Most of life on Earth is not like us at all. Barely 5% of all known living creatures are animals with backbones. The rest – at least 1.3 million species, and many more still to be discovered – are spineless. They are the invertebrates, animals of wondrous diversity, unique niches and innovative and interesting ways of making a living on this planet, which include insects (at least a million), arachnids, snails, crustaceans, corals, jellyfish, sponges and echinoderms.
And yet, despite their numerical advantage, originality and dazzling charisma, invertebrates are usually overlooked in favour of animals that more closely resemble ourselves. So, over the last two weeks, we’ve gone in search of the UK’s invertebrate of the year, and profiled 10 different invertebrates – plus the invertebrate nominated by readers, Lumbricus terrestris, the common earthworm.
And if you need a reminder of them, here they are: glowworm, Clifden nonpareil, swallowtail, Asian or yellow-legged hornet, barrel jellyfish, St Piran’s hermit crab, distinguished jumping spider, ash-black slug, minotaur beetle, shrill carder bee and the common earthworm.
And now we’re asking you to choose your favourite by clicking on one of the options below. In reality, of course, they are all winners, and we are winners, too, lucky enough to share the Earth with these amazing creatures.
As one reader, James Chisnall, put it: “It’s important to remember it’s not just our planet, and everything from the largest to the smallest deserves our respect and its place on this sphere we call home.”
Voting ends at 8am BST on Monday 15 April, after which the votes will be tallied and the champion invertebrate will be crowned.
Shell has argued that it âlobbies for, not against, the energy transitionâ on the final day of its appeal against an important climate ruling.
The fossil fuel company is fighting the decision of a Dutch court in 2021 that forces it to pump 45% less planet-heating CO2 into the atmosphere by 2030 than it did in 2019. In court on Friday, Shell argued the ruling is ineffective, onerous and does not fit into the existing legal system.
Lawyers for Milieudefensie (Friends of the Earth Netherlands), which brought the case against Shell, repeated their calls for the company to act in line with climate science and international agreements to stop extreme weather from growing more violent. They said the outcome of the case will determine how much the climate changes.
âItâs not just about Shell,â said Donald Pols, the Milieudefensie chief executive, after the hearing. âWe want to hold all companies accountable â to combat dangerous climate change.â
Shell argued in court that it plays its role in energy transition and pointed to the lobbying it had done in favour of climate policies such as the EU emissions-trading scheme and the US Inflation Reduction Act.
Milieudefensie said it was âquite clearâ that Shell had used its social influence to safeguard the role of oil and gas and that it had continued to do so with its policies. In recent months, Shell has backtracked on a series of clean energy ambitions.
âI think itâs a little bit far-fetched from Shell to argue they are in favour of the energy transition, at least to the extent of being in line with the Paris agreement,â said Roger Cox, Milieudefensieâs lawyer in the case.
The appeal wraps up just days after the European court of human rights sided with a group of 2,400 Swiss women who sued their government over its climate policy.
Both Shell and Milieudefensie cited the Swiss case to support their arguments on Friday. Shell argued that the decision of the 17 Strasbourg judges showed it was up to states, rather than companies, to rein in emissions. Milieudefensie said it showed that âjudges have an important role to play in the complex debate on preventing dangerous climate changeâ.
A report last week found that 57 companies are linked to 80% of carbon emissions since 2016, though the bulk of that comes from their customers burning the fuels they sell.
At the appeal, Milieudefensie argued that Shell should not achieve the original emissions reduction target by simply selling off fossil fuel assets, which may then land in the hands of companies with less public scrutiny and dirtier operations. Shell argued that the original ruling gave it the freedom to do so and said the activist group had failed to contest this point by lodging a cross-appeal.
skip past newsletter promotion
after newsletter promotion
Frans Everts, director of Shell in the Netherlands, said in the companyâs closing remarks that he was concerned by the âunintended consequencesâ of the lawsuit. He said the activists wanted to limit the supply of Shellâs products before its customers are âable, willing or ready to switch to less fossil fuelsâ.
He said: âAs long as the demand for these products doesnât change â and people can just go to the competitor â there is not one less carbon molecule in the air. And without a clean alternative to oil and gas products, the energy transition will not benefit either.â
In 2021, after evidence for the original case was filed, the International Energy Agency published a report on reaching net zero emissions by 2050 that found no room for new oil and gas exploration. Companies including Shell have since continued to invest in new oil and gas fields despite protests from climate scientists and activists.
A carer who says he was “dragged through the courts” and had to sell his home to pay back almost £20,000 in benefit overpayments is fighting to clear his name after the Department for Work and Pensions (DWP) acknowledged he made an innocent mistake.
George Henderson, 64, said he made a gain of just 30p a week while claiming carer’s allowance for his son John, who has learning difficulties and is addicted to heroin. He now costs the Treasury £1,000 a month more in benefits, having become homeless and too unwell to work.
Henderson said he was left suicidal after being prosecuted by the DWP, which accused him of fraudulently claiming the benefit for six years while he was caring for John, who is now 42.
He wrongly ticked a box saying he was unemployed while filling in the “tricky” application form for carer’s allowance in 2010. “I thought they were asking about John,” he told the Guardian.
The DWP has records of him working as a taxi driver since 2002, earning about £7.50 an hour. Yet it took more than six years for anyone at the department to tell him he was claiming the benefit incorrectly.
By that point he had claimed £19,506.20 – about £60 a week. The DWP not only wanted it all back but also prosecuted him for fraud. Investigators said he had lied about having a job and had ignored annual letters reminding him to report any changes in circumstances.
He protested his innocence but was found guilty. In 2018, a judge at Preston crown court gave him a 32-week suspended sentence and ordered him to wear an electronic tag for 16 weeks.
Never in trouble with the law before, Henderson found it humiliating having the tag fitted and suddenly having a 9pm curfew. “My stomach was churning watching them putting it on,” he said. “I just felt helpless, embarrassed, degraded … I’d been dragged through the courts like a criminal, and I’m not.”
Afterwards, he received letters from the DWP every three weeks demanding he sell his two-bed former council house to pay the debt or face a seven-month jail term, he said.
Henderson eventually sold the property for £115,000, and after paying off his mortgage and the DWP he was left with just £6,000. “It breaks my heart,” he said. “I’ve been back and looked at [the house] twice and I’ve actually broke down and cried.”
His mental health deteriorated to the point that he attempted to kill himself and became seriously unwell. “I’d lost four stone. You could actually see my ribcage.”
Henderson is one of a number of carers the Guardian has spoken to after exposing how people looking after disabled, frail or ill relatives are being forced to repay huge sums to the government and threatened with criminal prosecution after unwittingly breaching earnings rules by just a few pounds a week.
The government is facing calls to overhaul the system after the Guardian revealed that tens of thousands of unpaid carers are facing severe fines, some over £20,000, for relatively modest and unintentional breaches of rules branded “cruel and nonsensical”.
John, Henderson’s middle child, was born healthy but lost most of his hearing and developed disabilities after contracting measles aged three. He was unable to manage living independently as an adult, particularly after becoming addicted to heroin, and so moved in with his father.
Initially, John was claiming disability benefits worth about £60 a week. But Henderson soon realised that John’s drug dealers would wait by the cashpoint each week when he was paid, taking his money off him for heroin.
Henderson claimed that in 2010 a DWP official came to the house to assess John and they discussed the pros and cons of claiming carer’s allowance instead.
The new benefit was worth 30p a week more but meant Henderson could receive the money into his bank account and pay it to his son as a daily allowance, with the aim of stopping it being taken by the heroin dealers.
After his conviction in 2017, Henderson tried and failed to appeal. He was left homeless and had to be housed by the local council in sheltered accommodation, at a cost to the public purse. Too unwell to work, he now relies on universal credit, receiving £1,300 a month to cover his housing and living costs.
“Believe it or not, when I moved in I couldn’t get in and out of the bath because I’ve got two hip replacements and I’ve got a serious spinal condition. So it cost them £7,000 to put in a wet room. It’s costing them the universal credit. It’s absolutely ludicrous. It’s actually cost the taxpayer or the government money by doing this,” he said.
Recently, Henderson decided to try to clear his name and wrote to Mel Stride, the work and pensions secretary. Last month he received a letter from the DWP apologising for his ordeal but refusing to give him the money back.
The letter said: “The appeal conceded that you were a convincing and credible witness [and] it was more probable than not that you were telling the truth and that the false declaration was an innocent mistake.”
It went on: “I am so sorry that you feel that experiences with DWP have contributed to your financial problems, severe emotional trauma and mental health.”
Henderson refuses to accept the apology. “It’s not addressing what I need addressed,” he said. “Why did it take six years to find that I ticked the box incorrectly? Why not in the first year? Then it would be acceptable. I would have been able to pay the first year, I made a mistake.”
A DWP spokesperson said: “We are committed to fairly supporting all those who need the welfare system, while fulfilling our duty to treating taxpayers’ money responsibly.
“Claimants have a responsibility to inform DWP of any changes in their circumstances that could impact their award, and it is right that we recover taxpayers’ money when this has not occurred. We will work with those who need support with their repayment terms whilst protecting the public purse.”
A single fink. I stop for the call’s repeat. Instead, the confirmation that a chaffinch has joined the dawn chorus comes with a brief trill culminating in a wheezy flourish. The song is a little like the bird itself: a common thing that’s riven with significance. For the chaffinch is first among finches. With its chinking call, it named itself into Old English as finc – or finch – a name that extended to other species. Centuries later, the poet Gerard Manley Hopkins was surely thinking only of chaffinches when he praised “finches’ wings” in his paean to ordinary contrasts, Pied Beauty.
And here they are, those diagnostic bars of white flashing against the coverts’ black, as the chaffinch lands on a twig in front of me. Sunrise intensifies all his colours: the slate-blue head, the rust breast, the olive rump. His gleaming blue-black bill opens and a wisp of breath pulses from his gape as he sings.
Lagan Valley Regional Park. ‘There’s another chaffinch singing in the distance.’ Photograph: Mary Montague
Walking here a few weeks ago, I heard a chaffinch – possibly this very one – sing the trickle of notes that marks the incomplete song of a first-year bird. I’m reminded of the pioneering research of the evolutionary biologist Peter Marler. Working initially on chaffinches in the 1950s, he showed that birdsong is shaped by learning and memory. Songbirds have an innate capacity to produce a version of their species’ song, but they are influenced by the types of songs they hear around them, and youngsters fine-tune their efforts to those of their elders. These cultural aspects of birdsong give rise to local dialects.
There’s another chaffinch singing in the distance. The songs of the two birds sound quite different, but, as their voices become more strident, “my” chaffinch slides his rendition closer to that of his rival’s. This could be a signal that he’s up for any contest. He tilts his head. The other chaffinch has switched to finks. My bird responds with warning huits. As the intruder emerges into view, both birds fall silent. Fluttering their wings and flicking their tails, they bob their face-off up and down the branches. Finally, they leap at each other and tumble through the air before swerving in opposite directions to vanish into the trees.
A friendly if slightly tuneless chirp is the most ubiquitous birdsong in British gardens with the house sparrow topping the Big Garden Birdwatch charts for the 21st consecutive year, according to the annual RSPB survey.
Blue tits, starlings, wood pigeons and blackbirds were the next most-sighted birds by more than 600,000 participants in the world’s largest wildlife garden survey.
The long-running citizen science project provides conservationists with invaluable data on how common species are faring. Although an average of four house sparrows were spotted in every garden when the survey was conducted in January, the number recorded has declined by nearly 60% since the survey began in 1979.
Top 20 bird sightings table
The starling, the third most seen bird this year, is on the UK red list of most threatened breeding bird species because of a sharp decline in its breeding population since the 1960s. It remains a popular visitor in winter, when birds arrive from northern Europe, but gardens and house roofs may be an increasingly important refuge for this declining species.
Gardens are an important habitat for many birds, covering an estimated 4,330 sq km in the UK, an area larger than the county of Somerset.
Starlings were third on the most-sighted list this year. Photograph: Robert Bannister/Alamy
Beccy Speight, the chief executive of the RSPB, said: “Last year’s State of Nature report laid out a grim picture, finding that there’s been no let-up in the decline of our wildlife over recent decades, with one in six species at risk of being lost from Great Britain.
skip past newsletter promotion
after newsletter promotion
“However, with seven out of eight households lucky enough to have access to a garden, it is the place where many of us can make a positive difference to the ongoing nature crisis. Gardens and community green spaces can both give a crucial lifeline for struggling species by providing a huge patchwork of potential homes for nature.”
The US midwest typically spends the start of spring emerging from snow. But this year, after a warm winter left landscapes parched, the region instead was primed to burn. Hundreds of blazes ignited in recent months in states more accustomed to dealing with just dozens for this time of year, as extreme fire behavior defied seasonal norms.
Experts say the unusually early and active fire season was a symptom of El Niño, a climate pattern characterized by warmer surface temperatures in the Pacific Ocean that was predicted to supercharge global heating and extreme weather. But the climate crisis turned up the dial, and helped create conditions in the midwest where wintertemperature records were not only broken â they were smashed.
âThis was the strangest winter I have ever seen,â Stephen Marien, a predictive services fire meteorologist who works for the National Parks Service, said. Marien, a federal scientist based in Minnesota, added that he expected the season to trend warmer due to El Niño, but it was still shocking to see temperatures climb above 60F (16C) during the typically frigid months. For Marien it was a clear sign that âclimate change has added fuel to the fireâ.
The midwest â defined by the US census as Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin â includes a range of landscapes, including grasslands, plains and forests, but the warmer weather had widespread impact.
The balmy start to the year left the region with a larger window for higher-risk fire conditions, which tend to peak in early spring after the snow melts but before trees and grasses âgreen upâ. Vegetation that is normally hidden beneath the berms of snow was instead exposed to the sun weeks early and dried quickly. That unleashed unseasonal drought conditions and set the stage for the type of blazes that prove harder to contain.
Firefighters respond to a wildfire in Western Township, Minnesota, on 3 March 2024. Photograph: Fergus Falls Fire Department
In Minnesota, the agency responsible for coordinating fire suppression efforts said in a Facebook post that vegetation had dried out âroughly six weeks earlier than normalâ and that firefighters in the state had already responded to 50 significant blazes in early March.
While the fires have mostly been small and numerous rather than catastrophic, they contributed to an early jump in burn totals across the country. More than 1.7m acres have already burned in the US, a number more than triple the 10-year average for this time of year, according to the National Interagency Fire Center (NIFC).
These numbers were driven in large part by the explosion of fires across Texas and Oklahoma, including the Smokehouse Creek fire that burned more than a million acres in cattle country and left tens of thousands of livestock dead. The fires in the midwest, though small by comparison, laid siege to landscapes and communities where the means needed to battle big blazes are limited. The early onset of fire season is a troubling trend.
âWeâre not really having fire seasons any more. Weâre just having fire years,â Ben Bohall, public information officer for the Nebraska forest service, told KCUR, an NPR affiliate in Kansas City, adding that resources, as a result, were strained.
In Nebraska, a fire in late February scorched more than 71,000 acres (29,000 hectares) in just 24 hours destroying several buildings including two homes. In March, three people were injured when several fires blew across roughly 3,000 acres in Minnesota.
The Bettyâs Way fire in Nebraska in February 2024. Photograph: Nebraska State Patrol
The dangers continued in April. Fueled by drought and heat, a prescribed burn reportedly escaped control in Kansas this week, prompting evacuation notices and road closures. It is one of three active fires burning in the state, which have collectively charred roughly 15,000 acres. The danger is far from over.
âCalendar-wise it might seem like we are getting late into spring, but our fire season is still here in Kansas,â Chip Rebin, a meteorologist of the Kansas forest service, said in a broadcast update posted on Thursday. Temperatures are expected to soar in the coming week â potentially reaching 90F â with winds gusting at 40mph (65km/h) creating suppression complications and a high chance that contained fires will rekindle. âThatâs a bad scenario,â he added, noting heat 20 degrees higher than normal âwill rapidly dry out fuelsâ.
Fires burn differently in the region than those in California or other parts of the west, Marien said, and are typically snuffed out within the day. But intensifying fire conditions have created burns that are harder to contain. The local volunteer firefighters and state departments who battle these blazes can be quickly overwhelmed and may require outside resources, including aircraft, especially when embers are more difficult to extinguish.
âWhen you get longer-term droughts all the fuels on the ground can keep burning for quite a while,â he said, adding, âand that doesnât happen often over here.â
While a spate of storms offered a reprieve in the northern states in recent weeks and the promise of rains returning in the coming months has cooled some of the dangers across the region in the short term, many states in the midwest are still experiencing dry conditions, which could worsen as the weather warms. The latest federal forecasts also show above normal temperatures are likely across much of the plains and Mississippi valley.
âIt is the time of year when they are coming into their main wet season,â Andrew Hoell, a Noaa research meteorologist, said. But if those rains fail to appear, âyou can fall into a drought and you can get some fires pretty quicklyâ.
As the climate crisis sets the stage for more extreme conditions, with climbing temperatures, sharper swings between wet and dry, and a thirsty atmosphere that evaporates moisture faster, the conditions that fueled these winter fires may arise more often.
âThereâs no doubt that this is part of a trend,â Hoell said. âThis part of the world is warming and it is warming during the winter time.â The extremes seen in the last season were boosted due to El Niño, so a repeat performance isnât necessarily expected every winter. âBut the background warming is there,â Hoell added, âand itâs here to stay.â
The people have spoken and the choice of Guardian readers for the final nominee for UK invertebrate of the year is resounding: all hail Lumbricus terrestris, the common earthworm.
The common earthworm â also known as the lob worm, dew worm, nightcrawler and, in Germany, the rain worm â is the soil-maker. Without its labours, we would struggle to feed ourselves.
Worms can bring 40 tonnes of soil to the surface per hectare a year in Britain. They are the engineers of an ecosystem that may be as diverse as the Amazon rainforest. Their diggings aerate soil and they pull fallen leaves and other organic matter into the earth and recycle them. Worms make soils less prone to flooding in winter and less baking hard in summer, they boost microbial activity and, of course, support plant growth.
Gorgeous creatures, many shades of pink, coiling and gliding through the earth. Photograph: Blickwinkel/Alamy
But #VoteWorm is to celebrate majesty and dignity too. These are gorgeous creatures, many shades of pink, stretching out to 35cm long, and coiling and gliding â never âslitheringâ, as the pestilent centipede put it in James and the Giant Peach â through the earth.
The wormâs backers know this well. Lily, aged four, nominates the earthworm âbecause they help make compost to help our garden grow, they feel very soft and when they have got mud on them they are like a wiggly piece of stringâ.
We think the myopic adult world is blind to the brilliance of worms but they have long had influential advocates from Cleopatra and Charles Darwin to George Monbiot.
Today, Guardian-reading soil scientists and horticulturalists make a powerful case to Vote Worm but so, too, does Gill from North Wales, who has been earthworm-phobic since she was Lilyâs age. âMuch gratitude for all the thrashing ones, the little thready ones, the slimy ones, the knotted ones, the ones with âsaddlesâ, the blue-tinged ones, even the enormous ones stretching terrifyingly across my drive when the ground is sodden,â she writes. âThank you all, for what you do.â
Take heed of Trevor Lawson from Amersham. Not only are earthworms critically important, he argues, they are âthe best symbol of everything that matters about being an invertebrate in our anthropocentric worldview â vulnerable, crushable, rarely considered, even despised for their apparent blind ignorance, and yet through sheer force of numbers and extraordinary evolutionary adaptation, they are capable of shaping the entire world around us as we, in our own wilful ignorance, stumble blindly on.â
#VoteWormâs last word goes to reader Jacqui from Wiltshire who says: â200 words for this hero?! Really! Give the worm a gong!â
At midnight on Friday 12 April, voting will open to decide the Guardianâs UK invertebrate of the year with the winner to be announced on Monday 15 April.
Thirteen years ago, riding through central London on my way to meet a friend one evening, I found myself surrounded by hundreds of cyclists, some blaring horns, one popping wheelies, and even someone covered in lights, thundering out drumânâbass from a mobile sound system.
In spite of being overdressed in a shirt and my best trousers, I was taken by the spontaneous solidarity of this diverse group, who I later found was mostly made up of strangers.
Having been swept along in their pack, we made our way to the West End as other traffic momentarily came to a halt to let us pass, while perplexed tourists and shoppers looked on.
This was my first experience of Critical Mass, a monthly, leaderless event held around the world, which promotes safer cycling by riding in numbers.
As a nervous cyclist getting used to riding in London, participating in a ârideoutâ gave me a rare chance to briefly experience what roads in the capital could be like without cars. It was liberating.
This Sunday, hundreds of cyclists are expected to take part in the 30th anniversary of the first London event. Just like in 1994, the rolling demonstration will reiterate a message that cyclists have an equal right to use the road and that they should be able to ride in safety. Although numbers have been falling, about 100 cyclists still die on British roads each year, according to government data.
A Critical Mass ride in April 2014. Photograph: Janine Wiedel Photolibrary/Alamy
Inspired by rides first held in the US, Critical Mass tries to set off from the same starting point on the last Friday of every month; in London it is the South Bank, under Waterloo Bridge.
A mix of riders turn up, from cycling activists and environmentalists to those who just want to ride for fun.
There is no planned route; the pack simply follows riders who happen to be at the front. By forming a âcritical massâ and riding slowly around a city, riders take up as much road as is needed to keep everybody safe.
A Critical Mass website explains: âCritical Mass is not an organisation or group, but an idea or tactic, Critical Mass allows people to reclaim cities with their bikes, just by getting together and outnumbering the cars on the roadâ
There is no question that rides are disruptive in their nature. At roundabouts and junctions, a few âcorkersâ will move out to stop traffic coming in from sidestreets so the pack can stick together. Sometimes, the disruption leads to arguments, as I witnessed on my first ride. Fortunately, a standoff between a young rider and a motorist was defused quickly.
The rides often last for a few hours and their noise and colour give them a reputation for being a bit lively.
That Critical Mass London still exists is somewhat of an achievement given that there have been high-profile attempts to restrict or even ban it. In 2007 moves to outlaw it unless its route was notified to the police in advance were overturned when the House of Lords allowed an appeal against a previous ruling by the court of appeal.
The law lords held that the event, which had no organisers or set route and proceeded on a âfollow my leaderâ basis, was not governed by the Public Order Act 1986.
It is not easy to measure what 30 years of Critical Mass London rideouts have achieved, but its participants would probably want to believe that it has helped raise the profile of cyclists. They would also argue that they have helped change the stereotype that cyclists on the capitalâs roads are still the minority.
The event endures, and this weekend a diverse group of people will celebrate their right to use the road safely and in an environmentally friendly manner. In a symbolic act of defiance, many will also get off their bikes during the ride to hold their bikes above their heads and join in with a traditional âbike liftâ or âbike saluteâ (probably to a backdrop of car horns blaring).
In Chicago’s Field Museum, behind a series of access-controlled doors, are about 1,500 dinosaur fossil specimens. The palaeobiologist Jasmina Wiemann walks straight past the bleached leg bones – some as big as her – neither does she glance at the fully intact spinal cord, stained red by iron oxides filling the spaces where there was once organic material. She only has eyes for the deep chocolate-brown fossils: these are the ones containing preserved organic matter – bones that offer unprecedented insights into creatures that went extinct millions of years ago.
Wiemann is part of the burgeoning field of conservation palaeobiology, where researchers are looking to the deep past to predict future extinction vulnerability. At a time when humans could be about to witness a sixth mass extinction, studying fossil records is particularly useful for understanding how the natural world responded to problems before we arrived: how life on Earth reacted to environmental change over time, how species adapted to planet-scale temperature changes, or what to expect when ocean geochemical cycles change.
“This is not something that we can simulate in the laboratory or meaningfully observe right now in the present day,” Wiemann says. “We have to rely on the longest ongoing experiment.”
Jasmina Wiemann lays out three fossils: the dark brown Allosaurus bone (left) still holds organic matter; the light brown Tyrannosaurus rex fossil (right) also has extractable organics; the Cryolophosaurus bone (centre) is entirely bleached and cannot be used for metabolic assessments. Photograph: Tiffany Cassidy/The Guardian
To observe that planet-scale experiment, scientists have developed new methods of gathering information from the bones of the distant past. After collecting her fossils, Wiemann puts them under a microscope that shoots a laser at the specimen. She displays a section on her computer screen, 50 times its original size, and moves across the fossil’s surface until she finds a dark spot with a seemingly velvety surface – this is the fossilised organic matter.
Wiemann turns the room lights off, a tiny dot of light beams on to the fossil, and a curved line starts appearing on the computer screen. Every compound reacts differently to the laser, and where the bumps in this line are appearing across her chart suggest she was successful at finding organics. “This is beautiful,” she says. She will need to run through the data later, but this should reveal whether the specimen under her microscope was warm or cold-blooded.
Using this method, Wiemann studied when warm-bloodedness emerged around the Permian-Triassic mass extinction (the biggest in history) and the Cretaceous-Paleogene (when the dinosaurs went extinct). Warm-bloodedness was already established as a factor that made species less likely to go extinct, as they can regulate their internal temperature in changing climates. But Wiemann found a new result – that many animals evolved warm-bloodedness independently after each of these extinctions. This could have implications for how animals adapt and find resilience as the planet warms.
“If we want to, in any way, even in the short term, make meaningful predictions, we have to demonstrate that we understand these processes,” she says.
Wiemann shoots a laser at the fossilised organic matter to determine the metabolic rate of the animal. Photograph: Tiffany Cassidy/The Guardian
One of the first people to write about combining ecological and palaeontological approaches to predict extinction vulnerability was Michael McKinney, now the director of environmental studies at the University of Tennessee. After graduating with a degree in palaeontology he began working but says he kept feeling a need to be more relevant. “I love the dinosaurs, the big picture,” he says. “But I kept thinking that it gives us a great context, but it wasn’t teaching me a lot that I could apply directly to the immediate problems.”
McKinney went on to create his current department, which merges geology and ecology. Now, he sees palaeobiology as useful to predict what will happen. But understanding what to do about it is more difficult.
“If you think about what the world’s going to be like 1,000 years from now, I think deep time can help us answer that question,” he says. “But if I’m worried about the fact that the Amazon rainforest is disappearing in the next 20 years, I’m sceptical deep time can inform that.”
Humans, he says, have found new ways of driving species to extinction, from the passenger pigeon to the dodo. “We operate by rules that don’t really apply to the past. The things that we do are so fast and so unpredictable.”
But deep time can offer insights into how species respond to very large, systemic changes – such as the temperature shifts we are now seeing. Erin Saupe, a professor of palaeobiology at the University of Oxford, uses large datasets to look at patterns of extinction in the fossil record to see which traits make species most vulnerable.
In a recent paper published in Science, she and her co-authors asked whether intrinsic traits, including body size and geographic range size, were more or less important in predicting extinction than external factors such as climate change. “Nobody has looked at this question before,” Saupe says. Previous research has shown larger animals are typically less likely to go extinct in marine environments but are more prone to extinction on land, and larger “range sizes” – the distance a species is distributed over – help species avoid extinction.
A closeup of an acid-extracted diplodocid (Jurassic long-necked dinosaur) blood vessel. Photograph: Jasmina Wiemann/The Guardian
The team accessed a digital database to look at 290,000 marine invertebrate fossils from across the past 485m years, and used models to reconstruct the climate over that period. They found geographic range size was the most important predictor of extinction, perhaps because of its interconnection with other factors associated with a lower extinction risk. A large range size suggests the animal is also good at moving larger distances, and if a species is widely spread, a regional climate change in one area likely wouldn’t impact all populations. The team found all intrinsic traits they looked at, as well as climate change, were important in predicting extinction.
“Even if a species has traits that usually make them resistant to climate change and to extinction, if the magnitude of climate change is large enough, they will still go extinct,” Saupe says. “I think it’s quite an important message for the present day.”
When it comes to facing a possible future extinction of yet unknown degree, Saupe says the Earth has advantages it didn’t before. For one, we no longer live on one supercontinent, which means the climate regulates better and prevents the continental interiors from becoming so hot and dry. However, similar to McKinney, she is worried that resources are limited and humans are having a disproportionate effect on biodiversity.
“In the past when you’ve had these major climatic changes, although it was devastating for biodiversity … species had the time, they had the resources for species to eventually rebound,” she says. “Today, we’re worried that those climatic changes will continue, but there is no space – there are more limited resources for species to cope with those changes.”
Find more age of extinction coverage here, and follow biodiversity reporters Phoebe Weston and Patrick Greenfield on X for all the latest news and features
