Nature: quotes, facts and reflections - Page 4

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WonderNature

Bombardier beetles mix defensive chemicals in a reinforced chamber and eject a near-boiling spray as rapid pulses that help regulate pressure and heat.

The beetle stores two ingredients, hydroquinones and hydrogen peroxide, in a reservoir in its abdomen. When threatened, it squeezes them into a tough-walled reaction chamber containing enzymes (proteins that speed up chemical reactions), which set off a violent reaction that heats the mixture to about 100 degrees Celsius and turns part of it to vapour. A 1990 study showed that the spray leaves in about 70 pulses, at roughly 500 pulses a second, rather than as one jet. In 2015 researchers filmed living beetles with high-speed X-ray imaging and showed how the chamber's flexible walls and valves create this rhythm, which also keeps the beetle from scalding itself. Some species can swivel the tip of the abdomen to aim the spray almost anywhere.

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WonderOcean

The barreleye Macropinna microstoma has tubular eyes beneath a transparent, fluid-filled shield, and can rotate them from looking upward to looking forward.

The barreleye lives about 600 to 800 metres down in the northern Pacific and grows to around 15 centimetres. It was described in 1939, but for decades it was known only from specimens hauled up in nets, which destroyed the soft shield, and its eyes were thought to be fixed, pointing straight up. Bruce Robison and Kim Reisenbichler of the Monterey Bay Aquarium Research Institute filmed living barreleyes off California with a remotely operated submersible and, in a 2008 paper, showed the green eyes turning inside the intact dome. The two dark spots above the mouth that look like eyes are in fact its organs of smell. Robison has suggested that the fish may steal food from siphonophores, stinging relatives of jellyfish, with the shield protecting its eyes.

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WonderOcean

In polar seas, strong winds or warmer water welling up from below can keep patches of sea open where thick ice would normally form. These areas of open water or thin ice are called polynyas.

The name comes from a Russian word for a patch of open water in ice. Polynyas matter to wildlife: seals, walruses, whales and seabirds use them to breathe and feed. As new ice keeps forming at their edges, it leaves its salt behind in very dense water, which sinks and helps drive deep ocean currents. The North Water, between Greenland and Canada's Ellesmere Island, is one of the Arctic's richest wildlife areas; the Inuit call it Pikialasorsuaq, 'the great upwelling'. Other polynyas are rare: the Weddell Sea polynya in Antarctica, seen by satellite in the mid-1970s, opened again briefly in 2016 and 2017, and scientists are still working out what triggers it.

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WonderBiology

Archerfish shoot insects off overhanging leaves with a jet of water. They hit the target even though light bends as it passes from air into water, so the insect is not where it appears to be.

Archerfish live in mangroves and river mouths from India and South-East Asia to northern Australia. To shoot, a fish presses its tongue against a groove in the roof of its mouth and snaps its gill covers shut, forcing out a jet that can bring down prey up to about three metres above the water. Adults usually hit with the first shot, and they stay accurate from a wide range of angles. Young fish miss often at first and improve with practice; a 2006 study led by the German biologist Stefan Schuster found they can also learn by watching an experienced fish shoot. Schuster's team also showed that as soon as a struck insect starts to fall, the fish judges where it will land and swims straight there.

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WonderClimate

Atmospheric rivers are long, narrow bands of moist air that carry huge amounts of water vapour, often from the tropics. When mountains force them upward over land, the vapour cools and falls as heavy rain or snow.

Researchers Reginald Newell and Yong Zhu of the Massachusetts Institute of Technology named them in the early 1990s, after finding that much of the water vapour moving through the atmosphere travels in a few narrow plumes, typically thousands of kilometres long but only a few hundred wide. A single strong one can carry more water, as vapour, than the Amazon carries as liquid. Those that reach the west coast of North America from the tropical Pacific near Hawaii are nicknamed the Pineapple Express. They bring much of California's rain and snow, and also many of its worst floods. Since 2019, scientists at the Scripps Institution of Oceanography have ranked them on a five-level scale, from weak and mainly beneficial to exceptional and mainly hazardous, based on how much vapour they carry and how long they last.

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WonderClimate

Yedoma is ancient frozen ground in Siberia, Alaska and Canada's Yukon, packed with ice and with plant and animal remains tens of thousands of years old. When it thaws, microbes can finally break that old carbon down, releasing carbon dioxide and methane.

Yedoma formed during the Pleistocene, the ice-age epoch that ended about 11,700 years ago. Fine silt, carried by wind and water, piled up on cold plains that were never covered by glaciers, burying grasses and roots before they could rot, while huge wedges of ice grew in the ground. Ice now makes up 50 to 90 per cent of its volume, and the deposits, often tens of metres thick, cover more than a million square kilometres. Estimates of the carbon they hold range from about 210 to 500 billion tonnes, many times what burning fossil fuels releases each year. Because the ground is so icy, it slumps into pits and ponds, called thermokarst, as it thaws, exposing still more. Some of the carbon escapes as methane, a far more powerful greenhouse gas than carbon dioxide.

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WonderClimate

Dust from the Sahara crosses the Atlantic and falls on the Amazon, bringing phosphorus that helps replace nutrients washed out of the rainforest's soils by rain.

Studies suggest that more than half of the dust reaching the Amazon comes from one place: the Bodélé Depression in Chad, the dry bed of a much larger ancient lake. Its surface is made largely of diatoms, the fossil shells of tiny algae, and strong winds lift them high into the air. Summer winds carry the dust west over the Atlantic; plumes take about five to seven days to reach the Caribbean. Most Amazon soils are old and heavily washed out, and short of phosphorus, a nutrient that limits how fast trees grow. Dust supplies only part of the phosphorus that falls on the basin, but the amount is comparable to what the forest loses each year to rain and rivers, so without it the soils would slowly run down.

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StillnessClimate

Stalagmites and other mineral formations in caves grow in thin layers that can be dated precisely. The chemistry of each layer records how much rain fell above the cave thousands of years ago.

Scientists call these formations speleothems, from the Greek for 'cave deposit'. Rainwater picks up carbon dioxide from the soil, turns slightly acidic and dissolves limestone as it seeps down through cracks. Inside the cave, where the air holds less carbon dioxide, each drip gives up some of the gas and leaves a thin film of calcite behind; over centuries these films build a stalagmite. The calcite traps traces of uranium, which decays into thorium at a known rate, so layers can be dated precisely over hundreds of thousands of years. Scientists then measure oxygen isotopes, slightly heavier and lighter forms of oxygen atom, whose balance shifts with rainfall. Records from Chinese caves, for example, trace how the Asian monsoon strengthened and weakened through the last ice age.

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WonderEvolution

In Hawaii, silverswords, shrubs, cushion plants, vines and trees all descend from a single tarweed, a sticky plant of the daisy family from North America's Pacific coast, that reached the islands millions of years ago.

The ancestor belonged to the tarweeds, sticky, resinous relatives of sunflowers that grow along the Pacific coast of North America. DNA studies suggest it reached Kauaʻi about five million years ago, perhaps as a seed caught in a bird's feathers. With few competitors, its descendants spread into dry scrub, wet forest, bogs and bare lava fields, and today about 34 species in three genera make up what botanists call the silversword alliance. The best known, the silverswords themselves, form globes of silvery, sword-shaped leaves on the high volcanic slopes of Maui and Hawaiʻi Island; some species flower only once, sending up a tall stalk of flower heads before dying. Many members are now endangered, chiefly by grazing animals and invasive plants brought by people.

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WonderEvolution

Lake Victoria's cichlids, small and often colourful fish, split into more than 500 species with different jaws, colours and diets in only about 15,000 years. Much of the raw genetic material came from an ancient cross between two long-separated lineages.

Lake Victoria dried out almost completely about 17,000 years ago and refilled about 14,700 years ago, as the climate turned wetter. Its cichlids belong to a larger family group of more than 700 closely related species in the region's lakes, which scientists call the Lake Victoria superflock. A genetic study led by Joana Meier, published in 2017, found that the group descends from hybrids between two lineages that had long been apart, one from the upper Nile and one from the Congo basin. The mix gave natural selection a large stock of gene variants to work with as fish specialised in scraping algae, crushing snails, catching insects or hunting other fish. Since Nile perch were introduced to the lake in the 1950s, at least 200 of its cichlid species are thought to have died out.

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WonderTrade

Baltic amber is tree resin that hardened over tens of millions of years. It was carried from the shores of the Baltic Sea to southern Europe along a web of trade routes known as the Amber Road, reaching Mycenaean Greece and, later, Roman workshops at Aquileia.

Amber began as resin in ancient forests and hardened underground; it is light, feels warm to the touch, and sometimes holds insects trapped millions of years ago. Storms still wash pieces up on Baltic beaches. There was never one paved road: amber moved along rivers and overland tracks, passing from hand to hand. Archaeologists can tell Baltic amber from other kinds by its chemistry, notably its succinic acid, and so trace beads found far to the south back to the Baltic. The Roman writer Pliny the Elder tells of a knight sent north under Emperor Nero who came back with so much amber that it decorated an entire gladiator show in Rome.

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WonderScience

In 1936 the Danish seismologist Inge Lehmann used earthquake waves to show that the Earth's core has two parts: a solid inner core inside a liquid outer core.

Lehmann, a seismologist (a scientist who studies earthquakes and the waves they send through the Earth), headed the seismology department of Denmark's Geodetic Institute from 1928. Scientists then thought the core was a single ball of molten metal, which should bend certain waves away and leave a 'shadow zone' on the far side of the planet where they could not arrive. Studying records of a large 1929 earthquake in New Zealand, she noticed strong waves reaching stations in Russia that lay inside that zone. Her explanation was a smaller, solid core at the centre that reflects the waves. Leading seismologists accepted it within a few years, and computer calculations confirmed it in 1971. The inner core stays solid, despite temperatures similar to the Sun's surface, because of the enormous pressure. Lehmann died in 1993, aged 104.

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WonderTechnology

Lidar works like radar but with laser light: it measures distance by timing how long each pulse takes to bounce back. Flown over a forest, it can map the ground through gaps in the leaves and reveal ancient roads, walls and buildings hidden by trees.

The name stands for light detection and ranging. An instrument on an aircraft, drone or satellite fires rapid pulses and turns each round-trip time into a distance, building a “point cloud” of millions of measurements of roofs, branches and ground. Light cannot pass through solid leaves, but some pulses slip through small gaps, and software separates these ground returns from the canopy. Remove the digital forest and the bare terrain appears. In 2018 a lidar survey of the Maya Biosphere Reserve in northern Guatemala revealed more than 60,000 structures, from houses to raised roads and defences, many of them previously unknown, without a spade entering the soil. The same method maps flood plains, measures forests and helps self-driving cars see.

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WonderBiology

Environmental DNA, or eDNA, is the genetic material that animals and plants shed into water, soil and air. By collecting and testing it, scientists can find out which species live in a place without seeing or catching any of them.

Animals and plants constantly shed skin cells, scales, mucus, pollen and waste. Researchers filter a water sample or collect soil, extract the DNA and test it, either for one target species or for short, telltale DNA sequences that identify many species at once. The method finds rare, shy or invasive species with little disturbance. In June 2018 a team led by the geneticist Neil Gemmell sampled the water of Loch Ness in Scotland; they found no reptile DNA at all, but a great deal of eel DNA. A positive result is not a headcount, though: DNA drifts with currents, breaks down over time and can contaminate samples, so results still need careful interpretation by ecologists.

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DriveScience

Ynés Mexía, a Mexican-American botanist, took her first botany course in her fifties and began collecting expeditions soon afterwards. In about thirteen years of fieldwork she gathered some 145,000 plant specimens, around 500 of them species new to science.

Mexía came to botany by an unlikely route. In 1909, aged 39, she suffered a mental and physical breakdown and moved to California for treatment; hikes with the Sierra Club helped her recover and drew her to nature, and in her early fifties she enrolled at the University of California, Berkeley. On her first expedition, to Mexico in 1925, she fell from a cliff and broke ribs, yet came back with 500 specimens. In 1928 she collected more than 6,000 in what is now Denali National Park in Alaska, and a two-and-a-half-year South American journey, including some 4,800 kilometres by canoe on the Amazon, yielded about 65,000. She died of lung cancer in 1938, aged 68. A genus, Mexianthus, and about fifty species carry her name.

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StillnessMind

Seeing or hearing birds is linked to a better mood that lasts for hours, according to a 2022 smartphone study of 1,292 people. Participants who noticed birds at one check-in also rated their mental wellbeing higher at the next one, hours later.

The study used Urban Mind, an app developed at King's College London that prompts people several times a day to say what they can see and hear at that moment and how they feel. Asking in the moment avoids the distortions of remembering one's mood later. Between April 2018 and October 2021, the 1,292 participants answered 26,856 of these prompts. The link with birdlife showed up both in healthy people and in those with a diagnosis of depression, the most common mental illness in the world. Because the study only observed people rather than testing an intervention, it cannot prove that the birds caused the lift: places with birds may be pleasanter in other ways too.

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StillnessScience

Asperitas, a rough, wave-like underside to a layer of cloud, was added to the World Meteorological Organization's International Cloud Atlas in 2017. Amateurs got it there: the Cloud Appreciation Society collected its members' photographs of the pattern and campaigned for its recognition.

The International Cloud Atlas is the official reference that weather services around the world use to name and classify clouds. The 2017 edition was its first full revision in about 30 years, and asperitas, Latin for 'roughness', was one of its new supplementary features: a detail that can appear on several kinds of cloud rather than a cloud type of its own. Despite its menacing look, it does not usually bring severe weather itself. The Cloud Appreciation Society was founded in January 2005 by the British writer Gavin Pretor-Pinney to celebrate clouds for their own sake and now has more than 60,000 members in about 120 countries. It is a rare case of amateur observers shaping the official vocabulary of meteorology.

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StillnessMind

Forest kindergartens are early-years programmes, usually for children aged three to six, that use woodland or other natural settings as the main classroom. The children often spend most of the day outside, in almost any weather.

The idea is usually traced to Ella Flatau in Denmark, who in the early 1950s began spending her days with children in the woods near her home; neighbours' interest turned it into a regular kindergarten. Germany had informal nature kindergartens from 1968, but it officially recognised forest kindergartens as a form of daycare only in 1993, which opened the way to state funding. Their number grew from about 450 in 2005 to more than 1,500 by 2017. The model has since spread to Sweden, the UK, the US and beyond, sometimes under the name 'forest school'. Most keep a hut or shelter for the worst weather, but the day is built around outdoor play, with adults supporting it rather than directing it.

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WonderMind

The widely repeated claim that the human attention span has fallen to eight seconds, supposedly less than a goldfish's, traces to a 2015 marketing report. The figure it quoted has never been traced to any study.

The figure appeared in a 2015 report by Microsoft Canada's advertising team, which credited it to a statistics website, Statistic Brain, that named no traceable study behind it. In 2017 the BBC journalist Simon Maybin followed the trail and found neither research measuring an eight-second human attention span nor any study showing that goldfish manage only nine seconds. Psychologists do not treat attention as a single number. Staying focused on a task, noticing something new and keeping information in mind are measured in different ways, and each depends heavily on the task, the setting and how interesting the material is. Attention can fade in minutes on a dull task and last for hours on an absorbing one.

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WonderScience

Ice drilled from Antarctica holds an unbroken record of Earth's climate going back at least 1.2 million years. The European Beyond EPICA team reached bedrock at Little Dome C, about 2.8 kilometres down, in January 2025; the top 2,480 metres can be read in order, while the deepest ice is deformed.

Beyond EPICA follows the European Project for Ice Coring in Antarctica, or EPICA, whose core from nearby Dome C, drilled between 1996 and 2004, reached ice about 800,000 years old. Scientists wanted older ice because between about 1.2 million and 700,000 years ago Earth's ice ages changed rhythm, from roughly one every 41,000 years to roughly one every 100,000 years. The cause of this shift, called the Mid-Pleistocene Transition, is still debated. As snow is pressed into ice it traps tiny bubbles of air, so the core holds real samples of the ancient atmosphere, including carbon dioxide and methane, while the ice itself records past temperatures. Laboratories across Europe are now analysing it.

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WonderHistory

New College, Oxford, gave its 14th-century hall a new open oak roof in 1865, built with timber from woodland the college had owned for centuries. A famous story says the oaks had been planted long before for that very roof, but the college's records do not support it.

New College was founded in 1379, and by the end of the 18th century its hall's original open oak roof had been hidden behind a ceiling. After the students' Junior Common Room offered £1,000 towards restoring it, work on today's roof began in 1865 under the architect George Gilbert Scott. The popular version of the story, told by the anthropologist Gregory Bateson and retold in many books since, has a college forester reveal that oaks were planted at the founding for exactly this day. The college's records do not bear that out. What they show is less magical but still impressive: an institution that kept and managed its woodland for centuries simply had good oak to hand when it needed it.

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