Throughout human history we have strove and endeavored to push out past the horizon and the limits of what we can see, to go out into the world and indeed the universe to explore new realms in our innate, insatiable quest for discovery. We have gone out past the hills or mountains in the distance, over the vast sea that sprawls out as far as we can see, into the thickest jungles and down into the deepest, darkest abysses of our oceans. We have gone out past the blue skies above, launching out into space to our moon and the planets beyond, and one day we may go even further still, into the corners of our observable universe and beyond to who knows what. Yet, for all of the mysteries that lie out there in the seas and wildernesses of our planet and beyond our world, it is interesting to think that some of the more baffling frontiers lie not out beyond us, but rather within us, and the human body is in many ways just as unexplored and misunderstood as any far away realm.
Some of the puzzling mysteries of the human body are everyday things that we take for granted, and which no one really gives much thought to. Take yawning for instance, you have probably done this countless times today, hopefully not too much while reading this article, whether it be because you are tired, bored, or just because the person next to you did it. But have you ever thought about “why” we yawn? Or why it should be contagious? There are lots of ideas for why we yawn, such as that it regulates the temperature of our brains, or helps us shift from one condition to another, such as from sleep to wakefulness or alertness to boredom, or maybe it just gives us a physiological boost, but the fact is we don’t really know. Making it all more mysterious is the fact that yawning seems to be infectious, as you have no doubt already surmised from your own experiences, but why should this be? The closest we have to an answer for any of this is that it is some ingrained social bonding trait, a subconscious show of empathy, of which neuroscientist and professor of psychology, Robert Provine, has said in a statement to Healthline:
Yawning may be a primitive form of empathy that binds tribal members together and coordinates their physiology, such as synchronizing arousal and bedtimes. Diminished contagion, whether from yawning or laughing, may be a novel measure of social disorders as in autism or schizophrenia.
That is a rather unromantic and coldly scientific way of saying that yawing brings us together. It is interesting to note that contagious yawning is seen mostly only in social animals such as dogs, lions, chimpanzees, and humans. However, again we just don’t know, and yawning, one of our most common behaviors, remains little understood. Another contagious behavior that we do all of the time is laughing, which if you are lucky you have also done many times today already. Laughter, and its ability to infect others around us with its mirth, is also actually a rather mysterious trait, with no real concrete commonly accepted reason for why we should do it or why it should spread to others. The most widely accepted theory is that, like yawning, it is a sort of social behavior. In this case, it is likely an evolutionary trait designed to specify that we are playing and not engaging in threatening behavior or feeling threatened. In this way, our laughter puts others of our group at ease and they too laugh to show others around them that there is no immediate danger. The social angle helps explain why we laugh far less when we are alone, but the true reason for laughter and its contagious nature remains murky. It doesn't, however, explain why some people laugh at some things while others don't, or why in some cultures laughing is actually sometimes a sign of discomfort or even alarm.
So we have these behaviors and reactions so far of when we are sleepy, bored, or conversely happy and amused, so what usually happens when you are embarrassed? Do you blush? Well a lot of people do, and if so, there is another mystery we still don’t have an answer to, made all the more intriguing by the fact that humans are the only animals that do it. We know the “how” part of the equation. Blushing is basically caused by blood vessels dilating in reaction to the adrenaline stirred up by stress, and this allows the adrenaline to flow through your system faster and more smoothly. In the face, this results in that redness we call blushing, but this redness shows up nowhere else on the body. This stress can be caused by embarrassment, but it can also be caused by positive emotions such as being thrilled or receiving a compliment.
This we know, but more confusing is the “why” of it all. Why should only our faces turn red in these situations? What possible purpose or advantage could our faces turning red have, and why does it happen even in positive situations such as meeting the man or woman of your dreams? It is so baffling that Charles Darwin himself once said of it, “Blushing is the most peculiar and the most human of all expressions.” Again, there are many ideas for why we might blush, but no definitive answers. One of the main theories is that blushing serves as a social nonverbal form of apology, meaning that when you do something you know was a mistake or wrong you subconciously visibly blush to show others that you realize it and are sorry about it, visually representing your regret and remorse for all to see. This has actually been tested, and studies have shown that people who blush are indeed more likely to be forgiven than those who don’t. However, like the others we have looked at so far, nobody really knows for sure.
Another thing many of you might take for granted and do every day is write, throw a ball, or use a fork or knife with either your right or left hand. For most people it is just one of those “just because” things, yet the fact that we have a dominant hand at all, as well as why most people should have that be the right hand, have long been a baffling mystery of the human body. Wouldn’t it make more evolutionary sense for us to be able to use both hands equally? Yes, it would, and although a small percentage people are ambidextrous (able to use both hands equally), scientists can't seem to agree on why this isn’t the case for everyone, or why it should 7 to 9 times out of 10 be the right hand that is favored, no matter the culture or country.
One idea is that because of our advanced speech capabilities there are more brain resources dedicated to the complex wiring of the speech producing region of our brains, which is also linked to motor skills and which usually sits on the left hemisphere, but not always. However, many right-handed people have been found to have speech centers on the right hemisphere and many left-handed people have speech centers on the left as well, making this an unreliable indicator at best. There is also the fact that animals without the complex speech wiring and fine motor skills of humans have also been shown to have preferred dominant appendages as well. In the end, it is not fully understood, and it is difficult to study as many societies take naturally left-handed people and force them into right-handedness, making it difficult to get a fix on. The subject of the nature of handedness continues to be debated and discussed, and we are no closer to an answer.
Other mysteries of the human body have more to do with our actual anatomy and the make-up of our bodies. Some of these are external and you can see them right now. For instance, look at your hands and you’ll see that not only do you have fingerprints, but you may also know that their particular patterns of whorls and ridges are completely unique to you and you alone. Have you ever thought about why that should be, or indeed why you should have fingerprints in the first place? If you have been paying attention so far you can probably see where this is going. That’s right, we don’t know.
“Whoa, whoa, wait!” you might be thinking right about now. “They are for gripping things, right?” you may be asking. Well, here’s the thing about that, while indeed it was long thought that this was the purpose of fingerprints, that the ridges create friction, this has since been seen as more and more doubtful. In the June 12, 2009 issue of the Journal of Experimental Biology a report was published by Peter Warman, from the University of Manchester in England, that showed that fingerprints don’t seem to improve grip at all, and actually may even make our grip worse. It was found that considering that our skin behaves almost like rubber when producing friction with an object, we need more of the skin in contact with the object to get a better grip. In our case, those fingerprints of ours actually make sure that we have less of our skin in contact than we would if we didn't have fingerprints, worsening the grip, although they are still seen as perhaps helping to grasp rougher surfaces. Other theories for why we have fingerprints include that they help drain water from our fingers to keep our grip dry, that they could have a role to play in helping to prevent blisters, or that they somehow increase touch sensitivity, but at the moment those unique prints of yours are an evolutionary mystery.
Moving within the body we come to other inscrutable mysteries. Probably the one most people will immediately think of is the appendix, a seemingly pointless organ that is apparently only good for getting infected and having to be removed. Indeed, many of you reading this right now are probably without an appendix and also without any ill effects, and indeed even the word itself “appendix” in common usage denotes something that is sort of tacked on as an afterthought. One would think that after all of these years we would by now have discovered just what it is supposed to do, but actually no. All we have are ideas, such that it is a vestigial remnant of an organ that helped our ancestors digest food, that it helps develop the immune system of fetuses, or even that it plays an important role in attracting and providing a living environment for the “good bacteria” in your gut, but we are basically just as perplexed by this anomaly of the human body as we always have been.
The very blood that runs through our veins also holds mysteries. All human beings can be classified into different blood types, which have different enzymes that determine the types of sugars that stick to blood cells, and the main four types are classified as A, B, O, and AB. The differences between these types is such that for blood infusions it is a necessity that donors with compatible types be found. Yet why human beings should have different blood types in the first place has long remained an enigma. The closest we have come to an answer is that certain blood types and their antigens may be more useful for fighting off pathogens found in particular geographical areas of the world or that they have evolved for some other function, but there is no definitive reason and they are a mystery.
There is also the question of the very make-up of our bodies. It is no mystery that much of our body is made up of foreign agents, such as microbes, which compose around 1-3 per cent of our total body weight. This we know, and we even know the functions of some of the bacteria living in our bodies, such as helping with digestion, aiding healing, fighting infection, or keeping our skin clean, but there are vast numbers of these microbes that coexist with us and make up our bodies whose purposes we have no idea of. The fact that we have no clue what many of the microbes that make up so much of our bodies do is a sobering thought, and making it even more mysterious still is that among all of the bacteria permeating our bodies there are also quite a few viruses permanently floating about, even in healthy people, and it is a total mystery as to what function they are serving or why this should be.
Perhaps the biggest human body mystery of all, and the one we take for granted most, is the one that sits up in your head, the brain. It is a vast, supremely complex network of trillions and trillions of neural connections, a mind-boggling web that somehow runs and regulates our bodies, facilitates our mental functions, and bestows us with consciousness and self-awareness. How can this be? The full extent of the human brain and its workings are still little understood, and the most perplexing mystery of all is how this blob of jelly in our skulls gives us consciousness, spirituality, appreciation, self-awareness, love, art, literature, and everything else that makes us human. Neuroscientists still don’t know, and one neuroscientist, V.S. Ramachandran, has famously and eloquently summed it all up:
Any single brain, including yours, is made up of atoms that were forged in the hearts of countless, far-flung stars billions of years ago. These particles drifted for eons and light-years until gravity and chance brought them together here, now. These atoms now form a conglomerate — your brain — that can not only ponder the very stars that gave it birth but can also think about its own ability to think and wonder about its own ability to wonder. With the arrival of humans, it has been said, the universe has suddenly become conscious of itself. This, truly, is the greatest mystery of all.
It is spooky and profound to contemplate, indeed. Here we have looked at a selection of some of the baffling mysteries of the human body that, while they may be things that you take for granted every day, are nevertheless just as unknown, uncharted, and indeed impenetrable as the deepest unexplored sea, jungle, or the faraway landscape of some alien planet. Such aspects of our bodies and indeed who we are may one day be more fully understood, just as we will discover more of our universe as we continue our inexorable drive of exploration, but for now they remain strange frontiers that lie not out over the horizon or out past the stars, but right here with us now.