Evolution FAILS in the Human Body


Hey smart people, Joe here. Bodies. We’ve all got ‘em. Couldn’t live without ‘em! But why are they so dumb and unreliable?! I don’t know if it’s because I just got
over a sinus infection or because my wife just had knee surgery, or maybe it’s just
me getting older and hurting more… I’M A MILLENNIAL!!
but I have been noticing lately that the human body… it’s got a lot of problems. And this video is a big long rant about a
bunch of ‘em. I mean don’t get me wrong, humans are really
awesome. Look at all we can do! It’s just that, there’s so much about
our bodies that is flawed. Like, so many of our parts wear down or are
easy to break, and others look like Ikea furniture would look if you accidentally threw away
the instructions before putting it together… in that it basically functions, but you’re
pretty sure something’s backwards and somehow you have like three of those little twisty
things left over?! The great American poet John Mayer once said
“your body is a wonderland”, but I think he meant “your body is a blunderland”. From eyes that don’t work right and backs
that ache to needy diets and extra bones… what I’m saying is… sure, our bodies look
cool–especially if they’re wearing an awesome shirt–but who the heck designed
these things?! Well, no one did. We’ll get back to that, but first, instead
of talking about how great we are, let’s talk about some of our critical weaknesses. The first example… it’s staring right
at ya. I mean, I don’t wear these things to look
cool and smart. I mean, they do make me look cool and smart,
but I wear them because I can’t see! Like nearly half of Americans and Europeans
or nearly 7 in 10 people in Asian countries, my peepers don’t peep right. I’ve worn glasses since elementary school. Space shuttle. Nice! Very on brand, younger me. Anyway, before the invention of corrective
lenses a few centuries ago, people who couldn’t see just… couldn’t see. And back in our prehistoric hunter-gatherer
days, that could’ve meant starvation and death. Bad eyes, empty stomachs, you lose. Thing is, even if you don’t wear glasses,
you have eye problems. While looking at this image, cover your left
eye, and look at the dot while keeping your face centered in front of the screen. Slowly move closer or farther from your screen
and the cross will disappear. Did it work? Around 30 cm or 12 inches away works for me. Pretty weird huh? You can try it with the other eye too. Cover your right one, stare at the cross,
and move until the dot disappears. That’s your blind spot, and every animal
with a backbone has a blind spot in each eye because of how the eye is built. The light sensitive layer inside your eye
is filled with tiny cells called photoreceptors. They’re like little microphones. One end turn photons of light into electrical
signals, and the other end’s a wire that carries the signal away. Except our retinas are built so the cables
are pointed towards the light, like talking into the back of a microphone. The cables from all those little microphones
have to pass through a hole in the retina to get to the brain. And where that hole is, we have a blind spot. We just don’t usually notice it because
our brain lies to us and fills in the image. Why do we have it? Because at some point way back in evolution,
when our ancestors started to evolve the first light-sensitive tissues, that’s just the
direction the cells were facing. And later, when those patches morphed into
actual eyes, it was too late. The backwards pattern was already set. Evolution can’t suddenly flip a whole eye
around. It can only make tweaks to what’s already
there. But cephalopods–like octopuses, squid, and
cuttlefish–they don’t have a blind spot. This branch of animals evolved eyes completely
on their own, and in early octopus ancestors, the cables on all their microphone-shaped
light-sensing cells pointed toward the back, so their retina is unbroken. Am I saying that cephalopods have better eyes
than us? Mmm, yes. Point, cephalopods. And another point for having eight legs. Ok, enough about eyes! Why is there so much empty space in our skulls? You know I can take you off the set any time right? Watch it, globie. When we breathe, air enters our nose and passes
through four chambers called sinuses where the air gets warmed up, humidified, and filtered
by mucous membranes. The mucus then drains ure is plenty in YOUR
skullout and back down your throat to your stomach. Mmm, gross. That works pretty well for the sinuses on
top, they have gravity to help them. But the big ones behind your cheeks? They drain up. Up! And that difficult drainage is why humans
get so many head colds and sinus infections. You know who doesn’t get sinus infections? Dogs. Dogs and other animals that rely mainly on
smell tend to have elongated nasal cavities, which drain down and back with gravity, the
correct way. But as our ancestors became more dependent
on vision and less dependent on smell, our snouts got smushed up into our flat faces,
and now we have tiny noses and get sick all the time. If you accidentally eat some air, no biggie. You can just burp it out. But if you breathe in your food, you’re
gonna choke and maybe die. What’s up with that? It comes down to the fact that like most other
vertebrates, we breathe and eat through the same throat hole, another one of evolution’s
amazing bright ideas. But I once saw a bird swallow a fish as big
as its head. It did not die. If I did that, I would die. But snakes and birds can swallow huge meals
whole because their nostrils connect directly to their breathing parts without going through
the throat. Like an alternate breathing system. But in every mammal, we’ve just got the
one tube, and all that separates the digesting part from the breathing part is a little flap
called the epiglottis. Epiglottis open? You’re breathing. Epiglottis closed, you can eat or drink. Mess up that order, here’s how to do the
Heimlich maneuver. Now, lots of animals can choke. Even whales can choke if fish get stuck in
their blowholes. Yes, that actually happens. But humans are especially prone to choking
because our voice box, or larynx, has moved up so high in our throats. I tell ya, these throats were made for talkin’. Some languages even make vocal sounds using
the epiglottis, like in some African languages. That higher voice box has squished up the
swallowing parts of our throat so there’s not a lot of room for error. But on the plus side, we can yodel. So maybe we can call this bad evolutionary
trait a tie. So. Walking upright. Pros: We can run, kick a soccer ball, dunk
a basketball, do sports things with all the other balls, ride a pogo stick, surf, ice
skate, dance, and dance dance revolution. Cons: So many unique and painful ways to injure
ourselves. Some of your body’s joints are beautiful. I’m a huge fan of the jaw. And the hip? That ball, that socket. It’s like Michaelangelo sculpted it. But the human knee and ankle look like an
elementary school art project held together by rubber bands. Back when our ancestors walked on all fours,
they had twice as many limbs and muscles to carry their weight. But when they transitioned to walking on two
legs, it put a lot more stress on our knees and ankles. When you quickly change direction while running,
the anterior cruciate ligament is basically the only thing holding the two halves of your
leg together. It has basically no blood vessels, and if
you tear it, the only way to fix it is surgery, which we only invented like a hundred years
ago. I have personally known at least a dozen people
who have torn their ACL. If we were hunter gatherers or ancient hominids,
every one of them would probably be dead. I don’t even know why I’m laughing, that’s
horrible. And right under that is the Achilles tendon. Since we walk on the balls of our feet, that
tendon takes basically all the force of the lower leg like a big fleshy rubber band. If you tear that one, you also can’t walk. It’s maybe the most important tendon in
your body, so of course it sits there on the back of our leg completely exposed, waiting
for the person behind us at the grocery store to ram it with their cart or your mythical
arch nemesis to hit you with a poison arrow. This is not how you’d engineer bipedal legs
from the ground up. This is way too many weak spots for any crucial
structural system. But when the assignment was “turn an animal
that walks on all fours into a fancy dancing ape on two legs”, evolution had to work
with what it was given. Body parts are one thing, but evolution has
messed up our insides too. Like, we are really poorly cut out for eating. Pretty much every animal needs the same nutrients
in order to function. Stuff like amino acids, vitamins, a few minerals. But most animals make most of these things
for themselves. But we have to get a literal grocery list
of nutrients from our diet. Take “vitamins”. That’s what we call essential macronutrients
that we have to get from our diet to survive. Vitamin C, for example. More than half a dozen proteins need vitamin
C around to do their job. Without it, your bones get brittle, your tissue
breaks down, you just bleed. Oh, and your teeth fall out. Scurvy is no fun. Pretty important stuff, this Vitamin C! So of course, we can’t make any. At all. We have to get every bit we need from our
diet. Almost every animal on Earth makes their own
Vitamin C. My dog never has to drink orange juice. Neither does a cow, or a cat. But I do. Strangely, humans have all the genes necessary
to make vitamin C in our DNA. Yet somewhere in our evolutionary history,
in some ancestor of all primates, one piece of the vitamin C machinery mutated and broke,
and now we have to eat it or die, along with all these. Of the 20 amino acids we need to build proteins,
our bodies only make 11. Many animals can make all twenty, but we have
to get almost half from our diet. Needing to have ready sources of these essential
nutrients has placed restrictions on where and how our species could live, at least before
we could walk into any pharmacy and get them all in pill form. Pretty much everywhere you look, it seems
like our body has room for evolutionary improvement. Our teeth? Most people grow a third set of molars–wisdom
teeth–that won’t fit in their mouth and have to be removed. Do I need to mention the fact that a male’s
gamete producing organs sit dangerously exposed outside the body? And the pelvis? Most women can’t deliver a baby without
medical assistance because the human head is so large. Who came up with all these bad ideas? The answer, of course, is no one. Thanks to science, we know that the human
body isn’t engineered, or designed. It’s evolved. Everything is the way it is because it got
that way, making tiny tweaks to what was there before. That means that our backs hurt because we’re
walking upright with a spine that used to be horizontal. We get fooled and we fool ourselves because
our brains evolved in a different world than the one we invented in the past few decades. Sure, our bodies are full of parts that barely
get the job done, full of things that could be built way better. And that can be frustrating, sometimes even
painful. But nobody, and I literally mean “no body”,
is perfect. Because surviving isn’t about being perfect,
it’s about being good enough. It’s about being imperfect in the perfect
way. If you’re watching this today, then you
are good enough. Because you’re a survivor of a 4 billion
year story. Our flaws make us who we are, because evolution
and natural selection made us who we are. Flaws and all. Stay curious.

100 comments

  1. Your body is perfectly imperfect. Thanks evolution!
    What's your favorite/least favorite evolutionary body flaw?

  2. Body: "I am perfectly capable of growing an entirely new human being inside of me."
    Also body: "You really think I'm going to actually fix that ankle you sprained 20 years ago? PFFT!"

  3. Nice explanation. Just one tiny correction, vitamins and minarals are micronutrients, not macro. Macronutrients are fats, proteins and carbohydrates.

  4. What about the appendix? Oh right, it’s no longer considered a useless organ because it’s function was discovered. Seeing “bad design” stems from ignorance.

    When primitive peoples are studied they display an astonishing absence of the ailments common to “civilized” people; bad eyesight, prostate issue,impacted wisdom teeth, back problems, heart disease, susceptibility to illness, etc…

    The irony is you probably have modern science to thank for those ailments since they’re virtually unknown to people living in a more natural state.

  5. another thing is when you get scoliosis not only is your spine bent and twisted and not straight, but your shoulder moves up or down, one that is

  6. I'm a product of billions of years of evolution. Each and every direct ancestor of mine got laid without missing, starting from the earliest microorganisms that appeared in the depth of sea. Well, I'm sad to say that, by the looks of it, that heritage is going to end here. Sorry ancestors.

  7. Why our or ring fingers so inept at everything?

    "Ring finger, point at that thing over there!"
    "Can I bring middle finger with me?"
    "No, point alone."
    "OK…"
    "Hey! Let go of middle finger! I said you're doing this alone."
    "I'll try….."
    (Entire hand trembles.)

  8. cant your body deevolve? i mean think of it everyone wants to be positive… but the fact that we get fatter and cancer might just prove that your not evolving and you just off yourself.

  9. Well this isn’t a bad thing, but the reason that our bodies are flawed is because of how we survive so well, back when we were hunter scavengers the part of your genes that caused bad eye sight would be eliminated.

  10. you didnt get created… you are a pathetic accident according to "its ok to be smart"… . you are flawed and a piece of evolved crap. let you pain evolve.

  11. What if, God was still mad after Adam and Eve for eating the fruit, he made humans evolve to be brittle and easy food for lions tigers and bears?

  12. evolution is trying to develop human body but it can't anymore as the individual with evolved character will be treated as dfected and the evolve character as a disease

  13. OMG! Thank you so much! I am laughing so hard right now! An educational video and so much fun!! This channel is gold!🤣

  14. Religious people always say "God made humen and we are perfect"
    Our body : Are you sure about that?? 🙄😒🙄😒

  15. Lol all this we evolved from XYZ talk is absolutely ridiculous🤣🤣! I love and trust science. But the science of large scale evolution is just flawed 🤣🤣🤣! There is adaptation but no "evolution"

  16. LADIES AND GENTLEMEN….the search has ended ..a youtube channel which combines memes, witty sense of humour and real scientific facts and knowledge …that's like finding alien life in this vast universe…I got lucky today💝

  17. the rudimentary drawing about nerve pathways in our eye (blind spot explanation, as I understood it) as a fail seems more like a work around. it compacts all that info into a single "wire" and allows the eye to actually move. if the nerves just went straight from the back of the eye to the brain, mobility would be greatly hindered.

  18. I’m curious. Is there evidence that bipedal birds and dinosaurs suffered from weaknesses of the legs? Did they eliminate their problems by having many more millions of years of evolution with bipedalism?

  19. Not true at all.
    Human body is beyond perfect.
    Best engineers are still unable to figure out the most basic things about life and often look at nature for inspiration.
    The true fault is that humans dont use our bodies in the way they were designed for..

  20. Evolution is fine, we’re just supposed to be extinct. I’m legally blind, allergic to everything with fur or feathers and grass, pollen and mold. Basically, I’m allergic to outside. Yep, I should be extinct.

  21. In 1879 John Fordyce wrote asking if Darwin believed in God, and if theism and evolution were compatible. Darwin replied that "a man may be an ardent Theist and an evolutionist", citing Charles Kingsley and Asa Gray as examples, and for himself, "In my most extreme fluctuations I have never been an atheist in the sense of denying the existence of a God.— I think that generally (& more and more so as I grow older) but not always, that an agnostic would be the most correct description of my state of mind."

  22. purpose of sinuses is for the resonance of sound we produce to have a highly developed and evolved speech function that we have today. remember how you sound when your sinuses are blocked due to infection.

  23. Whenever this channel talks about global statistics they never include any African or South American countries, it's always European countries and the USA. Is it because these countries have mostly white people??

  24. Menstruation should have been included. Painful, messy, sometimes detrimental to health. Completely unnecessary! Other mammals don't do it. Even most other primates don't. I'm personally offended that roughly half of humanity has to put up with such bullshit, and I don't even menstruate.

  25. My DNA rolled a dice and won a nerf to hearing to zero hearing. Yeah I'm deaf in both ears. But Human Science said: "NO!" Then invented cochlear implant, hearing aid and sign language. Pretty neat, huh? As Joe mentioned in the video, humans are awesome.

  26. As someone with an invisible chronic disability that prevents me from doing almost everything without help, I am fully aware of how fragile our bodies are. If I had been born in a different time I wouldn't still be alive, therefore I'm choosing not to pass on my bad genes, and while everyone hadls the right to have children, evolution can't improve us if we all do.

  27. As far as I know most animals evolved to have specific nutrients they need that they can only obtain through food though.
    Vitamin C is just something that you primarily get from plants, so carnivores have evolved to produce their own vitamin c.

  28. it's not the blind spot, it's about your cells getting exhausted from receiving the same light over and over. so basically this is because you don't move your eyes and not of the blind spot. the blind spot implies you would stop seeing something immediately. anyhow just a nitpic, fun video

  29. I think this body is more about you getting old than actual fails in the human body. Some of what you talked about here has to do with a horrible lifestyle, which will break your body down. Or if you are born to parents with bad lifestyles, you will unfortunately inherit some of their choices. The rest is evolutionary compromise: a joint might be weaker in an area, but it allows for more mobility. Evolution took the middle ground in these cases. Engineers know about this conundrum all to well.

  30. I have heard an achilles tendon snap close up.
    It’s sounds really really really painful, and the snap mixed with the poor guy’s screams almost made me throw up.

  31. you do not think there is no engineering behind it ? how we leave out thinks that we do not need and develop new ones ? How our body came into being from one dot ? if I say my computer was created by change you would not except by our body is a creation from nothing ? no engineering behind this ?

  32. I've been trying to figure out the biology of a humanoid alien race that was engineered from the ground up to solve all the shitty evolutionary weirdness of humans (for a story) and I've been looking for a good complied list like this

  33. One quote I saw while on the Galapagos Islands was along the lines of "Evolution doesn't care if you are the biggest, strongest, fastest or smartest one around. It just cares if you can survive in your current environment"

  34. Some of these bad body parts may actually be tied to environmental issues we now have. For example nearsightedness is being linked with the fact that we’re not getting as much direct sunlight as we used to. That’s also why you can get huge regional differences (some people avoid sunlight more than others). Likewise birth. In communities and cultures where natural birth and good health are promoted complication rates and the need for surgical intervention drastically reduces. One community in the US known for Ina May has dropped their rate of c-section to 2% in 3k births. Our medical birth practices, not women’s pelvis, are the culprit here. We recommend stationary births, messages of fear and uncertainty whether your body can do it, and laying somewhat on our backs. I had a homebirth and let me tell you, the most painful part of labor was anytime i was asked to be on my back. Some parts were actually pretty nice and with a bit of movement or breathig just fine. But birth in the traditional hospital way was in every fashion uncomfortable and or painful. I hated it.
    Overall, i enjoyed the video though.

Leave a Reply

Your email address will not be published. Required fields are marked *