Steven D. Allison
Harvard University Press Out 3 November (US) and 27 November (UK)

It’s 2030. Heatwaves are scorching parts of the globe, while elsewhere, hailstorms or tsunamis ravage homes, cities and farmlands. Wildfires rage across continents, Arctic ice sheets dwindle, volcanoes spew left and right, and Earth cracks open along multiple fault lines. Death tolls – human, animal and plant – soar.

Amid this doom and gloom, a superhero arises from scientific labs, ready to fight our – human-made – enemy, climate change. The tiny figure can trap excess carbon from the atmosphere, or bury it underground or at the bottom of the sea, for near-eternity. It can fuel jet engines with clean energy, replace chemical fertilisers, save coral reefs from bleaching and disease, and re-engineer trees, food crops and other plants to survive, even thrive, in droughts.

This scenario is at the heart of Steven Allison’s book, . Allison, professor of ecology at the University of California, Irvine, maintains a balance between realism and optimism as he introduces his as yet unsung hero, the microbe.

These resilient, highly adaptable and primarily single-celled organisms could, he insists, play a far larger role in controlling or maybe even reversing climate change than we imagine. Many of these bacteria, archaea, fungi and viruses are currently dismissed as insignificant or even targeted as pathogens to be wiped out. But the microbes he and others envision using against climate change are non-toxic and non-pathogenic.

The tiny superhero can trap excess carbon from the atmosphere or bury it underground for near-eternity

They are also, unlike other proposals – installing solar mirrors in space or sucking carbon dioxide out of the air – cheap, abundant, easy to produce and totally organic. For Allison, they “offer a rare glimmer of hope”.

His book explores how microbes live and interact with each other, and with “newcomers” such as humans. He focuses especially on how scientists are uncovering the mysteries of microbes and glimpsing the extraordinary properties they could offer if we only understood enough to stop fighting them.

Allison is a captivating storyteller, taking us on colourful journeys to different regions and times. Along the way, we meet fascinating characters, like Antonie van Leeuwenhoek, who ran his own draper’s shop in the Dutch city of Delft during the 17th century, and discovered bacteria by looking at his dental plaque using microscopes and lenses he had custom-built.

Microbes also appear as characters in their own right. We encounter bacteria-eating viruses engaged in an “insidious lifestyle” known as lysogeny inside their hosts, and zooplankton, which, like cattle, graze – and “poop a lot”.

He ensures we stay focused as we navigate complex concepts and vocabulary, like “phycoerythrins”, light-harvesting and naturally fluorescent proteins in certain cyanobacteria. We also get better acquainted with biofilms – layers of slime made of carbohydrates, proteins and other sticky biomolecules. Unlike the ones we know and hate – dental plaque and toilet bowl rings – these biofilms stop important microbes from being swept away in moving water by holding on to water like a sponge. Those microbes are also protected from desiccation, while predators, such as animals or viruses in soil, find it hard to get at prey inside a biofilm. Inside, microbes can gain the carbon and nutrients they need to grow.

In passing, Allison provides us with what can seem like cool facts to use at dinner parties. But they are offered in service of the big picture. Did you know that Sequoia trees can live a thousand years or that their bark is fire-resistant? That the annual per capita energy usage in the US is 76,300 kilowatt-hours, equivalent to the energy in 2300 gallons of petrol? Or that there are nearly 3 billion billion billion oxygen-producing Prochlorococcus cyanobacteria floating around the ocean, thousands more than the stars in the known universe?

One way or another, the core message of The Age of Microbes is delivered: we can get microbes right or we can get them wrong. They are incredibly good at taking carbon in – and at letting it out again. The trick is to get them to swallow carbon and harbour it for thousands of years. That is exactly what they already do when their remains are preserved in the ground or at the bottom of the ocean as “microbial mummies”, forming clumps called necromass.

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Enter the other superheroes in Allison’s book: the researchers and bioengineers studying microbes. There is a refreshing amount of overdue credit given to women scientists. What we now call the greenhouse effect was discovered by Eunice Newton Foote, who published a paper on it in 1856. A century or so later, biologist Mary Mandels pioneered cellulosic ethanol using fungal enzymes. If we ever fly on jets powered by carbon-neutral fuel, Allison says, “you’ll have microbes and Mary Mandels to thank”. He also pays due debt to the Earth wisdom of Indigenous peoples, including the Pacific Northwest Karuk, who understand the importance of mushroom networks.

Today’s labs are investigating the genes behind necromass, hoping to selectively breed for them or to produce “designer microbes”. Others study how to help plants resist climate change. Still others are slogging through complex risk-benefit analyses of commercial products touting microbial benefits. And there is key work on improving soil, depleted or destroyed by millennia of agriculture, using microbial “inoculants”.

We also have some “long-shot” solutions for climate adaptation, especially when it comes to protecting coral reefs, Allison tells me later in an email. There are scary forecasts about losing most of the world’s coral reefs by the end of this century, so “probiotic” microbes that boost heat tolerance and reduce bleaching could save reefs that millions depend on.

Overall, The Age of Microbes is a must-read as climate change bites deeper. Let’s hope that microbes do indeed prove to be an excellent addition to our armoury.

Three more great reads about biology’s frontiers

by Rob Dunn

Rob Dunn explores the biology of homes, from moths in cupboards to thousands of species of insects, bacteria, fungi and plants under our noses. Kill them in the name of “cleanliness” at our peril.

by Michael Grunwald

We might be making things worse by following bad science (and politics) in the fight to feed (maybe) 10 billion people by 2050. Michael Grunwald offers an intriguing narrative.

by Karen G. Lloyd

For more great storytelling, check out microbial biogeochemist Karen Lloyd’s journey to Earth’s deep biosphere. Its “alien” life forms could make us rethink how life is supposed to work.

Christa Lesté-Lasserre is a science journalist specialising in animal health and behaviour

When you make a purchase via the links on this page, we receive a commission.

The world’s largest sand sea, the Empty Quarter in the Arabian peninsula, was once dotted with freshwater lakes and lush oases – but prehistoric humans appear to have avoided settling around them.

Today, scientists have found out why: the early inhabitants chose to live near useful deposits of rock instead. After gathering data during a 1500-kilometre expedition across the vast desert and using computer modelling to understand the evidence, researchers have concluded that even plentiful fresh water wasn’t enough to attract early humans if they couldn’t also find exposed formations of suitable tool-making stone like flint and quartz.

“People who live by stone tools never stray far from good stone,” says at the University of Algarve in Portugal, who was involved in the analysis. “You just really don’t see Stone Age sites unless you’re within a few kilometres of an outcrop.”

The Sahara is the world’s largest hot desert, with landscapes ranging from rocky highlands to vast gravel plains. But the Rub’ al-Khali – the Arabic name for the Empty Quarter – is the world’s largest continuous expanse of wind-swept dunes, known as a sand sea. It covers 650,000 square kilometres of the southern Arabian peninsula.

Today, the region is overwhelmingly dry, other than for a few permanent lakes in its interior that are fed by groundwater. But over the past century, scientists have uncovered evidence of numerous ancient lakes that formed during wetter periods, when stronger Indian Ocean monsoons helped .

Researchers have long suspected that these greener periods opened routes for early humans spreading out of Africa and across the Arabian peninsula – an idea supported by the . However, all these sites line the desert’s margins, whereas its vast interior is still largely unexplored by researchers.

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In 2023, Rose’s colleague at the University of Vienna and his team spent 35 days crossing the Empty Quarter’s dunes, examining 125 locations for traces of ancient lakes. They focused on lakes that were present between about 122,000 and 67,000 years ago, when early humans were spreading into Arabia.

The team found evidence of ancient lakes at 55 of the locations. This evidence included freshwater snail and clam shells, ostrich eggshell fragments and traces of animals that once burrowed into the muddy lake beds. But despite these signs of a once-thriving environment, they found no stone tools or other evidence that prehistoric humans had settled by any of the 55 lakes.

“If we could spot a snail shell the size of a fingernail, we would have spotted a stone tool,” says Dellmour. “But there were none.”

To test whether the shortage of suitable stone could explain the lack of human settlements, Rose and Dellmour and their colleagues turned to computer modelling. They mapped ancient water sources and the geology of the Arabian peninsula, then compared the results with the distribution of hundreds of archaeological sites found across the region in earlier research.

The analyses revealed that 57 per cent of the peninsula’s terrain within reach of water lacked suitable stone for making tools – and that prehistoric human settlements were concentrated in places offering both resources.

That could be partly due to ancient tool-making being extremely “wasteful”, requiring abundant access to raw material, says Rose. “They weren’t thinking about efficiency,” he says. “So, you’d have a pile of garbage produced for one spear point.”

Neanderthal Europe was as much a wooden age as a stone age

When Neanderthals dominated Europe, it was likely that wood was at least as important to them as stone for working into tools

Groundwater-fed lakes in the Empty Quarter wouldn’t have brought flint, chert, obsidian or quartz into the sand sea like rivers could have, says Rose. And while people could have carried tools into resource-poor areas, this would probably have supported only small groups for short periods.

The findings show that geology was potentially just as important as climate in shaping prehistoric human migrations, says Rose.

The study sheds important light on a long-standing debate among archaeologists about the importance of raw stone in ancient human sites, especially in harsh environments like the desert, says at the University of Tübingen in Germany. “Probably what’s most surprising to me is the lack of archaeological stone tools in otherwise perfectly fine circumstances, and close access to fresh water,” he says. “It really shows that early humans were picky with where they went and that they did not settle for just any spot.”

Wind turbines have killed nearly 19 million bats in the US over the past four decades, according to the most comprehensive analysis of its kind to date. The problem seems to have worsened in recent years, with more than 1.5 million deaths now occurring annually.

But there may be ways to make this green energy source safer for wildlife without overly affecting energy production. This data can help “advance research to really support effective conservation measures and science-driven decision-making in the future”, says at Fort Collins Science Center in Colorado.

Bats play a vital role in ecosystems, particularly by controlling insects like mosquitoes and moths that produce crop-killing caterpillars. But many species face growing threats from habitat loss, disease and human activities, with some now classified as threatened or endangered.

These human-activity threats include use and the building of . Researchers have also previously found during required monitoring to comply with wildlife protection regulations. But not all wind farms share their results, and monitoring methods vary from site to site, says team member , also at Fort Collins Science Center.

“We know bats are being impacted, but could we change the engineering or sites of a turbine to minimise those impacts?” she asks. “There’s been an increasing interest in this, but we just haven’t had the appropriate data yet.”

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Now, Straw, Labuzzetta and their colleagues have analysed 499 reports from wind farms across the 48 adjoining US states to estimate how many bats were killed by turbines from 1981 to 2024, focusing on 10 species. They used a statistical model that considered differences in how wind farms searched for dead bats, the size and design of their turbines, and the surrounding environment.

Their results suggest that wind turbines killed an estimated 18.7 million bats between 1981 and 2024. Annual deaths seem to have exceeded 1.5 million from 2021 onwards, which may be the result of more wind turbines being installed.

Hoary bats (Lasiurus cinereus) had the greatest losses, with an estimated 6.7 million deaths, followed by 5.8 million deaths among eastern red bats (Lasiurus borealis), 3.4 million among silver-haired bats (Lasionycteris noctivagans) and 1.5 million among big brown bats (Eptesicus fuscus).

Wind farms near rivers and turbines with longer blades were linked to more deaths among certain species, while having more space between the blades and the ground may reduce the risk.

Don’t forget birds and bats when renovating or building new homes

As newer homes are built or older homes are renovated, empty attic spaces are disappearing – this eliminates a vital refuge for birds and bats during a biodiversity crisis

The researchers aren’t sure why bats fly so close to wind turbines. suggests that migratory bats mistake the structures for trees and approach them in search of food, shelter or mates. A recent European study also found that , potentially attracting females into the path of spinning blades. Differences in species prevalence and behaviours may partly explain why some seem to be more at risk than others.

The researchers hope their findings will help wind farm developers protect bats by choosing safer locations and adjusting turbine designs. For example, research suggests that stripy wind turbines could prevent seabird collisions.

Changing when turbines operate might also help. shows that temporarily shutting them down during periods of high bat activity, particularly in low winds, can substantially reduce fatalities with limited loss of electricity production.

Elephants appear to harmonise their vocal rumbles when they join together to form choruses, tuning their voices to sound more alike as the chorus unfolds.

The findings come from a machine learning study, which also reveals that this convergence is particularly likely to occur during specific kinds of choruses – such as when elephants reconnect with one another or organise group activities – and that the calls themselves may contain information about what the animals are doing. 

The findings could offer new insights into how elephants communicate and navigate life within their complex societies, says  at Earth Species Project, a US non-profit organisation that uses artificial intelligence and machine learning to attempt to decode non-human animal communication.

“It’s sort of like what humans do in conversation, where you almost start to adopt the speaking patterns or accents of whoever you’re interacting with,” says Keen. 

Elephants communicate using a , but also a wide range of sounds. These include their iconic trumpet call, and also throatier roars. The most common call is the rumble – so low-pitched it is often undetectable by humans – which can travel up to 10 kilometres, transmitting long-distance information that can potentially include the identity of the caller and what’s happening at the time.

 at Elephant Voices, a non-profit organisation based in Washington DC, that promotes the study and protection of elephants, says scientists have long been intrigued by the way elephants will rumble together in choruses. Studying those complex sounds, however, has proved extremely difficult because it is hard to pick out any given rumbling elephant in the chorus – what researchers call “the cocktail party problem”.

With significant developments in machine learning, however, Poole, Keen and their colleagues have found that computers are up to the task. They used a collection of 902 recordings of rumbles collected across four decades, emitted by wild female African savannah elephants (Loxodonta africana) from dozens of family groups in Kenya’s Amboseli National Park. The calls were grouped according to six distinct social situations: staying in contact while separated; preparing to move; coordinating what to do next; comforting or reassuring calves; greeting close family members; and participating in large family reunions. 

Machine analyses revealed that elephant choruses carry multiple layers of information at once, and vary in a way that suggests they encode information about what a family is doing together and what happens next, says Keen. Tracking rumbles of individual elephants in the same chorus, the data showed that in some cases, the calls became more acoustically alike as the chorus progressed. Specifically, this convergence occurred when elephants were staying in contact while separated, coordinating what to do next, and greeting after a separation. This suggests that vocal convergence may play a role in helping elephant families build a plan of action, says Keen.

Earlier research that Poole and her colleagues published in 2005 showed that elephants can  when they are calling more generally: the new work shows that this imitation involves the rumbles, too. 

Camera trap spots endangered elephant mother and calf on the move

A weatherproof box and motion-trigger camera help photographer Will Burrard-Lucas capture images of rarely seen African elephants

Combined with other communication tools, including body language, the rumbling calls seem to help facilitate complex social interactions. “They appear able to negotiate, agree and disagree – and make a plan of action,” says Poole.

The findings not only shed light on elephant communication and cognition, but they could also eventually aid conservation by helping researchers track their behaviour and movements remotely, the team says.

Because rumbles allow for long-distance communication, elephants’ ability to unite through their voices is an exciting reflection of their advanced cognition and evolution in their environment, says Andrew McLean, a member of the International Union for the Conservation of Nature’s . “Evolving and elaborating this for social cohesion, group survival and foraging efficiency is very adaptive,” he says. “This is a fascinating finding – although it’s not really surprising, given how intensely social elephants are.”

Young orangutans who spend little time working out for themselves how to build a broad diet can partly compensate by watching how other orangutans choose what to eat.

The findings suggest that orangutans have different strategies for developing broad survival skills, says at the Max Planck Institute of Animal Behavior in Germany.

Young orangutans acquire a substantial body of knowledge before they can survive independently, which they must do by the time they are 8.5 years old. This includes understanding what foods are safe to eat, where to find them and how to process them in a rainforest offering hundreds of food options of varying levels of accessibility – from easy-to-access leaves to the more inaccessible but also more nutritious seeds at the heart of a tough, spiny neesia fruit.

Scientists already know that orangutans can acquire this knowledge both by observing their mothers and other individuals in their social circle – a process known as social learning – and by exploring entirely on their own without any input from others, which is known as individual learning. But how these two forms of learning work together – and how they affect what orangutans learn to eat before becoming independent – hasn’t been clear.

To find out, Thillaikumar and her colleagues analysed nearly 7000 instances of learning recorded during more than 1700 hours of observations of wild Sumatran orangutans at Suaq Balimbing, a research station in Indonesia. The observations, collected over 12 years, tracked 21 youngsters as they closely watched other orangutans who were interacting with foods and other objects.

The young apes varied considerably in how much they relied on different kinds of learning, with some using more social learning, and others exploring independently much more often. This might, in part, reflect personality differences, and might also be influenced by early development – including differences in how mothers care for their young, says Thillaikumar.

Youngsters who learned by watching others also tended to continue manipulating new objects or trying new foods for about 145 minutes after they had closely observed another orangutan. This activity is reminiscent of the way in which children will spend time imitating an activity they have just seen demonstrated by an adult, says Thillaikumar. “Yeah, it’s practice.”

Next, the researchers drew on about 4700 hours of feeding observations for 13 of the youngsters to estimate the range of foods they had learned to eat by the time they reached independence. Unsurprisingly, the team found that the individuals who had engaged in plenty of social learning and plenty of individual learning had acquired the broadest diets.

But they also found that young orangutans who engaged in very little truly individual learning could partially compensate and develop a reasonably broad diet if they were good social learners.

Orangutan is first non-human seen treating wounds with medicinal plant

A male Sumatran orangutan chewed the leaves of a plant used in Indonesian traditional medicine and placed them on a wound on his face

at Duke University in North Carolina says she’s impressed by the sheer scale of the work, following young orangutans through the rainforest across their entire, lengthy period of dependency on adults. She was particularly intrigued by how often social observation was followed by young orangutans practising the techniques they had observed. “In simpler terms, they show clearly what we see in human children and other apes – that they watch others perform a behaviour and then go try it out on their own.”

The variability in learning styles – even at an individual level – is especially interesting, says , also at Duke University. It suggests that no single form of learning can tell the whole story. “Predicting dietary breadth at maturity requires looking at all types of learning.”

A backpack can detect when muscles become fatigued and automatically massage the affected areas. This seems to help muscles recover better than heat therapy or pre-programmed massages, like those delivered by chairs and cushions.

About . This can occur when back muscles become fatigued through exertion or prolonged or repetitive activity. Persistent fatigue can impair local blood flow and tissue recovery, potentially contributing to chronic pain.

Tired back muscles can be relieved through heat therapy and automated massage, which often involves rollers moving across the back in pre-programmed patterns. But these tend to be standardised treatments that don’t take into account people’s individual muscular issues, says at the Wuhan Institute of Technology in China.

Looking for a more bespoke approach, Yu and his colleagues have developed a wearable system, like a backpack, that uses electrodes on the skin to monitor electrical activity in four groups of back muscles. The system then determines which muscles are fatigued, and how much. Cables move a soft massage head to the affected areas, where sensor feedback allows the system to continually adjust the force according to the fatigue levels, says Yu.

To test their device, the researchers asked 11 men and four women, aged 20 to 26, with no known health issues, to spend 2 minutes resting, followed by 2 minutes repeatedly lifting dumbbells while seated. This induces fatigue in the rhomboids, the muscles between the shoulder blades.

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All the participants wore the backpack during the dumbbell exercise so it could record their muscles’ electrical activity, but only some then received the backpack’s massage. The remaining participants divided into groups that received another type of pre-programmed massage, had heat therapy or rested.

During the exercise, the electrical activity in the participants’ rhomboids fell as the muscles became fatigued, indicating weaker muscle activation. But after the backpack treatment, this activity was about 2.6 times higher compared with after the pre-programmed massage, indicating greater recovery. It was also about 1.9 times higher than after heat treatment, and four times higher than after resting.

“We were encouraged by how clearly the adaptive system improved muscle recovery compared with preprogrammed mechanostimulation and thermal stimulation,” says Yu.

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at Harvard University says the device is a move in a “creative direction” for combining soft robotics with mechanical therapy to address back pain and muscle fatigue. But it needs to be lighter and less bulky before it can become a practical solution, he says.

“There are definitely some very interesting engineering features in the system, and I see a lot of value in this as a proof of concept for this technology,” says at ETH Zurich in Switzerland. “But if you want to use it in the context of people working on the assembly line as they claim, I think this is a bit far into the future.”  

The team hopes to make the design smaller and more compact, and to test it in a larger group of people working in real-world conditions that may cause back pain, says Yu.