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Thread: Giant animals on the Moon

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    Giant animals on the Moon

    Will we be able to gengineer animals six times their normal size on Luna with its lower gravity, like a mongoose the size of a tiger?

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    Quote Originally Posted by Tom Mazanec View Post
    Will we be able to gengineer animals six times their normal size on Luna with its lower gravity, like a mongoose the size of a tiger?
    There's nothing stopping you from engineering a mongoose the size of a tiger here on Earth...tigers work just fine, after all.

    Animals wouldn't simply scale up 6 times in linear dimensions. As far as being able to stand and walk goes, they could scale up 6 times in weight for the same body size and proportions, but of course scaling up in weight is going to change either size or proportions or both, likely in a way that increases strength. Note that the relationship between mass and inertia would remain unchanged, though, so animals that jump or fly will have lower weight limits in order to survive the impact of landing, or will have to move a lot more carefully. And there's issues like being able to deliver oxygen and bloodflow.

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    Quote Originally Posted by Tom Mazanec View Post
    Will we be able to gengineer animals six times their normal size on Luna with its lower gravity, like a mongoose the size of a tiger?
    I don't think the problem is the gravity but rather the fact that size is not a simple trait controlled by a gene. Our bodies grow by a very complex process that is controlled by various chemicals being produced in a scheduled way. I am not sure what you envision by "gengineer," but I think it would be much easier to breed them to be bigger, as we have done with dogs or turkeys or whatever.
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    Well, there would be the complication of engineering a Tiger sized Mongoose space suit.
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    Quote Originally Posted by captain swoop View Post
    Well, there would be the complication of engineering a Tiger sized Mongoose space suit.
    Is the mongoose-sized mongoose spacesuit solved now, then?

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    Sorry, I wasn't just being flippant.
    There isn't an atmosphere because of the size and density of the moon resulting in lower gravity.
    The very big animal speculation comes with a built in drawback.
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    Quote Originally Posted by captain swoop View Post
    Sorry, I wasn't just being flippant.
    There isn't an atmosphere because of the size and density of the moon resulting in lower gravity.
    The very big animal speculation comes with a built in drawback.
    Hmm. This question is a much larger animal than it first appears.

    Seriously, Moon colony first. Then see how big humans get.

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    Don't ignore the square-cube law.
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    Quote Originally Posted by John Mendenhall View Post
    Hmm. This question is a much larger animal than it first appears.

    Seriously, Moon colony first. Then see how big humans get.
    Humans grow to adult size even if they spent their life lying down (e.g. due to being sick or handicapped). So while the body's muscles would be weaker on the moon, the body's size would hardly differ.

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    But human heads can be cone-shaped if you bind them (like some cultures did in the Andes), in the same way one can grow a cube-shaped melon by putting it inside a box. The action of epigenetics means humans grown in lower-g will probably adapt morphologically. However, that doesn't necessarily mean they'll be well suited to the lower-g environment, since it's not clear to me yet that the body's growth and repair systems will bridge the larger distance between normal low impact activities (i.e. sitting in a low-gravity field) with high-impact collisions (like tripping and falling).
    Et tu BAUT? Quantum mutatus ab illo.

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    Quote Originally Posted by SkepticJ View Post
    Don't ignore the square-cube law.
    Right. The cube root of 6 is 1.817, so a giraffe on the Moon (that is about 1.8 times as tall as an Earth giraffe) would weigh the same as a normal sized giraffe on Earth, everything else being equal.

    But the bones are now 3.301 times as large in cross sectional area, so they could potentially carry more weight. I think that means the animal could be 3.3 times as massive and still have the same proportional physiology. An animal that was 3.3 x as massive would be 1.489 times as tall as a normal-mass animal; 1.8 X 1.489 = 2.7 or thereabouts. I think this means that genetically-engineered giraffes (or humans) living in sealed habitats on the Moon could be comfortably 2.7 times as tall as on Earth.

    If I've dropped a clanger here please do let me know.
    Last edited by eburacum45; 2017-Dec-08 at 02:05 PM.

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    However Ara Pacis makes a good point; falling over would be potentially dangerous for a human who is 2.7 times as tall as an Earth human, even in 1/6 gee . So either they would need to wear very efficient crash padding or they would need to be quite a bit smaller.

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    Quote Originally Posted by eburacum45 View Post
    Right. The cube root of 6 is 1.817, so a giraffe on the Moon (that is about 1.8 times as tall as an Earth giraffe) would weigh the same as a normal sized giraffe on Earth, everything else being equal.

    But the bones are now 3.301 times as large in cross sectional area, so they could potentially carry more weight. I think that means the animal could be 3.3 times as massive and still have the same proportional physiology. An animal that was 3.3 x as massive would be 1.489 times as tall as a normal-mass animal; 1.8 X 1.489 = 2.7 or thereabouts. I think this means that genetically-engineered giraffes (or humans) living in sealed habitats on the Moon could be comfortably 2.7 times as tall as on Earth.

    If I've dropped a clanger here please do let me know.
    Please let me know too because I have absolutely no idea what you just said. Except for the fact that the square-cube law says its feasible to have a 55 foot tall Giraffe on the moon...YES! Giraffe-Zilla! Woohoo! I can see the movie posters now...
    Chuckle - seriously though; I have little ability in modern science and had always assumed the square-cube law was more appropriate to defining why we don't have giant mosquitoes et cetera running around. Or buzzing...whatever.
    Given the lighter gravity and assuming an artificial biome that would support Savannah life, would large mammals such as a giraffe naturally grow larger given time, or would they grow to the size they are on Earth? This question assumes a few generations; not hundreds.
    My personal guess would be that they would grow to the level needed to graze on trees; just as they do in Africa. Without the need to expend energy to grow past their food source, increased growth would not happen. That is of course, just a guess.
    Last edited by NorthernDevo; 2017-Dec-13 at 04:52 AM.
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    Quote Originally Posted by NorthernDevo View Post
    My personal guess would be that they would grow to the level needed to graze on trees; just as they do in Africa. Without the need to expend energy to grow past their food source, increased growth would not happen. That is of course, just a guess.
    Yes, that's correct as long as you let them die if they can't reach the trees. There is no reason for them to get any bigger or any smaller if there is no pressure.
    As above, so below

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    Quote Originally Posted by Jens View Post
    Yes, that's correct as long as you let them die if they can't reach the trees. There is no reason for them to get any bigger or any smaller if there is no pressure.
    So 1/3rd gravity would provide the possibility for much larger growth, but not necessarily determine such. Unless of course that same gravity gave the trees an increased growth rate. I get it.
    Still, I'm uncertain. Let me rephrase the question:
    Like most ruminant species, a giraffe calf born on the Savannah has one imperative: grow as fast as bloody well possible. The faster it grows from 6 feet of unbearable cuteness to 20 feet of leggy, weirdly graceful majesty the better its chances of survival.
    If we were to place out mythical lunar biome in the very near future - say the next 20-30 years, the species Giraffa Luneria would not have time to adapt the evolutionary imperative to the Moon's light gravity. The body would - so to speak - be 'expecting' to grow in a 1G African environment.
    Therefore, were I to guess, I would suspect that calves born on the Moon would 'overshoot' the growth target, with associated medical problems of over-long bones and insufficient density.
    To be clear: my first question referred to evolution; this one refers to relocation.
    Would I be correct in this assumption?
    Thanks
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    Maybe one day there'll be farms and zoos on the Moon, with animals being raised in enclosures provided with breathable atmosphere. Let's see how large they can grow under those conditions.

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    Quote Originally Posted by DonM435 View Post
    Maybe one day there'll be farms and zoos on the Moon, with animals being raised in enclosures provided with breathable atmosphere. Let's see how large they can grow under those conditions.
    It would certainly be nice - in order to have either animal farming and/or zoos, the lunar population would first have to be large and developed enough to support the infrastructure needed.
    I'm uncertain whether really, really big cows would be an efficient meat source (as opposed to a whole bunch of little cows) but it would certainly something to see.
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    Quote Originally Posted by NorthernDevo View Post
    would large mammals such as a giraffe naturally grow larger given timeexisting,
    There wouldn't be enough nature on the Moon for natural selection to play out. You'd need an unchecked ecosystem of evolutionary drivers (predators, food, disease, etc.) to do that.

    However, if there is existing natural variance in the height of giraffes, their average height might increase by the fact that the tallest ones would probably not suffer from life-shortening problems as much as they do here on Earth.

  19. #19
    Quote Originally Posted by Tom Mazanec View Post
    Will we be able to gengineer animals six times their normal size on Luna with its lower gravity, like a mongoose the size of a tiger?
    How big will the snake will be?
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    Quote Originally Posted by NorthernDevo View Post
    Still, I'm uncertain. Let me rephrase the question:
    Like most ruminant species, a giraffe calf born on the Savannah has one imperative: grow as fast as bloody well possible. The faster it grows from 6 feet of unbearable cuteness to 20 feet of leggy, weirdly graceful majesty the better its chances of survival.
    If we were to place out mythical lunar biome in the very near future - say the next 20-30 years, the species Giraffa Luneria would not have time to adapt the evolutionary imperative to the Moon's light gravity. The body would - so to speak - be 'expecting' to grow in a 1G African environment.
    Therefore, were I to guess, I would suspect that calves born on the Moon would 'overshoot' the growth target, with associated medical problems of over-long bones and insufficient density.
    I see what you're asking. I think it is a very interesting question, and to be honest I would have to say I don't know. However, it's tricky because I don't think you can even assume that it would "overshoot" rather than "undershoot" the target. Growth is a very complicated and well-coordinated process, so it could be even for example that the lack of gravity would lead to atrophied muscles, and that somehow the growth of muscles is required for the growth of strong bones, if you see what I mean. In zero gravity, I think that humans would be unable to develop because, just for starters, bone cells die as they develop if there is no gravity. So I think it is fair to say that there would be modifications, but whether faster growth would be among them is AFAIK uncertain.
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    And actually, that adds a bit to the earlier post I made about the complexity of development and why it isn't simple to modify the growth. Here is an article about how height is controlled genetically, by hundreds of genes.
    As above, so below

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    Quote Originally Posted by Jens View Post
    I see what you're asking. I think it is a very interesting question, and to be honest I would have to say I don't know. However, it's tricky because I don't think you can even assume that it would "overshoot" rather than "undershoot" the target. Growth is a very complicated and well-coordinated process, so it could be even for example that the lack of gravity would lead to atrophied muscles, and that somehow the growth of muscles is required for the growth of strong bones, if you see what I mean. In zero gravity, I think that humans would be unable to develop because, just for starters, bone cells die as they develop if there is no gravity. So I think it is fair to say that there would be modifications, but whether faster growth would be among them is AFAIK uncertain.
    Excellent response, thanks - it does make for an interesting question, dunnit?
    Thanks for the article too - I'll spend some time reading it before answering more fully.
    Cheers!
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    Quote Originally Posted by astrotimer View Post
    Where will all the waste go?
    The farms, of course.

    Man cannot live by meat alone.

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