Climate and health activist has been immortalised in a sculpture, The Solomon Siren – recently installed on her now-flooded former home: Kale Island in the Solomon Islands.

Rising tides completely flooded the 50,000-square-metre Pacific island in 2016. The sculpture sits in the intertidal zone, where patches of rubble and sand rise above the ocean surface from time to time.

Sculptor Jason deCaires Taylor made the sculpture as part of his Sirens series of installations around the world highlighting warming seas, sewage pollution and the presence of microplastics.

When flooding made life untenable, Bartlett and her family had to evacuate to one of the main islands. “Back then, [the island] was land – green, vibrant, full of life,” says Bartlett in a film accompanying the sculpture’s installation. “Kale became one of the first documented islands in the Solomons lost to sea level rise.”

The sculpture consists of a marine-grade stainless steel tree on which a life-sized figure of Bartlett leans. The artwork also uses biochar and pH-neutral cement. Hauntingly, as the tide rises and falls, it is intermittently hidden as waves roll over.

Incorporated into the sculpture are inscriptions recording past milestones of Kale’s submergence along with predictions for a sea level rise of up to 20 centimetres by 2046. But as Taylor says, the sculpture isn’t intended to work as a scientific measuring instrument, but as a “symbolic representation” of a changing relationship between land and sea.

“What happened is a warning not only for us, but for the world,” says Bartlett.

The discovery of layers of grass ash stretching back 25,000 years suggests that a cave in south-eastern Australia was home to elaborate rituals for over 1000 generations of Indigenous inhabitants.

Cloggs cave is in the homeland of the GunaiKurnai people in south-eastern Victoria. In 2024, archaeologists and traditional owners announced the discovery of ancient artefacts inside the cave, providing evidence for the extraordinary possibility that a ritual had survived for 12,000 years through to modern times.

Now, at Monash University in Melbourne, along with , a GunaiKurnai elder, and their colleagues have uncovered evidence that more than doubles the amount of time that cultural practices took place in the cave. The purposes of these rituals are thought to have included magic, healing and cursing.

The team found thousands of microscopic, silt-sized preserved cells called phytoliths that form when plants absorb soluble silica from the soil and deposit it within their structures. Grasses were the dominant vegetation type, making up 97 per cent of the burnt phytoliths found in the cave.

David thinks this is because grasses immediately turn to ash, rather than charcoal, when burnt, and the ash was considered important for rituals.

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These phytolith fossils indicate that people had brought whole grasses including their roots into the cave and burnt them to repeatedly make thin layers of ash, he says.

The researchers were then able to link this practice of burning ashes with cultural practices described by the Alfred Howitt. In the 1880s, in other parts of GunaiKurnai country Howitt recorded the rituals of powerful medicine men and women that he described as “wizards”. His accounts show that ash was an important part of GunaiKurnai rituals in the 19th century.

“Such burning of grass goes back to 25,000 years ago inside the cave, but between 4400 and 1600 years ago, the burning of ash layers became more frequent and more widespread across the floor of the cave,” says David.

Around 2000 years ago, a standing stone was erected in the cave and over the next 400 years, grass was burnt all around it.

Unlike pollen, which can be transported by wind, phytoliths are usually deposited immediately beside the plants from which they originate. The team also ruled out the possibility that the fossils were washed in by a flood.

The cave also contained phytoliths deposited in the scats of common brushtail possums (Trichosurus vulpecula), but these were unburnt, distinguishing them from the phytoliths created by human activities.

The ashes weren’t always associated with the same kinds of archaeological remains, suggesting they were created by a range of practices in the cave, says David.

“The common theme here is that people repeatedly piled grasses and burnt them,” he says. “Prior to 4400 years ago, the bringing and burning of grass into the cave was more sporadic and less frequent, not resulting in the repeated dense ashy layers that we see after 4400 years ago, although other kinds of ritual activities involving stalactites and miniature fires with single fat-smeared sticks were performed during those earlier times.”

at the Australian National University in Canberra says archaeobotanical research has been underrepresented in Australian archaeology, which has meant that a “large portion of past life has been understudied”.

“This is a great study, weaving careful scientific analysis of phytoliths with GunaiKurnai cultural knowledge to show that grasses were specially collected and burnt at Clogg’s cave to support ritual practices over many millennia,” says Florin.

Hunter-gatherers transported brown trout into the mountains of Norway at least 7000 years ago so they could be harvested during summer foraging trips into the highlands.

That is the only possible explanation for how fish could have populated isolated mountain lakes that had been covered by a kilometres-thick ice sheet for tens of thousands of years, says at the University of Oslo, Norway.

“This is the oldest documented example of human-mediated translocation of fish in the world,” says Mjærum.

Until around 8400 years ago, Lake Tesse, at an elevation of around 850 metres, was covered by the Fennoscandian ice sheet, leaving an ecological blank canvas once it retreated.

Yet before it was transformed for hydropower storage in the 1940s, Lake Tesse was regarded as one of the richest brown trout waterways in Norway, yielding 9 tonnes of the fish annually.

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While it has long been suspected that humans had a hand in establishing the brown trout population in Lake Tesse, we had no idea how long ago this happened.

Alternative ideas have included transportation by birds or natural migration of fish and eggs upstream. But most Norwegian mountain lakes, including Lake Tesse, only had brown trout until recently, and geographical features such as large waterfalls make natural dispersal upstream impossible.

Mjærum and his colleagues studied the partially buried remains of elaborate wooden fish traps, discovered in 2022 when the lake level was lowered.

Radiocarbon dating showed that the oldest trap dated from around 4950 BC. By correlating the recovered wood with the pine tree ring chronology available for the central Scandinavian mountains, the team was also able to precisely date some of the posts that were part of the younger traps.

One came from a tree felled between spring 2669 BC and winter 2669-2668 BC, and another 12 years later during the winter of 2657-2656 BC, demonstrating that the traps must have been maintained to keep them in good working order.

“Therefore, it is possible that this form of trap fishing was ongoing in Tesse during much of the period between 5000 and 2650 BC,” says Mjærum.

The transport of fish into the lakes is an early example of people managing the environment to provide food, centuries before the advent of farming in Scandinavia. There is evidence that fish farming began even earlier in other parts of the world,

How people transported the fish is unknown, but they may have used waterskins. People probably stayed in the mountains for part of the summer season, hunting reindeer and fishing, but spent the winters in the valleys or along the coast where the climate was milder, says Mjærum.

“A good and predictable food supply also made longer stays possible, not only for hunters aiming for big game, but for whole family groups,” he says.

A monkey with a distinctive mask-like face, found in a remote part of the Democratic Republic of the Congo, has been declared a new species – only the fifth new species of monkey documented from Africa in the past 75 years.

The monkey is known as likweli to local people who hunt it for bushmeat, and it has been given the scientific name Colobus congoensis. It lives in one of the most inaccessible parts of Africa, without paved roads or infrastructure.

“A typical expedition involves multiple modes of transportation: a flight, followed by a motorcycle ride, two days of hiking on foot and finally travel by dugout canoe to reach the monkey’s range,” says at Florida Atlantic University.

One of the most intriguing features of likweli is its facial appearance, says Detwiler. The light-coloured skin around the mouth and beneath the nose is unlike that of any other African colobus species, but resembles the facial pattern seen in some Asian colobine monkeys.

Detwiler and her colleagues believe the species’ mask-like face may represent ancestral traits that were present before the African and Asian colobine lineages diverged over 8 million years ago. “If so, likweli may have retained characteristics that were subsequently modified or lost in the other African colobus species,” says Detwiler.

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Like other colobus monkeys, likweli also has a distinctive body odour that defies description, she says.

Scientists first became aware of the species in 2008 when a team surveying on the banks of the Lomami river, in what is now Lomami National Park, took a photo that showed only a part of a monkey that had not been seen before, high in the canopy.

Then, in November 2018, another group again spotted the monkey, which is about 1.3 metres long and weighs around 7 kilograms. Between 2018 and 2022, there were 114 recorded observations of the new species, 25 of which were from vocalisations.

In 2021, several monkeys that had been killed by hunters for bushmeat were confiscated and handed over to researchers. Detailed morphological and genetic analysis confirmed they were indeed a wholly separate species. Genetic tests and recordings of their vocalisations also added to the evidence of their uniqueness.

“The genetic analyses revealed that likweli is a deeply divergent lineage that split from its closest known relative, Colobus satanas, approximately 4 to 5 million years ago,” says Detwiler. “That was much older than we expected and provided strong evidence that likweli represents a distinct species.”

Likweli is isolated from C. satanas by more than 1200 kilometres and several major river barriers. Unlike most other members of the genus, which have habitats exceeding 60,000 square kilometres, likweli is only known to exist in 1700 square kilometres of rainforest.

“Hunting is one of the primary threats facing likweli, particularly because the species has such a small known range and appears to occur at low densities,” says Detwiler.

Because of the risk of poaching and the monkey’s small population and home range, the team is proposing that the species should be listed as endangered. “Now that likweli has been recognised as a distinct species, another important step would be to grant it protected status under national law,” says Detwiler. “This would make it illegal to hunt the species, including in the buffer zone surrounding the park.”

An ancient Maya astronomer-mathematician has been identified for the first time along with his complex calculations made around 1200 years ago, predicting the orbital cycles of Mars and Venus.

“This is the first direct mention of an ancestral Maya astronomer-mathematician by personal name,” says at the Massachusetts Institute of Technology.

It is also the oldest recorded name of an astronomer-mathematician ever known from anywhere in the Americas, he says.

The Maya civilisation flourished in Central America between roughly 2000 BC and AD 1697. They had advanced knowledge of mathematics and astronomy, but much of it was lost after the mass burning of their books by Spanish missionaries.

Since 2010, excavations at the site of Xultun, Guatemala, have revealed astronomical and mathematical inscriptions inside a small masonry building.

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On the east and north-east walls of the building are around 50 texts that scientists believe are “rough drafts” made by Maya mathematicians as they charted and predicted the cycles of celestial objects relative to Earth and to one another.

Rossi and his colleagues have painstakingly deciphered one of these murals, named Text 19. At the bottom of the mural is the name of Sak Tahn Waax, which translates to White-chested Fox, who is believed to be the author of the formula.

Text 19 consists of 11 hieroglyphs, which had to be scanned, photographed and magnified under different illumination angles, and compared with other, later, astronomical-mathematical writings, before their meaning could be deduced.

While similar mathematical and astronomical expertise is found across Maya cities, the mention of Sak Tahn Waax, who the researchers believe was probably male, is unique.

“Whether this is an instance of the scribe himself signing his own calculation or attributing the intellectual work to another, we have a formula and the name of its creator, which serves to demonstrate the importance of this kind of intellectual contribution for Classic Maya people,” says Rossi.

The calendar system on display in Text 19 uses maths in relation to time periods, he says. These time periods were drawn from a 260-day calendar, a 365-day solar calendar, a 584-day approximation of Venus’s synodic cycle (when the planet returns to the same position relative to both Earth and the sun) and a 780-day approximation of Mars’s synodic cycle. The total length of the formula is five Venus synodic cycles or 2920 days, and the date that Text 19 most likely refers to is 7 November of AD 781 in the Julian calendar.

Exactly how this formula would have been applied is unknown, says Rossi, as it “isn’t incorporated into any larger body of work”.

“We think it is meant to concisely and meaningfully show the relationship between these two planets and human counts of time in ways that could then be applied to political ceremony, predictive astronomy and understandings of seasonality,” he says.

Such meticulous mathematical legwork would have been critical to structuring life in a world before computers, smartphones and weather apps, says Rossi.

A 555-million-year-old worm had a predilection for turning right, possibly indicating the oldest known example of handedness.

Although these worms lacked limbs and so couldn’t be considered left- or right-handed in the way that we understand, the development of a tendency to favour one side over another is evidence of an advanced nervous system.

It remains a feature of free-living mobile life today, but until this discovery, it wasn’t thought to have emerged until the Cambrian Period, which began around 541 million years ago.

at the American Museum of Natural History in New York and his colleagues analysed 100 fossil specimens of a small flatworm-like creature, Spriggina floundersi, collected in South Australia over recent decades.

These animals lived during the Ediacaran Period, when multicellular life first became widespread. It preceded the Cambrian explosion, when animal life diversified dramatically and many groups of animals first appeared.

Spriggina lived in what was, half a billion years ago, a shallow ocean and is thought to have foraged on or close to the seafloor, moving by wriggling to the left or right.

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“We have around 50 specimens of Spriggina that are clearly bent,” says Evans. Twice as many of the fossilised worms are bent to the left than to the right, he says. This means the creature itself bent to the right, as the specimens are mirror-image impressions of the animals, made when storms buried them in sand.

“This appears to be statistically significant and matches what biologists find when they study handedness in different animals today,” says Evans. “Some specimens have multiple bends to both the right and left, suggesting that they all could bend both ways, which makes sense if you don’t want to be stuck moving in a circle.”

While the majority seem to demonstrate right-handedness, it is hard to tell if any were left-handed, he says. “I imagine it’s like taking a picture of 100 people waving with one hand today. You would likely be able to count that more people are waving with their right hand, but you wouldn’t be able to tell who is right- or left-handed.”

Discoveries like this demonstrate that many foundational characteristics that are common to a variety of animals today, such as the ability to move around, bilateral symmetry and handedness, evolved in the Ediacaran, says Evans.

In the Cambrian, organisms built on that foundation to become more complex, for example adding legs to move more efficiently, becoming “less alien and more like the major groups of animals we know today”, says Evans. “This is cool because it suggests that, while the Cambrian was an amazing time in animal evolution, those organisms didn’t just come out of nowhere: they built on the foundations established in the Ediacaran.”

“The presence of handedness in any kind of functional asymmetry, really deep into the fossil record, gives us important and interesting information about how these behaviours have evolved and how deeply in time they emerged,” says at Flinders University in Adelaide, Australia.

A huntsman spider found in Queensland, Australia, has been crowned the fastest spider in the world with a top speed of nearly 3.6 metres per second, according to a global study of arachnid sprinting prowess.

Currently, is held by the Moroccan flic-flac spider (Cebrennus rechenbergi) which can hit speeds of 1.7 metres per second when it is startled, using a rolling-tumbling motion. But some experts regard this as incorrect.

“The flic-flac is a special type of locomotion,” says at University of Greifswald, Germany. “It is not running and it only works downhill on sand dunes.”

To get a comprehensive picture of running speed in spiders, Shreyas Kuchibhotla at Imperial College London and his colleagues, including Wolff, collected 162 live spider species during fieldwork throughout the UK, North America, southern Europe and Australia, along with dozens of specimens sourced from pet shops.

Each of these was carefully weighed then tested for their speed on A4 or A3 grid paper, in an attempt to understand the biomechanics across as many species as possible.

Most species were coaxed into running by gently touching them with a paintbrush, but others weren’t so cooperative, says Kuchibhotla. “This project would have been over in a month if spiders could understand English,” he says. “Tarantulas aren’t built for running; they’d much rather stand their ground, so they had to be blown at with puffs of compressed air.”

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Kuchibhotla and his colleagues also collected speed recordings of a further 96 species made by other research teams. The 3-gram jungle huntsman spider (Heteropoda jugulans) was by and his colleagues at the University of the Sunshine Coast in Australia.

These spiders can achieve such high speeds because they are “relatively large as far as spiders go, but not large enough that their legs get over- burdened by a heavy abdomen,” says Clemente.

In general, bigger spiders tended to be faster, but some are much faster than expected for their size. The biggest surprise was the orange goblin spider (Oonops pulcher), which weighs a mere 0.1 milligrams but moved at over 20 centimetres per second. “Nothing could have prepared me for how it practically teleported across the arena,” says Kuchibhotla.

, a team member at Imperial, says speed is, in principle, entirely determined by physics. But it is lifestyles such as hunting strategies that drive the evolution of extreme anatomical and physiological adaptations, he says.

“A cheetah, say, comfortably outruns most similarly sized dogs. This is, of course, because its lifestyle has made this speed beneficial, but it is still dictated by physics,” says Labonte.

After accounting for both body size and shared ancestry, the team’s conclusion is that fast running is associated with relatively longer legs but not with leg slenderness or, surprisingly, whether a spider lives its life upside down or not.

at Edith Cowan University in Perth, Australia, says long legs appear to be a spider’s “speed gear”. “The huntsman supplies the record-book hook, but the deeper discovery is that spider speed is shaped by leg architecture and evolutionary history, not simply by size or whether a spider spins a web,” says Mason.