The decades that make up a typical human lifespan can seem like vast stretches of time to us. But to the forces of evolution, they are mere temporary blips. Common wisdom has it that evolution occurs over geological timescales – thousands and millions of years. As such, evolutionary biology takes a lot of criticism for being a ‘descriptive science’, being less open than other fields to that fundamental aspect of science – experimentation. Though there are exceptions, those who study evolution must mostly be content to observe snapshots of life, either present or entombed in rock, and make inferences from there.

But this isn’t always so. Occasionally, evolution happens at astonishingly fast rates, as epitomised by the case of the peppered moths. Today, canny scientists are on the look-out for situations where the evolutionary pressures that weigh upon a species change speedily and which are more amenable to testing. Jonathan Losos and colleagues at Washington University, St Louis, have found one such example in a small Caribbean lizard.

The brown anole lives in the Bahamas and spends much of its time foraging on the ground. Islands provide great opportunities for evolutionary biologists because invading species can drastically change or reverse the evolutionary pressures on the locals. The Bahamas are no exception to this – occasionally, the islands that the brown anole calls home are invaded a larger predatory species, the curly-tailed lizard.

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Genetically modified crops have received a frosty welcome in the UK, and more widely in Europe. Those opposed to such crops worry (among other things) that they could affect the flora around them by outcompeting them or by spreading their altered genes in a round of genetic pass-the-parcel. Now, a new study shows that genetically-modified crops does affect surrounding plants – but in a positive way. 

Kong-Ming Wu from the Chinese Academy of Agricultural Sciences found that genetically modified cotton designed to kill an insect pest can also protect other species plants from its jaws. In doing so, this “Bt cotton” could help to reduce the need and demand for other sprayed insecticides. 

Bt cotton has been loaded with insect-killing genes taken from a bacterium called Bacillus thuringiensis (hence “Bt”). This species lives in soil and the surface of plants, and it produces crystals of proteins that are toxic to hungry insects. If they are swallowed, they stick to molecules in the pest’s gut, breaking down its lining and allowing both B.thuringiensis spores and colonies of normal gut bacteria to invade. It’s this wanton spread of bacteria that kills the animal.

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When we’re suddenly confronted with a shocking image, our skin becomes moist and we blink strongly. These actions are automatic and unintentional; they happen without conscious thought. So it may come as a surprise that they can also predict some of our most seemingly considered beliefs – our political attitudes.

According to a new American study, the stronger these responses, the more likely people are to support the Iraq War, Biblical truth, the Patriot Act and greater defence budgets. Conversely, people who show weaker “startle reflexes” are more likely to support foreign aid, immigration, gay marriage and abortion rights. 

Douglas Oxley from the University of Nebraska-Lincoln led the study and he suggests that the factor that unites these attitudes is an interest in protecting one’s social structure from threats. These “threats” can come both from abroad or from within; they can be physical dangers like hostile foreign powers, or threats to the status quo, such as policies that violate longstanding traditions.

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Our languages are replete with phrases that unite words evoking a sense of cold with concepts of loneliness, social exclusion or misanthropy. When we speak of icy stares, frosty receptions and cold shoulders, we invoke feelings of isolation and unfriendliness.  But cold and solitude are more than just metaphorical bedfellows; a new study shows that social exclusion can literally make people feel cold.

Chen-Bo Zhong and Geoffrey Leonardelli from the University of Toronto recruited 65 students and were asked to recall a situation where they either felt included within a group or left out of it. Afterwards, they asked the students to estimate the temperature in the room under the ruse of providing information for the maintenance staff. The estimates varied wildly but volunteers who had social exclusion on their minds gave an average estimate of 21C, while those who remembered fitting in guessed an average of 24C.

So far, so interesting. But Zhong and Leonardelli were not content with simply bringing social memories to the surface; for their next trick, they created real feelings of exclusion. They recruited 52 more students who were led to a computer cubicle and told that they were taking part in an online game with three anonymous players. The object was simply to throw a virtual ball between the group but unbeknownst to the volunteers, their “partners” were computer-controlled programmes. These avatars either intermittently passed the ball to the real player throughout the game, or left them out after a few cursory passes. 

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We like to idolise fearlessness and we equate it to bravery but there is a fine line between that and stupidity. Immunity to the pangs of fear would leave someone unable to assess threats to themselves and to other people, which means that fear not only has consequences for an individual but for their entire social circle. Guillaume Martel and colleagues from Rutgers University demonstrated these far-reaching consequences by examining a special group of mice which had been genetically engineered to be fearless.

Martel’s team focused their attention on the amygdalae, a pair of almond-shaped structures, one in each half of the brain, that play an important role in emotion, and particularly in creating and storing memories linked to emotional events. Each amygdala can be divided up into a few distinct regions depending on their role and which other parts of the brain they connect to. One of these regions – the basolateral complex, or BLA- is specifically involved in learning about fear.

The team worked with mice that were missing a gene called stathmin, which is particularly active in the basolateral amygdala. In previous research, they had already showed that removing this gene switches interferes with a mouse’s ability to fear. Not only are they inherently bolder than their normal littermates, they also fail to record long-term memories about frightening experiences.

This time, Martel showed that the loss of stathmin also turns female mice into neglectful ones. In a normal situation, a virgin female would react strongly to the sight of abandoned pups, even foster ones. If three isolated pups are placed in the far corner of a female’s cage, she would quickly bring them over to her nest within about three minutes. But not if her basolateral amygdalae isn’t working properly -the stathmin­-less mice took much longer (about 10 minutes or so) to retrieve the pups.

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As you read this post, your computer is probably busy. You may have multiple programs running in the background, with email clients, anti-virus software or file-sharing software all competing for valuable memory. The ability of computers to multi-task has grown substantially in recent years, as processors have become increasingly powerful.

Evolution has chartered a similar course, and humans are particularly talented at dividing our attention among multiple priorities. Now scientists are showing that the asymmetrical differences between the two sides of our brain are essential for this ability to multi-task.

In the animal world, the ability to multi-task is a matter of life and death. Many species must be ever-watchful for food, while simultaneously looking out for predators who would view them in the same way Like too many open applications that slow down a computer, these multiple tasks compete for the brain’s finite resources. Those who survive life’s challenges are those with an edge at efficiently dealing with multiple demands.

One way of doing this is to use parallel processing – to delegate different parts of a problem to different pieces of hardware. This is exactly the situation found in the human brain, with two asymmetric hemispheres associated with different mental abilities. And this ‘lateralisation’ is not unique to us, but seems to be present in all back-boned animals, from fish to apes. An explanation for this asymmetry now becomes obvious – it may allow animals to multi-task, acting as a sort of cerebral division of labour.

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Some 230 million years ago, giant reptiles walked the Earth. Some were large and fearsome predators; others were nimble and fleet-footed runners; and yet others were heavily armoured with bony plates running down their backs. Their bodies had evolved into an extraordinary range of shapes and sizes and they had done so at a breakneck pace. They were truly some of the most impressive animals of their time. They were the crurotarsans.

Wait… the who and what now? Chances are you’ve never heard of the crurotarsans and you were expecting that other, more famous group of giant reptiles – the dinosaurs. There is certainly no doubt that the dinosaurs were an evolutionary success story, diversifying from a standard body plan – a small, two-legged meat-eater – into a dazzling selection of forms.  Today, living dinosaurs – the birds – still rule our skies and back in their heyday, they were the dominant back-boned animals on land for millions of years.

But what was the secret to their rise to power? Many palaeontologists believe that they simply outcompeted other animal groups that were around at the same time like the bizarre, buck-toothed rhynchosaurs or mammal-like reptiles like the cynodonts. Perhaps their upright postures made them faster or more agile; perhaps they were actually warm-blooded and able to cope with a wider range of climates. Either way, the fact that they and not the other reptile groups ascended to dominance is often taken as a sign of their superiority.

But Stephen Brusatte from Columbia University challenges that view. According to his take on Triassic life,  the dinosaurs fared no better than their competitors, the crurotarsans, and were actually less successful for about 30 million years. They eventually supplanted these other groups because of luck rather than because they possessed any special advantage.

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The forests of east Asia are home to giant honeybees. Each one is about an inch in length and together, they can build nests that measure a few metres across. The bees have an aggressive temperament and a reputation for being among the most dangerous of stinging insects. Within mere seconds, they can mobilise a swarm of aggressive defenders to repel marauding birds or mammals. But against wasps, they use a subtler and altogether more surprising defence – they do a Mexican wave.

Wasps, and hornets in particular, are major predators of bees and the largest ones can make even the giant bees look puny. Some invade hives and steal grubs, while others swoop in and pluck loitering bees from the surface of the colony – a technique known as “bee-hawking”. The giant bees are particularly vulnerable to this strategy  because their nests are open and typically covered in a blanket of workers. They might seem easy pickings for a hungry hornet, but the workers have a trick up their abdomens.

When hornets approach, individual workers raise their rear-ends by ninety degrees and shake them in unison. Nearby workers start doing the same and the result is a ripple of booty-shaking that passes over the surface of the hive. The technical term for the behaviour is “shimmering”, but it could be described equally well as a “Mexican moon”. Either way, it is mesmerizingly beautiful to watch.

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There’s a growing tendency for advertisers to hype up modern movies with hyperkinetic trailers that end with a blitz of imagery from the film. Seconds after the clip ends, the onslaught of explosions, punches and screeching tyres are probably crystal clear but minutes later, and your recollection of the images starts to fade. By the time you leave the cinema, you can probably only remember a few sparse details, if that.

These experiences jibe with psychological research, which suggests that the photographic clarity that accompanies initial memories tends to fade as they are transferred into long-term storage. The older our memories are, the fewer details they contain. But a new study challenges this view of long-term memory as a set of fuzzy depictions, by showing that it can actually store a massive number of different objects at an unexpectedly high level of detail.

The size of our long-term memory hasn’t been in doubt for decade. In the 1970s psychologists showed how deep this storage system goes by presenting people with tens of thousands of pictures for mere seconds. Even after this deluge of imagery, the volunteers were still able to tell the pictures they had seen from ones they had not with an 83% accuracy.

But these tasks didn’t require people to remember many details about the scenes they saw. The images were different enough from each other that just remembering the gist of them would have been enough to choose the familiar one. Remembering that you saw a picture of a wedding rather than a football match would be enough; it wouldn’t be necessary to know the bride’s face or the colour of the players’ shirts.

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In September last year, a team of scientists launched a squad of tiny animals into space aboard a Russian satellite. Once in orbit, the creatures were shunted into ventilated containers that exposed them to the vacuum of space. In this final frontier, they had no air and they were subjected to extreme dehydration, freezing temperatures, weightlessness and lashings of both cosmic and solar radiation. It’s hard to imagine a more inhospitable environment for life but not only did the critters survive, they managed to reproduce on their return to Earth. Meet the planet’s toughest animals – the tardigrades.

Tardigrades are small aquatic invertebrates that are also known as “water bears”, after their impossibly cute shuffling walk (see video below). They also happen to be nigh-invincible and can tolerate extreme environments that would kill almost any other animal. They can take temperatures close to absolute zero, punishing doses of radiation and prolonged periods of drought. And now, they have become the only animals to have ever survived the raw vacuum of space.

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