"Evolution IF Artificial Gravity Does NOT Become The Norm" Topic

If we become a space-faring race despite not having perfected artificial gravity, I've heard it said that . . .

Either the lower limbs will disappear entirely (Casper-like), or that we will develop another pair of hands in place of feet (naturally or by design – like chimps), to make an extra useful pair of limbs for weightless living.

QUESTIONS:

1) Is there any cool concept art out there showing what humans would look like if they gave up legs for convenience in a permanently weightless environment?

2) And, do you think a line of miniatures like that would be successful?

Dan
TMP link

Hi Dan –

Guessing it'd be genetic modification before evolution. Space is pretty hard on the old bones… Astronauts lose a lot of bone density even on relatively short jaunts in space – we need to overcome that problem before we'd start evolving in zero gee.

Walter Jon Williams had a book called Angel Station that described folks genetically modified for zero-gee. Haven't ever run across any images.

Miniatures might be intesting. Of course with all the folks bringing out new lines of plastic figures we'll soon be able to create our own "four-armed" space-farers.

Cheers – Mike

Here is an interesting comic about genetically modified people in space

link

Remember this fella?

picture
link

Dan

Given that "artificial gravity" really isn't that hard to do for longer ship voyages, I don't think it will become an issue. You can achieve "artificial gravity" in two very simple ways:

1.) Constant acceleration. ("Down" is merely towards the opposite the direction of the engine's thrust.) At the midpoint of the journey, rotate the vessel and decelerate, producing the same effect. Microgravity conditions will only exist at the start, end, and midpoint of the vessel.

2.) Spin the ship. (Either using a wide torus design, or by using a counterweight— made up of cargo or whatever— on a long tether. "Down" is away from the central axis or center of gravity around which the structure rotates.) This assumes a ship that does not undergo constant acceleration (or at least acceleration at significant fractions of G).

Both are far simpler than genetic modification, or certainly reliance on evolution.

But in the case of long term microgravity conditions, I expect we'd largely see bone loss all the way around, not just the legs, and muscle loss only if no effort is made to exercise the limbs. I can't see any reason for the DNA structure of humans— arms, hands, legs and feet— to otherwise change absent an outside force acting at a genetic level.

Transhuman Space has artwork that covers people living in freefall. Assuming you have medical treatments for the long-term degenerative effects of zero g, it's perfectly reasonable that people would start to live in microgravity.

Before evolution kicks in (long before), you'll see genemods to take advantage of it. In THS, you have Tennin: a genetic upgrade that, among other things, gives you long, skinny bodies with modified feet that have opposable thumbs. They are agile in a variety of gravities, and in zero gravity they can use their feet to hold onto handholds and manipulate things. The kumo is a variant that goes whole hog: they have four arms. Both have pictures in the books.

Of course, if no treatments are ever developed, the most important evolutionary advance would be for us to EVOLVE resistance to microgavity. That would take ages, but even if we have artificial gravity, you can't always have it. For example, asteroids and moonlets don't have enough gravity to protect you. So there's an advantage either way.

In 'Transhuman Space' or other RPG, I think they had genetic modifications for hands w/arms instead of feet…but I'll have to find the image.

What about the humans from 'Wall-E' movie…they had Gravity, but apparently decades of NOT doing anything/laying in anti-grav chairs etc…made them 'blobular' which makes me wonder how they managed to 'stand up' or could attempt to re-colonize earth, but hey, it was a DISNEY movie…

YEARS ago…(before the microgravity thing) there was a story in Boy's Life about a Colony ship that was zero-g and the humans used power suits, amost like 'armor' with just their heads sticking out? to help them when they got to their destination planet….(they probably would have died from calcium loss or 'crumbled'…etc/heart attacks?) based on current studies…

but in the story…before landing…their generation ship encountered a 'lost' sleeper ship…were the original crew left earth in hibernation/basically frozen/stasis…so no 'loss'/changes per se. In fact…their ship would have overflown the system and kept going if the generational ship hadn't 'saved them'…(no, I don't remember the story, would love to find it again!)

Anyway…the two 'cultures/crews' joined forces to colonize the planet…each had it's 'advantages' and each had it's….flaws….and it was the youngsters…(young men, of course!)…who brought the two societies/crews into 'harmory'…Ta-Da!!!!

Even if some medical treatment/medication plus exercise could help stop de-conditioning…in microgravity…(as far as bone-loss etc…some type of 'artificial gravity' would be needed if the crew ever planned to return to a planet!

There was a science fiction book, I don't remember the title, that had a "race" of genetically modified human beings who were optimized for working in zero gee. They had hands in place of feet. I don't remember the author or the details. I just remember the basic structure that it had humans with arms instead of feet for zero gee work.

C'mon guys. You sound as though you are just so attached to your legs and bones!!! :)

Dan

I prefer to keep all my body parts, thank you … And evolution takes a long, long time …

Why would lower limbs disappear? That is a bogus understanding of the mechanics of evolution, and in any event woule require millions of years. Is this future human race never to walk on any planet?

"Is this future human race never to walk on any planet?"

What's the problem, John? Can't you walk on your hands? :)

Dan

No, I can't. But if I could, where am I supposed to hold my weapons of whatever class with which to oppress the inhabitants of said planet?
Since my hands have become feet, I suddenly need hands again!

If we need hands for weaponry, we are not in the far future.

If we need hands for weaponry, we are not in the far future.

I'll remember that as I shoot that 8 legged thingie that is trying to eat me.

Well with some of the pictures you see of globs of water and such float around in spheres, because of the generations of bone lost, bones, which keeps us in our general shape and form, in a zero G environment with no structure we would in up as round globs with eyes and four limbs that maybe with hands maybe not, just tentacles Dances With Words should enjoy that thought. Soft and squishy

Ain't none of it going to happen until Humanity first develops a workable and reliable zero-gee toilet…. ;-)

Man After Man, by Dougal Dixon, had a bio-engineered human for zero gravity. It had four arms, and it's body was spherical, with a hardened shell to survive in hard vaccuum without a suit! They had bristly whiskers to communicate by touch, and special eyes with polarize lenses.

Falling Free by Lois McMaster Bujold

I read a couple short stories about warships built with extremely limited space. The crew were sealed into sleep-pods and everything was run virtually through the ship's network.

In the virtual ship, it was a big, spacious liner-like affair, but during action stations you instantly transported yourself to your battlestation.

To save space on the ship, all the crew had their legs amputated. They were re-grown later when they returned to earth (assuming they survived).

To be honest, that actually sounds reasonably probable to me. At least the prospect of a "sleeping" crew with a virtual interface. Faster reaction time, less wasted mass on useless things like living space and recreational areas, or even decent food for that matter.

The amputating legs bit could be possible if we ever get to the point where re-growing a lost limb is no bigger a deal than putting a cast on is today.

There is a rather large lack of understanding of the process of evolution in this thread…

…and bio/genetic engineering is NOT evolution, it is engineering. There is a difference.

Fritz Leiber had some thoughts about this in one of my favourite old-timey sci-fi books, A Spectre is Haunting Texas

link

In this book, after a nuclear war Texas is ruling North America (frightening, I know, but thankfully sci-fi) and there are orbital technocracies – one of the people from the orbit comes to earth to re-claim property (this part turns out badly) – he is called a "Thin" because the orbital dwellers are tall, skinny and thin-boned – they depend on exo-skeletons to get around on Earth

Further to John's point, I don't see why you would get rid of your legs – but you would use them differently

Also, I agree about time scale – evolution takes forever – after all, we still have the vermiform appendix and fifth toes, which seem to serve no purpose whatsoever – genetic engineering, though – that could be quick

No legs? By that time, we'll start looking like the kid on the left: picture

Not something I'd particularly want to spend time painting.

The Xeloxians are ideally suited for zero-G, but then, some would say that the Tentacs are even more adapted: link

Wyatt

If I had hands instead of feet then I'd get a lot more painting done. And in zero gravity, I'd never have to worry about spilling paint because it would just float there until it dried…

A large-scale evolutionary change is also dependent upon the concept of natural selection. The mutation must offer such a significant environmental advance that the new "breed's" opportunity to survive and mate (produce similar offspring) far surpasses the survivability of the "root stock." While four hands might be useful to a microgravity-dwelling human, there is nothing inherent to such an environment that will increase the likelihood that the new breed will supplant root stock humans— especially as the microgravity environment will be an artificial one, created by root stock humans to begin with. While humans have certain physical characteristics that give us survivability advantages in general— namely opposable thumbs— other species also possess similar physical characteristics (primates and raccoons). The true advantage humans possess is the ability to deliberately alter any environment to suit our needs. Two hands or four hands makes no real difference.

Lastly, there does come in the question of physical attractiveness. While I can imagine some might be interested in the possibilities of mating with someone in possession of an extra pair of "sensory manipulators," I suspect for the most part humans will still prefer others who look "normal" and are likely to produce offspring that look like themselves. The only possible distinction is if four-handed individuals prove themselves capable of generating significantly more income than the two-handed, because as we all know, wealth attracts the opposite sex. However, I see little reason to assume such a disparity would be the case.

Ace From Outer Space, not likely. You would need more sensory organs and some kind of brain enhancement in order to handle the multitasking capability needed to do two highly precise tasks at one time.

The tall/thin trope seems plausible but is actually laughable. Humans were not meant to be born in zero-gee. Gravity is required for the development of the long bones in the human fetus. A human born in zero gee would look like a Thalidomide baby. Plus there are other effects which are quite dangerous, a list as long as my arm. The effects go right down to the cellular function level.

It will take a LOT of engineering to get around the lack of gee, which life on Earth has depended on for 1+ billion years.

Lampyridae 07 Feb 2010 10:29 p.m. PST:

Humans were not meant to be born in zero-gee. Gravity is required for the development of the long bones in the human fetus. A human born in zero gee would look like a Thalidomide baby. Plus there are other effects which are quite dangerous, a list as long as my arm. The effects go right down to the cellular function level

This sounds very interesting. It'd be obvious that evolution on Earth has produced forms that are "meant to be born" in ca. 1g, but I'm not at all familiar with how the specific effects of gravity on foetal developement has been determined. I presume there have been experiments with mice and the like, but an inquiring mind wants to know the specifics.

And now for the curt version: citation please.

Larry Niven's The Integral Trees and its sequels develop this concept pretty well. A colony settles a breathable atmosphere region created by the intersection of several stellar bodies without a planet-sized mass. Plants evolved without roots, rotating axially with leaves at both ends, floating in low gravity, following the wind towards accumulations of moisture and nutrients. Villages are established on free-floating bigger-than-redwood-sized trees; these have gravity at their far ends due to their rotation.

The cover art shows a tall human, who grew up in low gravity and uses her toes prehensilely. Amazon link: link

Niven's science is generally as current as he can make it; I can't remember if he refutes Lampyridae's point or not. It's been years since I read the book but I think possibly it was stated that pregnant women and young children are kept in sections with as much gravity as attainable.

A British Interpanetary Society (BIS)* study a few years ago collated all the known facts and details on this from the various space medicine agencies and they came to some conclusions.

While there would be a trend towards the tall, thin lo-g human, this would not be so pronounced as some fiction would have; Such people would resemble a certain Chinese-born basketball player in form, rather than anything else. The Heavy world 'dwarves' are more likely.

As to zero-g forms, since humans develop prehensile toes in many Earth environments, it's more likely to happen there as anything else in the short term. Longer term adaptations are harder to predict, especially as the nature of evolutionary development is as a population as a whole and dep[ends on randome factors and environmental interactiosn as a totality, including some genetic drift and interplay. I would expect that in some environments, there might be a loss of limbs to a more mermaid-like form, in which the lower limbs might be used as a balancing organ, particularly in open-plan habitats: Redevelopment of grapsing functions in legs might be expected in cluttered ships and suchlike.

I've also read some things to back up Lampy's statement (scifi source, so not entirely sure about the technical details). Supposedly there are some real challenges with low-g placental interchange (ie, basically doesn't work except under 1g +/-0.005g)

This sounds very interesting. It'd be obvious that evolution on Earth has produced forms that are "meant to be born" in ca. 1g, but I'm not at all familiar with how the specific effects of gravity on foetal developement has been determined. I presume there have been experiments with mice and the like, but an inquiring mind wants to know the specifics.

And now for the curt version: citation please.

Citation follows…

The fetus cannot exercise like an astronaut: gravity loading is necessary for the physiological development during second half of pregnancy
Medical Hypotheses, Volume 64, Issue 2, Pages 221-228
S.Sekulić, D.Lukač, N.Naumović

Abstract:

On the basis of published Magnetic Resonance Images and the values of the specific fetal and amniotic fluid weights, apparent weight of the fetus from the 18th week of gestation until term was determined. Up to the 21–22nd gestation week the fetus is in conditions similar to neutral floating, while after the 26th gestation week the apparent weight of the fetus is 60–80% of the actual weight. Decreased effect of the buoyant forces that affect the fetus in human species during the last trimester has a number of implications for the colonization of the solar system. During space flight it is impossible to apply the existing countermeasures against microgravity deconditioning of the muscular and cardiovascular systems to the fetus. Absence of gravitational loading during the last trimester of gestation would cause hypotrophy of the spinal extensors and lower extremities muscles, reduction in the amount of myosin heavy chain type I in the extensor muscles of the trunk and legs, hypoplasy and osteopeny of the vertebras and lower extremities long bones, and hypotrophy of the left ventricle of the heart muscle. Because of decreased capacity of postural and locomotor stability, acquisition of the gross developmental milestones such as sitting, standing and walking could be delayed. In the authors' opinion, only artificial gravity (rotating platform) during space flight will allow physiological development of the human fetus. Independency of offspring's of the guinea pig as regards locomotion and nursing increases probability of successful breeding in microgravity compared with rat offspring's, and make this species a candidate for future experiments under conditions of microgravity and hypergravity. Examining the gestation of this species in different gravities requires first the experimental determination of the amount of buoyant force to which the fetus is exposed in physiological conditions.

I have many, many papers on zero/low gee and artificial gravity. Bad news is you need 1g, anything else is still varying degree of bad (it is believed). Zero gee is still very bad and drugs and exercise only slow the damage in certain areas. Good news is it is easy to achieve 1g with centrifugal rotation, spin rates can be much higher than was previously believed possible (5-10 RPM instead of 1-2 RPM, or a 10m radius centrifuge as opposed to a 1000m one).

I've also read some things to back up Lampy's statement (scifi source, so not entirely sure about the technical details). Supposedly there are some real challenges with low-g placental interchange (ie, basically doesn't work except under 1g +/-0.005g)

Have not read that but you are correct, changes in fluid functions (such as lack of convection and buoyancy) mean that cellular functions are altered somewhat. It has the effect of driving bacterial mutation 10x higher than in 1gee, which could mean problems with disease outbreaks and infections.

Constant violent outbreaks of flatulism caused by zero-gee conditions would also have detrimental effects on human breeding.

Lampyridae 08 Feb 2010 8:21 p.m. PST

The fetus cannot exercise like an astronaut: gravity loading is necessary for the physiological development during second half of pregnancy
Medical Hypotheses, Volume 64, Issue 2, Pages 221-228

Hmm, too bad it doesn't appear to be publicly available on teh Interwebz. Or at least I failed to immediately find a spot where it is. I assume it's been tested on guinea pigs specifically?

@Lampy: I'd read that in Laurie Reeve's second novel 'Vigilante'. She does a really good job of the rest of the hard-science, so I assumed this bit was also correct. It was only mentioned in passing to establish the reason for a terrorist takeover of a slow boat (FTL tech in the series requires a slow boat to drag the nav buoy to the destination system). Short version, terrorists needed the artificial wombs on the generation ship.