Reptiles' Breathing Hack Helped Birds Dominate the Air

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When we breathe out, we empty our lungs. But an ancient reptile figured out a more efficient way to breathe, which ultimately helped birds dominate the skies.
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  1. SciShow


    8 өдрийн өмнө

    Go to to try their Physics of the Everyday course. The first 200 subscribers get 20% off an annual Premium subscription.

    • Kevin Tewey

      Kevin Tewey

      6 өдрийн өмнө

      I have COPD I need this

    • Elizabeth Henning

      Elizabeth Henning

      7 өдрийн өмнө

      @SoulsBorne Geralt I think the limiting factor is hypoxia and not lift, although birds that fly high have bigger wings relative to their body size. Cranes can fly over the Himalayas.

    • Croak Mcgloak

      Croak Mcgloak

      7 өдрийн өмнө

      fast fact sounds weirder than fun fact

    • SoulsBorne Geralt

      SoulsBorne Geralt

      7 өдрийн өмнө

      How high can birds take off? as in at what altitude does birds stop being able to take off and fly?

    • Joe DaSnifferBiden⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻

      Joe DaSnifferBiden⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻

      8 өдрийн өмнө

      @Trav2016 i had to look up the story Hank green never even heard of him but what he tried to do is cray cray! someone needs to sniff him.

  2. Sara B

    Sara B

    13 цагийн өмнө

    It also means parrots can scream non stop when they are scared or upset source: My birds

  3. DavidFMayerPhD


    2 өдрийн өмнө

    You ignored the BIGGEST advantage of unidirectional respiration: counter-flow, air and blood move OPPOSITE DIRECTIONS. Counter-flow is far more efficient than any other method. It works for heat exchangers as well as vapor exchangers (lungs). Gasses are moved by diffusion from zones of high concentration to zones of low concentration. The counter-current arrangement sees to it that the maximum concentration gradient is always available.

  4. Bigfoot


    2 өдрийн өмнө

    What I want to is if this mode of breathing might be part of why the Dinosaurs were able to grow to such gigantic proportions.

  5. wim0104


    2 өдрийн өмнө

    cooler lungs? more airways & airbags? enjoy your long list of airway diseases!

  6. thetommantom


    2 өдрийн өмнө

    Also wearing ear plugs you can hear your heart beat and pulse your lungs at the same time or offset then every thing in slow mo kind of like fogging up a motor cycle helmet or controlled breathing while wearing a face mask

  7. thetommantom


    2 өдрийн өмнө

    I saw this in the desert at 120F. If you breathe slowly you can feel your lungs slowly twitch its like 10 breathes every full inhale and exhale. Kind of feels like a heart attack not gonna lie but if you feel your throat you can feel your pulse

  8. James Runyon

    James Runyon

    2 өдрийн өмнө

    Birds are probably excellent didgeridoo players

  9. RaeDaBirb


    3 өдрийн өмнө


  10. Austin Stevens

    Austin Stevens

    3 өдрийн өмнө

    I know the evolution tree in this video is a simplified diagram but im pretty sure the turtles and lizards are swapped from where they are suposed to be. Then again ive been wrong before, either way awsome video. Always learnig somthing new here!

  11. Doom Muffinz

    Doom Muffinz

    3 өдрийн өмнө

    That diagram with the green airways was really poorly done :/

  12. bmoturtleco


    4 өдрийн өмнө

    Did no one else notice that at 1:55 its says turtles but shows a tortoise?

  13. Zanko


    4 өдрийн өмнө

    So they basically have a air-capacitor built in their bodies

  14. Jarvis Sdot

    Jarvis Sdot

    4 өдрийн өмнө

    it probably has something to do with the way they consume food thats why they breathe that way.

  15. Aleksandra Królak

    Aleksandra Królak

    5 өдрийн өмнө

    2:03 - Your favourite reptile? - A Parrot. - O_o...

  16. Tfin


    5 өдрийн өмнө

    But... we don't lack oxygen while exhaling. We use only some of the oxygen in each breath, and some air remains in our lungs even when we try to exhale everything, so our lungs can continue to move oxygen into our blood all the time, unless we breathe out and don't breathe in for some time.

  17. illesizs


    5 өдрийн өмнө

    Next step in evolution: air just passes through a tube, and comes out at the other end. The faster the animal moves, the better performance it can achieve. Next step after that: the air mixes with a flammable liquid inside the lungs, expands, and comes out at a much higher velocity. Resulting in much greater flight speeds. Final step: instead of air, the creature will ingest oxygen rich substances which can mix with the fuel directly, thus eliminating the need for air or an atmosphere, and allowing interplanetary flight.

  18. Monkey Monk

    Monkey Monk

    5 өдрийн өмнө

    Birds have unidirectional breathing but not unidirectional hearts. Bird hearts aren't 4 chambered, so deoxygenated blood gets mixed with oxygenated blood from the lungs in the heart, they lucked out on that. Mammals lucked out on unidirectional lungs but a 4 chambered heart means oxygenated blood going to the body doesn't mix with the deoxygenated blood going into the lungs. Well that's my understanding of the comparison. Excuse my attempt at sounding intellegent. It would be sweet to modify ourselves to have bird breathing, and singing.

  19. Bazooka Llama Productions

    Bazooka Llama Productions

    5 өдрийн өмнө

    make sure to vote in the election. we need more smart people to vote

  20. Dracodracarys 233

    Dracodracarys 233

    5 өдрийн өмнө

    so birds can use Hamon

  21. Rotor Blade

    Rotor Blade

    5 өдрийн өмнө

    But when it breathes in they don’t get fresh air because it fills the sacks ?! So what’s the point? Turns out part of the breathing in air goes through the lungs and then when it exhales the rest goes through the lungs again so the lungs have fresh air almost all the time. Also chest muscles that they use to flap the winds help them breathe every flap of the wings

  22. cory zillmann

    cory zillmann

    5 өдрийн өмнө

    i just saw a clip of Hank Green spouting political propaganda you were the reason i had been watching SciShow for years as you were witty and humorous and smart now not bye

  23. silica dogo

    silica dogo

    5 өдрийн өмнө

    Hank why cant I eat grass

  24. Jenny Cooper

    Jenny Cooper

    5 өдрийн өмнө

    Of course, it's only logical.

  25. Emma Hodges

    Emma Hodges

    5 өдрийн өмнө how come birds don't blow up like balloons? did I miss the part where he said where the air goes??

  26. Patrick Loney

    Patrick Loney

    5 өдрийн өмнө

    Another reason to like pelicans

  27. Ashmeed Mohammed

    Ashmeed Mohammed

    6 өдрийн өмнө

    and amphibians?

  28. Kelleen Louchart

    Kelleen Louchart

    6 өдрийн өмнө

    "Wow! That was inefficient." 😂😂

  29. Zeta Belotto

    Zeta Belotto

    6 өдрийн өмнө

    I remember something about the torax being more flexible in the mamalian family than in the rest of the tetrapods. Does it have something to do with the airsacs?

  30. Camille Cirrus

    Camille Cirrus

    6 өдрийн өмнө

    Scientists, get on it, i want my birb lungs already.

  31. Misanthropic Humanist

    Misanthropic Humanist

    6 өдрийн өмнө

    I wonder what the intermediate forms looked like? Assuming the system didn't develop in one breath, as it were.🤔

  32. sagacious03


    6 өдрийн өмнө

    Neat explanation! Thanks for uploading!

  33. Diane Wallace

    Diane Wallace

    6 өдрийн өмнө

    This will help them when the atmosphere becomes oxygen poor again.

  34. phoenixsong38


    6 өдрийн өмнө

    I guess correlation doesnt mean causation with this unidirectional air flow.

  35. Unmutual


    6 өдрийн өмнө

    Evolution is a hack now?

  36. Viktor Radermacher

    Viktor Radermacher

    6 өдрийн өмнө

    I think one VERY important thing this video leaves out is that those air sacs in birds are not present in other lineages with unidirectional breathing. They were only present in theropods, sauropods, and pterosaurs. Squamates and crocs DO NOT have air sacs but still breathe unidirectionally. I've recently submitted a paper that explores this topic so keep your eyes peeled :)

  37. SunnyD


    6 өдрийн өмнө

    Can we bio engineer that into ourselves sone day then bevause i personally could benefit greatly from having more oxygen

  38. Anthony Batres

    Anthony Batres

    6 өдрийн өмнө


  39. Sophie W

    Sophie W

    6 өдрийн өмнө

    Isn't this kind of how Scottish bagpipes work?

  40. TheOtherNeutrino


    6 өдрийн өмнө

    The birds have mastered the art of Hamon.

  41. Samita Shrestha

    Samita Shrestha

    6 өдрийн өмнө

    no one: me: * breaths * hank green: “lmao loser”

  42. BoB 13

    BoB 13

    6 өдрийн өмнө

    Bird breathing...1st form...

  43. Adriel Lightvale

    Adriel Lightvale

    6 өдрийн өмнө

    Listen to me. Bird Hamon Users.

  44. Say Hoe Lee

    Say Hoe Lee

    6 өдрийн өмнө

    Can we mod human to do that?

  45. freshbingo


    6 өдрийн өмнө


  46. lilepopinyou


    6 өдрийн өмнө

    One way breathing sounds like that first hit of molly lol

  47. Eph Imp

    Eph Imp

    6 өдрийн өмнө

    When will genetic engineering be advanced enough so I can upgrade my lungs with superior unidirectional breathing mechanism?

  48. ninpo14


    6 өдрийн өмнө

    So birds are considered feathered reptiles?

  49. Patrick Staight

    Patrick Staight

    6 өдрийн өмнө

    that diagram wasn't very helpful

  50. Bhuv-


    6 өдрийн өмнө

    How did watching Biden on multiple devices go??

  51. TheSkystrider


    6 өдрийн өмнө

    Wow so wouldn't it be pretty easy to add artificial air bags to our athlete's bodies?

  52. Mazequax


    6 өдрийн өмнө

    *heavy inefficient breathing*

  53. Greg Gallacci

    Greg Gallacci

    6 өдрийн өмнө

    Birds and crocadilians have a physiological tie-in: they are both ready for instant action even after long periods of rest. Crocs can move explosively; look at the lunging and leaps they can do. Birds are similar 'fast off the line' performers. Maybe super-charged lungs are part of that: no dead-air in the lungs to overcome.

  54. Tony


    6 өдрийн өмнө

    If birds could talk they could smash the record for the longest "yeah boii" ever

  55. Belligerent Instigator

    Belligerent Instigator

    7 өдрийн өмнө

    JOE BIDEN IS CORRUPT! Hunter Biden Corruption pay for access scandal is being covered up by most of the news channels. The US is for sale if Biden wins!

  56. Pi Squared

    Pi Squared

    7 өдрийн өмнө

    Mammals are more primitive than reptiles and birds in some other ways too. Mammalian kidneys are less efficient in that their kidneys produce up a lot more waste water (ever seen a bird or reptile taking a piss?). Mammalian skin is also more permeable than a reptile's or birds, and looses water more rapidly than birds or reptiles. In these respects, mammals appear to be intermediate between amphibians and reptiles. As mentioned, mammalian lungs are based on breathing in and out which appears at first to be a primitive feature. Other features of mammals is that are unlike fish, amphibians, birds and reptiles, is that mammals have flattened red blood cells with no nucleus - fish, amphibian, bird and reptile red blood cells have cell nucleii. Mammals have blood platelets (which cause clotting of blood to stop bleeding) which also do not have cell nucleii, while birds and reptiles have cells called thrombocytes which have the same function but also have cell nucleii. Mammals appear to have evolved warm bloodedness at an earlier stage than reptiles and dinosaurs (which preceeded birds). Early mammals/proto mammals had heavy bones, eyes and nostrils close to the top of their heads (like modern Hippos), and were surprisingly squat compared to dinosaurs (which is surprising for an active warm blooded animal). Mammals all have a mechanism called the mammalian diving reflex, All of these things seem to point to mammals having first evolved as aquatic/semi-aquatic animals: - sweating as a way of thermo-regulation, permeable skin, kidneys which are inefficient in conserving water are not a disadvantage for an aquatic animal or one that lives in or near water. - Warm bloodedness is important for an active aquatic animal swinning in cold water, as is the mammalian diving reflex. - Simple breathe in/out lungs may not be as efficient for a given lung volume as the one way breathing system of birds and reptiles, but they do have one big advantage over birds and reptiles in that they allow you to take a large breath of air and hold it while diving. The mammalian red blood cells with no nucleus also allows mammalian blood to hold a lot more red blood cells and therefore oxygen in their blood per unit volume of blood than birds or reptiles during diving, and therefore would have allowed mammals to hold their breath better. - Mammals like birds have a high pressure blood circulatory system because they are very active animals, which makes blood clotting very important on suffering cuts. However mammals may have required more rapid and effective clotting if cuts took place in water because of blood being washed out of the cut and the risk of bacterial infection in water. Platelets without nucleii allow more platelets to be contained in mammalian blood than bird or reptilian blood. - The heavy bones, eyes and nostrils close to the top of their heads, and squat stance of early mammals/proto mammals (as compared with dinosaurs) is indicative of mammals evolving from wading animals which walk on the bottom of rivers like hippos do today. The mammalian diving reflex also supports a wading/diving lifestyle. The decline of proto-mammals/mammals and the rise of the dinosaurs a little while after the Permian extinctions when the climate on Earth became very dry and very hot is probably the reason why dinosaurs replaced mammals as the dominant land animal. Mammals being inefficient in conserving water, and adapted to living in or close to water couldn't compete with reptiles or dinosaurs in a hot dry climate away from small niches. When the dinosaurs became extinct and the climate became cooler and wetter after the Cretaceous-Paleogene extinction event, mammals regained their dominance over reptiles and the decedents of the dinosaurs - birds.

  57. rillloudmother


    7 өдрийн өмнө

    imagine if john coltrane and miles davis breathed this way...

  58. Cookey Monster

    Cookey Monster

    7 өдрийн өмнө

    Humans: Damn I wish I could breathe like a bird Birds: Damn I wish I could dominate every aspect of the planet like humans

  59. Ian Kurz

    Ian Kurz

    7 өдрийн өмнө

    So... where does the air go? Do they have holes just for exhalation?

  60. Muhammed I. Jhaban

    Muhammed I. Jhaban

    7 өдрийн өмнө

    I want this installed on my system please :D

  61. huldu


    7 өдрийн өмнө

    FeelsBad being that turtle group that got left out lol.

  62. Marcelo Pinheiro

    Marcelo Pinheiro

    7 өдрийн өмнө

    We are 2 strokes engine and birds are 4 stroke engines...

  63. HenryManson


    7 өдрийн өмнө

    i think the question : "Why aren't there large, actively breezing Insects out there ???" is waaay more interesting!

  64. David Bergmann

    David Bergmann

    7 өдрийн өмнө

    What about bats? Bats are mammals 🍄

  65. Dr Gutowski

    Dr Gutowski

    7 өдрийн өмнө

    Follow up question; can your farts kill a pet parrot? I always worry about this when snuggling with mine under the covers, but need to pass gas

  66. Dr Gutowski

    Dr Gutowski

    7 өдрийн өмнө

    Yet another trait that would be GREAT to insert into the human genome with Germline Genetic Engineering...

  67. T1Oracle


    7 өдрийн өмнө

    I still have no idea how birds breathe. Where is the simply animation that even a 3 year old can follow?

  68. Cailyn90


    7 өдрийн өмнө

    0:42 speaking about cool dinosaur hacks: what's the thing inside the upper part of it's beak right there? o.o

  69. 666Tomato666


    7 өдрийн өмнө

    Permian Extinction: The largest mass extinction in Earth's history Antropocene: hold my plastic

    • Monkey Monk

      Monkey Monk

      5 өдрийн өмнө


  70. kimobugman


    7 өдрийн өмнө

    Is this why they used to take a canary in the coal mines? Their super efficient breathing makes them vulnerable to toxic gases.

  71. Lucas Duberger-Deret

    Lucas Duberger-Deret

    7 өдрийн өмнө

    Why aren't all human muscles like the heart muscle? The heart muscle is both strong, powerful and endurant. What would be the cost to the other muscles being like that? Is there an evolutionary reason? What would happen if a human being was born with all their muscles like the heart muscle?

  72. Steven Stinnett

    Steven Stinnett

    7 өдрийн өмнө

    Spirits control the world. They can control peoples emotions and thoughts. They “possess” people to use and abuse. I am being harassed by one 24/7. Pretty easy to contact speak out loud and don’t be scared. A lot.

  73. Glenn Tiosen

    Glenn Tiosen

    7 өдрийн өмнө

    Am I the only who's while watching this is very conscious in breathing?

  74. stephiskhan


    7 өдрийн өмнө

    Ngl- that bird at the beginning of the video made me cower with its alpha energy. Also the row of teeth on the roof of its mouth.

  75. 92laird


    7 өдрийн өмнө

    That's how dinosaurs were so good at hunting

  76. Gilles Marchal

    Gilles Marchal

    7 өдрийн өмнө

    Earth: If the great dying was so great why isn't there a great dying two ? Humanity: I got you fam !

  77. denmaroca 2

    denmaroca 2

    7 өдрийн өмнө

    And yet, mammals dominate the land and have taken significant roles in the air and the sea. Now this might be despite their supposedly inefficient lungs, but maybe their lungs are perfectly suited for the lifestyles they lead? There's more to efficiency in the sense of evolutionary fitness than this simple analysis might suggest.

  78. Arthur Spilmann

    Arthur Spilmann

    7 өдрийн өмнө

    Kenny G can breath like this!

  79. Jase Poag

    Jase Poag

    7 өдрийн өмнө

    So birds are basically a 2-stroke engine, while we're 4-stroke?

  80. mike32131


    7 өдрийн өмнө

    So like a lung capacitor?

  81. Jess Renee

    Jess Renee

    7 өдрийн өмнө

    But....birds ARE reptiles....

  82. benedict


    7 өдрийн өмнө

    All those highschool lessons on anatomy, and they DIDNT mention this!?

  83. Randy Raccoon

    Randy Raccoon

    7 өдрийн өмнө

    Down vote just because it is Hank. And Hank should not support corruption in his personal media.

  84. Lam Soon Goh

    Lam Soon Goh

    7 өдрийн өмнө

    IMO.. you are better than the other host in the channel

  85. Jonathan Green

    Jonathan Green

    7 өдрийн өмнө

    This makes sense because when I do pushups, I feel more oxygenated and my muscles don't get tired as quickly when I inhale slowly and exhale quickly. It feels like when I spend more time inhaling and less time exhaling, my muscles are constantly supplied with fresh oxygen so the "burn" doesn't hit me as hard.

  86. Eli Nope

    Eli Nope

    7 өдрийн өмнө

    How does "The Great Dying" compare to the current human made extinction event going on now? Was it faster with more species going extinct in a shorter amount of time or what?

    • Kelly Clowers

      Kelly Clowers

      6 өдрийн өмнө

    • Kelly Clowers

      Kelly Clowers

      6 өдрийн өмнө

      Our current situation is a piddly little thing compared to the Permian extinction

  87. CiderDivider


    7 өдрийн өмнө

    With unidirectional breathing, is it ever needed for them to “catch their breath”? Like over exertion leading to taking a pause with some deep breathing before continuing. I’ve definitely seen mammals tire and have to sit and breathe, but I’ve never seen a tired bird...

  88. FunkYeah


    7 өдрийн өмнө

    That animal chart seems off... Aren't turtles anapsids, and thus, outside of all the other reptiles (including birds)? Also, it would explain why turtles don't have that breathing arrangement, because such physiology was evolved _after_ anapsids and diapsids (and synapsids) had split.

    • FunkYeah


      6 өдрийн өмнө

      @Kelly Clowers I've read into that, but it's still not convincing enough. Turtles are ancient animals, even existing before sharks.

    • Kelly Clowers

      Kelly Clowers

      6 өдрийн өмнө

      No one knows what turtles are, but it currently looks like they are diapsids of some sort

  89. Djorz


    7 өдрийн өмнө

    Breath of the Bird: 7th form: Unilateral Airflow

  90. Iam Dredlamb

    Iam Dredlamb

    7 өдрийн өмнө

    that is how alligator hold their breath underwater longer than larger mammals, because while breathing they kept and auxiliar sack of fresh air for a secondary supply. I think it is Darwinian evolutionary adaptation for flying and diving, that explain efficiency in fishing birds. De facto nature is lazy, if you do not need it you will lose it. Do worms and other underground insects have similar lung system? just asking

  91. Jason Remy

    Jason Remy

    7 өдрийн өмнө

    ... Starts singing "Machinehead" by Bush...

  92. Marco Pohl

    Marco Pohl

    7 өдрийн өмнө

    why are the turtles placed between archosaurs and lepidosaurs in 1:53? I thought their placement was unknown but generally agreed to be outside of true reptiles.

  93. Patrick Degenaar

    Patrick Degenaar

    7 өдрийн өмнө

    So what is the negative of this breathing form? If it could make humans super athletic, why dont we have it?

  94. Jonatan Romanowski

    Jonatan Romanowski

    7 өдрийн өмнө

    Go go Sci Show

  95. Daniel Solis

    Daniel Solis

    7 өдрийн өмнө

    Wouldn't this result in a lot more long term side effects of oxygenation?

  96. Marcos Victor

    Marcos Victor

    7 өдрийн өмнө

    But then, we would probably age twice as quickly for having so much oxygen causing our cells to rust.

  97. Micha El

    Micha El

    7 өдрийн өмнө

    Question: Can unidirectional breathing have disadvantages in some cases, too? In former times miners often used birds to check for "bad air". If I'm right they didn't use mice (which faster metabolism should also cause early symptoms of suffocating) or other mammals. Could there be a connection?

    • Massimo O'Kissed

      Massimo O'Kissed

      7 өдрийн өмнө

      Maybe it's just easier to do a quick visual check of a bird. Mouse curled up in its nest: is it sleeping or dead ? Bird fell off its perch: probably time to evacuate the mine.

  98. CaptainHugs


    7 өдрийн өмнө

    What I learned from this video is to be grateful that alligators don't fly

  99. Jeroen Jager

    Jeroen Jager

    7 өдрийн өмнө

    Great, now I'm aware of my breathing again.

  100. longnamenocansayy


    7 өдрийн өмнө

    it's also possible they were just created that way. no evolution necessary.

    • Massimo O'Kissed

      Massimo O'Kissed

      7 өдрийн өмнө

      No, that's not possible.