to 7 million years ago.
A later method of fossil dating, based on analysing different forms of the element beryllium, pushed the estimate further back to somewhere between 6.5 and 7.5 million years ago.
In 2004, a femur found among the bone pieces was identified as potentially belonging to a hominin by Aude Bergeret-Medina and Roberto Macchiarelli at the University of Poitiers in France. They later lost access to it, but in 2020 they published work based on measurements and photographs that argued that its shape suggests the owner didn’t walk on two legs.
Now, Franck Guy, who is also at the the University of Poitiers, and his colleagues, who still have access to the fossils, have published a full analysis of the femur as well as two forearm bones, including computed tomography scans to see their internal structure. It took so long partly because the team didn’t initially have the right expertise to analyse bones other than the skull, says Guy.
It is unknown if all the hominin bones came from the same individual or from several, but the researchers have assumed they belong to S. tchadensis as this was the only large primate with bones found at the site.
The researchers compared the S. tchadensis thigh and forearm bones with those from modern humans as well as chimpanzees, gorillas, orangutans and some extinct hominins and great apes. They conclude that S. tchadensis spent some time clambering in trees but usually walked on two legs, based on several features of the femur that they say are closer to those of modern humans than great apes that usually walk on four limbs. These include the distribution of thicker sections of the dense outer layer of bone, called the cortex, and the presence of a rough surface at the top of the femur where the buttock muscles attach.
“When on the ground they would have preferred to move bipedally. [When in trees] they would sometimes choose to use clambering. All the features point to this kind of behaviour,” says Guy.

But Macchiarelli isn’t convinced. This is partly because the small angle the femur makes with the pelvis is more similar to that seen in quadrupedal apes, he says. “It’s mechanistically unstable to walk on two legs with a small angle.”
Other primates that mainly walk on four legs occasionally stand up and walk on two, which could be why S. tchadensis has some features of bipedalism, says Macchiarelli. “There’s a bipedal signal in any primate,” he says.
Fred Spoor at the Natural History Museum in London says the authors “make a good case” for bipedalism, but that the debate is likely to continue. “Unless you have a time machine, you can’t go back and see for yourself,” he says.
The question is an important one because more recent hominins such as the australopiths both walked on two legs and climbed in trees as recently as 3 to 4 million years ago, he says. “That would mean that for the first 3 million years [of our history] there was this mixed locomotion, and not much was happening.”
Kelsey Pugh at the American Museum of Natural History in New York says it would be useful to compare the S. tchadensis femur with a wider range of living and extinct primates. “It will be vital for independent teams of palaeoanthropologists to study these exciting fossils in the coming months,” she says.
Journal reference: Nature, DOI: 10.1038/s41586-022-04901-z
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Researchers used a plastic dome placed over people’s heads to measure how much energy they expended chewing gum versus sitting idly. They found chewing gum uses a significant amount of energy

Humans

17 August 2022

By Jason Arunn Murugesu
Chewing gum can significantly increase the body’s energy useKondoros Eva Katalin/Getty Images
Chewing uses a surprising amount of energy. An experiment that looked at the energy use associated with chewing gum found that it can increase bodily energy expenditure by up to 15 per cent.
Adam van Casteren at the University of Manchester in the UK and his colleagues measured energy use in 21 people between 18 and 45 years old as they chewed gum for 15 minutes.
The gum was tasteless, calorie-free and odourless. “This way it doesn’t activate the digestive system to the same extent as it otherwise would,” says van Casteren. “We wanted to measure just chewing or as close to chewing as we could get.”Advertisement
Each participant was asked to chew two types of gum – one soft and the other stiff – so they could compare the effects of the gum’s properties on the participants’ energy expenditures.
Energy expenditure was measured using a plastic dome covering the participants’ heads. A monitor inside the dome measured oxygen intake and the amount of carbon dioxide released. “You can use this information to work out how much energy is being expended,” says van Casteren.
Before the experiment, the participants had all worn the plastic dome while they sat watching a film in order for the researchers to capture their base level energy expenditures.
The researchers found that chewing the soft gum elevated energy expenditure by about 10 per cent, while chewing the stiffer gum increased this expenditure by around 15 per cent. Van Casteren says it’s interesting that a small change in the properties of the gum had such a notable effect on energy expenditure.
He says he expects the energy used to chew real food will be even larger as many foods such as steak and nuts require a lot of effort to break down. “I want to look at how much energy chewing nuts and seeds expends next,” he says.
The findings suggest that the energy expenditure required to chew may also explain why we developed such strong teeth and jaws for the action. Any amount of energy lost while chewing food, makes the meal a less efficient source of energy.
Dylan Thompson at the University of Bath in the UK says the increase is still only a small amount overall. “It will contribute less than 1 per cent of total daily energy expenditure because of relatively short daily chewing times,” he says.
Thompson says the results are similar to a study he conducted in 2019 which found that standing for 20 minutes increased energy expenditure by about 12 per cent.
Journal reference: Science Advances, DOI: 10.1126/sciadv.abn8351

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Feedback explores a shocking Mayan game in Mexico, while discovering the true nature of Amazon and trying to avoid autonomous cars

Humans

17 August 2022

Josie Ford
Bounced out of office
A month after Wimbledon, Feedback’s summer of sport travels to Central America and a claim that one ancient Mayan ball game required some extremely specialist equipment. As if the capital “I”-shaped court used to play this form of pelota weren’t fiendish enough, the ashes of dead rulers were used to make the game’s rubber balls.
At least, that is the suggestion made by Juan Yadeun Angulo, an archaeologist at Mexico’s National Institute of Anthropology and History. An article in Science Alert concludes that Angulo’s physical evidence, from a 1300-year-old crypt in Toniná, Mexico, beneath a … More

Rather than helping, lessons may be encouraging pupils to dwell on negative feelings without the necessary support to address them

Humans

| Comment

17 August 2022

By Lucy Foulkes
Michelle D’urbano
TEENAGERS are experiencing a mental health crisis. I am not just talking about the increase in mental health problems that have been reported in them over the past decade or so. I am talking about what UK schools are being asked to do in response.
Many secondary schools in the UK – which educate those aged 11 up to 18 – now teach mental health skills, such as mindfulness or techniques from cognitive behaviour therapy (CBT). In a “universal” approach, these lessons are taught to all students, regardless of their level of need. The idea is to give all teenagers … More

Campsite coding Deerpunk costumes, tacos delivered by drones and a game called “Beerocracy” featured at this year’s ToorCamp for hackers – it was a blast, writes Annalee Newitz

Humans

| Columnist

17 August 2022

By Annalee Newitz
Annalee Newitz
LIGHTS in every colour of the rainbow illuminated the forest. People wearing antlers on their heads wandered through a barrage of soap bubbles that released puffs of dry ice smoke as they popped. In the distance, I could hear the sound of music and video game bleeps. No, it wasn’t a rave, nor had I gone back in time to some kind of Druid ritual. I was on a tiny island off the coast of Washington in the US Pacific north-west, attending a five-day festival for hackers called ToorCamp.
According to security researcher David Hulton, one of the camp’s … More