Beyond Identical or Fraternal: 6 Rare Types of Twins

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Twins can be a lot more complicated than just identical or fraternal, and the rarer types of twins suggest that we have a lot more to learn about human development.
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  1. sayit likeitis
    sayit likeitis
    7 orë më parë

    Not only that I've heard there's like 125 genders too. Man how confusing

  2. Astrid von der Moon
    Astrid von der Moon
    2 ditë më parë

    The lady on the right of the thumbnail looks like Abby from Broad City

  3. Soirtemeht
    2 ditë më parë

    Did guy just say an egg that was fertilized by two diffrent sperm. Sounds like someone's a good egg, pun intended.

  4. Derek Stinson
    Derek Stinson
    2 ditë më parë

    I’m a person can I release eggs, Focker?

  5. Zachary Christensen
    Zachary Christensen
    3 ditë më parë

    We're pretty sure that my sister is a chimeric twin

  6. Tawroset
    3 ditë më parë

    Mind blown.

  7. Pink Lion Gaming
    Pink Lion Gaming
    3 ditë më parë

    "Less than 200 reported cases have ever been reported" Thank you didn't expect that

  8. DarkChylde
    4 ditë më parë

    Guess we need that artificial womb (baby in a bag) from Grey's Anatomy

  9. infinitebombdog
    5 ditë më parë

    2:54 soo we have the technology to look 13 billion lightyears away, BUT we cant look inside moms at all stages of development to better understand how we come to exist..??

  10. Regan W.
    Regan W.
    5 ditë më parë

    I thought I'm dumb for thinking that sesquizygotic twinning is possible (I never heard of that term before) but it turns out my assumption is right!

  11. Ailfe Giggles
    Ailfe Giggles
    6 ditë më parë

    I knew someone who was there own twin. She had 2 DNA. And 4 kidneys. 2 of them were smaller and worked.

  12. Maddie Joy
    Maddie Joy
    6 ditë më parë

    Imagine having legs sticking out of your chest for your entire life and then you find out those legs aren't technically a part of your body. Like, just when you thought it couldn't get any stranger, it does.

  13. kimm hughes
    kimm hughes
    8 ditë më parë

    I am an identical twin.

  14. Allysha Hooper
    Allysha Hooper
    8 ditë më parë

    Also there are twins when a woman still produces another egg while already pregnant!

  15. Allysha Hooper
    Allysha Hooper
    8 ditë më parë

    Now imagine finding out you have a twin in your 20s when you grew up as an only child lol

  16. Athena Hill
    Athena Hill
    10 ditë më parë

    My grandma was a identical twin, my dad is a fraternal twin.. lmao I’m so screwed if I have kids because I think I have the gene to have them 🥴🥴🥴

  17. spoopytime
    10 ditë më parë

    1:13 I once saw a pair of identical twins and asked their mom how she tells them apart, turns out the kids had a spot on each of their faces but on the opposite side from each other, and it was an exact mirror image.

  18. r0kus
    10 ditë më parë

    I learned stuff -- thanks! Isn't there a type of twin where they have the same mother but two separate fathers? It would be like a fraternal situation, but the woman had relations with two guys at about the same time, and both resulted in pregnancy. Perhaps these would be "bifraternal twins".

  19. Francisco Cubero
    Francisco Cubero
    10 ditë më parë

    Why didn’t the talk about the mother who’s children did not have her dna. She was a chimera. Had two sets of dna. Probably absorbed her twin completely. Lydia Fairchild You should ALfirst her.

  20. EyeLean5280
    11 ditë më parë

    A WORD TO THE WISE: an image search for fetus in fetu is not for the faint of heart.

  21. S R
    S R
    11 ditë më parë

    Thank you for the inclusive language! I just wrote an opinion piece in my uni newspaper about its importance!

  22. Joshua Orion
    Joshua Orion
    12 ditë më parë

    a friend of mine as a teenager had a half-twin my friend was the typical pale, freckled, red headed ginger and her twin was mixed, with a white mother and black father, and had the super tight afro curls and dark skin they both looked so ridiculously different that it actually took their mother explaining that they really were twins for people to believe them

  23. HaythamFPV
    12 ditë më parë

    10:45 I mean... something much more likely has happened there hahahah

  24. Elizabeth Ward
    Elizabeth Ward
    13 ditë më parë

    heyyy i'm a chimera

  25. Eterna Phoenix
    Eterna Phoenix
    14 ditë më parë

    Halfway through this video, my face completely morphed into that meme of that guy with the accent saying a pound of steel is heavier than a pound of feathers.

  26. The Inkling
    The Inkling
    14 ditë më parë

    This further confirming my theory that the Olsen twins are absolutely homozygous twins. All the "explainations" about them being fraternal are inconclusive

  27. Borach McTeague
    Borach McTeague
    14 ditë më parë

    Nobody knows the true meaning of terror until the second head pops up on the sonogram.

  28. Cooper Myers
    Cooper Myers
    14 ditë më parë

    Man that fathered a child with his twins dna. Either something interesting scientifically or his wife cheated on his twin.

  29. Felix Goroncy
    Felix Goroncy
    15 ditë më parë

    What about twins from two individual eggs and fertalized by different partners? Are they just fraternal twins or not called twins at all?

  30. Broke Ann Broken
    Broke Ann Broken
    16 ditë më parë

    The 1st time I read about women having 2 different DNA's. I thought to myself nothing is absolute!

  31. JustKeith
    16 ditë më parë

    Couldn't twins have two different fathers? If she dropped two eggs...

  32. Muggles Cake Sniffer
    Muggles Cake Sniffer
    17 ditë më parë

    Person? Wouldn't a genetic female release two ova?

  33. Neko Tamo
    Neko Tamo
    17 ditë më parë

    Am I the only one annoyed by this "pregnant people" thing? It's women, virtually all people who end up pregnant are women. I have nothing against trans men but this is really silly. They are such a tiny minority of people, last I checked half a percent or less. And I am sure a big majority of trans men don't want to give birth for obvious reasons. And of those who do will they really get terribly offended if you just say women? They are genetic women after all and it is what lets them give birth. So it is not really to right some terrible wrong it is just PC virtue signaling for its own sake. The confusion created by speaking like this far outweighs the tiny social good, especially on a science show.

  34. Abbey Cat
    Abbey Cat
    18 ditë më parë

    Cheeky comment - the narrator says ‘when a person becomes pregnant.’ No matter how gender natural we may want to be, the female becomes pregnant. Or did something happen during COVID?!

  35. Conrad Smith
    Conrad Smith
    18 ditë më parë

    Well some of these I have heard of, I even have a friend that said that they absorbed their own twin. Now I get it.

  36. Sarah
    18 ditë më parë

    Hi I'm an identical twin

  37. Noah
    19 ditë më parë

    damn. Double homicide

  38. Deborah Duthie
    Deborah Duthie
    20 ditë më parë

    My sister-in-law twins were monozygomatic but are nothing alike. Every said thy must have been fraternal twins but no, thee were not. Of course Embrios split unevenly, evenly, early and late. A feotus in featu was excised from a family friend, when she had her first born. It had long hair, nails and a tooth too. They found it at ultra sound scans, where it was diagnosed as her own twin. She did have a modest funeral.

  39. Saurav Kumar
    Saurav Kumar
    20 ditë më parë

    ⓘⓝⓓⓘⓐⓝⓢ ⓑⓔⓛⓘⓔⓥⓔ ⓒⓞⓝⓢⓤⓜⓘⓝⓖ ⓐ ⓒⓞⓝⓙⓞⓘⓝⓔⓓ ⓕⓡⓤⓘⓣ ⓜⓐⓨ ⓛⓔⓐⓓ ⓨⓞⓤ ⓣⓞ ⓞⓒⓒⓤⓡⓡⓔⓝⓒⓔ ⓞⓕ ⓣⓦⓘⓝⓢ ⓢⓞ ⓘⓝⓓⓘⓐⓝ ⓜⓤⓜⓢ ⓐⓥⓞⓘⓓ ⓣⓗⓔⓘⓡ ⓒⓗⓘⓛⓓⓡⓔⓝ ⓔⓐⓣⓘⓝⓖ ⓒⓞⓝⓙⓞⓘⓝⓔⓓ ⓕⓡⓤⓘⓣⓢ

  40. Lacey Lynn
    Lacey Lynn
    21 ditë më parë

    Love that you chose the language "a person becomes pregnant" rather than gender-specific!

    1. hxhdfj ifzir st c
      hxhdfj ifzir st c
      7 ditë më parë

      Men can't get pregnant, though. Science.

  41. MysticDragonWolf
    21 ditë më parë

    Either I’m up way too early but I thought this person was yelling at me I had to put down the volume

  42. a 8205
    a 8205
    21 ditë më parë

    I have a friend that have a twin sister. The odd thing is that he is black and she is white.

  43. S Waldron
    S Waldron
    21 ditë më parë

    Me and my twin brother are the most too different each other, I’m taller, dark hair, fair skin, wearing glasses, etc, his hair is blonde, tan skins, never wearing glasses, etc, even every my mates told me we looks are big different I wonder it to do fraternity whatever or different fathers?!?

  44. A Stick
    A Stick
    22 ditë më parë

    I have an identical twin though I might be a mirror twin because i am left handed while my brother is right handed.

  45. Samuel Hoult
    Samuel Hoult
    23 ditë më parë

    I "absorbed" my twin due to being an IVF child. Does that make me have a vanishing twin?

  46. DizzyUG 2113
    DizzyUG 2113
    23 ditë më parë

    Okay, but the Olsen twins gotta be Sesquizygotic twin if they aren't identical.

  47. Sarah Fortin
    Sarah Fortin
    24 ditë më parë

    What about siblings that look exactly like each other but have the mirror image thing? My younger sister and I look more like twins than my actual twin and we have similar birthmarks but on the opposite side of our faces.

  48. pdonettes
    24 ditë më parë

    What about twins from 2 different fathers? Or is that just fraternal twins?

  49. Zuko Fire lord
    Zuko Fire lord
    24 ditë më parë

    im fraternal lol

  50. Patrick Campbell
    Patrick Campbell
    24 ditë më parë

    My identical twins both have a fraternal twin.

  51. brennenderopa
    24 ditë më parë

    And THEN there is the movie with Arnold Schwarzenegger.

  52. Gerrad foster
    Gerrad foster
    24 ditë më parë

    Twins born years apart. Two eggs with identical genetic makeup, released at vastly different times, are fertilized by two sperm cells with identical genetic makeup, where one sperm fertilizes the first egg and one fertilizes the other egg.

  53. Sterling Perkes
    Sterling Perkes
    25 ditë më parë

    The way you snip out the natural spaces between one sentence and the next is really, really irritating. We need that little pause to absorb the first sentence before we start decoding the next.

  54. David Sims
    David Sims
    26 ditë më parë

    persons get pregnant, huh? Hank went overboard on PC gender-neutrality here.

  55. Terry Wade
    Terry Wade
    26 ditë më parë

    I’ve seen some really interesting twin stories. One, was a man in rural China who was born with an undeveloped twin growing on his body. He had part of a head on the side of his face. It was several decades ago on National Geographic. The “head” on his face had hair on its scalp, a mouth with teeth and it could smile when he smiled and could open & close its mouth! No, eyes or nose. He was finally examined by doctors when he was middle aged and X-ray showed he had another partial skeleton inside his body! The second story I saw was recently in ALfirst of a chimera twin woman who had a color differentiation down the middle of her midriff. One side was her body color and the other side was slightly darker. She had many autoimmune issues growing up and the doctors discovered that she had two different DNAs, two different blood types and veins! The next story was also on ALfirst about quadruplets. The mother submitted their DNA separately to to see how accurate their testing was. She had three boys and one girl. It turns out they were two sets of twins! One identical & one fraternal! That means she had to of had 3 eggs fertilized at the same time! The last story, I recall, was a woman who had twins a month apart! The reason why was, she had two uteruses with pregnancies occurring in both at different times!

  56. awesomage1
    26 ditë më parë the chimeric twin phenomenon why I'm the spitting image of my dad’s twin sister?

  57. sirvemon
    27 ditë më parë

    10:42 yep, the only possible explanaition

  58. Lars-Erik Strid
    Lars-Erik Strid
    27 ditë më parë

    Could temperature be a thing in the fusioning? Nuclear fission-fusion-fission theory or thermonuclear. We call the twins Teller and Ulam.

  59. Nacereddine Challal
    Nacereddine Challal
    27 ditë më parë

    I love how you use the term "person" instead of "woman" xhen speaking about pregnancy . Since some transman can and decide to get pregnant. Very considering and supportive .

  60. Heart of Dawnlight
    Heart of Dawnlight
    27 ditë më parë

    Curious as to the odds that would be at play for sesquizigotic twins to actually just be fraternal twins with absurdly close DNA Also if it's possible for a mutation or other cause for a parent to create multiple eggs or sperm that are identic DNA wise 🤔

  61. Prem Kumar
    Prem Kumar
    27 ditë më parë

    mirror image identical twins definition is so vague that any 2 person can be mirror image identical twins 😆😂😂 1 is rightie other "might" be leftie 1 has organ in right places other "might" has organ in opposite places other might be born to different parents other twin might be all different species other twin might come from other planet or universe. so many mights 😂😂😂

  62. Schokoladentoertchen
    28 ditë më parë

    Thank you for saying "person releasing an egg" instead of women! It's these small things that matter a lot in the fight for more trans and intersex rights!

  63. Kate *
    Kate *
    28 ditë më parë

    What if two eggs fuse together, And then the egg splits in half... Would that result in semi-identical twins?

  64. Hazel Equinox
    Hazel Equinox
    28 ditë më parë

    I’m pregnant with a fraternal twin. Her twin was not viable so she absorbed her. Or I absorbed her twin. It’s hard to say. They didn’t share the same sack so I’m not really sure how that works. But yeah twinning is rather curious. Sometimes the mother absorbs the baby according to my OB. I was really sad to hear I lost a baby. But my OB explained that sometimes this is just nature doing it’s job because they have chromosomal issues that aren’t compatible with life. So maybe it’s for the best you know if the twin was born they might have been in a lot of pain and suffering and I don’t think I could bear to watch my baby in such suffering.

  65. Zero Exodus
    Zero Exodus
    28 ditë më parë

    What about the evil twin ? Where you are born then you look in a mirror and another baby comes out ? Happened to me.... I miss the mirror verse......

  66. Jason J. Samuel
    Jason J. Samuel
    28 ditë më parë

    I always forget as a chimera I’m a twin

  67. David Wright
    David Wright
    28 ditë më parë


  68. Surg net
    Surg net
    28 ditë më parë

    10:44 I am sure this is what happend ;)

  69. sobreaver
    28 ditë më parë

    Engineering failures of a simple complex biological process in its mechanical nature makes for a dark horror spot in our mind and sadly, sometimes in front of our eyes. As much as the system has specific laws of function, it still sometimes fails. The mechanical approach kinda ruins human individuality and uniqueness into s simple idea of a blueprint realization gone wrong :! Consciousness (and everything it entails), despite the mechanic, is as a fragile concept/construct. Fetus in fetu seems like a weird biological fractal disconformity o0 Keep up the researches, you'll eventually figure out the secrets of the Bene Tleilax's Axlotl tanks ;)

  70. Tom Harner
    Tom Harner
    28 ditë më parë

    "When a 'person' releases two eggs"... "... A 'person' might not know that they're pregnant." Seriously, how much mental gymnastics do you have to go thru to intentionally avoid referring to the pregnant "person" as being female in a science lecture? The mind boggles how invasive political correctness has gotten.

    1. Tom Harner
      Tom Harner
      20 ditë më parë

      @na No worries. It's just that it's becoming one of the most, if not THE most, profound divisions amongst peoples in the western world today. It's a heavily politicized and propagandized issue...

    2. na
      20 ditë më parë

      @Tom Harner I'm not good with slang like that lol.

    3. na
      20 ditë më parë

      @Tom Harner Ah okay. Sorry I just didn't know what the term meant.

    4. Tom Harner
      Tom Harner
      20 ditë më parë

      @na where've you been for the last decade?

    5. na
      20 ditë më parë

      @Tom Harner woke tribe? What? You lost me dude. What does woke mean??

  71. Russell Schiwal
    Russell Schiwal
    29 ditë më parë

    mirror image twins: you know which one is the original and which one is the clone.

  72. OrganicSoulJazz
    29 ditë më parë

    10:43...🤔 You are not the father!

  73. Richard Rawlings
    Richard Rawlings
    29 ditë më parë

    I recently found out that a woman can be pregnant with multiple babies at the same time without them being twins. This happens because of uterus didelphys, which is when the vulva branches off into two vaginas and each one has a uterus. This is how all female babies start out but usually the two uteruses fuse together.

  74. Chobaca
    29 ditë më parë

    Why is it called paternal twins?

  75. Soham Ray
    Soham Ray
    29 ditë më parë

    This is why debugging properly before final deployment is important people. Nature should take notes.

  76. knn7
    29 ditë më parë

    me and my twin are fraternal twins and I'm right handed and she's left handed which makes us mirror image twins. I only figured this now

  77. laure189
    29 ditë më parë

    Watching this while pregnant is unnerving 😅

  78. Kionala
    Muaj më parë

    you didnt talk about oppaset gendered identical twins but thats ok no one is perfect.

  79. Angel Bear
    Angel Bear
    Muaj më parë

    "Man fathers a child that has his twin's DNA" Umm, are we SURE about that? O_o

    Muaj më parë

    More evidence of fusion is that if you sit on a toilet for a year. This has happened.

    Muaj më parë

    If your entire body is mirrored, you see and feel exactly the same, in that your left feels like your left and your right feels like your right.

  82. John Lenin
    John Lenin
    Muaj më parë

    “A person”’ just happens to release two eggs?

    1. na
      20 ditë më parë

      If they have a working uterus yeah.

  83. navoff1
    Muaj më parë

    My nieces are semi-identical twins. It took the hospital quite a while to come to that conclusion by studying the afterbirth. What my family was told is that the egg split in two before fertilization and was fertilized by 2 separate sperm. The girls are nearly identical in appearance.

  84. Amy Smith
    Amy Smith
    Muaj më parë

    Weren't there a few cases where there was a possibility that a XXY egg split into twins? One being female and the other male? In a sense that would be identical twins, right?

  85. Sophia S
    Sophia S
    Muaj më parë

    i know someone who is a monozygotic twin, and also has a dizygotic triplet. 2 eggs and 2 sperm created separate embryos, which would have formed a non identical twins, but one of the embryos then split into identical twins. so she and her sister are identical but they have a non identical triplet brother.

  86. Christa VerDuren
    Christa VerDuren
    Muaj më parë

    Chimera Twins- Check out CSI-Las Vegas just Whoa (sorry, not sorry for the spoiler)

  87. CaptainCat017
    Muaj më parë

    “Less than 200 reported cases have ever been reported” yup, seems legit

  88. Dominica Roberts
    Dominica Roberts
    Muaj më parë

    2:47- bizarre staged video clip of someone performing an ultrasound without gloves on and the gel all gooped up on their fingers... wtf

  89. Dan Sanger
    Dan Sanger
    Muaj më parë

    I remember watching a TV show years ago that featured a young man from China, shunned by local villagers, who had a partially-developed twin embedded in his body, with parts of it sticking out. Sticking out of his back was the head of the twin, not fully formed, but still with hair and other identifiable features such as a mouth. The twin was somehow connected to the nervous system of the young man, so that when the young man moved his mouth, so did the twin. It was a little disturbing to watch. Anyway, the point of the show was that a charity group had intervened and arranged for surgeons to remove the twin, which is what they did.

  90. Bright Cloud
    Bright Cloud
    Muaj më parë

    So im a twin, and im fraternal She actually was concieved later than me, ive been told that it was because my moms body went “oop you miscarried ig new child!” So the whole reason i watched this was to see if that had a special name

  91. creating space
    creating space
    Muaj më parë

    A person released two eggs? A person? A woman. A male cannot release an egg as they do not have a womb or ovaries.

  92. Little Rocker
    Little Rocker
    Muaj më parë

    My grandpa is a twin and has a twin sister. Gramps is "6'2 ( I think) and my aunt is only three feet tall ( a little person). This makes them a very unusual twins themselves. They are very nice :)

  93. Matthew Antaya
    Matthew Antaya
    Muaj më parë

    I only know of 3 types of twins

  94. Jonathan Höppner
    Jonathan Höppner
    Muaj më parë

    10:42 Sure that was the reason? 😏😂

  95. D G
    D G
    Muaj më parë

    Having an existential crisis as a twin must really be tough.

  96. Grim The
    Grim The
    Muaj më parë

    I'm surprised he didn't mention the case of heteropaternal superfecundation. Strictly speaking, they would be fraternal twins, but it's when two ova are simultaneously fertilized by the sperm of two different men. Some girls are getting more than their fair share. :P

  97. Primal Neon
    Primal Neon
    Muaj më parë

    Living in 2021 and scientist still dont fully understand how baby making works.

  98. Da5id C
    Da5id C
    Muaj më parë

    Surely you guys could do a few animations or diagrams instead of just plopping text in the middle of a lecture? It's a pretty lazy way to do a video - maybe think of starting a podcast

    1. Shannon T
      Shannon T
      Muaj më parë

      @Da5id C They kinda did 👍

    2. Da5id C
      Da5id C
      Muaj më parë

      @Shannon T maybe they should stick with that 😕

    3. Shannon T
      Shannon T
      Muaj më parë

      They literally have their podcast link in this video description 😹

  99. Fosuke M
    Fosuke M
    Muaj më parë

    this video has sent me on an existential crisis. Not in the way you are thinking. I went to high school with twins who claimed to be half identical and gave the reason being the egg split before the two separate sperm fertilized. Getting that part slightly different then the current theory is fine, but the rarity of the that is making me question if they were really half identical. Especially since the two reported cases don't seem to fit the timeline of being in my high school. This information rocks me because knowing them and the existence of half identical twins has been one of the trivia facts I bring up in conversation.

    1. Fosuke M
      Fosuke M
      Muaj më parë

      Like were those twins lying? Were they an undocumented case? Were they misled? I have so many unanswered questions.

  100. Fosuke M
    Fosuke M
    Muaj më parë

    Seriously, Hank Green! I keep running into him randomly on youtube. I like him, but it's weird I just keep finding videos with him in it.

    1. Shannon T
      Shannon T
      Muaj më parë

      @Fosuke M Hank & John are kinda the OG nerds of ALfirst! They get around! 😹👍

    2. Fosuke M
      Fosuke M
      Muaj më parë

      @Shannon T That... is a fair point. Though he has shown up as a guest in channels I was already subscribed too.

    3. Shannon T
      Shannon T
      Muaj më parë

      Almost like an algorithm has led you to this video, on a channel that he owns. 😹