If there were a human colony on the moon for several generations, how tall would its inhabitants be?

Question

I'd like to know what humans would look like if they'd been living on the moon for several generations. Exactly how tall would they be? What other changes would their bodies undergo after time? How fast would they run? How high would they jump? Would their skin change at all? Would their voices change?

Answer 1

If it was a long enough time the humans would be shorter, weaker, jump lower, and run slower.

Answer 2

I've read about a problem with astronauts losing large amounts of calcium in their bones because of lack of pressure from their muscles in space. Basically, they are suffering from Osteoperosis. Another thing is muscle atrophy, which happens fairly quickly and over long periods of time would be pretty devestating. The humans would most likely be taller, since the gravity is not contracting their spines as much. Without some kind of specific medication regime or training programs, the earthborn humans would most likely be on average 3-6 inches taller and a lot leaner. However, no one honestly knows the effects of space or lowered gravity on human physiology. Perhaps the human body wouldn't have as much stimulus to grow as tall. Maybe they would be much taller, leaner and slower. As for their voices, that has nothing to do with gravity; it is sound waves - air molecules colliding with one another. Since we need air to live, there will always have to be air, hence, sound waves. The only thing that will change that is the density of the air. You've problem heard of someone inhaling helium. They're voice becomes higher pitched because helium is a lot less dense than the regular old air we normally breath and hold in our lungs. As the vocal cords and lungs pass sound waves through the helium, the pitch increases. There is another factor though, on Mars (since it has an atmosphere) if someone were to speak, the sound would not travel very far because the molecules are so spread out. Back to the original set of questions though; the first group would be a little taller, after that it's speculation. The next generation of humans would probably be taller as well, but then again, there could be unknown effects of living under less gravity or in an enclosed space that would affect this. Another thing to consider is the solar radiation. Our atmosphere protects us from a lot of UV rays and the Van Allen Belts redirect a lot of harmful radiation. The moon has neither, so either a colony would have to be set up on the dark side of the moon so the mass of the planet would shield the colonists from the radiation or very very thick walls and ceiling overhead, basically a bunker. Long term exposure to solar radiation would cause cancer, much much quicker than someone getting skin cancer here on earth. It's also a wash to say how fast they would run and how high they would jump, because on one hand there would be less gravity, but on the other, their muscles would be much weaker. The safest assumption would be about the same. Their skin would be virgin, like a babies if they were born there, unless they had exposure to the sun. However, this wouldn't be possible for long enough periods to get anykind of tan because the radiation would be so much more intense. They would be much more prone to skin cancer. One last conjecture: I think if someone where to live long enough in space or on the Moon, they probably would not be able to return to the Earth at all. Their bodies would not be able to take it. Their muscles would be to weak and their bones to brittle. Also, their inner ear (the thing that controls balance) would probably have made a long term adjustment and these colonists would have a difficult time orientating themselves on Earth. I enjoyed the question. There is a trilogy by Kim Stanley Robinson, I think, called Red Mars, Blue Mars, Green Mars with some of these ideas exhibited.

Answer 3

What effect would haveing 1/6th gravity have on the human body.... Height may change, but slower than 5 generations, unless people on the moon start breading for height reasons. Usualy survival of the fittest wold rule, ie, if the houses that are occuipied by the people on the moon are small, (to conserve air and not have to contain pressure) then people would be shorter, because the tall people would keep hitting there head.... not a attractive trait.
Over time I could see there muscle systems developing diffrently, and weaker than on earth. walking would take a diffrent stride, here we push off the ground aginst gravity as well as to propel forward. on the moon that would make us practice a sliding type step, again, our current way of walking would make us hit our heads. Running speed, even with a specialy designed shoe, slower than on earth. Jumping on the other hand would be alot higher.... as long as they have muscles for it and the head room to make it posable.
Skin change, most likely whiter over time, due to a complete lack of sun on the body, less pigment, maybe on the face when they walk outside.... but unlikely a full body tan anymore. I don't think the voice would change unless we add helium to the air , but that is unlikely in space verses undersea, where we sould have to mix O2 with helium to allow for higher pressures.
I woud be more intrested to see how a bird would change it's manor of flying in 0 G. now that would be intresting. :)

Answer 4

Firstly - awesome question. Secondly, I don't think several generations would be enough to affect the characteristics of the human species. Natural selection has completely gone out of the window since money and plastic surgery arrived on the scene, so people would not be picked for reproduction because of any specific attributes, not would our bodies react fast enough to perhaps have an effect on the attributes of our children.

But I can tell you this, muscular atrophy would more than likely be rife, as would athletes foot from being stuck in a stinky spacesuit all day.

Answer 5

I don't know about the height question, but I suspect that anyone who was born on the moon and lived their through adolesences, would not be able to move to earth and live a normal life. They wouldn't have the bone or muscle mass to meet the demands of Earth's gravity. Same reason you couldn't move Jupiter and live with its crushing gravity.

Answer 6

i went to kennedy space center last fall and they briefly touched on this issue. they were saying that there would be changes to the human body--the changes still unknown to us--because if women were to become pregnant on the moon, the change in gravity within the womb would effect the fetus.....they didn't go into details but i thought it was a fascinating/scary idea.

Answer 7

i never really thought about this but it is a good question

i would say that several generations isnt enough to effect the evolution...they would be better adapted to the moons conditions but i suspect they could easily adapt to earth conditions...as long as they had some way of working out like the astronauts do...but still muscular atrophy would be the major effect...

Answer 8

My first thought is, if space suits must be kept inviolable for the people to live, just how would they procreate? Some pretty fancy space suits would have to be designed - oh, unless they lived in a community sized bubble where they could remove their space suits.

Answer 9

few generations is too little time to get any significant changes.
they will probably be weaker than earth humans and have paler skin due to being indoors all the time, but they will become regular people if they return to earth.