August 1, 2012
I was born on 8th December, 1993, the year of the Chicken*.
Ever since that fateful day, I have embarked on a pilgrimage with one purpose and one purpose only – to turn my awful predicament on its head by freeing Gallus gallus domesticus from all the unfair stereotyping it is caged by.
You see, chickens are not exactly held in high esteem by the general public. True, they make a splendid meal when oven-roasted and complemented with caramelised onions and garlic sauce. But as an animal, they are seen, at best, as silly birds that can’t fly and, at worst, as poor, pathetic poultry that squawk stupidly and flap around frantically, constantly repapering their enclosures with a thick layer of brown feathers.
When compared with other members of the Chinese Zodiac, you can see why chickens may not have the most favourable of reputations. There’s the Dragon – powerful, majestic and wise; the Horse –elegant and a reliable companion; the Tiger – a brave, graceful yet devilishly cunning hunter; and there’s the chicken – the bird-brained fowl that can’t even fly to save its life.
The word “chicken” is practically synonymous with “coward” in modern usage. I think Mrs Tweedy from the charming 2000 British stop-motion film Chicken Run rather accurately sums up society’s unfortunate sentiments towards the fowl. As she so eloquently put it to her fumbling husband, “They’re chickens, you dolt! Apart from you, they’re the stupidest creatures on the entire planet!”
This rather unhealthy negativity surrounding the chicken is such that it has even masked the undisputable fact that the chicken is, in fact, the closest living relative to the Tyrannosaurus Rex. “How the mighty have fallen!” you might exclaim. How could the towering King of all Lizards, the 40-foot-long predator that roamed the earth 65 million years ago, be reduced to this diminutive, feathered creature that so often pops up, grilled and sliced, in your plate of Caesar salad**?
In this article, I hope to enlighten you to the fact that chickens are by no means dull organisms. While lacking the physical grandeur of an extinct dinosaur, they are actually subject of a whole host of interesting scientific facts, surprising historical anecdotes and a philosophical question that has baffled thinkers for centuries.
Their usefulness to humans
The very first argument I came up with many years ago to defend the poor bird was quite simply its immense usefulness to us, humans.
For starters, the success of chickens in kitchens cannot be contended. From the chicken wings we clamoured for as children to the honey-roasted chicken steaks so universally adored, these birds have, without doubt, served our palates well.
Lesser known, perhaps, is the creativity with which my Chinese ancestors treated the animal with in the kitchen. Chicken feet are but the least bizarre on the list of seemingly unpalatable dishes the Chinese indulge in. The heart, liver, kidneys and tongue are all edible to us folks, as is the brain – a rare delicacy. Chicken blood is, of course, drained, congealed and then served in soups. One of my best friends in Hong Kong has a particular partiality to chicken testicles, and is always sure to order a plate of them each time we go out for hot-pot dinners. The remaining bones are then used to make the most excellent of soup bases – as they say, “Waste not, want not”.
Chickens also produce an array of useful by-products. Take eggs for example. Forgetting for a moment that egg yolks contain just about the highest concentration of cholesterol of any food, eggs are an incredible source of nutrients, comprising the most complete battery of proteins of all foods nutritionists have come across.
In the West, eggs are boiled, fried, scrambled, poached and even steamed. Predictably, though, the Chinese are a step ahead in terms of creativity. Salted eggs are a commonplace in East Asia, as are tea eggs – brown in colour and veiny in texture, but delicious nonetheless. The thousand-year egg is arguably the most foreboding of egg variations in terms of looks. It is a semi-translucent brown with a creamy, black yolk, and is prepared by burying the egg in clay infused with a mixture of wood ash, quicklime and salt for several months.
It is perhaps unfortunate that the Chinese have united their creativity and wits with their sometimes unscrupulous business mind-set to manufacture fake chicken eggs. But for the lack of a tiny air bubble present in real eggs, the synthetic eggs are practically indistinguishable from the real thing – that is, at least, until you start turning blue and sprouting extra arms from you belly-button.
Meat, organs, bone and eggs have all been stripped down so far. That leaves just the outermost layers. Chicken skin, when not eaten, can be used to make leather, and chicken feathers, both in the East and the West, are used to make feather dusters. Western children might remember them being used for cleaning purposes. Chinese children will more likely associate them with corporal punishment – the thin end for beating, the other end for torturous tickling.
I hold that the chicken may well be the most multi-faceted animal of all and, among the entire animal kingdom, only the sheep comes close to rivalling it, providing us with tender meat, sheepskin leather, woollen jackets, milk, cheese and experimental subjects for high-profile cloning experiments. Let this be some consolation for my brother, born two years earlier than me, in the year of the sheep.
The abundance of chicken-themed scientific facts
Another great aspect of the chicken is quite simply how many useless but remarkable scientific facts you can spout out about the animal.
– The belief that chickens can’t fly is a misbelief; chickens are perfectly capable of flight – just for short periods of time. The Guinness Book of World Records puts the longest flight time of a chicken at 13 seconds, and places the farthest distance flown at 301 feet, meaning that the Olympians of chickens would just about make it across a football field without interfering with an on-going match! I confess I am glad, though, that the script-writers for Chicken Run decided to ignore this particular fact. It would have made for a much shorter and far less exciting film.
– It comes in handy to know that there are more chickens than humans on the planet – in fact, they outnumber us four to one. As you plough through yet another useless factoid on chickens, there are over 25 billion of them in cages hatching plans of vengeance on humanity, attempting to escape from chicken pie factories, and trying to break various poultry-related world records.
– It might interest you to know that an unfertilised chicken egg (the sort you eat for breakfast) is in fact one single cell. Counter-intuitively, the yolk is not the nucleus, but rather a giant nutrient storage tank within the cell (the actual nucleus is the tiny disk on the side of the yolk). This means that the egg of an ostrich (incidentally, another close relative of our friend, the T. Rex) is the largest single cell known to exist.
– You may consider that state of semi-wakefulness most usually experienced during early-morning classes as being half-asleep. Let me tell you: chickens sneer at your idea of “half-asleep”. They are able to put themselves into a state called “unihemispheric slow-wave sleep”, whereby one cerebral hemisphere goes to sleep and the other half of the brain stays awake! This allows the bird to rest half its brain while (absolutely literally) keeping one eye out for predators. Unihemispheric slow-wave sleep is also seen in some dolphins and whales. Instead of napping for short periods of time or snoozing at the surface of the water, certain species can slumber for days on end by keeping one side of their brain conscious (and one eye open) to surface and breathe periodically.
– How can an article on biology be complete without mention of genes? It turns out that the chicken was the first bird to have its genome sequenced. Scientists have found that its genome is made up of 78 chromosomes (packages of DNA), whereas each human cell only houses 46! Still, it is no match for the hermit crab. At a whopping 254, the crab contains more than twice the number of chromosomes chickens and humans have put together. Fortunately for us, though, the number of chromosomes an organism has is no measure of its complexity. Otherwise, it would be disturbing that a chimpanzee has the same number of chromosomes as a potato, or that the single-celled amoeba has more chromosomes than a human being!
The urban myths surrounding the chicken
I think, deep down, everybody knows how remarkable an animal the chicken is. As a result of our subliminal reverence for it, chickens have a tendency to crop up everywhere in popular culture.
“Cock-a-doodle-doo” – the rooster’s crow at the crack of dawn. That is, in English, anyway. In French, it’s “cocorico”, in Spanish – “quiquiriqui”, in Thai – “ake-e-ake-ake”, in Icelandic, allegedly – “gaggala gaggala gu”. Personally, I think “Err-uh-errrrrrrrooooo-uh” is a far more accurate representation, and find myself baffled at the bizarre representations the various countries around the world have chosen.
But the point I’m trying to get at is that roosters don’t crow at the crack of dawn at all! Despite what numerous authors and cartoon producers have been trying to indoctrinate us into believing, roosters do not have some mysterious ability to detect the sunrise and act as some farmland alarm clock. Rather, they crow all the time. They crow when they see other roosters, when they feel threatened, when a bright light is shone in their faces, when they want to mate, when they’re hungry and, perhaps most of all, when they’re being slaughtered by Mrs Tweedy.
Like most animals, roosters have a biological clock called the circadian rhythm which dictates when they go to sleep and when the wake up. If their rhythm is upset, they’re just as likely to crow in the middle of the night (as many sleepless farmers would know) as they are during any other time of the day.
Another common myth is that when chickens cross-breed with turkeys, they give birth to little “turkins”, which are supposedly mouth-wateringly delicious. Unfortunately, despite admirable persistence by farmers and scientists alike, turkeys and chickens remain stubbornly incompatible. There exists, however, an American dish consisting of a chicken stuffed inside a duck stuffed inside a turkey, called a “turducken”.
The idea that chickens might be able to mate with turkeys isn’t as outlandish as one might think. Animal hybrids do occur. The most common example is probably the mule – a cross between a female horse and a male donkey. Other hybrids are rarer, and tend to have more comical names. The zorse, for example, is the product of breeding a zebra with a horse, the yakow is a cow/yak hybrid, and the liger boasts a lion father and a tigress mother (the tigon is vice versa).
The final myth is that all chickens can survive without their heads. The disproof for this widely perpetuated myth is quite simple – simply remove a chicken’s head and see how long it lasts. Countless people have attempted to behead their chickens in hope of being the proud owner of a headless chicken, but all attempts thus far have ended in failure – and spectacularly messy failures at that. However, there is more than a grain of truth in this urban legend, and the true story that sparked it all off is a fascinating one.
With regards to the story of Miracle Mike, I believe the phrase “the truth can be stranger than fiction” comes into apt usage. It is one of those rare occurrences in science where a story commonly believed to be a hoax is, in actual fact, the complete truth.
Miracle Mike, more commonly known as Mike the Headless Chicken, was – as his name suggests – a headless chicken. The miracle about the cockerel is that he managed, astonishingly, to stay alive and well for a whopping eighteen months after parting from his head.
Upon the chicken’s beheading on 10th September, 1945, farmer Lloyd Olsen was rather astonished to see that Mike, as opposed to falling limp and as most roosters do after having their heads removed, refused to die and end up on his owner’s dinner plate (in case you’re wondering, yes, roosters can be eaten; they just tend not to be as tender as the hens we most commonly consume).
Aware that many who heard the story would consider it a hoax or scam, farmer Olsen took Headless Mike to the University of Utah to have his story authenticated. Upon examination, it became apparent that, thanks to the American farmer’s poor aim, the rooster’s head had not been completely severed. The axe had missed the jugular vein, and left an ear and the brain stem intact. It was later revealed that a conveniently-located blood clot prevented the bird from bleeding to death upon departure from most of its head.
Miracle Mike was an instant celebrity and spent the rest of his life on tour with a two-headed calf, earning obscenely large amounts of money for his owner. His story was even published the following October in LIFE magazine. He was fed through his oesophagus, being given water and milk via an eye-dropper and, occasionally, kernels of corn to swallow. After one-and-a-half-years of headless survival, Mike passed away. Some sources say he choked to death on his own phlegm, others say he simply couldn’t breathe properly and suffocated. In the city of Fruita, an annual festival is held in honour of Mike, whereby a number of chicken-related games and competitions are held, such as the “5K Run Like a Headless Chicken Race”.
Mike’s case does sound unbelievable and, despite a huge surge of copycat chicken beheadings reminiscent of the French Revolution in its bloodiness, nobody has since managed to reproduce a headless (or almost headless, for that matter) chicken that has survived for more than a day.
For those still doubtful about the authenticity of Mike’s heedlessness, some of the following cases of brain loss in humans might just change your mind about the necessity of a complete brain for survival.
Take Phineas Gage, for example, whose neurological mishap predated Mike’s head-loss by a century. The 25-year-old was working with explosives when a three-and-a-half-foot-long iron rod was propelled clean through his head. After vomiting out “half a teacup full of brain”, Gage was patched up by his doctor and recovered in a matter of months. In his remaining twelve years, he was remarkably healthy for someone who had lost most of his left frontal lobe though, admittedly, he did suffer from a drastic personality change, spurring intense discussion among neurologists about the role of certain parts of the brain in human behaviour.
Similarly astounding is a surgical technique called hemispherectomy. In certain forms of the most extreme, untreatable cases of chronic seizure, half the brain is removed from the patient’s skull. This radical procedure is seen as the single most invasive surgery in existence. Incredibly, patients not only survive with just half a brain, they continue to lead normal lives. Loss of vision in one eye and paralysis in one arm is common, as is some speech difficulty (usually following the loss of the left hemisphere), but there is minimal change in personality and intelligence. The younger the patient, the higher the chance of a full recovery.
Another lovely example of someone functioning with very little brain is a 44-year-old married father of two who, after experiencing a weakness in his left leg, was given a CT scan and put through an MRI. Doctors were completely flabbergasted, to say the least, when they discovered the man had very little brain. Due to a childhood case of hydrocephalus, a build-up of fluid had compressed his brain to a thin sheet plastering his skull. Remarkably, with less than a third of the usual brain volume, the French civil servant had an IQ that, while extremely low, was considered within the normal range.
So maybe a chicken staying alive after losing the majority of its brain is not that far-fetched after all, especially taking into account how much simpler and how differently-structured the chicken brain is when compared to our own. Still, with nothing but the brain stem intact to maintain only the most basic of bodily functions, one can’t help but wonder if Miracle Mike could truly be considered “alive” after his little accident. On that philosophical note, we shall move on to my final reason for considering the chicken to be such an intriguing animal.
The Chicken or the Egg
If an egg is laid by a chicken and a chicken is hatched from an egg, which one came first? This part-philosophical, part-biological conundrum that has plagued thinkers for millennia is one that has a surprisingly straightforward answer.
In evolutionary terms, chickens are a very recent animal. The red junglefowls from which chickens were bred were egg-layers, and so were the earlier birds predated the junglefowl. The more ancient reptiles laid eggs, and so did the amphibians before them. The lobe-finned fish that first ventured onto land reproduced by laying eggs, as did the all the fish it left behind in the ocean. In a nutshell, eggs were around for half a billion years before the chicken, so the answer is: eggs came first.
That, of course, is not the answer you were looking for. To keep more in the spirit of the apparent paradox, we might want to rephrase the question to “Which came first, the chicken or the chicken egg?”
Well, in this case, we need to ask ourselves what we mean by “chicken egg”. If you define it as “an egg from which a chicken hatches”, then the answer would be that the egg came first. Two not-quite-chickens mated and the female laid an egg that contained the genetic material we would now consider a chicken’s. Since genes don’t change after fertilisation, the egg must have been a chicken egg – which obviously came before the chicken it fostered. On the other hand, if we take “chicken egg” to mean “an egg laid by a chicken”, than the answer is quite simply the reverse – the first chicken egg would have been the first egg laid by that first chicken. Q.E.D.
A question more worthy of today’s scientific minds, in my humble opinion, is whether DNA or proteins came first.
The DNA carries the information necessary to manufacture proteins, yet proteins make up the molecular machinery capable of assembling DNA. We have a true paradox here – neither could have existed without the other, so which came first?
The answer is that neither came first. It is RNA that was the true precursor of all life on earth. RNA, while simpler in structure than the more stable DNA, is capable of both information storage and self-replication. It is thought that RNA may have been the first molecule of life to emerge from the primordial world three-and-a-half billion years ago, leading to the emergence of DNA, proteins and the whole host of other organic molecules that form the basis of life now.
That’s quite enough about chickens now, I think
If, once upon a time, you ever considered chickens not to be the most interesting creatures on the planet, I sincerely hope that I have succeeded in changing your mind.
There is no doubt in my mind that these fowls have, through the centuries, been a huge influence on the evolution of society and on human cognition, shaping the world as we see it. On the off chance that I am mistaken, well, I’m sure we can all agree upon the fact that they do, at least, make for intellectual dinner conversations.
*In the English translation of the Chinese Zodiac, the sign is more typically referred to as the year of the Rooster. However, since the originators of the Chinese language saw no reason to differentiate between chickens, roosters, hens, cocks, cockerels, capons, chicks, chooks, yardbirds and domesticated fowls, I see no reason to complicate the matter.
**You might be interested to know that the reason why crocodiles taste like chicken is that birds and dinosaurs share a close common ancestor, and dinosaurs, in turn, are anatomically very similar to modern-day reptiles.
May 17, 2010
Fast food products are bad for you. I don’t deny it.
They contain way too much monosodium glutamate; their saturated and trans fat contents are off the charts; they contain hardly any of the essential nutrients your body actually does need. Excessive consumption of fast food can potentially cause obesity, high blood pressure, elevated risk of heart attack and a general lack of respect from dietitians.
Recently, I watched a rather amusing video on YouTube whereby author and obesity activist Julia Havey stood up and condemned fast food, which I found admirable. Unfortunately though, her scientific thinking in that video was rather flawed, and I feel obliged to point out exactly what she got wrong.
Ms Havey claimed to have kept a McDonald’s cheeseburger and french fries in a lunchbox for four years. She said that they had not been frozen or in any way preserved. Now anyone halfway sensible would know that any food left in room conditions for just a few weeks would be enough for sinister-looking white and black mould to grow all over it. Imagine sticking a burger and some fries in a stuffy old tin can for four years!
Miraculously, when she took the contents of the lunchbox out all those years later, the food was still in perfect condition! There was no fungal or bacterial growth; no slimy moss crawling over it; no observable signs of decay whatsoever.
Ms Havey isn’t the only person claiming to have achieved such astounding results. A certain Matt Malmgren even keeps his own collection of dozens of such burgers. He claims some have lasted an incredible 20 years! Most people put this amazing lifespan of the burgers down to too much pesticides in them, even though there is no obvious reason why fast food would have a higher concentration of pesticides than any other food. Ms Havey came forward with some interesting explanations of her own.
Ms Havey’s explanation for the longevity of her burger was simply: “McDonald’s food is not real food”. Fair enough. She then went on to explain the effects of such an immortal burger. She said that if even microorganisms can’t break down the food, we most certainly can’t. According to her, this means that the food stays in our bodies after we absorb them, leading to irreversible obesity.
It seems she was being reasonably logical.
She made a hypothesis that fast food stays inside the body and doesn’t get broken down.
She set up an experiment comparing fast food and normal food.
She used a control in her experiment showing that potato strips do decay.
She made a logical conclusion that the food is not broken down.
She constructed her arguments into a theory that we can’t break down the food, leading to obesity.
Unfortunately, there are actually several mistakes in her reasoning that most people should be able to spot so long as they care to use a little scientific thinking.
Attack the Hypothesis
Ms Havey gave the hypothesis that fast food cannot be broken down. Not by microorganisms, not by human beings. If this was really true, it would mean that the McDonald’s food that we eat would stay inside our bodies for ever, or at least for several years, leading to irreversible obesity. “There’s no breakdown,” she said, brandishing her burger. “It doesn’t go anywhere!” However, there is actually a very big problem with this argument.
Let’s assume for a moment that Ms Havey is right, that fast food in our bodies doesn’t get broken down. How can she explain how people slim down after dieting? How is it that people can lose weight by exercising? Ms Havey herself was once obese, and said she used to eat at McDonald’s frequently, yet she herself succeeded in losing 130 pounds at one point. How can she insist that we can’t break down McDonald’s fast food when she managed it herself years ago?
But for the moment, let’s neglect this point and see what else she got wrong in the video.
Make Sure the Experiment is Reliable
Don’t believe everything you see.
I was sceptical about whether McDonald’s food really could last years without preservation, yet I was reluctant to try the experiment myself for fear of what might eventually emerge from my lunchbox. So instead, I consulted YouTube and found that there were already a couple of brave souls who had tried the experiment out themselves.
In each of the experiments, the bold experimenters placed multiple burgers in glass jars or plastic boxes, and left them in room conditions. In both of those experiments, the McDonald’s burgers decayed within months. Clearly, their burgers did not have the same resistance to decay as Ms Havey claimed hers did.
Now, it is possible that Ms Havey was lying when she said her burger lasted four years. She might even have inadvertently placed the McDonald’s food in conditions unfavorable to decay. We don’t know why or how her results came to be, but what we do know is that others who have conducted the same experiment have come up with very different results.
So it is important to always treat the results of a single experiment with scepticism, and make sure you have multiple sources of information before making conclusions.
It is interesting to note, though, that in one of the other experiments, some french fries did actually survive at least ten weeks without any decay whatsoever. So, for the moment, let’s give Ms Havey the benefit of the doubt and assume that her burger and fries really did last four years.
For reference, here are the links to the videos of the other brave experimenters. In some cases, their experiments were successful, in others, not so:
Verify the Conclusion
Okay, assuming for the moment that Ms Havey’s burger and fries really are four years old, there are actually many alternate reasons for the phenomenon, other than McDonald’s food having something dangerous inside them.
Ms Havey said, when she demonstrated her unblemished McBurger and McFries, that she had not added any preservatives to the products. While it may have been true that she herself didn’t add anything, there still could have been preservatives already present in the burger when she purchased it.
Many of you may think that there is no reason for McDonald’s to put preservatives in their food, and you’re probably right. After all, people tend to buy and eat their burgers immediately afterwards, not stick their food in a lunchbox for four years as an experiment. That being said, however, there are other reasons why there may have been preservatives in the burger and fries.
First up: the bread. McDonald’s may not have put any additives in the bread, but what about McDonald’s supplier? During the making of the bread itself, it is likely that additives were introduced to extend the lifetime of the bread. Common examples of additives include ascorbic acid (a.k.a. Vitamin C, which is an antioxidant that can prevent oxidation of the bread) and sorbic acid (which is an antimicrobial agent effective at inhibiting the growth of mould, yeast and fungi). These are preservatives very often found in bread and have no known adverse effects on human health, and in no way inhibit the digestion of carbohydrates for humans.
Then: the Cheese. During the making of cheese, there are actually a few ways that it is naturally preserved. First of all, the bacteria used to ferment milk into cheese produce lactic acids, which in turn prevent the survival of other microorganisms. Secondly, in the production of cheese, salt is added, which has antiseptic properties. Thirdly, it is fairly obvious that the cheese you find in cheeseburgers are processed cheese. Though this means that the cheese is shiny, bland and tasteless, it also means that the cheese has been processed in order to extend its shelf-life (by pasteurisation or by adding preservatives such as sodium nitrate). These additives do not prevent the digestion of cheese in the human alimentary canal.
Next, the Meat: Processed meat is used in burgers. I’m not saying that processed meat is in any way good for you. It is fatty, oily, contains heavy metals, and some say it causes cancer. What I am doing, is debunking Ms Havey’s argument that McDonald’s meat cannot be broken down. Processed meat, like processed cheese, contains additives that either kill or prevent the growth of bacteria and mould. Examples include sodium nitrites, benzoates, sulphites, sodium chloride (table salt) and sugars. On top of that, processed meat is sterilised before distribution by irradiation, killing almost all microorganisms. As if that wasn’t enough, the meat is cooked at high temperatures at McDonald’s before being put into the burger, once again, eliminating nearly all microbial agents. None of these treatments affects a human’s ability to digest the food.
Finally, the Chips: Chips are basically deep-fried potato strips. Being cooked in oil at almost 200 degrees Celsius, it is almost certain that no microorganisms survive the process. Moreover, any enzymes present in the potatoes that could have potentially caused decay would have been denatured by the extreme temperatures, again reducing the chances of decay. It is also possible that the crispy coating of oil on the outside of a french fry is impermeable, thus preventing external bacteria from penetrating it and decaying the potato within. The lack of bacteria and presence of an outer coating does not inhibit breaking down of food inside our bodies as it is broken apart by mechanical digestion (a fancy phrase for ‘chewing’).
Check the Control
The above arguments also shows that Ms Havey made a mistake by using raw potato strips as a control. In her experiment, Ms Havey compared McDonald’s french fries with raw potato strips.
Observation from the control: Normal potato rots.
Observation from the experiment: McDonald’s french fries don’t rot.
Conclusion: McDonald’s french fries are not normal.
Convincing as Ms Havey’s line of thought may be, there is actually a problem with it.
As I have explained above, deep-frying of the potato strips kills almost all microorganisms inside it, as well as denaturing naturally occurring enzymes that might cause decay. The potato strips that Ms Havey used were not cooked and thus could well have contained bacteria, fungal spores and enzymes that were responsible for the eventual decay.
In a nutshell, the difference between the raw potato strips and the french fries was most likely a result of the cooking, rather than a result of something unnatural McDonald’s put in their fries.
Since we still can’t yet fully disprove Ms Havey’s claims with the above explanations, let’s move on to the next step: Getting a good knowledge in biology.
Question the Theory
Good knowledge is perhaps the most important factor to defeating Ms Havey’s points. With proper knowledge of how the digestive system works reveals that her arguments are flawed at the most fundamental level possible. Most people who have studied basic biology should have the necessary knowledge to completely refute Ms Havey’s claims.
What happens after swallowing a burger?
According to Ms Havey, the food is absorbed into our bodies first. Then, after it has been absorbed into our arms and legs in the form of excess flab, it can never be broken down and hence never gets removed from our bodies. A convincing argument to most. Unfortunately, there is a very basic problem with the argument (that one should be able to spot using secondary school level biology).
Imagine swallowing a coin. Everybody knows that humans cannot break down metal in their digestive systems. However, does the coin get absorbed into our bodies and never removed as a result of its inability to be digested? No. The coin will never be absorbed at all, and instead simply pass through our gastrointestinal tract and out the other end.
After swallowing, food enters our digestive tract, whereby digestion occurs. It is only after digestion that it is possible for food to be absorbed into our bodies, via the bloodstream. Any food that cannot be digested is not absorbed into our bodies. In fact, it is physically impossible for us to absorb food that hasn’t in some way been broken down by your digestive system. All the food that is not digested (and hence not absorbed) is passed out of the body in the form of faeces (the scientific term for ‘poo’).
It turns out, a lot of food we eat every day is indigestible. This component of food is called ‘dietary fibre’, and is present in most fruits and vegetables. This dietary fibre, far from accumulating inside our bodies and making us fat, is in fact essential to a healthy digestive system.
As I’ve just explained, even if McDonald’s food really can’t be digested, it still doesn’t contribute to obesity. In fact, if McDonald’s burgers and fries really were indigestible, we’d never get fat because we’d never absorb any of it in the first place!
To Wrap up
Okay, what have we talked about today?
1. People who get fat on McDonald’s can get slim again. So obviously McDonald’s doesn’t lead to the sort of irreversible obesity Ms Havey was talking about.
2. The experiment has been conducted by others and their results have been drastically different from Ms Havey’s. So it is possible that McBurgers and McFries don’t really last four years after all.
3. There are actually many many different possible explanations for the long life of McGoods. So there might not actually be something dangerous or sinister in the food at all.
4. Even if McFood is indigestible, there is no reason why it would lead to obesity.
Ms Havey had good intentions, I’m sure, and I admire her for her outspokenness against fast food. However, her reasons for us to stay away from McDonald’s are so severely flawed that all they succeed in doing is reducing her credibility.
All that being said, it is undeniable that fast food is bad for you.
So stay away from it.
April 25, 2010
Take a look at a banana.
It has just the right length and just the right thickness to fit snugly in your hand. The surface of a banana is anti-slip, making it easy to hold and to eat. There is a finger-sized tab on the top of every banana, all you have to do is to pull it lightly, and the skin peels away from the edible fruit inside. Banana skin also acts as a comprehensive ripeness indicator: Green – not ripe yet; Yellow – perfect; Black – time to throw it away. Bananas are sweet, easy to chew and good for your digestive system.
These arguments were presented by evangelist Ray Comfort in an attempt to prove the existence of God. Obviously bananas were designed by God, he argued reasonably, how else could so perfect a fruit have come to exist?*
While hardly irrefutable proof of God, his arguments certainly do provide fairly compelling evidence of a supernatural power that in some way influenced the course of nature. In fact, it would have been a brilliant argument if not for one fatal flaw: God didn’t create the bananas; we did.
Bear with me for a moment. I’m not suggesting that we magically made bananas appear out of thin air, I’m merely saying that bananas were developed by humans over the course of hundreds of years through a process called ‘selective breeding’, or ‘artificial selection’.
You have probably never seen a true wild banana before, and if you ever do in future, you might not even recognise it as a banana. In the wild, bananas are small and oval; they have thick, tough skin that is difficult to peel; they are peppered with large, hard seeds that make eating them a thoroughly unpleasant experience.
So, how was it that bananas came to be the way they are today?
Around seven thousand years ago, the first bananas were discovered. In the wild, bananas were not easy to eat. They probably had to be peeled using sharp rocks and whoever was eating them would have had to constantly spit out big seeds. However, not all the bananas were exactly the same as each other. Just like humans, some bananas were thinner than the others, some had different skin colours, some were especially seedy and some were sweeter than the rest.
Now humans were fairly intelligent even back then, and they didn’t fail to notice this diversity in the banana trees. So what they did, was to collect the bananas with the most desirable qualities they could find, and breed them. They found bananas with the smallest seeds, bananas with the thinnest skin, bananas that were longer than the others, and used them to plant new banana trees.
Just like with humans, bananas pass on traits to their offspring. A seed from a sweet banana is more likely to produce a sweet banana, just as a tall parent is more likely to produce a tall child.
Over generations of breeding, bananas with desirable traits were bred and encouraged to grow, while bananas with undesirable traits (i.e. fatter, more bitter and thicker ones) were tossed back into the wild, where their chances of survival were much lower.
As a result, an entirely new breed of banana was produced. These were bananas that had over the centuries been selectively bred so that only those best suited for human consumption were cultivated, spread and became widely available to humans.
Bananas, unsurprisingly, are not the only organisms that have been created by artificial selection. Dogs, for example, are descended from the gray wolf, but most breeds of dogs don’t look anything like a wolf. The answer is that wolves were domesticated by humans some 15,000 years ago and through thousands of years of selective breeding, evolved into the dogs we see today.
For plants, selective breeding can increase the crop yield, make fruits more tasty, improve the plants’ resilience to pests and viruses, increase the tolerance to environmental fluctuations such as temperature and humidity and much more besides.
Through artificial selection, animals can be bred to have specific behaviours (e.g. Despite their origins from pack animals, dogs have been moulded to be reasonably independent, and protective of humans) or to develop certain physical traits (e.g. The Belgian Blue was bred to be exceptionally muscular).
Artificial selection is everywhere. Whether intentionally or accidentally, humans have swayed the course of nature. Most of what we eat has been selectively bred to enhance desirable traits. Many animals we come into contact with every day did not exist before humans domesticated them.
So next time someone asks you why a banana seems to be specially designed for us, you’ll be able to answer them:
*Upon hearing this, my very first impulse was to ask, “Who, pray, invented the coconut, the pineapple, the durian and the whole host of poisonous berries?”