Steve Connor

Not Even a Global Catastrophe Can Stop the Growth of Human Population?

The global human population is “locked in” to an inexorable rise this century and will not be easily shifted, even by apocalyptic events such as a third world war or lethal pandemic, a study has found.

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Air Pollution Kills More People Than HIV/AIDS

Air pollution from outdoor sources kills about 3.3 million people per year worldwide and the numbers are likely to double by 2050 even if every country imposes existing air-quality legislation, a study has found.

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2015 Will Be the Hottest Year on Record

Climate scientists are predicting that 2015 will be the hottest year on record “by a mile”, with the increase in worldwide average temperatures dramatically undermining the idea that global warming has stopped — as some climate-change sceptics claim.

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Global Warming Makes Trees Grow at Fastest Rate for 200 Years

Forests in the northern hemisphere could be growing faster now than they were 200 years ago as a result of climate change, according to a study of trees in eastern America.

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Millions of Tons of Plastic Debris Floating in Oceans Is Now Thought to Be Toxic

Scientists have identified a new source of chemical pollution released by the huge amounts of plastic rubbish found floating in the oceans of the world. A study has found that as plastics break down in the sea they release potentially toxic substances not found in nature and which could affect the growth and development of marine organisms.

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The Frightening New Evidence Scientists Have Just Learned About Global Warming

Scientists have found the first unequivocal evidence that the Arctic region is warming at a faster rate than the rest of the world at least a decade before it was predicted to happen.

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A Miracle Drug for Malaria

The lives of more than a million children who die each year from malaria could be saved by a new technique for making a drug based on an ancient Chinese herbal remedy first used more than 2,000 years ago.

Scientists said yesterday that the drug will be the first product of a new approach to making pharmaceuticals using "synthetic biology", where genetically engineered microbes with implanted artificial chromosomes, or gene "cassettes", are grown in giant fermenting vats.

The plan is to be able to make enough quantities of the drug in a single fermenter, or bioreactor, within two years to supply the needs of everyone in the world suffering from malaria -- up to 500 million people -- at a 10th of the cost of existing drugs.

The drug, artemisinin, is based on extracts from the Chinese plant Artemesia annua, or sweet wormwood, which is known to have been used in China as a remedy for malaria fever since at least the second century BC.

Artemisinin is already produced by laboriously extracting it from the dried leaves and flowers of the sweet wormwood, but at more than $2 (£1) for a course of treatment it is too expensive for the majority of people in the developing world who contract malaria from mosquito bites.

Between one and three million people die of malaria every year, 90 per cent of them children under five. The people who survive suffer bouts of severe pain and fever from what has been called one of the biggest sources of misery in the world.

The new way of producing artemisinin involves inserting about a dozen synthetic genes into yeast cells, which are then grown by fermenting them with sugar. The added gene cassettes control the biochemical reactions, or pathway, leading to a precursor chemical, artemisinic acid, which is then converted chemically into the final active ingredient, artemisinin.

By making artemisinin in living yeast cells it is possible to change its biological structure to keep ahead of any future artemisinin-resistant strains of malaria that develop.

Scientists hope that by producing a semi-synthetic form of artemisinin on an industrial scale using a single bioreactor as big as a three-story town house, they will be able to bring down the price of treatment to less than 20 cents a course, making it the cheapest and most effective anti-malarial drug on the market.

Professor Jay Keasling of the University of California, Berkeley, said that the low price and widespread availability of the semi-synthetic drug will directly help millions of sufferers, as well as undermining the counterfeit market in artemisinin, which increases the risk of drug resistance as well as doing little to help malaria patients. "We want it to be affordable to people who need it, to be available to people who need it, and we don't want it to be abused," Professor Keasling said during a two-day conference on synthetic biology at the Royal Society in London.

"The process is very similar to brewing beer ... but we're talking about turning on 12 genes simultaneously in the genetically engineered yeast cells and controlling their outputs to balance the metabolic pathway leading to artemisinin," said Professor Keasling. The research pioneered by the professor was funded with the help of a $42.6 million research grant from the Bill and Melinda Gates Foundation and is being taken into industrial production with the help of the French company sanofi aventis, which will build a bioreactor in Europe by 2010.

The bioreactor will be between 50,000 and 100,000 liters in size and will produce continuous amounts of the drug in sufficient quantities to treat the 500 million people a year who develop malaria, he said.

Producing semi-synthetic artemisinin on an industrial scale will also undermine speculators who have hoarded stockpiles of the wild plant, raising prices fourfold, since artemisinin was endorsed as the most effective malaria treatment by the WHO in 2004. "We can drive down costs, hitting the market price at its launch and significantly reducing costs further over time," Professor Keasling said.

Taken with other anti-malarial drugs, treatment with artemisinin is said to be almost 100 per cent effective in blocking the life cycle of the malaria parasite within the human body.

Plastic Is Killing our Oceans

One cigarette lighter, a toothbrush, a toy robot and a tampon applicator. The list of plastic items recovered from the stomach of a Laysan albatross chick that died on a remote Pacific island reads like a random assortment of everyday household objects.

It is now clear this chick is among many thousands of seabirds that have died from ingesting plastic debris, and nowhere in the world seems to be too isolated for this deadly form of marine pollution.

Dutch scientists have found that more than nine out of 10 European fulmars -- seabirds that eat at sea -- die with plastic rubbish in their stomachs. A study of 560 fulmars from eight countries revealed they had ingested an average of 44 plastic items. The stomach of one fulmar that died in Belgium contained 1,603 separate scraps of plastic.

Birds are not the only ones to suffer. Turtles, whales, seals and sea lions have all eaten plastic. But the most sinister problem may be a hidden one at the other end of the food chain.

Small sand-hoppers, barnacles and lugworms have also been found to have ingested tiny fragments of plastic, some of which are thinner than a human hair. Apart from the physical damage these particles cause, they may also transfer toxic chemicals to creatures at the base of the marine food web.

It is fairly well established that certain toxins in the ocean, such as polychlorinated biphenyls (PCBs), the pesticide DDT and other potentially dangerous substances, can become concentrated on the surface of plastic debris.

The reason why plastic is so ubiquitous in our homes and offices, of course, is for the same reason why it builds up in the wider environment: it is resilient and takes years to break down into its constituent molecules.

This is even more so in the marine environment, where the sea tends to protect plastic from the ultraviolet light that helps to break it down.

In fact, it is estimated that much of the plastic rubbish that fell into the sea 50 years ago is still there today, either floating in the huge circulating "gyres" of the Pacific or sitting on the seabed waiting to be gobbled up by a passing sea creature.

It is estimated that the amount of plastic we are consuming will continue to grow substantially, by as much as a third in the space of a single decade in the case of each American consumer.

The only way to deal with the growing threat plastic poses to wildlife and the environment is to curb our consumption and to no longer treat plastic as an innocuous disposable commodity. Indeed, there is now a case for it to be treated as a potentially toxic waste product with the stiffest sanctions for its desultory disposal.

DNA Breakthrough Could Give Humans Lifespans Lasting Hundreds of Years

A genetically engineered organism that lives 10 times longer than normal has been created by scientists in California. It is the greatest extension of longevity yet achieved by researchers investigating the scientific nature of ageing.

If this work could ever be translated into humans, it would mean that we might one day see people living for 800 years. But is this ever going to be a realistic possibility?

Valter Longo is one of the small but influential group of specialists in this area who believes that an 800-year life isn't just possible, it is inevitable. It was his work at the University of Southern California that led to the creation of a strain of yeast fungus that can live for 10 weeks or more, instead of dying at its usual maximum age of just one week.

By deleting two genes within the yeast's genome and putting it on a calorie-restricted diet, Longo was able to extend tenfold the lifespan of the same common yeast cells used by bakers and brewers. The study is published later this week in the journal Public Library of Science Genetics.

There is, of course, a huge difference between yeast cells and people, but that hasn't stopped Longo and his colleagues suggesting that the work is directly relevant to human ageing and longevity. "We're setting the foundation for reprogramming healthy life. If we can find out how the longevity mechanism works, it can be applied to every cell in every living organism," Longo says.

"We're very, very far from making a person live to 800 years of age. I don't think it's going to be very complicated to get to 120 and remain healthy, but at a certain point I think it will be possible to get people to live to 800. I don't think there is an upper limit to the life of any organism."

For most gerontologists -- people who study the science of ageing -- such statements are almost heretical. There is a general view in this field that there is a maximum human lifespan of not more than about 125 years. Jeanne Calment, the oldest documented person, died at the age of 122 years and 164 days. According to the orthodox view of ageing, she was one of the few lucky enough to have reached that maximum, upper limit of human lifespan.

The attitude of most mainstream gerontologists towards the idea that people may one day live for many centuries -- or even 1,000 years, as one scientific maverick has suggested -- is best summed up by Robin Holliday, a distinguished British gerontologist, in his recent book Aging: The Paradox of Life. "How is it possible to make these claims?" Holliday asks. "The first requirement is to ignore the huge literature on ageing research... The second is to ignore the enormous amount of information that has been obtained by the study of human age-associated disease; in other words, to ignore the many well-documented textbooks on human pathology. The third is to propose that in the future, stem-cell technology, and other technologies, will allow vulnerable parts of the body to be replaced and/or repaired. The new 'bionic' man will therefore escape from ageing," Holliday says.

Like many experts on the science of ageing, Holliday is deeply sceptical about the idea that the ageing process can somehow be circumvented, allowing people to extend their lives by decades or even centuries. "The whole [anti-ageing] movement not only becomes science fiction; it is also breathtakingly arrogant," Holliday says. An immense hinterland of biomedicine suggests that death at a maximum age of about 125 is inevitable, he says.

But that is precisely what Valter Longo is suggesting with his work on the yeast that can live longer than 10 weeks. "We got a tenfold life-span extension, which is, I think, the longest that has ever been achieved in any organism," he says.

By knocking out two genes, known as RAS2 and SCH9, which promote ageing in yeast and cancer in humans, and putting the microbes on a diet low in calories, Longo achieved the sort of life extension that should in theory be impossible. As Anna McCormick, head of genetics and cell biology at the US National Institute on Aging, remarked: "I would say tenfold is pretty significant."

Calorie restriction is now a well-established route to extending the lives of many organisms, from yeast and nematode worms to fruit flies and mice. But the jury is still out on whether calorie restriction can extend the life of humans, although a diet rich in calories certainly increases the risk of obesity, diabetes and other life-shortening conditions.

Biologists believe that restricting calories causes many animals to flip into a state normally reserved for near starvation. Instead of spending their precious energy reserves on reproduction, they shut down everything but their basic body maintenance, in preparation for better times ahead when breeding would stand a better chance of success.

This idea fits in with the more general view that animals tend to follow one of two life strategies -- either one of high fecundity and short lifespan, or one of long lifespan and low reproductive capacity.

Mice, for example, divert much of their limited resources to high reproduction, having several litters of young a year, but they have a short life of just a couple of years. But bats, which are roughly the same size as mice, have just one or at most two offspring a year, and can live for 30 years or more.

Why one species of animal lives longer than another of comparable size, and why some animals appear to age faster and die younger, have been the subject of extensive scrutiny for decades. As bats and mice show, it is possible for genes to extend lifespan -- so the question is: why do they not do it more often, or even all the time? And the logical extension of this question is: why do we age at all? Why don't we live for ever?

One of the most convincing answers to this is known as the disposable soma theory. In short, the idea is that genes can extend an organism's lifespan, but only as a trade-off between the costs and benefits of doing so. It is possible to keep on mending the machinery of the body as it suffers daily wear and tear, but there comes a point when it is no longer worthwhile and the costs become too expensive, much like the point when fixing an increasingly decrepit car gets too much. At this point the body, or "soma", becomes disposable. By then, though, from the gene's point of view, it won't matter -- as long as it has managed to "escape" this broken-down body and replicated itself inside the younger, fitter bodies of the next generation.

Longo says that the disposable soma theory, invented by Professor Tom Kirkwood of Newcastle University in the late 1970s, is one of the strongest ideas around to explain the nature of ageing.

However, Longo has another theory that is causing a second group of scientists to tear their hair out. He believes that ageing may not simply be a side-effect of the wear and tear of life, but is also a genetically programmed condition designed to rid the population of aged individuals to make way for younger ones.

It is an alluring idea, albeit one thought to have been discredited by the evolutionary biologists George Williams and John Maynard Smith 40 years ago. It is a common assumption among non-scientists that ageing and death occur in order to make way for the next generation, but this suggests that ageing is a genetic programme honed by natural selection. It also assumes that it is an altruistic act brought about for the benefit of the future population.

Evolutionary biologists know that such an idea is based on "group selection" and that mathematically this cannot occur because it will always be undermined by more selfish mutants. Organisms carrying the altruistic genes for premature ageing and death would, for instance, be susceptible to selfish-gene cheats that decide to exploit the situation to their own, and their offspring's, advantage. They could simply live a bit longer than their peer group and so make sure they are the ones that exploit the available resources left behind by their prematurely dead peers.

But Longo is convinced that his experiments on manipulating the genes of yeast show that ageing is not a mere side-effect of life, but a deliberate, genetically programmed process honed by natural selection. "Basically, it is the first demonstration, to our knowledge, that ageing is programmed and altruistic," Longo says. "The organisms we have studied die long before they have to in order to provide nutrients for 'mutants' generated within their own population. Thus, billions of organisms die early so that a few better-adapted individuals can grow."

This raises the possibility that the same process happens in humans, and that, as a result, many people are dying earlier than they need to. "Programmed human ageing is just a possibility. We don't know whether it's true yet or not. But if ageing is programmed in yeast, and the [metabolic] pathway is very similar, then isn't it possible that humans also die earlier than they have to?"

Valter Longo says that no one has so far proved him to be wrong on his programmed-death idea. But this may be one heresy too far for the rest of science.

Animals Do the Cleverest Things

The chimp who outwits humans; the dolphin who says it with seaweed; the existential dog
An elephant that never forgets its extended family, a chimp that can outperform humans in a sophisticated test of visual memory and an amorous male dolphin that likes to say it with flowers -- well, a clump of river weeds to be more precise. These are just some of the recent observations from the field of animal behaviour. They appear to show that there is no limit to the intelligence of animals, but what do we really know about the true cognitive powers of the non-human brain?

Experiments on wild elephants living in Kenya found that individuals can remember the whereabouts of at least 17 family members, and possibly even as many as 30. Tests in a laboratory in Japan found that chimps, and young chimps especially, have an incredible photographic memory. Finally, there was the story of the romantic river dolphins of Brazil. Males collected river weeds, sticks or even lumps of clay in their mouths to act as a form of sexual display to prospective mates. Scientists are convinced that it is not merely playful behaviour but a serious attempt at wooing the opposite sex with the cetacean equivalent of a Valentine's gift -- surely a sign of emotional intelligence.

The latest studies into the unusual behaviour of a range of species suggest that we should no longer assume that animals are just the dumb creatures that we've been led to believe since the days of St Thomas Aquinas, the 13th-century Italian monk whose moral philosophy formed the basis of our modern-day ethical treatment of animals. Indeed, scientists have found that animals are capable of all sorts of clever behaviour that we normally associate with human intelligence. They not only have good memories and a perception of the world around them, they also display feats of apparent far-sightedness and understanding that seem to go beyond the mental abilities of many people.

It used to be thought for instance that humans were the only tool-maker. Then it emerged that chimps in the wild have learnt to strip leaves off twigs, which they use to poke termite nests for food. Some years ago, scientists found that chimps, in fact, select a range of tools for different jobs, such as cracking nuts or carrying water. They were even found to pass on their knowledge to successive generations as a form of acquired, cultural inheritance.

Then last year, scientists revealed even more remarkable tool-making behaviour in chimps. They had video footage of chimps in the wild using a "tool kit" to dig for termites. A chimp would use a thick stick like a spade to dig a hole in the ground above a termite nest. It would then use a second, more delicate stick, which had been deliberately frayed at one end, to poke down through the open hole to search for termites, which would cling conveniently to the end of the frayed stick like peas on a dinner fork.

"These chimpanzees use something that doesn't happen anywhere else. They use a tool kit," explains Professor Andrew Whiten of St Andrew's University. "They use their hands and their foot to dig down, so they look like Mr McGregor with his spade digging down with great effort. We don't understand how possibly they could have worked out how to do that."

Even more remarkable tool-making was seen in the case of the New Caledonian crow. Oxford University scientists showed in 2002 that a particularly clever specimen of this species, called Betty, was able to fashion a hook out of a piece of straight wire and use it to "fish" for food concealed in a long tube. It was a bizarre demonstration of a basic understanding of cause and effect known as "folk physics". Even chimps have not shown such skills.

Another trait of intelligent life is being able to distinguish one creature from another but this has been taken to an extreme in the case of the biggest land animals. Elephants were already known to mourn their dead and to communicate with one another over long distances using barely audible, low-frequency growls. More recently, however, scientists have demonstrated that elephants in the Amboseli National Park in Kenya can distinguish between members of the two local tribes, the Maasai and the Kamba. A study found that the elephants became more nervous and wary when shown garments worn by the Maasai, whose young men sometimes spear the animals to prove their virility, but show no such behaviour in the presence of clothes worn by the Kamba.

"We expected that elephants might be able to distinguish among different human groups according to the level of risk that each presents to them, and we were not disappointed," says Professor Richard Byrne of St Andrews University, who led the study. "In fact, we think that this is the first time that it has been experimentally shown that any animal can categorise a single species of potential predator into subclasses based on such subtle cues."

But do these examples of unusually clever animal behaviour constitute intelligence? It depends of course on the definition of "intelligence". Most biologists and psychologists would agree that the human mind has an extraordinary intellectual ability, infinitely more sophisticated than anything seen in the natural world. We converse in a complex language, we think symbolically and creatively, we can plan for and anticipate the future and, perhaps most important of all, we can imagine what it must be like to be someone else.

Scientists call this latter attribute of human intelligence the "theory of mind" and it is one of the defining features of the human condition. It explains, for instance, why we enjoy watching plays and films -- we can imagine what the actors must be going through. We can also imaging someone's pain and pleasure, which is necessary for empathy. It is also at the routes of so-called Machiavellian intelligence, or the art of deception and manipulation. If we can imagine what another person is thinking about us, perhaps we can manipulate those thoughts to our advantage. But do animals show this level of intelligence. They can, and do, deceive one another, but is it because they have this theory of mind we know to be so human?

The theory of mind is best illustrated by a classic psychology test given to young children. Imagine two puppets called Sally and Ann who are given an apple to share. Sally puts the apple in a red box, watched by Ann. Sally then leaves the room and, in her absence, Ann switches the apple to a nearby blue box. When Sally comes back in the room, which box will she open to retrieve the apple?

Children over a certain age -- usually between four and five -- get the right answer. But younger children who have not yet acquired the theory of mind (and interestingly children with autism) say Sally will look in the blue box. They are incapable of seeing the world from Sally's perspective. They only see it from their own. To them, the apple is now in the blue box and that is where Sally will look.

This theory of mind is at the heart of much research into animal intelligence. Many experiments have been performed on chimps and dolphins, for instance, to see if they are capable to seeing the world from another's point of view. The theory of mind is one of the most important attributes of intelligent behaviour and scientists are keen to know whether it exists elsewhere in the animal kingdom.

"There have been a number of studies on animals showing absolute compatibility with the theory of mind but none of them have excluded the possibility of other explanations," says Alex Kacelnik, professor of animal behaviour at Oxford University, who carried out the study on Betty the New Caledonian crow. The difficulty with testing the theory of mind on dumb creatures is that you cannot ask animals what they are thinking.

Perhaps one of the best studies yet into theory of mind was carried out on captive orang-utans by Professor Byrne and his colleagues at St Andrews University. These apes were accustomed to begging for food from their zookeepers so Professor Byrne decided to try to exploit this behaviour to test whether the apes could imagine themselves inside the minds of their human keepers.

The keepers were asked to place two items of food outside the cage of the orang-utans, but just out of their reach. One item was a tasty banana, the other something not quite so tasty, such as a leek. Not surprisingly, the apes made lots of begging gestures towards the banana. The scientists reasoned that if the orang-utan was capable of theory of mind then the ape should respond differently according to whether the keeper gave them the banana or the leek.

If the keeper responded to the begging pleas by giving the orang utan the leek, then the ape might vary its behaviour realising that the keeper does not realise that it is the banana it wants, not the leek. This is exactly what the scientists found. It was also reasoned that if the keeper gave the orang-utan half the banana then the ape would continue with the same style of begging behaviour that had earned it half the reward. Again, this is exactly what happened.

So has the orang-utan been shown to have a theory of mind? Not quite. It is true that one explanation for the findings is that the orang-utan was able to judge whether its gesturing to the keeper was having the desired effect because the ape was capable of a theory of mind. However, there are also other possible explanations, admits Professor Byrne. A more mundane suggestion, for instance, is that the orang-utans were simply exasperated with not getting a banana, and so employed a different set of begging gestures.

Both Kacelnik and Byrne say that it is unhelpful to talk about animal intelligence in the context of comparisons between species, and especially with human intelligence. So often we tend to compare what an animal can do with other animals, or with people, which is unfair and artificial, they say. "It makes no sense to say that a fly is smarter than a pig just because it can fly," says Kacelnik.

The point they both make is that animals are exquisitely adapted in their behaviour to survive in their particular habitats. If that means displaying a form of behaviour that we perceive to be intelligent, then we are guilty of anthropomorphism. The New Caledonian crow, for instance, is a comparative genius when it comes to making tools in a laboratory. But this is because food is scarce in its wild habitat on the Pacific island of New Caledonia, and the most nutritious beetle grubs it needs to survive are difficult to get to without the help of a simple tool made from twigs, grass or leaves.

Betty the crow showed that she was clever at making a hook-shaped tool from straight wire to fish for food. But she shared her cage with an older, and perhaps wiser, male bird called Abel, who took no interest in making tools. He simply waited for Betty to fish out the food from the tube before bullying her into giving him a piece. So who was the most intelligent?

Homing Pigeons

Homing pigeons owe their name to the ability to return home from distant, unfamiliar release points -- in some cases, even if they've been transported, anaesthetised and deprived of all information about the journey. They were used to carry messages in both ancient Greece and China, and by the 16th century were being used in formal postal services. In 1860, Paul Reuter employed a fleet of 45 to deliver news and stock prices between Brussels and Aachen. Only in 2002 did India's police force retire its pigeon messenger service, when it was made redundant by e-mail. Homing pigeons have proved especially useful during times of war. One bird, "Cher Ami", was awarded the French Croix de Guerre for his heroic service during the First World War in delivering 12 important messages, despite sustaining a bullet wound. Equally amazing, but for different reasons, is the unfortunate bird that set off from Pembrokeshire in June 1953. It returned, dead, in a box postmarked "Brazil", 11 years later.


Viewers of Flipper do not need to be told that dolphins are cleverer than most inhabitants of the sea. Whether he was upholding the law, or embarking on a daring sea rescue, the iconic TV hero's brainpower never failed to amaze. Even without television trickery, dolphins are smart. The latest evidence of intelligence came this week, when researchers published the results of a study in the Brazilian Amazon which showed male members of pods carrying "gifts" in the form of sticks, or, most endearingly, makeshift bouquets made from seaweed, to attract mates. DNA tests revealed that the males who carried the most gifts proved the most successful fathers. Research in Australia showed bottlenose dolphins use bits of marine sponge to protect their noses while they probe the seabed. Scientists say the behaviour is evidence that they show signs of culture learned from their forebears, rather than passed down in genes.


While they may not yet have developed the power of speech, as exhibited in the upcoming Jerry Seinfeld film, Bee Movie, and are all too easily snared by beer traps in summer, bees are unexpectedly clever insects. As early as 330BC, Aristotle described the remarkable "waggle dance" bees use to communicate with members of the hive. It was originally thought the dance was designed simply to attract attention, but in 1947, Karl von Frisch, who was later awarded a Nobel Prize for his work, deduced that the apparently random runs and turns of the dance, which bees perform in groups, correlates directly to the position of the sun in relation to the location of food. If a bee runs from the six to 12 o'clock positions, it means food is in the direction of the sun. The number of waggles dictates how far away the food lies.


Most dog owners will claim their pooch is the smartest in the park. But retrieving sticks or barking at postmen, while impressive when compared with the skills of, say, a jellyfish, is hardly rocket science. However, new research suggests mutts are capable of much more: in an experiment at the University of Vienna, two border collies, an Australian shepherd and a mongrel were presented with images on a touch screen. The pairs of photos offered the choice of a landscape or a dog. When the dogs used their nose to push against the dog image, they got a treat. If they plumped for the landscape, they were forced to wait a few seconds before the next round. The training stage complete, the dogs were shown landscape and dog photos, and continued to correctly pick out the dogs. In the final phase, the dogs were shown an unfamiliar dog superimposed on a landscape they had seen in training. Even then, the animals were able to pick out the dog. Scientists say the results show that dogs can use abstract concept, a skill which had been attributed only to birds and primates.

Leatherback turtle

The 65 million-year-old leatherback turtle has witnessed the fall of the dinosaurs and the rise of humanity. But the giant sea creature is most extraordinary for its ability to travel huge distances, from the cold waters in which it feeds to the tropical and subtropical beaches where it hatches its eggs. Female turtles originally tagged in French Guiana off the coast of South America have been recaptured on the other side of the ocean in Morocco and Spain. In 2006, the so-called "Dingle turtle" made headlines after being tagged off the west coast of Ireland and embarking on an astonishing 5,000-mile journey to the Cape Verde islands, off West Africa. Leatherbacks are found from Alaska to New Zealand.


Everyone knows man's closest living relative is the sharpest tool in the animal box. After all, what other animal can brew up a cup of PG Tips while wearing a bowler hat? This week, however, the publication Current Biology has shed new light on the brain power of chimpanzees, revealing them to have photographic memories far superior to our own. Until now, it was not thought chimps could match humans in mental tests. But researchers in Kyoto discovered that chimps could recall a sequence of numbers displayed to them (for a fraction of a second), outperforming students who took the same test. The research suggests that short-term memory may have been more important to earlier humans, possibly because of our modern reliance on language-based memory skills.

Humpback whales

Whale song, which is associated in particular with the humpback, is something of a mystery to scientists. Male humpbacks sing mainly during the mating season, but it is not known whether the song is used to attract females or to ward off other males. The song itself is complex. At any one moment, all the males in a population sing the same song. Over time the song slowly evolves into something new, with all the whales making exactly the same changes to their pattern of singing. Studies suggest that, once a population of whales has moved on from a particular pattern, it will never again return. Other whales such as the sperm and beluga also make songs but none are as complex as that of the humpback.


The old adage that elephants never forget was proved to have a basis in scientific fact in 2001, when research showed that matriarchs, who lead the herd, have an uncanny ability to remember faces. This enables them to know when alert their brood to menacing interlopers. Now, scientists at the University of St Andrews have shown that pachyderms are even smarter than that: a study of 36 family groups in Kenya suggests that elephants can build a mental map of where herd members are by combining their memory with a keen sense of smell. Researchers lay urine samples from wild elephants in the path of a herd. When the leader encountered the scent, it reacted with surprise because its memory told it the animal was walking behind, and could not have been able to lay its scent ahead.

The Arctic tern

Even more prone to wander than the leatherback turtle, the Arctic tern takes the longest regular migration of any known animal, from its Arctic breeding grounds to the Antarctic and back again every year. On this journey of about 22,000 miles, the seabird enjoys two summers and more daylight than any other creature on the planet. One chick demonstrated its flying ability by setting out from Labrador, Canada, in July 1928 to arrive in South Africa four months later. Another unfledged chick tagged on the Farne Islands, off the coast of Northumberland, in 1982 flew 14,000 miles to Melbourne, Australia, in just three months. Over its life, the Arctic tern will travel about 500,000 miles.


They might be famous for their brawn -- ants can carry up to 20 times their body weight, the equivalent of a woman strapping a hippo to her back -- but ants are not renowned for brains. When it comes to delegation, however, they're smart. Males cannot claim much credit for this -- they spend their days wandering around accepting food until they mate, when they promptly die -- but worker ants, who are generally sterile females, are clever. They perform tasks such as foraging, defending, preparing food, construction and attending to the queen. The most dangerous task is foraging, so older, more expendable ants are given the job, while the younger ones wait on the queen.

New Caledonian Crows

The ability to fashion tools has always been held as uniquely primate, distinguishing us from (apparently) less intelligent creatures. But humans and apes are not alone in having tool-making skills. Crows amazed the science community in October when footage -- recorded using tiny "crow-cams" on the tails of New Caledonian crows -- showed the birds creating advanced implements. One crow was observed whittling twigs and leaves with its beak to fashion grabbers designed to retrieve grubs from the ground. The New Caledonian crows are the only known non-primate to create and use new tools.


Chimps might be able to outwit Japanese university students in a test of photographic memory, and are traditionally considered to be second only to humans in the intelligence stakes, but research published earlier this year suggested that orang-utans were the smartest swingers in the ape world. Scientists from Harvard University studied orang-utans in Borneo and found them capable of tasks that chimps could only dream of, such as using leaves to make waterproof hats and roofs. They also gathered evidence that the orange-haired apes have developed a culture in which adults teach the young how to make tools. Viewers of David Attenborough's documentaries will remember the astonishing film of an orang-utan climbing into a canoe and using a paddle.

Additional reporting Simon Usborne and Richard Molloy

Scientists Have Found the Gene That Decides How Long We Live

Scientists have come a step closer to understanding the secret of a long, healthy life with the discovery of a gene that plays a central role in the ageing process.

The gene appears to be critical in extending the lifespan of animals that are subjected to a calorie-restricted diet -- when they are slightly starved of high-calorie food but are given all the other nutrients they need.

It is well established that calorie-restricted diets lead to longer maximum lifespans in practically every animal in which they have been studied, although the evidence it not as strong for humans.

The latest study focused on a gene common to nematode worms, mice and humans. When the gene was blocked in the worms, the benefits of a calorie-restricted diet were lost and the worms lived shorter lives. Similarly, when the scientists were able to stimulate the gene they found that they could enhance the longevity of the worms so that their extended lifespans came close to matching those worms on a calorie-restricted diet.

Scientists believe that the findings could unlock a genetic treasure-chest of potential pharmacological targets for developing drugs that can extend the human lifespan without having to follow a rigorous and difficult diet.

"After 72 years of not knowing how calorie restriction works, we finally have genetic evidence to unravel the underlying molecular programme required for increased longevity in response to calorie restriction," said Andrew Dillin, of the Salk Institute in San Diego, California. "It's likely to play a role in the human condition, although we still don't know whether calorie restriction really works in humans. Studies in primates suggest it does."

The first experiments in calorie-restricted diets go back to the 1930s. Laboratory rats and mice fed a severely calorie-restricted diet, but with normal levels of vitamins and minerals, lived almost twice as long as rodents with unrestricted access to food. Experiments with other creatures found that the phenomenon appeared to be ubiquitous in the animal kingdom. Some scientists suggested it was an evolutionary adaptation to surviving hard times until enough food became available.

The longevity-associated gene identified by Dr Dillin and his colleagues is known as PHA-4 -- the name of the protein for which the gene is responsible. The same gene also exists in mice and humans and is known as the Foxa family of genes. Both PHA-4 and Foxa are involved in the complex process of glucose metabolism. In mammals, the gene is linked with a hormone called glucagon which increases levels of glucose in the bloodstream to maintain the body's energy balance especially during fasting.

Scientists from Louisiana State University are monitoring a group of 48 overweight men and women aged between 25 and 50. The study found that those who were able to cut down on their calorie intake improved in terms of metabolic markers that are linked to longer living.

The accepted view among scientists is that there is probably an absolute upper limit to human lifespan of no more than about 125 years -- the oldest person with an authenticated birth record was a Frenchwoman called Jeanne Calment, who died aged 122 years, five months and 14 days. People in the West are living longer, but the extra years are not necessarily healthy ones -- an ageing population is leading to a dramatic rise in senile dementia.

There has been a dramatic increase in longevity over the past couple of centuries due to improvements in housing and sanitation, nutrition and health.

Some 60 per cent of boys and 70 per cent of girls born in 1981 are expected to survive to celebrate their 75th birthday in 2056. In 1881, only a third of girls and just one in five boys reached the same age.

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