The Human body is a marvel of natural evolution with an array of amazing and disgusting abilities,
like did you know that humans are the only animals with chins or that on average you
will pass enough wind in a day to inflate a party balloon.
However, despite being around for nearly 200,000 years and being the most intelligent species
on the planet, there are plenty of misconceptions about our own bodies.
Here, we’ll look how unique your fingerprints aren’t, how useful your appendix really
is and how your body isn’t very human at all!
Plus a few more mind blowing misconceptions!
I’m Stu, this is Debunked, where we sort the truths from the myths and the facts from
the misconceptions.
Number 6.
The Tongue Taste Map!
Many of us will be familiar with this tongue taste map and some of us might have even been
taught it in school.
It dates all the way back to Germany in 1901, when a study was published showing different
areas of the tongue to be more sensitive to tastes than others.
Since then, this research has been misinterpreted, mistranslated and has evolved into the illustrated
map you see right here, with different sections of the tongue dedicated to Sweet, Sour, Salty
and Bitter tastes.
Aside from the fact that the original map missed out the fifth distinct taste, umami,
the truth of the matter is that your tongue doesn't determine the taste at all,
it’s actually your brain that ascertains it.
Your tongue has up 10,000 taste buds spread across it, and each of these have 100 taste
receptor cells and these respond to different substances in your food.
Up until very recently it was believed that these taste cells would detect one of the
five basic flavours and then send a signal to our brain that tells us what we’ve tasted.
A study in 2015, lead by Charles Zuker at Columbia University turned this idea on its
head.
“TASTE, THE WAY YOU AND I THINK OF IT, IS ULTIMATELY IN THE BRAIN,”
“DEDICATED TASTE RECEPTORS IN THE TONGUE DETECT SWEET OR BITTER AND SO ON, BUT IT’S
THE BRAIN THAT AFFORDS MEANING TO THESE CHEMICALS.”
In the last decade Dr Zuker has proved that the tongue has dedicated receptors for each
taste, and that each class of receptor sends a specific signal to the brain.
In fact studies have now shown that the brain can detect tastes like Carbon Dioxide, the
distinct taste you get from carbonated water.
BUT Zuker’s more recent experiment proved that each individual taste is sensed by a
unique set of brain cells that are located in the brain’s cortex, which interestingly
generates a map of taste qualities in the brain.
So we’ve gone full circle with the taste map, it’s just now in the brain.
In the study Zuker’s team manipulated specific brain neurons in mice, causing them to taste
sweet when they were actually tasting something bitter and vice versa.
They could even activate the neurons to taste either sweet or bitter when they were simply
drinking water.
“DEDICATED TASTE RECEPTORS IN THE TONGUE DETECT SWEET OR BITTER AND SO ON, BUT IT’S
THE BRAIN THAT AFFORDS MEANING TO THESE CHEMICALS.”
In other words, taste is all in the brain.
Number 5.
We lose most of our body heat through our head?
You’ll get told it a hundred times as a kid and you’ll still get told it as an adult,
and it was even stated as fact in a US military field manual claiming...
So surely it must hold some weight, right?
Well, I’m afraid not.
The idea that we lose more heat from our head than anywhere else, is simply not true.
The human head is no more efficient at losing heat than any other part of the body.
A 2006 study by the conducted tests by dunking test subjects into cold water, with their
heads submerged and with their head above water.
The study found that we only lose around 7 to 10% of our body heat through our heads.
To us it may feel like your head is colder as there are five times as many nerves in
your head than any other part of your body making your face more sensitive to the cold
But the fact is, if you expose your arms to the cold, then you will lose more heat from
them, as they have a larger surface area from which to lose heat.
According to Dr Daniel Sessler,
the myth originated from a military experiment carried out in the 1950s, where test subjects
were dressed in Arctic survival suits and exposed to low temperatures, the resulting
heat loss was then measured.
But rather unfairly their heads were uncovered so naturally this is where they lost most
of their heat.
Subsequently, the military field manual at the time stated that we lose 40 to 45% of
our body heat through the head.
Despite this, seven to ten percent is still a high enough amount of heat that you don’t
want to lose it in cold weather, so it’s still worth popping a hat on in the winter.
Number 4.
No Two People Have Identical Fingerprints.
We leave fingerprints behind on pretty much every surface we touch.
Why?
Because the patterns on the end of your fingers, called ‘friction ridges’, are connected
to sweat glands which secrete sweat to the skin’s surface.
Then when you touch something a pattern of sweat matching your fingerprint is left behind.
Simple.
The patterns themselves however, are far more complicated.
You see, fingerprints shape into 3 main patterns: whorls, loops and arches, with it possible
to have all 3 types across all 10 of your digits.
Feel free to take a look at your own, I imagine that’s what you’re doing anyway.
The ridge paths, breaks and forks that you see there, make up these patterns in countless
combinations,
hence the concept that ‘no two people have the same fingerprints’.
In fact, they’ve been used to identify individuals and solve crimes since the late 1800s and,
as you well know, they now unlock your phone, online accounts and personal details,
but are they completely unique or could you end up being the suspect for a crime you didn’t
commit?
Simon Cole, a professor of criminology, law, and society at UCI, has identified 22 people
who were wrongly convicted in the US because of their fingerprints since 1920.
This wasn’t however because there are 22 pairs of people with identical fingerprints,
rather that the print analysis was mistaken.
You see for a fingerprint to ‘match’, they don’t need to be identical but instead
need to have a certain number of points of similarity, and in the US the number of required
reference points varies dramatically between states and examiners, with the average being
12.
In fact one judge in California threw fingerprint evidence out of court when he learned that
there wasn’t a standard number of points to prove a match.
A
“I DON’T THINK I’M EVER GOING TO USE FINGERPRINT TESTIMONY AGAIN,”
Cole points out that his findings are only the tip of the iceberg and that when evidence
from qualified fingerprint examiners are brought into the mix, it’s estimated that the average
rate of mismatch is 0.8%.
So in the sense of fingerprint impressions, it’s quite possible for your fingerprint
to match with someone else's.
But what about having a physically identical match, with indistinguishable patterns?
How about identical twins, surely the clue is in the name?
Well, despite inheriting similar size and shape patterns on their fingerprints, the
identifying characteristics are still different.
In fact everyone’s fingerprints are completed a whole 3 months before they’re even born.
And incredibly as your entire body grows, changes and ages, these patterns on your fingertips
and thumbs remain the same, they essentially just scale up.
With old age, the ridges can become less prominent, as your skin loses its elasticity but nonetheless
the actual patterns remain the same.
There are of course things like scars or burns that can alter your fingerprints, but even
then it can be quite hard to make it a permanent change.
Notorious gangster John Dillinger attempted to destroy his fingerprints with fire and
acid, only to have them grow back mostly the same.
But for some people this wouldn’t be the case, because if you were born with a condition
known as ADERMATOGLYPHIA, you wouldn’t have any fingerprints to lose in the first place.
This rare genetic disorder means that your fingertips, palms, toes and soles are entirely
smooth.
But for most, as ‘individual’ as these identifying ridges seem to be, it has never
been proven that they are entirely unique to each person, and it’s almost impossible
to prove either way without having catalogued the fingerprints of every person that has
ever lived.
As Forensic Science Regulator Mike Silverman puts it...
“ESSENTIALLY YOU CAN’T PROVE THAT NO TWO FINGERPRINTS ARE THE SAME.
IT’S IMPROBABLE, BUT SO IS WINNING THE LOTTERY, AND PEOPLE DO THAT EVERY WEEK.”
And it was originally estimated that odds of a match were 1 in 64 billion.
Those may sound like some pretty low odds, but considering there are over 100 billion
people that have ever lived on Earth, most with 10 fingerprints each, that’s around
a trillion combinations across human history, meaning at least 1 pair of those is likely
to match.
But to counter those odds again, mathematicians now suggest that when you include details
that aren’t even visible to the human eye, the number of individual finger print configurations
would be pretty much countless.
Number 3.
Your Appendix Is Useless
Long believed to be an utterly useless ticking time bomb waiting to kill you,
it has now been discovered that the Appendix has a reason to exist after all.
It has been long established that the appendix is full of immune system tissues, but it has
not been known what these tissues are for.
Now, a series of observations and experiments co-authored between several educational and
research bodies
has suggested that they are there to protect good bacteria and provide what is being termed
a “safe house” for these beneficial bugs.
Assistant Professor William Parker explains how the appendix comes into its own after
a nasty bout of illness.
“ONCE THE BOWEL CONTENTS HAVE LEFT THE BODY, THE GOOD BACTERIA HIDDEN AWAY IN THE APPENDIX
CAN EMERGE AND REPOPULATE THE LINING OF THE INTESTINE BEFORE MORE HARMFUL BACTERIA CAN
TAKE UP RESIDENCE,"
Number 2.
The color of your pee indicates whether you’re dehydrated.
It’s likely that you’ve been told that the darker your urine is the more dehydrated
you are, and the lighter and clearer it is the more hydrated you are.
Athletes are even specifically advised
“OBSERVE URINE OUTPUT OVER THE COURSE OF A DAY AND NOTICE CHANGES IN URINE FLOW AND
COLOUR.
OUTPUT VOLUME AND FREQUENCY SHOULD BE CONSISTENT AND THE COLOUR SHOULD BE GETTING LIGHTER TOWARDS
THE END OF THE DAY, AIMING FOR THE LAST OUTPUTS OF THE DAY BEING CLOSE TO CLEAR.”
So what’s the science behind this theory?
Well, when you’re dehydrated a hormone is released that increases the amount of water
your kidneys absorb, this then lowers the volume of urine when you pee and concentrates
the substances left behind, making your pee appear darker in colour.
After this process, less water then needs to be absorbed, so your urine increases in
volume and appears to be more pale and clearer.
However, researchers at Oxford discovered that the science behind this guidance isn’t
quite so clear.
They looked at 8 studies and found that the results were very divided, with none of them
advocating the use of urine colour as an accurate measure of hydration.
There were 3 studies that suggested it could be used as ‘a tool to roughly estimate hydration
status’ but these also found the problem that some foods, vitamins, medication and
dietary supplements can alter the colour of your pee.
These results have raised concerns that attempts to achieve the pale clearer colour could instead
lead to overhydration and hyponatremia, essentially the dilution of your body salts, which in
extreme cases can be life threatening.
Number 1.
Your body is 100% Human
I would expect most reactions to this to be along the lines of, get out of here, what
nonsense are you talking, if I’m not human what am I?
Now this might make you feel a bit weird, itchy maybe, but the fact is, every inch of
your body is inhabited by little creatures.
As Professor Rob Knight puts it:
"YOU'RE MORE MICROBE THAN YOU ARE HUMAN."
PROF.
ROB KNIGHT, UNIVERSITY OF CALIFORNIA, SAN DIEGO
& CO-FOUNDER OF THE AMERICAN GUT PROJECT
Because incredibly it’s estimated that only 43% of the body’s cell count is human, the
rest is our microbiome made up of organisms like bacteria, viruses, fungi and archaea.
Microbiologist, Professor Sarkis Mazmanian,
takes this figure even further and suggests that genetically we’re outnumbered up to
1000 to 1
"WE DON'T HAVE JUST ONE GENOME, THE GENES OF OUR MICROBIOME PRESENT ESSENTIALLY A SECOND
GENOME WHICH AUGMENT THE ACTIVITY OF OUR OWN.
Your first thought may be to grab a scrubbing brush and make a dash for the shower, but
hold up, because you really don’t want to lose these little guys.
Besides a shower wouldn’t do a great deal because most of them exist inside you, in
your guts.
"WHAT MAKES US HUMAN IS, IN MY OPINION, THE COMBINATION OF OUR OWN DNA, PLUS THE DNA OF
OUR GUT MICROBES."
Although it was originally thought that the Microbiome’s job was pretty simple - protecting
our gut from invaders, synthesising some vitamins and gobbling up the fibre that our body’s
can’t digest.
It’s now understood that your Microbiome regulates your entire immune system, it can
influence your mood and it can even affect your weight.
As Dr Michael Mosley puts it:
“THE MICROBES CAN DECIDE HOW MUCH ENERGY YOUR BODY EXTRACTS FROM THE FOOD YOU EAT AND
MUCH MORE.
CAN YOUR MICROBIOME MAKE YOU FAT?...
IT CERTAINLY CAN!”
Understanding the incredible world of our microbiome is a relatively recent process,
but it is hoped that Microbial Medicine known as "bugs as drugs" will become common practice,
where you can essentially have a microbiome transplant, by taking good bacteria from a
lean healthy person and inserting them in to an obese person with either bad or missing
bacteria, and making them lose weight.