The South-Paw Shuffle: Why Left-Handed People Are Freaks

The great thing about running a science website is that keeping up with your “competition” takes on the same feeling as visiting with friends. One of our personal best friends in this regard is the popular science juggernaut called RadioLab. The brilliant folks that create their articles and podcasts produce a constant stream of topics that get me thinking. Their podcast “What’s Left When You’re Right?” got me thinking enough to write this article. I highly recommend giving it a listen.

Humans have all kinds of strange quirks. We love food that is terrible for us. We jeopardize secure lives and careers to chase crazy dreams. But few of our quirks are as tangible and as complex as our tendency to be right-handed. As most elementary school kids know, a whopping 90% of us Have brains that pull to the right in the vein of a poorly aligned sports car. The result for the remaining 10% (which includes our tireless illustrator over here at Sketchy Science) is that the world is not always an easy place. Among the things that left-handers face unfair challenges with are bank machines (all the slots are on the right), typing numbers (number keys are on the right of your keyboard), driving a manual transmission car, using scissors, and writing in binders/notebooks.

On top all the practical disadvantages, researchers at Yale University have found some evidence suggesting that south paws are at a higher risk of suffering from bi polar personality disorder, schizophrenia, and depression. But in a world with no numpad, who could blame them?

Given that the world seems out to get them, why do left handed people still exist? Darwin has made it perfectly clear that nature should phase out any trait that leaves an individual at a disadvantage. Well, as it turns out, there may be one thing working in their favour: lefties will kick your butt at most athletic/physical competitions. If you’ve ever watched a baseball game or a boxing match you may have heard the commentators mention that the pitcher, batter, or one of the fighters is left-handed. This is not an idle observation. Research has shown that a significantly greater number of pro athletes are left-handed than you would expect given that they make up only 10% of the general population (Grouios et al., 2000).

It makes sense when you think about it. Staying with the boxing example, most fighters you face when you start out (like most people overall) are right-handed. Your training will therefore bias you towards attacking and defending against people with a right-handed bias. When you one day face off against a left-hander, however, everything you knew about boxing is suddenly completely backwards. You may be faster, stronger, and even more intelligent, but if you're suddenly fighting a mirror image of what you expect, you will look as awkward as a newborn horse trying to stand for the first time.

Athletic superiority also leads to reproductive success. A study published in Evolution & Human Behaviour found that athletes reported having significantly more sexual partners than non-athletes (Faurie, Pontier, & Raymond, 2003). The authors point out that athletes are generally more physically fit and attractive than non-athletes and that this might have something to do with it. Fortunately, we can all agree that science writers are even more attractive than athletes, on average.

Many people don’t buy the whole left-handed athlete explanation for why south-paws persist despite the drawbacks. The scientists who disagree offer another possible explanation. They believe that as humans evolved the ability to speak, we became more right-handed. For whatever reason, when language evolved in people, it took over a good chunk of the left half of the brain. Since language and speech require such fine control over tiny muscles in your mouth and throat, as the left side of our brains got better at speaking it also got better at controlling motor skills. And since the left side of your brain controls the right side of your body, the side effect is that most of us are now right-handed.

This would explain why evidence for right-handed dominance can be found all through human history, from the time of Greek philosophers through the middle ages. It can also help shed some light on when language first evolved. Evidence of right-handed preference has been found in stone tool use dating back nearly 2 million years! (Toth, 1985) This could mean that humans were first learning to speak (and becoming right-handed) before we were even technically humans (2 million years ago we were either Homo habilis or Homo erectus, depending who you ask). Homo sapiens (modern humans) first appeared about 200,000 years ago.

That's the amazing thing about science. What starts as a seemingly meaningless difference between people eventually gives us insight into neuroscience, evolution, and the incredibly distant past. Think about that next time you reach for a can opener.

References:

Toth, 1985. http://www.sciencedirect.com/science/article/pii/S0047248485800877

Faurie, Pontier, and Raymond, 2004. http://www.ehbonline.org/article/S1090-5138(03)00064-3/abstract

Grouios et al., 2000. http://www.amsciepub.com/doi/abs/10.2466/pms.2000.90.3c.1273?journalCode=pms

Sketchy Fact #37: The Stench of Flowers

The giant Sumatran flower Titan Arum smells like rotting flesh. Its common name is the “Corpse Flower” and it very rarely blooms, presumably to the relief of everyone in Sumatra.

The Trouble with Chairs: How Doing Nothing is Doing You Harm

Living a healthy lifestyle is as difficult as it is important. We saw in our discussion of Epigenetics that the bad decisions we make about our health today can have consequences for not only ourselves, but generations of our offspring. Eating right and exercising regularly are the two crucial things that everyone knows to do to protect their health; however, recent research is beginning to realize that there may be a third factor that is just as important: sitting.

A paper published by the American College of Sports Medicine suggests that if you spend too much time with your feet up, your lifespan may be headed down (Katzmarzyk et al., 2008). The study included over 17,000 Canadians between the ages of 18 and 90 and compared overall mortality with a number of lifestyle factors. The researchers determined that even after controlling for obvious factors like age, diet, and exercise, time spent sitting was correlated with a significantly increased risk of death from any cause.

That is a complicated thought so let’s take a second to think about it. When researchers “control” for something they are trying to rule it out as a cause of some effect. In this case when the researchers control for exercise, for example, they are basically comparing their findings across groups of people who exercise similar amounts. Ditto for diet and age. Even after doing this the effects they found were significant. That means that even if you go for an hour long run after sitting behind a desk at work for 8 hours, you are still at an elevated risk of death compared with a mail carrier, for example.

Other research has linked excess sitting to colon cancer, breast cancer, heart disease, and chronic chest pain. To understate things dramatically: this is bad news. We live in a world that is designed to promote sitting. Buses and trains are basically mobile rooms full of chairs. We sit to eat, we sit to work, we sit to read about how bad sitting is for us (caught you). So what can we do?

Doctors have begun taking this research to heart and have offered several recommendations. First, if you have a job that requires you to sit all day, use your time away from work to be more active. Stand while you watch TV, stand while you eat dinner, go for a walk before breakfast. Much of the problem comes from the fact that when we sit, our muscles don’t contract. The minor contractions that go along with shifting from one foot to the other or moving things around with our arms help our bodies to metabolize and remove fats and sugars. When we sit, those processes shut down and we store harmful waste products in our bodies. The science has even specifically shown that sitting all day increases fat storage around the middle of your body… and beach season isn’t far off.

If you’re the especially wacky type, Amazon offers a plethora of stand-up work station options. You can buy the exercise bike with the laptop tray. There are plenty of desks with the work platform at chest height. You can even buy a treadmill complete with a desk, file sorter, and pen organizer. In his book  Drop Dead Healthy: One Man’s Humble Quest for Bodily Perfection, A.J. Jacobs brags that he walked over 1000 miles (1,600 km) while doing his writing.

Clearly not all of us are cut out for that sort of dramatic undertaking, but we can do some of the little things that the experts recommend. Take a 5 or 10 minute break once an hour to get up and walk around your office. Instead of sitting in a boardroom for a meeting, invite your coworkers to go for a walk while you talk about your next project. An evening stroll after dinner won’t only prolong your life, it might make you enjoy it a little more too.

Usually when bad news makes its way down the scientific grapevine we need to make big changes to our lives if we want to keep enjoying them. Working out is tough and there are days when the thought of going to the gym is tantamount to cruel and unusual punishment. Walking by a pizzeria, smelling the delicious aromas and not going in for a slice is an act of willpower worthy of a medal. By comparison, a little extra standing isn’t such a big deal. Besides, if anyone tries to judge you for it, you are already in position to look down your nose at them. And, in case you were wondering, yes researching this article scared me into action myself. I now spend 6 of my 8 working hours a day standing at this wonderful monstrosity trying to avoid an early grave:

If a lazy blogger can do this, what's your excuse?

Other References:
http://revdesportiva.pt/files/form_cont/Sitting_Time_and_Mortality_from_All_Causes.pdf

Sketchy Fact #36: Avast, Ye Scurvy Guinea Pigs!

Most wild animals don't ever get scurvy because they create Vitamin C inside their bodies. Humans, guinea pigs, and bats are among the few animals that can’t make their own Vitamin C.

Infecting with Immunity: How Vaccines Actually Work

One of the major challenges scientists face is communicating important information to the general public. As brilliant as many of them are, hours spent in a lab hunched over a microscope do little to improve a person’s ability to explain things simply and comprehensibly. Complicating things further is the fact that scientists are trained to constantly question and test their ideas so they say a lot of things like “we believe” and “these results suggest” when really they mean “I am sure this is true, these are facts.” When you’re talking about the evolutionary history of Amazonian frogs or something like that, it tends not to matter; but occasionally a topic comes along where a clear explanation of how things work is even more important than a detailed reporting of the facts. Vaccines are one of those topics.

Right now in the Fraser Valley of British Columbia Canada, several hundred people (mostly children) are infected with an unpleasant and occasionally fatal illness that scientists basically cured a long time ago. Over 200 cased of highly contagious measles have popped up in the region and a few infected people have found their way to Ontario and the Atlantic coast, largely because the Fraser Valley has one of the lowest measles vaccination rates of anywhere in Canada (between 70 and 80%).

Much of the problem lies in the fact that vaccines inject viruses and bacteria into people’s bodies. Generally speaking we are taught that this is a bad thing, so our instinctive reaction is to avoid it. Teaching people that infections are bad and then telling them that you need to inject them with a virus is generally a hard idea to sell because, quite frankly, it makes you seem insane.

The truth is vaccines actually are made of the viruses and bacteria that they are trying to prevent. To understand why that is necessary we need to understand the immune system. You see, when an unfamiliar virus or bacteria makes its way into your body it sounds an alarm that activates an immune system response. These invading organisms are called antigens and their goal is to replicate as much as possible. 

Since our bodies are not designed to handle that sort of thing the results can be very bad, resulting in sickness and sometimes even death.

Your body doesn’t like dying, so once that alarm is sounded you’re white blood cells get to work. Your T-cells identify which cells in your body are infected by the intruder and destroy then to try to contain the infection. Meanwhile your B-cells produce antibodies, which attack antigens directly and try to prevent them from infecting more of your body’s cells.  

Vaccines take advantage of this response by tricking your body into thinking it has been infected by a specific virus or bacteria, but in order to do that they need to introduce some of these intruders into your body. Obviously the goal of vaccines is to prevent infection so it wouldn’t make much sense to pump you full of measles. Instead, vaccines use a weakened or inactive (dead) form of the intruder/antigen.

Vaccines that use weakened antigens are called live-attenuated vaccines, because they inject still living infections. The trick with live-attenuated vaccines, however, is that they use the dumbest, laziest individual viruses and bacteria possible. To create these vaccines scientists take something dangerous like measles and give it a relaxed, cushy life in a test-tube. The infection is continually transferred from one test tube to another, each time getting a little more used to the good life. After enough time and transfers (77 in the case of the measles virus) the infection is so used to not have to do anything to survive that it has lost most of it’s tenacity. When injected into the bloodstream these infections reproduce at most 20 times rather than the thousands and thousands of times they normally would. Your body is easily able to identify and destroy these antigens.

The cool thing is that you immune system has a great memory, so once the infection is gone your B-cells continue to produce the antibodies that can kill it, making you immune for life.

Inactivated vaccines use dead viruses that don’t reproduce at all. The benefit to this is that there is zero chance of any kind of negative reaction (live-attenuated vaccines can lead to soreness at the injection site and occasionally some mild symptoms), the downside is that you often need multiple shots to maintain immunity because your body thinks the disease is a dud.

One of the most publicized fears about vaccines is so-called link between vaccination and autism. This link is a myth. It arose when some people discovered that a disinfectant used in some vaccines (Thimerosol) contained mercury. There is however no reliable research supporting this claim (Parker et al., 2004). Even still, most vaccines now contain no Thimerosol because the companies that produce the treatments want to make parents feel as safe as possible. One real health concern that goes along this vaccines is the risk that some flu shots pose to people with egg allergies. Since influenza is grownin eggs to create the vaccine, there is a chance it can cause an allergic reaction. If you’re allergic to eggs to can still get a flu shot, you just have to talk to your doctor about getting one of the varieties that is not developed using eggs (there are plenty).

Vaccines are clearly a very cool topic. They have eliminated diseases like polio and smallpox from much of the world and continue to save millions of lives each year. In closing, I just want to say that it is okay to question things. Skepticism is a great quality that can lead to critical thinking and amazing ideas and innovations. That being said, the science behind vaccines is inarguable. They prevent needless suffering and protect at-risk people from terrible diseases. If you have questions about them, by all means continue to read up on the subject; but rest assured, vaccinating yourself and your children is the most responsible decision to can possibly make. It’s a no-brainer. 

Sketchy Fact #35: Putting the "bow" in Rainbow

Rainbows are bent because we can only see the sunlight refracted through rain droplets at an angle of 42 degrees. The rainbow you see is the product of the sunlight, the droplets, and where you are standing. That means that if you move somewhere else you are actually seeing a new rainbow made by new raindrops beaming light to your new location, but always bending it 42 degrees first.

Sketchy Science Storybook Corner Presents: Curious Geoff and the Antibiotic-Resistant Superbug

The following is loosely based on actual events... But we made up a lot of the non-sciencey bits.

“Why didn’t you see a doctor sooner?!” exclaimed the man in the yellow hat.

“Mind your own business.” Geoff replied in his increasingly raspy voice to the only other person in the waiting room. He didn’t even know this guy and after five minutes of conversation he was getting a lecture on personal health? There were days when the usually agreeable illustrator for the 6^th most popular Canada-based, illustrated science blog on the internet would have tolerated unsolicited advice, but this wasn’t one of them.

What had begun as a tickle in his throat had progressed over the past month to become an omni-present burden on his existence. Every swallow and syllable he spoke ignited an intense fire just below his jawline and Geoff had had enough. Fortunately he didn’t have to deal with this guy or his questionable fashion sense anymore because the doctor’s receptionist stood and called his name before a fist-fight could break out.

“Why didn’t you come see me sooner?!” The doctor asked. Still holding the recently-used tongue depressor in her right hand, the question seemed all the more accusatory. Geoff didn’t really have an answer aside from his hope that whatever was wreaking havoc on his esophagus would work itself out.

“I’m going to give you some antibiotics. Make sure you finish the bottle, even if you start to feel better.” The doctor scribbled something onto her prescription pad, ripped off the page and handed it to Geoff in the manner of an irritated police officer writing a ticket to someone caught speeding home to watch the season finale of The Biggest Loser. That is to say, she was both irritated and disappointed.

Over the next week, Geoff dutifully obeyed the doctor’s orders. Twice a day he summoned his courage and drank a tablespoon of the goopy, greyish antibiotic. "At least it came with a cool spoon shaped like an alligator" he thought to himself. 

Pretty soon things appeared to be getting back to normal. Inside Geoff's body the medicine was beginning to turn the tide in his favour. Antibiotics can either kill bacterial cells directly by impairing their ability to build cell walls or they can smother them, binding to receptors on the outside of the intruder cell and stopping it from interacting with the body. Geoff’s medicine did the latter and it did it quite effectively… That is, until the weekend rolled around.

Earlier in the week, Geoff had considered cancelling his planned weekend adventure to the maple syrup factory with his friends. Now that he was feeling better, temptation got the best of him. By Friday he could hardly believe he had ever been sick. He loaded up his suitcase, got on the bus and rode to meet his friends. As he closed the door and turned the key to lock it, the half full bottle of medicine sitting on the bathroom counter was the furthest thing from his mind.

By Monday night, the game had changed. As Geoff indulged his sweet tooth with his friends, the bacteria in his throat had regrouped. Many of them had been killed the previous week by the medicine, but those that were left were the strongest of the strong. There had only been a few of them left when Geoff got on the bus, but in the absence of the killing blow from the medicine, they had multiplied. To make matters worse, a new bacteria had found it’s way into Geoff’s throat over the weekend. It was a largely harmless bacteria but it contained a piece of DNA that helped it form a smooth, slippery outer membrane. 

This new bacteria made friends with the remaining disease causing bacteria and (as bacteria sometimes do) they traded DNA. Now the bacteria that the medicine had been meant to kill had mutated so that the antibiotic could not stick to them properly.

The new and improved super-bug used its good fortune to regroup.

Things had gone from bad to worse.

When he got home, Geoff resumed taking his medicine, but it was too late. The super-bacteria continued to multiply, unimpeded. He went back to the doctor who prescribed stronger antibiotics, but before long Geoff found himself in the hospital.

The next few weeks were rough on his body, but fortunately he was a young, physically fit person and over time his body was able to fight off the infection. He lost a bunch of weight and had a miserable time (despite having all the jello he could eat), and as he left the hospital he vowed to never let a bug turn super on him again.

Geoff would never know it, but the reason that his infection was able to mutate was because of the steak he enjoyed on Friday night. Many farmers around the world use antibiotics to help their livestock grow larger, faster. Over-using antibiotics gives bacteria more chances to evolve resistance to them. That is exactly what happened with the bacteria that eventually traded DNA with Geoff’s infection.

From that day on, Geoff did his part to combat the evolution of antibiotic-resistant bacteria. He didn’t take antibiotics when he had the cold or a flu because he knew that these infections were caused by viruses and not bacteria. Viruses aren’t alive in the same way bacteria are, so antibiotics are useless against them. He also stopped using antibacterial hand soap and instead used alcohol-based hand sanitizer which bacteria can’t evolve resistance to.  Over many years, Geoff’s good behaviour influenced his friends to do likewise. Eventually even farmers got the message and stopped needlessly pumping animals full of medicine that could have been used to help creatures that were actually sick.

And they all lived happily ever after… Except they got sick a lot from viral infections, but that’s another story.

References:

http://health.howstuffworks.com/medicine/medication/question88.htm

http://science.howstuffworks.com/environmental/life/cellular-microscopic/question561.htm

http://chealth.canoe.ca/channel_section_details.asp?text_id=5778&channel_id=1020&relation_id=96449

http://motherboard.vice.com/read/good-news-theres-a-plan-to-save-us-from-antibiotic-resistant-superbugs

http://www.theglobeandmail.com/news/british-columbia/hospitals-choose-whether-to-classify-something-as-an-outbreak-in-canada/article16624144/

http://www.ecosmagazine.com/paper/EC14051.htm

Sketchy Fact #34: Speedy Sight

Dogs can detect movement and react to it far better than humans. If you’ve ever wondered why dogs are generally not interested in TV it’s because their eyes are so perceptive that they can see the gaps between the pictures that make up the video. 

Plastic Wraps and Colony Collapse: All the Buzz from the World of Bees

If you’re the sort of person who keeps up with bee news, you are probably not the best dinner guest. First off, although bees are very interesting when you’re in the mood to nerd-out on them, you can only get so much conversational mileage out of a single topic. Second, you probably end up being the bearer of a lot of bad news.

Recent years have not been great for bees. You may have heard that honeybee populations have been dramatically declining because of a mysterious ailment called Colony Collapse Disorder (CCD). When a hive is hit by CCD the bees lose their gusto for teamwork and all fly off on their own, leaving the queen to tend to the larvae all by herself. The end result  is a lot dead bees and a lot of upset beekeepers.

No one is quite sure what causes CCD, but there is general agreement that it is a pretty major problem. You may not realize it, but a lot of the food you eat depends on bees for its production. Up to 15% of the fruits and vegetables you eat are pollinated by honeybees. If you eat meat, another 15% of your grocery list is made up of animals that eat plants that bees pollinate. That means, without bees, up to one third of the shelves at the supermarket would suddenly be bare.

There are a few competing theories about the origin of CCD. Mites or viruses have been implicated as bee killers. A disease that impacts the bees ability to navigate to and from their hives has been suggested. You also won’t be surprised to hear that human behaviour may be playing a role. Beekeepers routinely move hives around so the bees can pollinate specific fields and crops. This could be stressing the bees out, leaving them more susceptible to whatever causes CCD.

Another problem is the lack of genetic diversity among honeybees. When we humans domesticate something, we tend to breed it with specific traits in mind. That means that when we see something we don’t like, we remove it from the breeding pool. The end result is a lot of bees that are physically and genetically very similar. That may mean that they all show characteristics we want (like a reduced tendency to sting), but it also means that they are all susceptible to the same diseases.

Fortunately, there appears to be a few glimmers of hope for our striped, buzzing friends. Research from the University of Guelph in Ontario, Canada has found that some bee colonies are beginning to adapt to a human-dominated world.  Several species of wild, solitary bees (unlike the hive-minded honeybees) have been seen using plastic materials from old grocery bags and window caulking to build their nests. Researchers have found nests where up to one third of the plant material that is usually used in construction has been replaced with scavenged plastics.

If it wasn’t cool enough that bees are changing their building code, the changes seem to be having a positive effect. Offspring raised in the plastic nests are significantly less likely to be impacted by mites and other parasites that normally raise bee mortality rates.

So, as centuries of human interference in the domestication of honeybees is leading to empty hives and withering crops; nature is adapting to some of the garbage we are producing by recycling it into healthier nests for wild bees. When you consider the fact that honeybees didn’t exist in the Americas until Europeans brought them here in the 1600’s, and that their presence has led to a decline in most wild bee populations, the irony really starts to sting. Pun intended.