Founding An Inbreeding-Free Space Colony

Founding An Inbreeding-Free Space Colony

Thanks to 23AndMe for supporting SciShow. These kits make great gifts, so check out

How much genetic diversity would we need to found a colony on another planet?

Hosted by: Stefan Chin
Support SciShow by becoming a patron on Patreon:
Dooblydoo thanks go to the following Patreon supporters: KSam Lutfi, Kevin Knupp, Nicholas Smith, Inerri, D.A. Noe, alexander wadsworth,
سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Bella Nash, Charles Southerland, Bader AlGhamdi, James Harshaw, Patrick Merrithew, Patrick D. Ashmore, Candy, Tim Curwick, charles george, Saul, Mark Terrio-Cameron, Viraansh Bhanushali, Kevin Bealer, Philippe von Bergen, Chris Peters, Fatima Iqbal, Justin Lentz
Looking for SciShow elsewhere on the internet?


You may also like...

97 Responses

  1. Ryan says:

    Incest the game the whole family can play

  2. Telly TheToaster says:

    No don’t do it

  3. ddave104 says:

    Thank you Game of Thrones.

  4. Verlisify says:

    Interesting video

  5. Michael Lyden says:

    I love how you’re so concerned about inbreeding on Mars, when any humans living there will be killed by the low gravity and cosmic radiation before they even get to the third date.

    • Zutaca says:

      the other prophet F All of the problems with bone and muscle loss in extended low gravity can be averted by wearing really heavy clothes.

    • Panic Wolves says:

      stefanos2691 Exhaustion from wearing metal shoes… You can get used to that. Weaker muscels and Bones… I’m pretty sure that only really becomes a problem if you ever visit earth or some other planet with higher gravity.

    • ipissed says:

      Well you don’t know what you are talking about because, going to Mars to begin with would never work, you would just fall off the side of the flat Earth.

    • Ken O says:

      “Life finds a way.” – Jurassic Park (Yeah, that’s my science reference.) Some will adapt.

    • Håkan Lundberg says:

      The cosmic radiation will solve the problem with an inbred genome. Everyone knows in changes our DNA. Radiation may even be an important factor in evolution here on earth. So we might evolve into Martians faster than we think. 👽

  6. Pink Sparke says:

    If you can’t keep it in your pants, keep it in the family!

    …at least that’s what my aunt-mother-grandma says.

    • PlasmicOcean says:

      If I did my math right if your mother was also your father’s mother, and your father’s father (paternal grandfather) was your mother’s father as well then this particular familial relationship could actually be possible, without even the need for any in-laws, though I can’t recommend it…

    • Multi Gamer says:

      Pink Sparke Lmao wtf

    • Zutaca says:

      For your mother-aunt-grandmother to be all three, your mother-aunt-grandmother’s mother would have to have a baby with your mother-aunt-grandmother’s father, who would also be your father-brother-uncle’s father, and your father-brother-uncle’s mother would be your mother-aunt-grandmother. Then your mother-aunt-grandmother would have a baby with your father-brother-uncle and that baby would be you, giving you an inbreeding coefficient of 0.375, or 37.5%.

    • Dr. Spatula says:

      PlasmicOcean nailed it

  7. Elino Villegas says:


  8. Daedhart says:

    Nothing quite as romantic as looking up your date to see if theyre related…

  9. Nacho ZombieKilla says:

    I guess my cousin Jackie better not come onboard my spacepod bc she sexy.

  10. David B says:

    I doubt we will achieve true space travel until after we are already capable of messing with our DNA. So the problem might easily be averted, once again, by the power of science.

    • Roman Yakunin says:

      “Investing in transforming the earth into a black hole, or what do you mean? :P”

      I mean the technological singularity. When AIs surpass human intelligence.

    • Roxor128 says:

      David B – Few hundred generations? It’s not going to take _that_ long to make a trip to a nearby solar system. At 10% of light speed, you could make a trip to Tau Ceti (which has five possible planets) in about 120 years. That’s only five generations (assuming people have kids at age 25 on average).

    • ismail Cem Eroglu says:

      大根 I am working on that with genetic enginnering give me couple of years I will figure it out I already found many of the animal genes which improved on body regeneration and cell enduerance
      here is a list blind roddent:cancer immunity and extreme cell enduarance genes
      lobsters:a gene that continuasly regrows telomers
      lab created cell sucidie arifical created : a gene created in lab used in rats that automatically kills harmfull old cells which create toxins normally they stick around and cause harm but these gene commands them sucide
      bug genes: for methamorphising to a age of 24 (the age where you body conditouns are at peak) also used to replace body woth enginnered cells creating a cacon still has work to do
      lab salamender: amazing regeneration capacity can even regrow its brain using steem cells its regeneration gene
      these are some of the genes neede for immortality

    • David B says:

      Roxor128 The closest star I know of is Proxima Centauri at 4.24 light years away. NASA reports that Apollo astronauts went at the max: 24,000 mph. Dividing 4.24 light years by 24,000 mph got me a total time of 118.5 thousand years. These numbers might be a little different with modern tech, as I think the New Horizons probe launched at 36,000 mph, but it is also tiny when compared to what would be necessary for a trip to another star.
      Due to the numbers I have found, I stand stand with my original estimate of “thousands of generations” in order to travel to another star system.
      p.s. Please correct me on any number or calculation errors. I am writing this on my phone, and I am also bad at math.

    • Enfant d'Omelas says:

      It makes a lot more sense to use small self-replicating robots (von Neumann machines) for space exploration than to send actual humans. As for colonization as a hedge against extinction due to a cataclysm on Earth, the Moon and Mars will do fine. We can almost get to Mars with present technology. So for Mars colonization in the near-term, I would suggest sending intelligent, small-statured (fewer calories, less life support needed) women (yes, you could use artificial wombs (almost there) but babies still need a primary attachment figure) and frozen sperm from a large number of small-statured men. It’s true – *Mars needs women.* Eventually they might genetically engineer a way to block out cosmic rays, possibly a new skin pigment (green? gray?).

  11. Master Therion says:

    Elon Musk is the founder of SpaceX.
    This video is about the Founder Effect and space sex.

    • Julio Espin says:

      CybershamanX Your prediction is too late, sex between siblings and cousins is already commonplace in many regional areas and trailer parks 😉

    • Michael Lin says:

      “They say SpaceX has big balls, and it’s true!”

    • Alex Mercer says:

      Fap Fap Fap? No?

    • CybershamanX says:

      +Master Therion I have this saying…a sort of personal axiom, if you will… “If I’ve thought of it, chances are very great someone else already has!” 😛 😉 So, I’ll have to check out some info on Ascension. Also, I was thinking in terms of first using generation ships to cross great distances to habitable planets. It would likely be many hundreds if not thousands of years between visits from new “breeding stock-worthy” humans. I guess my stream of consciousness comment didn’t take into account others couldn’t read my mind! 😛

  12. zseven says:

    Don’t we need artificial gravity to make babies in space? I mean, tears stick to your face on the ISS. If you know what I mean… 😀

    • Terible Teri says:

      At this point couldn’t we have babies in artificial wombs? Or perfected cryogenic humans for travel? At the very least what happens in Red Dwarf?

    • Mother Raven says:

      zseven sperm swim, tears don’t. But Mars had gravity so that doesn’t Matter.

    • Evelyn Rose says:

      James Burleson we should test it with a mouse or something else in space. It would be fascinating to see what happens, though I wanna do the science the animal lover in me wants not use the animal >.< i cant win.

  13. Angel Samael says:

    Couldn’t we just use genetic engineering to remove all negative traits?

    • RyDaddy says:

      You wouldn’t have to remove ALL negative traits, just those that are dominantly heritable. Things that are single-allele; if one of EITHER parent has it, the child will have it.

      Then pairings are strictly screened to ensure no couple where both carries the recessive allele are allowed to reproduce; 1 in 4 odds of those kids showing the negative trait, if they do reproduce.

    • Keyboard runner says:

      Even if we don’t populate any other celestial body it will be necessary in the not-so-distant future to engineer our offspring by removing detrimental traits. Methods like CRISPR are already bringing us close to making it possible.
      And contrary to the opinion of some here in this thread this will not be eugenics (in the historic sense), even less genocide.

    • Enfant d'Omelas says:

      As Alex Ye pointed out, overall diversity is desirable. Lots of frozen sperm would solve that problem easily (lots easier to do artificial insemination than IVF).

    • Devin Ward says:

      Angel Samael We aren’t anywhere close to understanding the genome that well. We don’t know which genes interact with which others and in which ways nearly enough to safely modify them.

    • Enfant d'Omelas says:

      Devin Ward I agree; it’s amazing to me that scientists have only recently recognized the impact and mechanisms of epigenetics*. On the other hand, research is progressing rapidly; machine learning is a big help. There are a number of interviews with / talks by Brendan Frey on YouTube on the subject that are really interesting; here’s one:

      * Though I did have one prof back in the late 80’s who noticed strange heritability issues for certain traits in crickets on different diets. It was puzzling to me back then why people were not making a big deal about it.

  14. John OBrien Gardener says:

    Space Colony Anthem ::: ‘ I Am My Own Grandpa ‘

    As sung by Ray Stevens.

  15. microbuilder says:

    Incest is *not* wincest!
    Humans born on another planet, coming back to earth, would be aliens.

    • sirdeadlock says:

      There was a real person on Earth scientist refer to as genealogical Eve. As far as has been found to date, everybody on Earth shares a common female ancestor. There were others around their time, but eventually everybody left has become a product of her offspring. So literally speaking… You’ve never had sex with a human that wouldn’t technically be incest.

    • Doctor Bram says:

      Trollzyn/Trazyn Mexico and indonesia are on Earth, so no.

    • Some may call this junk me I call them treasure says:

      Trollzyn/Trazyn Yes they are, technically “aliens” mean foreign.

  16. John OBrien Gardener says:

    FAKE NEWS BULLETIN: This just in to our newsroom:


  17. Hassan DM says:

    *Sniff Sniff* I smell Star Wars approaching.

  18. Snowball Effect says:

    I thought that loss in diversity was called the white ethno-state?

    • Chetz says:

      +Snowball Effect Two paragraphs are TL:DR for the internet expert apparently. What did I even type that was bigoted? That you’re wrong?

      +ismail Cem Eroglu ASIA is more diverse genetically yes (obviously, ASIA is a continent with many gene clusters, Europe just has one with three parent clusters), but generally because we all outside Africa got kids with the same neanderthals (you get a bottle necking phenomenon in mostly inactive DNA from that making us all very similar) and passed the same bottle necks, all humans away from sub-saharan Africa are very similar in pure DNA % compared to most animals.

      Sub-saharans didn’t do the whole neanderthal thing and didn’t pass any bottle necks, so sub-saharan Africa alone has a more diverse genetic make-up than the rest of earth combined. Asians and Europeans are very similar compared to the difference between different sub-saharan populations.

    • Snowball Effect says:

      you’re a bigot because you are lol. am i wrong? you don’t seem to deny it. you peddle falsehoods and excuses. “systemic migration”. there is no evidence of this happening. trade routes to europe largely did not exist. for thousands of years, europeans only had other europeans to breed with, hence heavy side effects of the founder effect and diminished genetic pool: red hair, blue eyes and other recessive phenotypes became commonplace. this is not controversial science.

    • Cthulhu Has Risen says:

      johnmburt1960 they want genetic diversity but absolutely no diversity of thought. 2+2=5. Big brother is watching.

    • Cthulhu Has Risen says:

      Chetz if you disagree, you are racist. Dont you watch cnn?

  19. Domdrok says:

    So I need to get my house built by the Amish before they become tiny, crazy bearded people.

  20. Computer says:

    Allow me to shake up your societal norms. Prepare your brain.

    Incest is only immoral if you have a child. Otherwise there is nothing wrong with it.

    • jeronic7 says:

      The Lightning American of course it would be *moral the Genes are not from them so who cares?

    • The Lightning American says:

      That’s not what I’m asking.

      Is it ethical as an incestuous couple to raise children at all? Do we know what happens to children that are raised in such a household?

      Perhaps if well-adjusted and normal adopted children can emerge from same-sex parents, then it can also be done with incestuous parents. But I wonder how difficult that could be. You don’t want to harm the psychologies of people who are not yet old enough to understand *why* incest is undesirable.

    • jeronic7 says:

      The Lightning American I still don’t think it’s immoral. And by the age they have sex you can explain it to them. You would not even need to explain to them that their parents are related to each other up to that point.

    • SuperBillytheawsome says:

      I assume that you are an only child

    • cough pillbox says:

      Computer I don’t think anyone said it’s immoral but it definitely disgusts a lot of people because we’re not all wired to think of family members as sex partners like some of you are lol

Leave a Reply

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