Plants produce more nectar when they ‘hear' bees buzzing, scientists find
The research suggests that plants are a more active partner than previously thought in their symbiotic relationship with pollinators. The behaviour could be a survival strategy that favours giving nectar and sugar to bees over so-called nectar robbers that do not offer plants any reproductive benefits.
'There is growing evidence that both insects and plants can sense and produce, or transmit, vibro-acoustic signals,' said Prof Francesca Barbero, a zoologist at the University of Turin, who led the research.
The findings add to the 'truly astonishing' multitude of ways that plants can perceive their surroundings, including the presence of beneficial and harmful insects, temperature, drought and wind, Barbero added. In future, the team suggested, buzzing noises could be used on farms as an environmentally friendly way of enhancing the pollination of crops.
The scientists are not yet sure how the plants might be listening in. They could rely on mechanoreceptors, cells that respond to mechanical stimulation such as touch, pressure or vibrations. 'Plants do not have a brain, but they can sense the environment and respond accordingly,' said Barbero.
After observing that bees and competing insects have distinct vibrational signals that are used in mating and other forms of communication, Barbero and her collaborators set out to investigate whether plants detected these signals.
They played recordings near snapdragons of the buzzing sounds produced by snail-shell bees (Rhodanthidium sticticum), which are efficient snapdragon pollinators, comparing the plants' response to sounds produced by a non-pollinating wasp and ambient sounds.
The researchers found that in response to the snail-shell bee noises, the snapdragons increased the volume of nectar and its sugar content and showed altered expression in genes that govern sugar transport and nectar production.
This could be an evolutionary adaptation to coax the pollinators into spending more time at the flowers. 'The ability to discriminate approaching pollinators based on their distinctive vibro-acoustic signals could be an adaptive strategy for plants,' said Barbero.
While it is clear that buzzing sounds can trigger nectar production, the scientists are now looking into whether sounds from plants are being used actively to draw in suitable pollinators.
They are also testing whether the plant responses enhanced the attraction for all flower visitors – including nectar robbers – or only the best pollinators.
'Our hypothesis is that the changes in nectar we observed after treating the plants with the sounds of the best pollinators specifically increase the attraction of this particular species (Rhodanthidium sticticum),' said Barbero. 'However, to confirm this, we need to conduct choice tests to assess how different nectar concentrations attract various species.
'If this response from insects is confirmed, sounds could be used to treat economically relevant plants and crops, and increase their pollinators' attraction,' she said.
The findings were presented on Wednesday at the joint 188th Meeting of the Acoustical Society of America and 25th International Congress on Acoustics in New Orleans.
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Daily Mail
3 hours ago
- Daily Mail
Mystery of ancient DNA marker rewrites story of how humans first reached the Americas
One of the world's greatest genetic mysteries is how a DNA marker present in Europe reached North America, leaving no clear trail through Siberia or Alaska. Scientists have been baffled by how Haplogroup X arrived more than 12,000 years ago, raising new questions about how the Americas were first populated. Haplogroup X is a rare maternal DNA lineage, passed down from mother to child, found in both Europe and North America. Its unusual presence suggests that early Americans may have arrived in multiple waves, challenging the traditional view that all Native American maternal lineages came solely from Siberia via the Bering Land Bridge. Today, the X2a branch of Haplogroup X is found in several Indigenous groups across North America, including the Ojibwe, Sioux, Nuu-chah-nulth, Navajo, and Yakama. It is also found in Europe and Western Asia, hinting at a far more complex migration history than previously thought. Dr Krista Kostroman, a genetic medicine specialist and Chief Science Officer at The DNA Company, told the Daily Mail: 'Haplogroups are like family seals. 'They are distinctive genetic marks passed down over thousands of years, connecting us to ancestors who lived in entirely different landscapes, climates, and cultures. Because they rarely change, they serve as identifiers for tracing ancient migrations.' Haplogroups A, B, C, and D are the most common maternal lineages among Native American populations. They each have distinct genetic signatures that trace back to different regions of East Asia and reflect separate waves of migration into the Americas during the late Ice Age. For example, haplogroup A is widespread among populations in North, Central, and South America, while B is more frequent in the Pacific Northwest and parts of Central and South America. Haplogroup C is concentrated in northern and western Indigenous groups, and D is found across North and South America but is particularly common in the Arctic and sub-Arctic regions. Together, these haplogroups provide a clear picture of the Asian origins of most Native American maternal lineages, which makes Haplogroup X's unusual distribution all the more striking. X2a appears among Indigenous groups in the Northeast and Great Lakes regions, while X1 is found primarily in North Africa, the Near East, and parts of the Mediterranean, though it remains rare even there. 'That rarity makes it a powerful clue for tracing human history,' Kostroman said. 'When an uncommon marker appears in distant, disconnected regions, it signals a shared connection in the deep past.' Despite speculation, Haplogroup X does not prove Native American ancestry nor a direct European migration. Haplogroup X is rare in Siberia and Alaska, with some researchers suggesting that it represents an earlier migration, possibly via a coastal route. The most widely accepted theory is that X2a arrived in North America during the late Ice Age as part of migrations across the Bering Land Bridge from Northeast Asia, arriving alongside other maternal lineages. 'Other possibilities are more speculative,' Kostroman noted. 'Small groups carrying Haplogroup X may have arrived earlier, or it may have entered the Americas in multiple waves alongside other lineages.' When Haplogroup X was first identified in the 1990s, its presence in Europe and among some Indigenous North Americans sparked controversy. Some researchers proposed a direct Atlantic crossing, known as the Solutrean hypothesis, though this has largely been dismissed. The X2a lineage differs from European and Near Eastern branches, reflecting a more complex migration history. Parallels with other rare haplogroups further illustrate the complexity of human migration. Haplogroup C1b, found in North and South America but rare in Asia, provides clues about secondary migration waves. Haplogroup B2a, present in some Amazonian populations, shows deep diversification within the Americas. And Haplogroup U5, a rare European maternal lineage dating to the Ice Age, demonstrates how rare lineages can survive in isolated populations, much like X2a did in North America. Some groups have speculated that Haplogroup X supports religious or pseudoscientific claims, including theories linking Native Americans to Hebrew ancestry or the Book of Mormon. Others suggest Europeans may have crossed the Atlantic during the last Ice Age. Kostroman cautions against overinterpretation: 'Over the past two decades, Haplogroup X has shifted from being the centerpiece of bold trans-Atlantic theories to a subtle but powerful clue in understanding human prehistory. 'It tells us that human migration was complex, involving multiple waves, exploratory groups, and connections across Eurasia long before people reached the New World.'
The Guardian
3 hours ago
- The Guardian
The power of pulses: 15 easy, delicious ways to eat more life-changing legumes
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'Many are 'nitrogen fixers', meaning they have the ability to convert nitrogen in the atmosphere into a form that can be used in the soil, making it more fertile for other crops,' she writes. Justine Butler, the head of research at Viva!, says: 'The lowest-impact beef still creates six times the greenhouse gases and uses 36 times more land per gram of protein than peas.' Pulses are filling and good value but, say the Reading researchers, the typical British adult eats only about 15g a day, with the average household spending just £1.68 on pulses a week. UK guidelines state that 80g of pulses (about a third of a tin) counts as one of your five a day. The University of Reading study is part of the Raising the Pulse project, which aims to increase pulse consumption to improve public and planetary health. One of its strategies is adding fava bean (dried broad bean) flour to white bread – similar to a successful programme in Denmark using rye flour to increase wholegrain consumption. Prof Julie Lovegrove, the director of the Hugh Sinclair Unit of Human Nutrition at the University of Reading, says: 'These foods are not only nutritious but also incredibly versatile, affordable and sustainable.' If you want to start eating more pulses, here are 15 things you need to know. You don't have to cook pulses for hours. 'Don't be put off by the idea that you have to soak dried pulses in advance,' says Maidment. 'I am rarely organised enough to do so, but thankfully there's a huge range of jarred and canned varieties that require no prep and are hugely convenient. If you can afford to spend a bit more, then jarred varieties have the edge over canned in terms of flavour and texture. Brands such as Bold Bean Co, Brindisa or Belazu are consistently excellent.' But batch-cooking dried pulses is the best value. Jenny Chandler, the author of Super Pulses and Pulse, soaks and cooks a big pot of pulses once a week. 'You will finish up with well over double their volume – it's a really economical way to have a ready supply. They will keep in their cooking water for five days in the fridge and you can freeze any leftovers. Use them in salads, soups, purees, curries, stews and even puddings – they will become the bedrock of your cooking.' Pulses are for everyone. 'You do not have to be vegetarian or vegan to enjoy pulses – far from it,' says Maidment. 'We should all be eating more pulses. For instance, in a traybake, I'll use one chicken thigh per person instead of two, and add a can of chickpeas or butter beans. I often add a can of lentils to bolognese. You're still getting filling protein, but with the added benefits of gut-friendly fibre and numerous other minerals, vitamins and antioxidants.' They make meals go much further. 'Most pulses are relatively cheap and quite mild in taste, making them ideal for bulking out soups, stews and curries without affecting the original flavour,' says Maidment. 'You can often use different varieties interchangeably, depending on what you have to hand.' Chandler adds a handful of cooked pulses to all sorts of dishes. 'Throwing a few chickpeas or cannellini beans into a simple tomato sauce with pasta not only ups the nutritional profile, but also keeps you feeling full for much longer,' she says. Baked beans are just the beginning. 'By far the most eaten pulse in the UK is the haricot bean due to its starring role in tinned baked beans,' says Maidment. 'Butter beans, cannellini beans, black beans and kidney beans are also popular, but there is a huge variety of beans to try. For instance, flageolet beans are delicate, pale-green beans popular in French cooking – try them in a slow-braised lamb stew with garlic, thyme and white wine.' 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He also uses chickpea (AKA gram) flour to make farinata or socca, a savoury pancake; panisse (chickpea fries); and bhajis and pakoras. 'Sometimes I use it as a base for a sort of non-traditional, don't-tell-the-Italians pizza.' Lentils cook more quickly than most pulses. Red split lentils are especially quick, cooking in about 15 minutes. Lentils don't need soaking, but it does reduce the cooking time. Maidment likes to experiment with different dals. 'Regional Indian dals can be made with a range of lentils – yellow moong, black urad, chana dal – each bringing a slightly different flavour and texture,' says Maidment. But she also has a soft spot for tinned lentils. 'I often roast drained, tinned lentils with olive oil and crushed garlic to boost their flavour and add crispness before throwing them into a salad – perhaps ricotta and prosciutto, or chopped fresh and sun-dried tomatoes, mozzarella and basil.' Pulses make delicious dips. 'Hummus is the classic, but you can blend most pulses into dips,' says Maidment. 'Fava, a fabulous Greek split yellow pea dip, is absolutely worth making.' Blend cooked split yellow peas with caramelised onions and garlic, lemon juice, olive oil, salt and a little of the beans' cooking liquor or water to make. Pulse liquid has many uses. 'Jarred and canned pulses are usually stored in a liquid known as aquafaba,' says Maidment. 'It can be great for adding creaminess to savoury dishes or used as an egg alternative in baking.' She advises checking the salt levels and ingredients list before using – some pulses have added preserving and firming agents. Black beans make the best veggie burgers, says Yonan. The Guardian's Meera Sodha agrees. She mashes a drained tin of black beans with breadcrumbs, garlic and onion powders, chipotle paste, dijon mustard, tomato ketchup and a splash of aquafaba, shapes them into patties, then fries them in olive oil until crispy. British pulses are having a revival. Maidment and Chandler both recommend carlin peas, pleasingly also known as black badgers, which are a heritage British pulse. They are available dried and cooked from companies such as Hodmedod's. 'They're small, nutty brown peas, and make a great alternative to chickpeas, with a similarly impressive nutrient profile,' says Maidment. She roasts cooked carlin peas until crispy, then adds them to salads such as quinoa, broccoli and halloumi. Chandler uses them in dips and curries, and to make a version of refried beans. 'They're much more versatile than yellow or green dried peas as they don't have such a pronounced 'pea' flavour,' she says. In the US, Yonan suggests the lady pea, a spherical white bean that is popular in southern cuisine. Pulses make great protein shakes. 'A handful of cooked pulses added into a smoothie will give it a great creamy texture and make it more nourishing,' says Chandler. She adds black beans or borlotti beans to dark berry smoothies, and chickpeas, cannellini beans or butter beans to green smoothies. Pulse-based pasta is worth a try. There is an increasing range of high-fibre pasta made from pulse flour: peas, lentils, chickpeas, black beans, mung beans … Chandler enjoys this alternative pasta, but says she doesn't use it in classical Italian dishes: 'I may use it in a pasta salad, say, or team it with a blue cheese and walnut sauce.' Yonan agrees that pulse pasta is best paired with 'pungent flavours – super-garlicky or spicy'. Pulses aren't just for savoury dishes. Yonan makes a chocolate and chickpea tart, and adds adzuki beans to brownies. 'Adzuki beans are used in a lot of Asian desserts, such as mochi and ice-cream,' he says. Maidment prefers to use kidney beans in her brownies, while Chandler has a recipe for a simple chocolate and cannellini bean mousse. Drain and retain the liquid from a tin of cannellini beans. Blitz the beans with 150g of melted dark chocolate and an optional tablespoon of cocoa powder. Whisk the liquid for five to 10 minutes, until frothy. Fold into the melted chocolate and bean mix, and sweeten with a couple of tablespoons of maple or date syrup. Chill the mix before eating, perhaps topped with some chopped stem ginger in syrup, or served with fresh raspberries. Do you have an opinion on the issues raised in this article? If you would like to submit a response of up to 300 words by email to be considered for publication in our letters section, please click here.
The Guardian
4 hours ago
- The Guardian
Why antibiotics are like fossil fuels
In 1954, just a few years after the widespread introduction of antibiotics, doctors were already aware of the problem of resistance. Natural selection meant that using these new medicines gave an advantage to the microbes that could survive the assault – and a treatment that worked today could become ineffective tomorrow. A British doctor put the challenge in military terms: 'We may run clean out of effective ammunition. Then how the bacteria and moulds will lord it.' More than 70 years later, that concern looks prescient. The UN has called antibiotic resistance 'one of the most urgent global health threats'. Researchers estimate that resistance already kills more than a million people a year, with that number forecast to grow. And new antibiotics are not being discovered fast enough; many that are essential today were discovered more than 60 years ago. The thing to remember is that antibiotics are quite unlike other medicines. Most drugs work by manipulating human biology: paracetamol relieves your headache by dampening the chemical signals of pain; caffeine blocks adenosine receptors and as a result prevents drowsiness taking hold. Antibiotics, meanwhile, target bacteria. And, because bacteria spread between people, the challenge of resistance is social: it's as if every time you took a painkiller for your headache, you increased the chance that somebody else might have to undergo an operation without anaesthetic. That makes resistance more than simply a technological problem. But like that British doctor in 1954, we still often talk as if it is: we need to invent new 'weapons' to better defend ourselves. What this framing overlooks is that the extraordinary power of antibiotics is not due to human ingenuity. In fact, the majority of them derive from substances originally made by bacteria and fungi, evolved millions of years ago in a process of microbial competition. This is where I can't help thinking about another natural resource that helped create the modern world but has also been dangerously overused: fossil fuels. Just as Earth's geological forces turned dead plants from the Carboniferous era into layers of coal and oil that we could burn for energy, so evolution created molecules that scientists in the 20th century were able to recruit to keep us alive. Both have offered an illusory promise of cheap, miraculous and never-ending power over nature – a promise that is now coming to an end. If we thought of antibiotics as the 'fossil fuels' of modern medicine, might that change how we use them? And could it help us think of ways to make the fight against life-threatening infections more sustainable? The antibiotic era is less than a century old. Alexander Fleming first noticed the activity of a strange mould against bacteria in 1928, but it wasn't until the late 1930s that the active ingredient – penicillin – was isolated. A daily dose was just 60mg, about the same as a pinch of salt. For several years it was so scarce it was worth more than gold. But after production was scaled up during the second world war, it ended up costing less than the bottle it came in. This abundance did more than tackle infectious diseases. Just as the energy from fossil fuels transformed society, antibiotics allowed the entire edifice of modern medicine to be built. Consider surgery: cutting people open and breaking the protective barrier of the skin gives bacteria the chance to swarm into the body's internal tissues. Before antibiotics, even the simplest procedures frequently resulted in fatal blood poisoning. After them, so much more became possible: heart surgery, intestinal surgery, transplantation. Then there's cancer: chemotherapy suppresses the immune system, making bacterial infections one of the most widespread complications of treatment. The effects of antibiotics have rippled out even further: they made factory farming possible, both by reducing disease among animals kept in close quarters, and by increasing their weight through complex effects on metabolism. They're one of the reasons for the huge increase in meat consumption since the 1950s, with all its concomitant welfare and environmental effects. Despite the crisis of resistance, antibiotics remain cheap compared with other medicines. Partly – as with fossil fuels – this is because the negative consequences of their use (so-called externalities) are not priced in. And like coal, oil and gas, antibiotics lead to pollution. One recent study estimated that 31% of the 40 most used antibiotics worldwide enter rivers. Once they're out there, they increase levels of resistance in environmental bacteria: one study of soil from the Netherlands showed that the incidence of some antibiotic-resistant genes had increased by more than 15 times since the 1970s. Another source of pollution is manufacturing, particularly in countries such as India. In Hyderabad, where factories produce huge amounts of antibiotics for the global market, scientists have found that the wastewater contains levels of some antibiotics that are a million times higher than elsewhere. Like the climate crisis, antibiotic resistance has laid global inequalities bare. Some high-income countries have taken steps to decrease antibiotic use, but only after benefiting from their abundance in the past. That makes it hard for them to take a moral stand against their use in other places, a dilemma that mirrors the situation faced by post-industrial nations urging developing nations to forgo the economic benefits of cheap energy. This may be where the similarities end. While we look forward to the day when fossil fuels are phased out completely, that's clearly not the case with antibiotics, which are always going to be part of medicine's 'energy mix'. After all, most deaths from bacterial disease worldwide are due to lack of access to antibiotics, not resistance. What we are going to need to do is make our approach to development and use much more sustainable. Currently, many pharmaceutical companies have abandoned the search for new antibiotics: it's hard to imagine a more perfect anti-capitalist commodity than a product whose value depletes every time you use it. That means we need alternative models. One proposal is for governments to fund an international institute that develops publicly owned antibiotics, rather than relying on the private sector; another is to incentivise development with generously funded prizes for antibiotic discovery. And to address the issue of overuse, economists have suggested that health authorities could run 'subscription' models that remove the incentive to sell lots of antibiotics. In one pilot scheme in England, two companies are being paid a set amount per year by the NHS, regardless of how much of their product is actually used. Finally, we have to remember that antibiotics aren't the only game in town. Supporting other, 'renewable' approaches means we get to use the ones we do have for longer. Vaccines are vital to disease prevention – with every meningitis, diphtheria or whooping cough vaccine meaning a potential course of antibiotics forgone. And the 20th century's largest reductions in infectious disease occurred not because of antibiotics, but thanks to better sanitation and public health. (Even in the 2000s, the threat of MRSA was addressed with tried-and-tested methods such as handwashing and cleaning protocols – not new antibiotics.) Given that antibiotics themselves emerged unexpectedly, we should also be investing more in blue-skies research. Just as we no longer burn coal without a thought for the consequences, the era of carefree antibiotic use is now firmly in the past. In both cases, the idea that there wouldn't be a reckoning was always an illusion. But as with our slow waking up to the reality of the climate crisis, coming to appreciate the limits of our love affair with antibiotics may ultimately be no bad thing. Liam Shaw is a biologist at the University of Oxford, and author of Dangerous Miracle (Bodley Head). Being Mortal: Medicine and What Matters in the End by Atul Gawande (Profile, £11.99) Infectious: Pathogens and How We Fight Them by John S Tregoning (Oneworld, £10.99) Deadly Companions: How Microbes Shaped our History by Dorothy H Crawford (Oxford, £12.49)
