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 thoughts on “Evolution FAILS in the Human Body”

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

  2. The problem is that thanks to modern medicine Natural Selection has been stopped. There are people alive and breeding that shouldn’t be. Eventually humans will be totally reliant on medicine from birth just to survive. Think about it!

  3. If we somehow manage to not kill ourselves, do you think that:

    Hundreds of thousands of years from now, evolution would make enough tweaks that a lot of these problems would fix themselves?

    Or because we found ways around all these problems and bypassed natural selection, none of these problems would be fix by evolution?

    Or maybe even a mix of both?

  4. Evolution doesn’t care about efficiency, it’s a matter if it benefits the life form or not. One of the biggest head scratching evolutionary moves is the male prostate. To put it simply the prostate is like an orange with a straw running through it. As males get older the prostate naturally starts swelling, and pinching on the straw. I think you get the picture. Thanks evolution!!!

  5. this is a great video to point to for those religious folks whose arguement is "how do you explain the human eye, it has to be intelligent design" etc… it's like nah, we might see a good few colours but its not that well designed.

  6. You do a wonderful job at explaining your case for our human failures but how about doing a follow up video about how your would re-engineer the human form so that it wouldn't have hardly any of these shortcomings? One example that comes to mind is backwards facing knees like the grasshopper. Or perhaps extra ribbing to protect our vulnerable heart, a thicker skull with more fluid to pad our delicate gray matter, and thicker epidermis to protect us from being bitten by ticks or stung by bees.

  7. 0:30 No wonder there is this specific time lord always come to Earth. She might have think that way as well. 😀
    The way Joe said it like, like he's not even human…

  8. Would you press the button?
    You have one of the best metabolisms and the best running stamina of any animal on earth.
    You're also doomed for knee, ankle and back pain.

  9. If we were to redesign the human body in order to fix thous flax how would it look? how would it look if our eyes didn´t have a blind spot? if we have a separate trout hole for eating and briding? what if we redesign our knees and ankles? how would it look if we had a spine design for walking in two feet? if a pelvis designed to allow a human head to pass through without a problem? would it make the part easier on females? if male's reproductive organs weren´t so exposed how would it look?

  10. Until 7-8 months old, we can drink and breath at the same time without any risk of choking, hence why Babies suck on the nipples for hours on end without pauses long enough to breath…

  11. I dont think evolution failed us, I think we just have stopped letting natural selection happen among our species, which is the force that drives evolution.

  12. Ugh! That shopping-cart-to-the-heel visual made me cringe.
    Kinda like when the screen door swings shut on your foot because you weren't fast enough getting into your house, except worse!

  13. Why is there a blind spot in my right eye but not my left? Is my brain just compensating because it knows the dot is there? Why would it not compensate with my right eye?

  14. So what would happen if we could make vitamin c? And our eyes were made the right way around? What if we had long nasal cavities instead? I would love to see what we would look and behave like.

  15. In the part about walking upright, you forgot our pelvis are too small for giving birth, specially considering our big heads when we are born.

  16. The Human body is kind of perfect… for people living in the savanna, running all day and hunting Animals. Long legs and arms, sweating, kind good eyes and very good ability to communicate.

  17. So, how's clickbait working for you? Oh, you're gonna love this one. I closed this trash video after I posted the first sentence. Then, suddenly I realized your channel just isn't all that good. So, I came back, wrote the remainder of the post and unsubscribed. So, clickbait on, dude.

  18. Not saying that your wrong, or right. But we simply do not know enough about who made it. It may be God or not, depending on what you believe, but we really can't say. even though there is proof for evolution, it doesn't mean it happened the way we think. All I'm saying is, you can simply just say that something is specifically one thing. I know, I am very confusing.

  19. I love your videos and share them with my grade schoolers.
    I just don't understand why you had to interject your religious beliefs and state them as fact. You believe there was no designer. Others, including scientists, believe evolution and a designer are not mutually exclusive.

  20. Why do you live past 30 or 40? 15 is enough to reproduce, 30 is enough for your kid to be fit enough to survive and reproduce? Essentially if you live till 90 you will for 50 or more years be using resources that by nature are more important to your child. So maybe even nature doesn't know what it wants.

  21. Being "weak" didnt mean death back in the day though. Humans lived in tribes and helped the weak just like today! The near sighted gpt other tasks, people that hurt themselves could do other things than hunting

  22. It's almost as if the sky wizard is a very very bad engineer……….. 🤔😑
    LoL, did you went and killed your editor, for making those comments? Or worse? 🤣🤣

  23. Lmao. Okay boomer. I love your videos man. I've been watching for years now. Please take this as a complement. Your like a proto-vsauce!

  24. There is a problem with your analysis of the human eye. The “backwards” light receptors are actually incredibly effective in that orientation! They work in a similar way to humanly engineered optical fibers and direct the correct frequencies of light to their respective receptors in the eye. It is actually quite remarkable! 🙂 I just learned that in my college classes last week so I thought I’d share 🙂

  25. You only think your body is crap because you haven't proven a better model for said body parts. Try to, I'm willing to bet it would be near impossible
    One stipulation you would still need to be able to do same task with said body part

  26. If man is man in God's image does that mean God bit the inside of his cheek so that it swelled up and He kept biting it again?

    This is rhetorical, I don't want answers saying that's a metaphor or man's soul is the image of God's not his body, because God doesn't exist. Evidence, not anecdote. Certainly not stories for scared children.

  27. Isn't the breathing hole sharing the same hole with our food hole gave it the advantage that we wouldn't instantly choke if our nose got blocked? I'm sure as hell greatful for this feature when my nose got blocked due to the cold and allergies.

  28. I had torn that ACL at age 33 and it happened in a movement of turning in a half-circle. I literally switched directions to head back to a room and swiveled on my feet, then I heard a pop and felt a pop in the knee and fell. I couldn't stand even to get to phone or to a car. I had to crawl to call for help then crawled to the car. Docs said that there was a small tear and when I switched directions, the bones caught that and tore it more. And Yes I had surgery and within 5-7 years I started to have osteoarthritis in that knee. Ten years after it, I was using a cane. by 15 years after the event, I'm using a walker.

    I've felt a lot of different types of pain, from having the air knocked out the lungs to having top layer of skin on toe being scraped off in bike spokes (don't ride as passenger on the back!), to falling and hitting back of head on metal corner of bed frame, to passing kidney stones, to having internal bruising of the chest from a car wreck with pain so bad ER gave morphine. The ACL tear ranked up there with that car wreck

  29. 3:30 couldnt evolution technically flip a whole eye around, if by some miracle, the mutations that would eventually lead to that somehow not kill the organism?

  30. well its probably for the better imagine your country having to fight an army that has to eant only bread to survive and be healthy

  31. We used to make our own vitamin C and all amino acids until Eve ate from that tree…Ha Ha just kidding fellow mostly hairless apes.

  32. Natural selection would have fixed all of this by centuries.. but our brains found a way to keep us alive no matter what. This is why we are growing more and more weak

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