• About 10% of the population is left-handed.
• There have been several theories over the years about why some people favor their left hand.
• A study published last year found that right- or left-handedness may have nothing to do with the brain — instead, it could be determined by gene activity in the spinal cord while you are in the womb.

Left-handed people haven't always been treated well throughout history. They've been persecuted for their disposition, being been labeled as evil — or even as witches — despite making up about 10% of the population. In fact, the word "sinister" comes from "left" or "left hand."

There have been a few theories over the decades about why some people are left-handed, including an outdated idea that it has something to do with mothers who are stressed while pregnant.

It's down to the spinal cord — not the brain

Research since the 1980s has found that our preference for our left or right hand is most likely determined before we are born — ultrasound screenings suggest as early as the eighth week of pregnancy. From the 13th week in the womb, babies tend to suck either their right or their left thumb.

It was previously thought that the genetic differences between the left and right hemispheres of the brain determine whether someone is left- or right-handed. But a study published last year in the journal eLife found that the answer could lie in the spinal cord.

The research — by Sebastian Ocklenburg, Judith Schmitz, and Onur Gunturkun from Ruhr University Bochum, along with other colleagues from the Netherlands and South Africa — found that gene activity in the spinal cord was asymmetrical in the womb and could be what causes a person to be left- or right-handed.

Arm and hand movements start in the brain, in an area called the motor cortex, which sends a signal to the spinal cord that's translated into a motion. The researchers found that while the baby is growing in the womb, up until about 15 weeks, the motor cortex and the spinal cord are not yet connected, but right- or left-handedness has already been determined.

In other words, the baby can already start movements and chooses a favorite hand before the brain starts controlling the body.

To study this, the researchers analyzed gene expression in the spinal cord in the eighth through the 12th week of pregnancy. They found significant differences in the left and right segments of the spinal cord that control arm and leg movement.

They concluded that the asymmetrical nature of the spinal cord could be down to something called epigenetics, or how organisms are affected by changes in their gene expression rather than in the genes themselves. These changes are often brought about by environmental influences and can affect how a baby grows.

These gene-expression differences could affect the right and left parts of the spinal cord differently, resulting in lefties and righties.

So why are lefties so rare?

Scientists have long tried to answer this.

In 2012, researchers at Northwestern University developed a mathematical model to show that the percentage of left-handed people was a result of human evolution — specifically, a balance of cooperation and competition.

In other words, they thought that, though the basis for right- or left-handedness may be genetic, there could be a social factor that explains why the ratio is so high.

"The more social the animal — where cooperation is highly valued — the more the general population will trend toward one side," Daniel Abrams, an assistant professor at the McCormick School of Engineering and Applied Science who helped develop the model, told LiveScience.

"The most important factor for an efficient society is a high degree of cooperation," he added. "In humans, this has resulted in a right-handed majority."

In other words, we may have, for some reason, evolved to favor right-handedness, so anyone deviating from this may have been conditioned to use that hand primarily despite their genetic predisposition.

But why people are left-handed is still a bit of a mystery — partly because left-handed people are often excluded from scientific research, experts say — and it's hard to predict whether a child will be left or right-handed once they are born.

One thing we do know, though, is that the neurological differences between left- and right-handed people are small, and supposed behavioral or psychological distinctions have largely been debunked.

SEE ALSO: Our brains sometimes create 'false memories' — but science suggests we could be better off this way

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NOW WATCH: I tried Gwyneth Paltrow's diet and workout routine for a week — here's what happened

• When you're ill, it can be hard to tell whether exercise will make you feel better or worse.
• If you're unsure, you can use the "neck rule" to determine whether working out is a good idea.

When you're ill, working out might be the last thing on your mind. The thought of training and getting sweaty and exhausted might not be high on your agenda, because you'd rather be snuggled under a blanket.

On the other hand, some people can't wait to get back to the gym. Some research shows that having a cold doesn't have much of a negative impact on your exercising abilities, and some people report feeling better once they have worked out.

It's not always a good idea though, as the Huffington Post points out, so when you're weighing up the benefits and costs of exercising while unwell, there is something called the "neck rule" which you should follow.

According to the Mayo Clinic, moderate physical activity is fine when you have a cold, as long as you don't have a fever. The reason it makes some people feel better is because exercise can open up your nasal passages which relieves congestion.

However, it's important to take note of whether your symptoms are all "above the neck," such as a runny nose, blocked nose, sneezing, or sore throat. You should not workout if you have any below the neck symptoms, such as a tight chest, a persistent cough, a bad stomach, or muscle aches.

Speaking to the Huffington Post, Ben Fletcher, fitness and conditioning expert at Push Doctor, said the loss of concentration you may feel when unwell can be dangerous, especially if you're using gym equipment. Also, keeping hydrated can be difficult when you're ill, which can make injury more likely.

Of course these are just guidelines, and if you listen to your body you should be able to tell if you're well enough to go for a run. But the Mayo Clinic recommends you take it easy and reduce the intensity and length of your workout to make sure you don't overdo it.

SEE ALSO: Taking a lot of ibuprofen could be putting men's fertility at risk, according to a new study

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NOW WATCH: TONY ROBBINS: 'Trading your expectations for appreciation' will make you more attractive

• A video showed alligatorstrying to stay alive in a frozen North Carolina pond by sticking their snouts through the ice.
• The cold-blooded reptiles at Shallotte River Swamp Park could be seen breathing through the gaps in the ice made with their snouts.
• The reptiles cannot generate their own body heat.
• Experts say once the alligators are able to breathe through the ice, they fall into a state of hibernation known as brumation.

In a rarely seen occurrence, video released on Monday (January 8) showed alligators trying to stay alive in a frozen North Carolina pond by sticking their snouts through the ice.

Footage taken by an NBC affiliate station showed a handful of the cold-blooded reptiles at the Shallotte River Swamp Park in Ocean Isle Beach breathing through the gaps created with their snouts in a pond frozen by a brutal cold spell ravaging the U.S.

The reptiles cannot generate their own body heat. Experts say once the alligators are able to breathe through the ice, they fall into a state of hibernation known as brumation by lowering their body temperatures and metabolism. Once it becomes warm and the ice melts, the creatures will thermoregulate their body temperatures to their regular state.

Bone-chilling arctic air has created dangerous conditions for a large portion of the U.S. and has resulted in at least 18 deaths since the beginning of the new year, including four in North Carolina traffic accidents and three in Texas.

Produced by Jasper Pickering

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• Google's Arts & Culture app is having viral success in the US.
• Users can match their faces with famous works of art in Google's art database, which is largely from museums in Europe and North America.
• But many users are complaining that the options for people of color are too limited.

Google is having viral success with its two year old Arts & Culture app now that it's including some new faces: yours.

The app rocketed to the top of the charts this week after Google added in a feature that lets people compare their selfies to works of art and see who they look like. 

The feature is only available in some states in the US, and is blocked in places like Texas and Illinois that have stricter privacy laws. But some people trying the new selfie-matching machine are voicing frustration about the differences between results for white people and people of color. 

SEE ALSO: Take the 10-minute mental test Trump's doctor said he scored 100% on

Some users, like Ryan Seacrest, got a host of decent match options.

But lots of users quickly expressed frustration that the app doesn't have as many options for people of color.

Some said the app highlights an ugly blind spot in art history.

• Many of us don't get enough sleep during the week, and then try to make up for it at the weekend with a lie-in.
• Sleep scientists generally don't advise people do this, as sleep is "not like the bank."
• However, a new study has shown that making up for lost sleep at the weekend might not be such a bad idea if you really need it.

It's no secret that unpleasant things happen when we don't get enough sleep. On the surface it can make us more irritable, but it can also have long term affects like an increased risk of dementia.

Unfortunately, many of us don't get the sleep we need due to work, social commitments, or behaviours like binge-watching our favourite shows. This means a lot of us are guilty of the weekend lie-in.

Previous research has revealed how trying to play catch-up with our sleep is a pretty bad idea. Sleep scientist Matthew Walker put it this way:

"Sleep is not like the bank. You can't accumulate a debt and pay it off at a later point in time. If I were to deprive you of sleep an entire night, and then in a subsequent night give you all the sleep you want, you never get back all that you've lost. You will sleep longer, but you will never achieve that full eight-hour repayment. The brain has no capacity to get back that lost sleep."

The odd lie-in might be okay

However, new research contradicts this belief of many sleep scientists, and has shown you might be able to make up for lousy sleep with the odd lie-in. The study from Stockholm University, published in the journal Sleep, looked at the sleeping habits and overall health of 43,000 people.

The results showed that people who slept less than five hours a night, or more than 8 hours a night, had much higher rates of mortality than those who slept more. Overall, it was the average amount of sleep somebody got that seemed to make a difference.

Torbjörn Åkerstedt, a biological psychology professor at the Center for Stress Research at Stockholm University, and lead author of the study, said this seems to show that if you suffer from bad sleep over the week, and make up for it at the weekend, you might be doing your body a favour.

"It seems like you actually can compensate by catching up on sleep during weekends,"Åkerstedt said. "This is in effect an argument for lazing around all weekend. There probably is an upper limit, but it's anyway better to increase [sleep hours] on the weekend rather than not doing it at all."

One reason we feel groggy and tired during the week is that we are out of sync with our circadian rhythms, otherwise known as the body clock. If we are on a regular schedule, our hormones make us tired when it's time to go to bed, and wake us up again in the morning.

Work schedules can lead to 'social jetlag'

"The body clock thrives off routine — the more regular you are, the better it is really," Elise Facer-Childs, a doctoral researcher specialising in sleep at the University of Birmingham, told Business Insider when she was interviewed about partners having different body clocks.

She explained something called "social jetlag," which is the misalignment between social and biological time, and how we keep chopping and changing out schedules depending on what day it is.

"A lot of our society suffers from social jetlag because we follow a certain schedule during the week for work, and then we follow a different schedule at the weekend because we're either having a lie in or going out for social activities," she said.

"If you get up at 6 o'clock for work during the week, and then at the weekend you sleep in until 10, that's a four-hour time difference. So for your body, it is like every Friday you jump on a plane and you fly to Dubai, which is a four-hour time zone change, and every Sunday you fly back. That's the sort of social jetlag that's happening to your body, but people just don't see it like that."

Our bodies like routine

It is very easy to stay up too late, or snooze our alarms. Even the slightest adjustment can make us fall out of whack, like when the clocks change in spring and autumn. Making up for lost sleep at the weekends is probably better than doing nothing at all, but the best thing is to keep to a schedule whenever you can.

"There does have to be a balance, because we do get up early during the week, and then that causes an accumulation of sleep debt, so were not sleeping enough during the week," Facer-Childs said. "So it's difficult to get the balance between keeping a regular schedule and catching up on some much needed sleep.

"I'd say the best thing to do is to try and keep a regular schedule, but that means getting up early during the week but not going to bed late."

The new study doesn't recommend always lying in at the weekend, as results also suggested too much sleep can increase the risk of death too. But if you've had a long week, and you really feel like your body could do with the extra rest, don't feel too guilty about it.

SEE ALSO: You might be better at sports at certain times of day thanks to your biological clock

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NOW WATCH: I quit social media for a month — and it was the best choice I've ever made

• The male Y chromosome is progressively degenerating. 
• Studies have shown that the chromosome is undergoing a structural rearrangement in order to slow the effects of decline. 
• In the future, genetic engineering may be able to replace the gene function of the Y chromosome. 

The Y chromosome may be a symbol of masculinity, but it is becoming increasingly clear that it is anything but strong and enduring. Although it carries the "master switch" gene, SRY, that determines whether an embryo will develop as male (XY) or female (XX), it contains very few other genes and is the only chromosome not necessary for life. Women, after all, manage just fine without one.

What’s more, the Y chromosome has degenerated rapidly, leaving females with two perfectly normal X chromosomes, but males with an X and a shriveled Y. If the same rate of degeneration continues, the Y chromosome has just 4.6m years left before it disappears completely. This may sound like a long time, but it isn’t when you consider that life has existed on Earth for 3.5 billion years.

The Y chromosome hasn’t always been like this. If we rewind the clock to 166 million years ago, to the very first mammals, the story was completely different. The early "proto-Y" chromosome was originally the same size as the X chromosome and contained all the same genes. However, Y chromosomes have a fundamental flaw. Unlike all other chromosomes, which we have two copies of in each of our cells, Y chromosomes are only ever present as a single copy, passed from fathers to their sons.

This means that genes on the Y chromosome cannot undergo genetic recombination, the "shuffling" of genes that occurs in each generation which helps to eliminate damaging gene mutations. Deprived of the benefits of recombination, Y chromosomal genes degenerate over time and are eventually lost from the genome.

Despite this, recent research has shown that the Y chromosome has developed some pretty convincing mechanisms to "put the brakes on", slowing the rate of gene loss to a possible standstill.

For example, a recent Danish study, published in PLoS Genetics, sequenced portions of the Y chromosome from 62 different men and found that it is prone to large scale structural rearrangements allowing "gene amplification"— the acquisition of multiple copies of genes that promote healthy sperm function and mitigate gene loss.

The study also showed that the Y chromosome has developed unusual structures called "palindromes" (DNA sequences that read the same forwards as backwards — like the word "kayak"), which protect it from further degradation. They recorded a high rate of "gene conversion events" within the palindromic sequences on the Y chromosome — this is basically a "copy and paste" process that allows damaged genes to be repaired using an undamaged back-up copy as a template.

Looking to other species (Y chromosomes exist in mammals and some other species), a growing body of evidence indicates that Y-chromosome gene amplification is a general principle across the board. These amplified genes play critical roles in sperm production and (at least in rodents) in regulating offspring sex ratio. Writing in Molecular Biology and Evolution recently, researchers give evidence that this increase in gene copy number in mice is a result of natural selection.

On the question of whether the Y chromosome will actually disappear, the scientific community, like the UK at the moment, is currently divided into the "leavers" and the "remainers". The latter group argues that its defence mechanisms do a great job and have rescued the Y chromosome. But the leavers say that all they are doing is allowing the Y chromosome to cling on by its fingernails, before eventually dropping off the cliff. The debate therefore continues

A leading proponent of the leave argument, Jenny Graves from La Tr obe University in Australia, claims that, if you take a long-term perspective, the Y chromosomes are inevitably doomed — even if they sometimes hold on a bit longer than expected. In a 2016 paper, she points out that Japanese spiny rats and mole voles have lost their Y chromosomes entirely — and argues that the processes of genes being lost or created on the Y chromosome inevitably lead to fertility problems. This in turn can ultimately drive the formation of entirely new species.

The demise of men?

As we argue in a chapter in a new e-book, even if the Y chromosome in humans does disappear, it does not necessarily mean that males themselves are on their way out. Even in the species that have actually lost their Y chromosomes completely, males and females are both still necessary for reproduction.

In these cases, the SRY "master switch" gene that determines genetic maleness has moved to a different chromosome, meaning that these species produce males without needing a Y chromosome. However, the new sex-determining chromosome — the one that SRY moves on to — should then start the process of degeneration all over again due to the same lack of recombination that doomed their previous Y chromosome.

However, the interesting thing about humans is that while the Y chromosome is needed for normal human reproduction, many of the genes it carries are not necessary if you use assisted reproduction techniques. This means that genetic engineering may soon be able to replace the gene function of the Y chromosome, allowing same-sex female couples or infertile men to conceive. However, even if it became possible for everybody to conceive in this way, it seems highly unlikely that fertile humans would just stop reproducing naturally.

Although this is an interesting and hotly debated area of genetic research, there is little need to worry. We don’t even know whether the Y chromosome will disappear at all. And, as we’ve shown, even if it does, we will most likely continue to need men so that normal reproduction can continue.

Indeed, the prospect of a "farm animal" type system where a few "lucky" males are selected to father the majority of our children is certainly not on the horizon. In any event, there will be far more pressing concerns over the next 4.6m years.

SEE ALSO: Scientists have discovered a new type of wolf for the first time in 150 years

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NOW WATCH: This 90-second animation will change your perception of the human body

• Many of us are familiar with "stress eating."
• Our brains are wired to seek out foods that will indulge our reward systems.
• Unfortunately, this means sugary, fatty foods which are bad for our health in a number of ways.

When the pressure is on, many of us may find our hands reaching for the biscuit tin. Eating is a common reaction to stress, and a lot of people find comfort in junk food in taxing situations.

There is actually a fair bit of biological truth in the term "stress eating." In the short term, stress suppresses our hunger. The hypothalamus — part of the brain that links the nervous system to the hormone system — produces a hormone that stifles appetite.

Our adrenal glands also pump out adrenaline, which triggers the fight-or-flight response, putting us in an agitated state. If you think about it, it's unlikely your brain would be focused on nourishment when you're highly anxious or alert about something.

In the long term, however, the effects are somewhat reversed. If you're stressed for a prolonged period of time, the adrenal glands start releasing cortisol, another hormone which can increase appetite. It can also increase our motivation, including the impulse to eat.

Lack of sleep can also be a factor

If stress is causing a lack of sleep, which it often does, this has been shown to increase appetites too. One study, published in the European Journal of Clinical Nutrition, found that sleep-deprived people on average consume an extra 385 calories per day.

When the stressful period is over — the exam season has finished, or you've completed that big project at work — your cortisol levels should fall, and you should be able to sleep again. But if you can't shake the anxious feeling, your cortisol levels will probably stay high, leading to a cycle of more and more binge eating.

Unfortunately, we rarely crave healthy snacks like carrot sticks. Instead, we want the kind of foods that indulge our brain's reward system. Sugary snacks like cookies, cakes, and chocolate cause a dopamine response — the happy, reward hormone.

Then, next time you're feeling stressed, you'll seek out these foods because you'll remember they made you feel better.

Sugar can also reduce the cortisol response, according to a study in The Journal of Clinical Endocrinology & Metabolism. Over time, your brain might become dependent on these foods to ease your nerves.

It's also bad for our general health. If we consume a lot of sugar, but we don't actually need that energy to run away from any dangers, we need to get rid of it. The pancreas has to pump out insulin to bring down our blood sugar levels, and if this happens too much over our lifetime we can develop type 2 diabetes.

Stress eating can also make us put on weight. A study published in the journal Biological Psychiatry found that women who reported feeling stressed burned about 100 fewer calories per day, which can add up to 11 pounds of weight in a year.

Channel anxiety into something positive

Instead of turning to food to calm your nerves, there are other ways to channel anxiety into something positive. You could try meditation, exercise to clear your head, or a relaxing hobby like yoga.

At the very least you can increase your chance of getting a good night's sleep by writing down anything that's in your mind before you put your head down, avoiding screens for at least an hour before bed, and making sure you're in a dark room.

SEE ALSO: The 'neck rule' could tell you if you're ill enough to skip your workout — here's how it works

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NOW WATCH: Those little bags found with new shoes and electronics are more useful than you think

• Brain scientists at the University of California Berkeley placed electrodes on the outer layer of the brains of 16 patients and watched how a thought developed in their heads.
• The insights shed new light on how the prefrontal cortex coordinates activity in the brain, like a conductor.
• The researchers also saw that when the brain engages in simple tasks, our motor cortex begins to work very early, suggesting we're sometimes preparing to respond before we've completely heard what's being said.

What happens in the brain when you're listening to a person's voice or looking at their face? 

Neuroscientists at the University of California Berkeley have some new answers to that question after peering inside the opened-up heads of 16 epilepsy patients.

The scientists' aim was to track what happens as a thought is developing inside the brain. 

They wound up with a near-perfect demonstration of how the front of the brain (the prefrontal cortex) directs what happens as a thought develops from perception into action. 

Based on their results, published in the journal Nature Human Behavior, here's what it looks like when people hear the word "humid" and repeat it back:

How do scientists venture inside the brain?

For this field trip into the brain, the scientists had to literally get inside the participants' skulls. They used a process called "electrocorticography," (ECoG) whereby several hundred electrodes are placed directly on to the surface of the brain. The patients in the study all agreed to take part in the experiment while their brains were being opened for a surgery anyway.

The ECoG method can more precisely detect where and how thinking is happening than the more common electroencephalography (EEG) scan, which only requires patients to wear electrodes on their scalp.

After the researchers set up the brain-touching electrodes, they asked the patients to perform tasks both simple and complex. Participants were prompted to repeat a word, identify the gender of a face or voice, come up with an antonym for a given word, or decide whether an adjective correctly described a given personality. 

The data the researchers collected revealed how the outer layers of the brain, which perceive stimuli and evaluate words (called the visual and auditory cortices), fire up to process what's being seen or heard. Then, the prefrontal cortex infers meaning, and finally the motor cortex kicks into gear to prepare a response.

It all happens in less than a second for simple tasks, but can take between two and three seconds for the more complicated prompts.

Like an orchestra, your brain has a conductor

Avgusta Shestyuk, lead author of the study, said the experiment shows how the prefrontal cortex— the outer layers of grey matter in the front of the brain — can act like a kind of conductor for the brain, coordinating and delegating tasks. 

"Here, we are able to see that this is not because the neurons are working really, really hard and firing all the time, but rather, more areas of the cortex are getting recruited," Shestyuk said in a release. 

When the participants' brains were working on an easy task, their motor cortex areas, which are responsible for the response, sometimes started lighting up as the initial stimulus was still being presented. Shestyuk thinks that might be a key reason why people sometimes utter quick responses seemingly "before they think." (This is evident in the gif above.)

Here's an example of how the brain processes a more complicated idea, coming up with an antonym for the word "humid:" 

That path shows, somewhat unsurprisingly, how much longer it takes to process a complex thought.

SEE ALSO: What power does to your brain and your body

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NOW WATCH: An evolutionary psychologist explains what happens inside our brain when we meditate and how that changes over time

• Homo sapiens have been around for about 200,000 years.
• But our modern-shaped human brains may have only come into existence about 40,000 years ago, researchers say.
• The rounder, bigger brain shape that researchers have tracked lines up with when people started heading out of the cave, developing tools, language, and self-awareness.

Homo sapiens, in our most "modern" form, have been roaming the earth for about 200,000 years now. 

But there's something rather special about the way our brains look today: human skulls are rounder, faces are smaller, and more retracted into the skull. It's different from the way our ancestors looked, more than a hundred thousand years ago.

And now, for the first time, scientists say they've pinpointed precisely when they believe we grew into our modern skulls.

Research published Wednesday in the journal Science Advances by a team at the Max Planck Institute for Evolutionary Anthropology in Germany says there's something distinct about the way our brains and skulls look now, and it likely developed around 40,000 years ago. 

Compared to our ancestors, the modern head shape features a bigger, rounder cerebellum (that's the area in the back of the brain, responsible for things like motor control and balance, as well as some memory and language). We also have more a bulging, rounded parietal lobe (which helps us orient, plan and pay attention), and smaller, more retracted faces than our predecessors.

The side walls of the brain became more parallel, the frontal area became taller, and the occipital area, in the back of the head, shifted to a rounder, less "overhanging" shape.

What's remarkable about the find is that our brain shape changes track almost perfectly with the development of modern behaviors, like carving tools, planning, developing self-awareness, languages and even the first cave drawings. In other words, that so-called "human revolution" of around 40,000 years ago, sometimes referred to as the "great leap forward" happened right around the time we were getting comfy in our newer skulls. 

As the researchers point out, this didn't all happen overnight, but instead was the result of tens of thousands of years of slight changes. They can't say for sure yet when our brains made the switch, but they're pretty sure it was "at some point after about 100,000 years ago and probably before 35,000 years ago."

Using 3-D scanning techniques to examine curves, shapes and features of 20 different homo sapien fossils, ranging from 300,000 years to 10,000 years old, the researchers have developed a groundbreaking theory: our modern ways would probably not have been possible without our rounder, more elegant brains.

SEE ALSO: What power does to your brain and your body

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NOW WATCH: An evolutionary psychologist explains what happens inside our brain when we meditate and how that changes over time

• Chinese scientists just cloned two monkeys, using the same method that birthed Dolly the sheep in 1996.
• Zhong Zhong and Hua Hua are the first primates cloned from a non-embryonic cell.
• "The technical barrier is now broken" for cloning humans, the researchers said, though they insisted "there is no intention to apply this method to humans."
• It's still pretty difficult to successfully clone primates: it took 127 eggs to produce two live macaque births.

By Ben Hirschler

LONDON (Reuters) - Chinese scientists have cloned monkeys using the same technique that produced Dolly the sheep two decades ago, breaking a technical barrier that could open the door to copying humans.

Zhong Zhong and Hua Hua, two identical long-tailed macaques, were born eight and six weeks ago, making them the first primates -- the order of mammals that includes monkeys, apes and humans -- to be cloned from a non-embryonic cell.

It was achieved through a process called somatic cell nuclear transfer (SCNT), which involves transferring the nucleus of a cell, which includes its DNA, into an egg which has had its nucleus removed.

Researchers at the Chinese Academy of Sciences Institute of Neuroscience in Shanghai said their work should be a boon to medical research by making it possible to study diseases in populations of genetically uniform monkeys.

But it also brings the feasibility of cloning to the doorstep of our own species.

"Humans are primates. So (for) the cloning of primate species, including humans, the technical barrier is now broken," Muming Poo, who helped supervise the program at the institute, told reporters in a conference call.

"The reason ... we broke this barrier is to produce animal models that are useful for medicine, for human health. There is no intention to apply this method to humans."

Genetically identical animals are useful in research because confounding factors caused by genetic variability in non-cloned animals can complicate experiments. They could be used to test new drugs for a range of diseases before clinical use.

The two newborns are now being bottle fed and are growing normally. The researchers said they expect more macaque clones to be born over the coming months.

Since Dolly - cloning's poster child - was born in Scotland in 1996, scientists have successfully used SCNT to clone more than 20 other species, including cows, pigs, dogs, rabbits, rats and mice.

Similar work in primates, however, had always failed, leading some experts to wonder if primates were resistant.

The new research, published on Wednesday in the journal Cell, shows that is not the case. The Chinese team succeeded, after many attempts, by using modulators to switch on or off certain genes that were inhibiting embryo development.

Even so, their success rate was extremely low and the technique worked only when nuclei were transferred from foetal cells, rather than adult ones, as was the case with Dolly. In all, it took 127 eggs to produce two live macaque births.

"It remains a very inefficient and hazardous procedure," said Robin Lovell-Badge, a cloning expert at the Francis Crick Institute in London, who was not involved in the Chinese work.

"The work in this paper is not a stepping-stone to establishing methods for obtaining live born human clones. This clearly remains a very foolish thing to attempt."

The research underscores China's increasingly important role at the cutting-edge of biosciences, where its scientists have at times pushed ethical boundaries.

Three years ago, for example, researchers at Sun Yat-sen University in Guangzhou caused a furor when they reported carrying out the first experiment to edit the DNA of human embryos, although similar work has now been done in the United States.

Scientists at the Shanghai institute said they followed international guidelines for animal research set by the U.S. National Institutes of Health, but called for a debate on what should or should not be acceptable practice in primate cloning.

(Reporting by Ben Hirschler; Editing by Peter Graff)

SEE ALSO: The modern human brain may only be 40,000 years old, scientists say

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The story begins with the Aztec God of death and lightning, the Xolotl. As legends have it, he was a monstrous dog that guarded the sun god and ushered souls to the underworld every night. One day, as Gods began sacrificing each other for the newly created sun, Xolotl, a master transformer, managed to escape death by turning himself into a salamander. And that creature came to be known as the axolotl.

In ancient Aztec tongue, the name 'Axolotl' translates to "water monster," and just as their name suggests, these creatures live their entire lives underwater using these adorable feather gills to breathe. After being driven to near extinction from their only natural habitats in Central Mexico, these creatures are now found more in labs than anywhere else. This is because the axolotl is one of nature's scrappiest creatures with a unique ability that has baffled the scientific community for decades.

Dr. James Godwin: "They are pretty amazing actually. So I mean obviously, they are famous for their ability to regenerate extreme structures like limbs and we all know that it's the only terrestrial animal that can regrow a limb and the only vertebrate that can regrow a limb. So if you amputate at the level of the wrist, you regenerate the hand. If you amputate at the upper arm, you can regenerate a full arm."

But the axolotl's regenerative ability doesn't stop there.

Dr. James Godwin: "There is a whole laundry list of structures that they can regenerate. They can regenerate the front portion of their brain, called the telencephalon. You can crush the spinal cord and in about three weeks, all of the spinal cord machinery would reconnect and the tail and the legs will work again. They can regenerate impressively their testes. But most importantly, they can regenerate like a third of the heart ventricle. So if you amputate or injure a third of the heart, of the pumping machinery of the heart, it will regrow that in the course of about 30 days to 60 days. Comparative to humans, where a tiny, little blockage in our heart vessel will lead to extreme damage and eventually death, these guys are pretty amazing."

Axolotls are able to achieve this sort of regeneration because they react to injuries in an entirely different way than humans. When we are injured, a wound from a severed limb simply gets covered with skin tissue. But not the axolotls. They transform nearby cells to stem cells, forming bones, skins, and veins in their exact original state. Scientists are still unable to explain why we react to injuries so differently.

Dr. James Godwin: "When humans or mice gets injured certain parts of the immune system participate in that in a different way that may lead to a scarring outcome or it may block the ability to activate or awaken that regenerative process. The other thing is that there may be some intricate difference in the salamander's cell. Salamanders may have cells that are poised, ready to take place in reaction of regeneration and human cells could be locked down in their potential."

Recently, researchers gained access to the full genome sequence of an axolotl allowing them to identify specific genes and proteins that could hold the key to regeneration.

Dr. James Godwin:  "Now that we have a sequence genome and we have all the molecular tools, I think it's going to be a very exciting future for this model. If we could learn from these regenerative organisms and use them as a template, we might be able to sort of unlock the natural way to regenerate."

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• Psychologists who scanned the brains of graduate students said they accurately predicted who people were friends with based on how their brains lit up while watching a video.
• Did the students pick out friends with similar brains, or could they be shaping the way their friends see the world? The study authors say it could be a little of both.

Maybe your friends really do "just get you" after all. 

At least, that's what a new study of graduate students at an Ivy League school suggests.

For that study, published Tuesday in the journal Nature Communications, a group of brain researchers and social psychologists at Dartmouth College looked at the brains of 42 students, and monitored their reactions as they watched some retro video clips.

The students watched America's Funniest Home Videos, saw an astronaut at the International Space Station, peeked in on a wedding ceremony, and glanced at footage of the discontinued CNN show "Crossfire."

MRI scans showed that friends watching the same clips reacted in strikingly similar ways: some of the same brain areas lit up, notably those associated with motivation, learning, affective processing, and memory.

The researchers said the similarities in brain reaction patterns were so striking, they could actually use them to predict who the participants' friends were. (The scientists based their assessment of students' friendships on the results of an online survey taken by the participants, as well as the other 279 students in their graduate program, about who their friends were.)

Conversely, people who weren't friends had different reactions to the same clips. The activity patterns were less similar in friends of friends, and even more divergent in people who were in separate social groups. 

"Our results suggest that friends process the world around them in exceptionally similar ways," lead author Carolyn Parkinson said in a release. 

The authors think that's because spending time with people who think like us feels pretty good. In their paper, they wrote that having close friends whose brains respond like ours "may be rewarding because it reinforces one’s own values, opinions, and interests."

Dartmouth business professor Adam Kleinbaum, who co-authored the study, told Business Insider that it's not clear whether people are seeking out friends whose brains are already like theirs, or if friends change the ways each other's brains react to stimuli.

"We think both are happening," he said.

An important caveat to note about this study, however, is that it only looked at how the brains of graduate students at one university react. The ways people choose and interact with friends at school are not necessarily representative of how everyone picks their pals. 

College and graduate students are often the subjects in psychological studies, since there are so many students near research labs. But social scientists have argued for years that college students aren't necessarily like the rest of us. In 1986, psychologist David Sears wrote in the Journal of Personality and Social Psychology that using college students as research subjects might skew the ways we perceive human nature.

"Compared with older adults, college students are likely to have less-crystallized attitudes, less-formulated senses of self, stronger cognitive skills, stronger tendencies to comply with authority, and more unstable peer group relationships," Sears wrote.

A 2010 paper in the journal Behavioral and Brain Sciences argued that college students are "WEIRD" research subjects: they're generally Western, Educated, Industrialized, Rich, and Democratic. 

Still, there's a growing body of research that suggests the way we pick out friends has a lot to do with the shape of our brain and our body.

A 2014 study of 1,932 adults (of all ages) showed that people tend to pick out friends with similar genotypes to their own.  The researchers found that the genetic similarities of friend "pairs" were, on average, as close as those of fourth cousins.

A new study by Korean researchers, which was released this month, also notes differences in the brains of people who have more friends. When lots of people reported being friends with a given individual, that person was found to have a bigger neocortex, an area sometimes referred to as the "social brain" since it's believed to play a role in social interaction. Those study participants weren't college students at all: they were Koreans over the age of 60.

SEE ALSO: The deadly flu epidemic sweeping the US is still spreading — here's everything you need to know

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• Synthetic biology, or the ability to use a cell to produce something beyond its intended purpose, is starting to have a bigger impact in our day-to-day lives, whether we realize it or not. 
• As funding pours into the space, the reality of having microbes that are able to produce substances they might not normally is becoming cheaper and more readily available. 
• "It's now becoming increasingly ready for the prime time," Synthetic Genomics CEO Oliver Fetzer told Business Insider. "It's no longer an academic toy."

Microscopic organisms that have been engineered to produce different material could one day be part of your daily life — and you might not even notice. 

People debate the definition, but at its core synthetic biology is the ability to design organisms to do something they wouldn't otherwise do. For example, that could be excreting a new drug, using yeast to create a new fragrance, or even producing silk for a tie. 

In the past few years, synthetic biology has gained a lot of interest. Tech venture capital firm Andreessen Horowitz launched a $450 million biotech-focused fund that will in part be looking to fund new ways to use biology, including using synthetic DNA. And Ginkgo Bioworks, a startup that designs microbes to produce things like fragrances or to create medications,raised $275 million in December 2017, valuing the company at $1.3 billion.  

Synthetic biology is based on the idea that we can now program cells to do what we want. In that way, it's like computer code, except for instead of 1s and 0s, it's A, T, C, and G, the building blocks that make up DNA. 

"If you can read and write code, you're programming, and it just so happens that this is another form of digital code," Ginkgo Bioworks CEO Jason Kelly told Business Insider. 

In the past two decades, scientists have figured out how to take genetic engineering — the ability to modify genes in an organism, such as inserting bacteria genes in corn to protect it from pests — and use it to get organisms to produce something they might not have otherwise. As sequencing technology's and the ability to produce DNA have gotten better, the applications of synthetic biology have started to expand beyond the experimental stage. 

Ultimately, the impact synthetic biology has on the world could be incredibly far reaching. 

"If you're in physical goods, you're a biotech company, you just don't know it yet," Kelly said.

Under-the-radar advancements

For the most part, the impact of synthetic biology has so far been behind the scenes. One of the projects Synthetic Genomics is working on is finding ways to program cells to make monoclonal antibodies in a simpler way than is currently done.

Monoclonal antibodies are the basis for many biologic drugs. Currently, these drugs are manufactured using genetically modified Chinese hamster ovary cells. In the end, if a drug is approved that comes from the cells Synthetic Genomics made, a patient might not know, in the same way they might not know they're getting a treatment produced by hamster ovary cells. 

"If your doctor prescribes a medicine today, I think most patients don't really spend to much time thinking about, 'Was that medicine made by a Chinese hamster ovary cell that was heavily genetically modified?' I don't think that many patients will have any appreciation of what happened behind the scenes to give them their specific medicine that the doctor prescribes to them," Fetzer said. 

The hope, though, is that this will help make treatments a lot easier to control and ideally cheaper to produce — and in turn cheaper for patients. 

But consumer applications are starting to catch on as well. 

So far, the clearest example of this has been by engineering brewer's yeast to make different scents. In September, Ginkgo formed a $100 million joint venture with Bayer to develop microbes that could lead to more sustainable agriculture practices, and the company's working with a biotech company called Synlogic to engineer probiotics as well. 

As the cost to re-engineer microbes comes down, the applications have a shot of extending beyond medications into products you might encounter day-to-day. For example, one company is using synthetic biology to make silk ties, while Impossible Burger uses engineered yeast to produce the ingredient in the plant-based burger that gives it its bloody, burger-like taste.

And soon, that lower cost is going to bring these products from experimental use to mainstream markets. 

"It's now becoming increasingly ready for the prime time," Fetzer said. "It's no longer an academic toy." 

Far-reaching potential

Synthetic biology has already had a major impact on medicine, but the hope is that it can go even further, by making personalized treatments available to more people, Fetzer said. 

Beyond that, Kelly's theory is that no industry that makes physical goods will be spared from the effects of synthetic biology.

The scope of synthetic biology's impact can be incrediblE. Massachusetts Institute of Technology professor Tim Lu, who runs the Synthetic Biology Group, told Business Insider that the best way to think about it is to think about all the parts of day-to-day life that interact with biology. 

"Everything in our life touches organisms," Lu said. So then when it comes to synthetic biology, the reach can be just as broad. 

"Synthetic biology is giving us the capacity to modify and change the way we interact by adding efficiency and new capabilities."

SEE ALSO: Top Silicon Valley VC Andreessen Horowitz is investing $450 million into biotech

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• Kissing each other is one of the most popular ways we show each other affection.
• However, we transfer around 80 million bacteria for every 10 seconds of kissing.
• Happy Valentine's Day.

Kissing is one of our favourite disgusting activities.

Looking at it objectively, sharing saliva with someone else is a pretty gross thing to do. In fact, we transfer approximately 80 million bacteria for every ten seconds we're kissing each other.

The majority of these germs are totally benign, so it's nothing to worry about.

But it's still weird to think about inviting someone to share their spit with you — so why do we do it?

First of all, it makes us feel good. Our lips are packed full of receptor cells, which make them very sensitive. In fact, along with fingertips, they are thought to have the highest concentrations of receptor cells.

When you enjoy kissing someone, these receptors shoot signals to your brain, and you release chemicals like dopamine, which fuels your reward system, and makes you want to carry on kissing.

Endorphins, your body's natural painkillers, are also released, which enhance the feeling of pleasure. If it's a really good kiss, your brain may also release oxytocin, the "love hormone," which makes us feel warm and cuddly, and increases our attachment to the other person.

Male saliva contains measurable amounts of testosterone, which could also increase your libido (if you're kissing a man.)

Dr Sarah Johns, an expert in human reproduction and evolutionary psychology at the University of Kent, told The Independent that as well as being an emotion-driven act, kissing helps us pick our most compatible partner.

"Humans don't have strong olfactory skills and kissing allows you to smell and taste a person and see if you have different immune responses as we tend to feel more attracted to someone with a different immune response," she said.

"The major histocompatibility complex is detectable in body odour, so by kissing and tasting someone it gives the opportunity to assess how similar or different that individual is to you biochemically."

In other words, somehow your body may be able to detect whether reproducing with the person you're kissing would be an evolutionary risk or not.

She added that feeling arousal can inhibit feelings of disgust, meaning we don't necessarily think of all the gross things we're doing while we're doing them, because we're too turned on.

Nobody really knows where kissing came from

There's some debate about whether we started kissing each other for cultural reasons, or if it's something we evolved to do biologically.

About 90% of human populations kiss in some way or another, with the majority of others doing similar things in replacement such as rubbing noses, suggesting it could be something instinctual.

Kissing also isn't unique to humans. Primates such as bonobos often kiss each other, and cats and dogs lick and groom one another.

Some scientists believe that kissing could have evolved from "kiss-feeding" behaviours, which is when mothers pass food from their own mouths to their offspring. Birds still do this with their chicks. One theory is that over time, pressing lips became known as an act of caretaking and love.

According to evolutionary psychologists at the University of Albany, the way men and women feel about kissing can differ quite significantly.

In a study of 1,041 college students, the researchers found that women placed more emphasis on kissing, seeing it more as a deal-breaker. They were more likely than men to insist on kissing before having sex, and emphasising the importance of kissing during and after sexual encounters.

Men were more happy to have sex without kissing, and weren't that bothered about whether their partner was a good kisser or not. They were also more likely than women to initiate french kissing (with tongues.)

So whether it's an evolutionary thing, or just something we've picked up, humans really enjoy kissing. It might be gross on paper, but it looks like the benefits outweigh the costs on this one.

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• The flu is a disease that works its way into the respiratory tract.
• Although the influenza virus attacks lungs, it's not the only thing that makes you feel bad.
• The activity of white blood cells, which are part of the immune system, can damage bodily tissue while mounting a defense.
• Other bodily chemicals trigger headaches and fever, which can have antiviral effects.
• Flu infections can also turn on genes that degrade muscles, making those tissues feel sore.

Every year, from 5 to 20 percent of the people in the United States will become infected with influenza virus. An average of 200,000 of these people will require hospitalization and up to 50,000 will die.

Older folks over the age of 65 are especially susceptible to influenza infection, since the immune system becomes weaker with age. In addition, older folks are also more susceptible to long-term disability following influenza infection, especially if they are hospitalized.

We all know the symptoms of influenza infection include fever, cough, sore throat, muscle aches, headaches and fatigue. But just what causes all the havoc? What is going on in your body as you fight the flu?

I am a researcher who specializes in immunology at the University of Connecticut School of Medicine, and my laboratory focuses on how influenza infection affects the body and how our bodies combat the virus.

It's interesting to note that many of the body's defenses that attack the virus also cause many of the symptoms associated with the flu.

How the flu works its way into your body

Influenza virus causes an infection in the respiratory tract, or nose, throat and lungs.

The virus is inhaled or transmitted, usually via your fingers, to the mucous membranes of the mouth, nose or eyes. It then travels down the respiratory tract and binds to epithelial cells lining the lung airways via specific molecules on the cell surface.

Once inside the cells, the virus hijacks the protein manufacturing machinery of the cell to generate its own viral proteins and create more viral particles. Once mature viral particles are produced, they are released from the cell and can then go on to invade adjacent cells.

While this process causes some lung injury, most of the symptoms of the flu are actually caused by the immune response to the virus.

The initial immune response involves cells of the body's innate immune system, such as macrophages and neutrophils.

These cells express receptors that are able to sense the presence of the virus. They then sound the alarm by producing small hormone-like molecules called cytokines and chemokines. These alert the body that an infection has been established.

Cytokines orchestrate other components of the immune system to appropriately fight the invading virus, while chemokines direct these components to the location of infection.

One of the types of cells called into action are T lymphocytes, a type of white blood cell that fights infection. Sometimes, they are even called "soldier" cells.

When T cells specifically recognize influenza virus proteins, they then begin to proliferate in the lymph nodes around the lungs and throat. This causes swelling and pain in these lymph nodes.

After a few days, these T cells move to the lungs and begin to kill the virus-infected cells. This process creates a great deal of lung damage similar to bronchitis, which can worsen existing lung disease and make breathing difficult.

In addition, the buildup of mucous in the lungs, as a result of this immune response to infection, induces coughing as a reflex to try to clear the airways. Normally, this damage triggered by arrival of T cells in the lungs is reversible in a healthy person, but when it advances, it is bad news and can lead to death.

The proper functioning of influenza-specific T cells is critical for efficient clearance of the virus from the lungs. When T cell function declines, such as with increasing age or during use of immunosuppressive drugs, viral clearance is delayed.

This results in a prolonged infection and greater lung damage. This can also set the stage for complications including secondary bacterial pneumonia, which can often be deadly.

Why your head hurts so much

While the influenza virus is wholly contained in the lungs under normal circumstances, several symptoms of influenza are systemic, including fever, headache, fatigue and muscle aches.

In order to properly combat influenza infection, the cytokines and chemokines produced by the innate immune cells in the lungs become systemic – that is, they enter the bloodstream, and contribute to these systemic symptoms. When this happens, a cascade of complicating biological events occur.

One of the things that happens is that Interleukin-1, an inflammatory type of cytokine, is activated.

Interleukin-1 is important for developing the killer T cell response against the virus, but it also affects the part of the brain in the hypothalamus that regulates body temperature, resulting in fever and headaches.

Another important cytokine that fights influenza infection is something called "tumor necrosis factor alpha."

This cytokine can have direct antiviral effects in the lungs, and that's good. But it can also cause fever and appetite loss, fatigue and weakness during influenza and other types of infection.

Why your muscles ache

Our research has also uncovered another aspect of how influenza infection affects our bodies.

It is well-known that muscle aches and weakness are prominent symptoms of influenza infection. Our study in an animal model found that influenza infection leads to an increase in the expression of muscle-degrading genes and a decrease in expression of muscle-building genes in skeletal muscles in the legs.

Functionally, influenza infection also hinders walking and leg strength. Importantly, in young individuals, these effects are transient and return to normal once the infection was cleared.

In contrast, these effects can linger significantly longer in older individuals. This is important, since a decrease in leg stability and strength could result in older folks being more prone to falls during recovery from influenza infection. It could also result in long-term disability and lead to the need for a cane or walker, limiting mobility and independence.

Researchers in my lab think that this impact of influenza infection on muscles is another unintended consequence of the immune response to the virus. We are currently working to determine what specific factors produced during the immune response are responsible for this and if we can find a way to prevent it.

Thus, while you feel miserable when you have an influenza infection, you can rest assured that it is because your body is fighting hard. It's combating the spread of the virus in your lungs and killing infected cells.

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Politically, Americans are more divided than ever.

When it comes to issues of race, immigration, national security, and environmental protection, they disagree about how the government should handle things like never before.

Relative to polls in the 1990s, Republicans are now much more likely to say poor people have it easy, while Democrats are less likely to say so. Conservatives are also more likely to say that environmental regulations are costing the US too many jobs. Liberals now seem less convinced that peace can be achieved through military strength than they were decades ago. 

The Pew Research Center reports that the country's political divisions now far exceed "divisions along basic demographic lines, such as age, education, gender and race." The share of Americans who sit in the middle of the political spectrum is lower, too.

Russian bots are taking advantage of these widening differences on Facebook and Twitter in an attempt to drive Americans' opinions further apart. 

But what in the brains of conservative and liberal voters actually drive their belief systems? Scientists have been researching the psychological differences between people with different stances, and there are a few key ways that people on opposite ends of the political spectrum see the world. Here's what the data shows:

SEE ALSO: A Yale psychologist's simple thought experiment temporarily turned conservatives into liberals

Being scared can make you more conservative.

Decades of research has shown that people get more conservative when they feel threatened and afraid.

Threats of terrorism make everyone less liberal — researchers found this was especially true in the months after 9/11. During that time, the US saw a conservative shift, and Americans displayed increased support for military spending and for President George W. Bush.

Americans aren't the only ones whose political leanings are influenced by fear. A 2003 review of research conducted in five different countries looked into 22 separate tests of the hypothesis that fear fuels conservative viewpoints and found it was universally true.

A conservative brain is more active in different areas than a liberal one.

Brain scans show that people who self-identify as conservative have larger and more active right amygdalas, an area of the brain that's associated with expressing and processing fear. This aligns with the idea that feeling afraid makes people lean more to the right. 

One 2013 study showed conservative brains tend to have more activity in their right amygdalas when they're taking risks than liberals do.

On the other hand, feeling safe and endowed with strength might make you lean a little more liberal than you otherwise would.

Groundbreaking research that Yale psychologists published in 2017 revealed that helping people imagine they're completely safe from harm can make them (temporarily) hold more liberal views.

The authors of that study said their results suggest that socially conservative views are driven, at least in part, by people's need to feel safe and secure.

That finding didn't hold true for people with economically conservative views, though.

• The Atacama Desert in Chile is one of the driest places on Earth and is comparable to the dry surface of Mars.
• Researchers recently discovered that when it rains in the Atacama, microbial communities that lay dormant for decades or even thousands of years spring back to life.
• It's possible that similar life could have evolved on Mars and may persist in subsurface niches where there's moisture.

Long ago, small oceans and lakes dotted the surface of Mars.

Microbial life could have thrived in the waters of the now hyperarid red planet. Currently, there are only traces of this past environment — water hides frozen in the soil, and potential nighttime snowfalls dust the dry surface.

It might be easy to assume that the loss of atmosphere and liquid water would have killed off all traces of life on our neighboring planet. But a new study of one of the most Mars-like environments on Earth, the Atacama Desert in Chile, reveals that life may persist, lurking beneath Martian soil and waiting a chance to re-emerge.

Researchers found that in the extremely rare occasions when rain falls on the Atacama, there's an explosion of microbial life. This is the first thriving life that has been observed in this desert, the driest non-polar environment on the planet. 

In the rare rainy conditions, long dormant bacteria below the surface wake and reproduce until the area starts to dry out again and they revert to a dormant state, leaving behind traces of DNA and decaying material.

"We believe these microbial communities can lay dormant for hundreds or even thousands of years in conditions very similar to what you would find on a planet like Mars and then come back to life when it rains," Washington State University planetary scientist Dirk Schulze-Makuch, who led the study, said in a news release.

Life in extreme environments

This discovery comes thanks to a stroke of luck. It happened to rain while the research team was in the desert in 2015. (It's so dry in the region that there are weather stations in the desert that have never seen rain).

That rainfall allowed the team to see that even this extreme environment can be habitable. The creatures that live there only become metabolically active after an increase in moisture.

This remarkable finding suggests that similar forms of life could persist on Mars in some subsurface niche that gets periodically exposed to moisture, the authors wrote in the study.

The team plans to continue their analysis of life in extreme environments. They will return to the Atacama in March and Schulze-Makuch said he'd also like to examine the Don Juan Pond in Antarctica, a pool so salty that it remains liquid even at a Martian-like -58 degrees Fahrenheit.

"It has always fascinated me to go to the places where people don't think anything could possibly survive and discover that life has somehow found a way to make it work," Schulze-Makuch said. "Jurassic Park references aside, our research tell us that if life can persist in Earth’s driest environment there is a good chance it could be hanging in there on Mars in a similar fashion."

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• Scientists surveyed Trump and Clinton supporters a month before the 2016 election, and found differences in how the two groups reacted to body odors.
• Socially conservative voters were more sensitive when presented with the idea of a stinky fart or smelly armpit.
• It's a finding that aligns with years of study on psychological differences between people who hold socially conservative and liberal views.

Does the idea of a smelling someone's stinky feet gross you out? How about accidentally sniffing a stranger's fart, or standing next to someone wearing a sweaty t-shirt? 

Turns out, supporters of President Donald Trump are especially grossed out by these ideas.

That's according to a new study released Wednesday from scientists at Stockholm University in Sweden.

The psychologists surveyed 391 American adults online in October 2016, a month before the presidential election. The participants represented a mix of personalities and demographics: 172 were men and 219 women, 36% supported Trump over Clinton (a number that tracked closely with national polling at the time), and roughly half of the group were college grads.

Time and again, the researchers found that when they asked questions like whether a participant would be grossed out by a neighbor's stinky feet, farts, urine, feces, or armpit smells, Trump supporters were predictably more sensitive to the idea of foul body odor.

The researchers said the finding isn't true across the board for all conservatives; but it was closely linked with people's support for socially conservative ideas and endorsement of President Trump.

"This relationship seems to be explained by a particular aspect of social conservatism called right-wing authoritarianism," lead author Marco Tullio Liuzza told Business Insider in an email. This "right-wing authoritarianism," he said, includes an acceptance of authority and a hostility towards groups that don't closely adhere to a traditional social order.

Conservatives don't like being grossed out

Psychologists have previously found that socially conservative people look away from gross images like blood and vomit quicker than liberals. Conservatives' brains are also more active in areas that are associated with processing fear.

Being grossed out is not a bad thing — such reactions have helped humans survive for millennia. As we wade our way through a world of pathogens, it's helpful to get turned off by any potential germy foreign objects or stinky stuff. 

Liuzza said the strong reaction of conservatives "may share an evolutionary source with an emotion that evolved to protect our bodies by poisonous substances and diseases."

But other recent research has suggested that socially conservative people's ability to get easily grossed out can extend into prejudice for unfamiliar groups like immigrants or gay people.

The researchers caution that while the trend is an interesting psychological finding, it accounts for only a small portion of individual differences when it comes to people's political preferences. 

In other words, you can't know for sure who your neighbor voted for just because they're wrinkling their nose. 

SEE ALSO: Scientists have discovered the key psychological differences that can make you liberal or conservative

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Dogs have been our furry companions for thousands of years, but they didn't always look the way they do today.

Many well-known breeds have changed a lot physically in the last century, thanks to humans.

By identifying specific traits — such as size, coat color, and demeanor — and allowing only those animals to mate, we've created at least 167 different "breeds," or groups of dogs with unique physical and mental characteristics. Still, they're all part of the same species.

The Science of Dogs blog put together a side-by-side comparison of several popular breeds from the 1915 book "Dogs of All Nations" by Walter Esplin Mason, showing what they look like today.

Here are some of the dogs from that list, plus a couple more we found ourselves.

Tanya Lewis contributed to an earlier version of this post. 

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Bull terrier then

The bull terrier was first recognized as a breed by the American Kennel Club (AKC) in 1885. In 1915, it appears to have been a fit, good-looking dog, with a well-proportioned head and slim torso. "Dogs of All Nations" called it "the embodiment of agility, grace, elegance and determination," and the "gladiator of the canine race."

Bull terrier now

But today, bull terriers are bred to have a football-shaped head and a thick, squat body — a far cry from the lean and handsome dog of 1915.

The AKC now states that the dog's face"should be oval in outline and be filled completely up giving the impression of fullness with a surface devoid of hollows or indentations, i.e., egg shaped."According to Science of Dogs, it also developed extra teeth and a habit of chasing its tail.

English bulldog then

Few dogs have been as artificially shaped by breeding as the English bulldog. In the UK, the dogs were used for bull-baiting— a blood sport where dogs were used to bait and attack bulls — until it became illegal in 1835. In 1915, the bulldog already had some of the characteristic features we see today, like saggy jowls and a squat stance.

• Chemical weapons called nerve agents were likely used in the attempted murder of Sergei Skripal, a former Russian spy, and his daughter Yulia.
• The chemicals attack the spaces between nerves and muscles to overwhelm essential bodily functions.
• Victims may stop their breathing and convulse, which can lead to death.

Nerve agents kill victims with gruesome efficiency — after triggering unconscionable suffering through their powerful poisoning effects.

UK authorities now think nerve agents were used in the attempted murder of former Russian spy Sergei Skripal and his daughter Yulia.

On Sunday, passers-by found the two collapsed on a public bench. Paramedics rushed them a nearby hospital, where they remain in critical condition as of Thursday.

The BBC reported that a "very rare" nerve agent was used against the Skripals. So it was probably not one of the five most common: tabun, sarin, soman, GF, and VX. (North Korean leader Kim Jong Un is accused of having his agents use VX in the 2017 assassination of his half-brother, Kim Jong Nam.)

In pure form, each agent a colorless and mostly odorless liquid. Any nerve agent can affect a person through the skin, breathing, ingestion, or all three routes, depending on how it's used. For example, VX resembles a thick oil but dissolves in water (a drop killed Kim Jong Nam), while sarin (which was spread over a Syria's Idlib province on April 4, 2017) quickly evaporates into the air.

How nerve agents attack the body and brain

These two graphics illustrate what nerve agents do to the body and how they work.

To produce these symptoms, nerve agents attack the body's cholinergic system, which is used to transmit signals between the brain and muscle tissues.

The chemicals specifically target an enzyme that drifts in the spaces, or synapses, between nerve cells and muscle cells. There, they persist and constantly trigger muscles into overdrive.

This can paralyze victims, stop their breathing, and trigger convulsions, all of which can lead to death.

Diana Yukari contributed to a previous version of this post.

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