Why might it be desirable to engineer aquatic humans?

Question

Consider a space opera sort of universe in which there exist communities of water-dwelling humanoids. These ocean people are derived from rootstock humans, descendants of genetically engineered human-variants who pioneered the colonisation of water worlds, or of Earth’s oceans. They may live their entire lives without setting foot on land or contacting the open air above the surface.

We set aside the technical complications of actually performing the handwavery of genetic engineering for the moment. This question concerns how it still appears rather difficult to justify the existence of the ocean people: in most cases, it tends to seem much easier to first construct closed environments, fill those with air, put usual humans in them and work from there.

What good reasons might there be for undertaking a project that would result in engineered humans adopted for survival underwater?

Potentially relevant constraint: despite the setting being futuristic in tone, introducing alternative history (perhaps some events that end up causing biotechnology to have developed comparatively faster, or cultural developments that change the way people evaluate different strategies of space colonisation?) is also an open option. Neither does the original goal of the project have to specifically be space colonisation; this question only asks for some combination of circumstances to exist at some point such that building a race of merfolk would be something that would reasonably be done.

Answer 1

1. Science/because we can
The main reason we haven't already tried that in real life is moral. It is considered wrong to alter the human DNA. Remove that moral bias and there is no reason why scientists would not try to create humans that can live under water or fly or have scales and are super strong...
And that is the problem with that reason. You ether get a lot of "collateral" races or have to think of a reason why science created aquatic humans and only aquatic humans.

2. War/Stability
Building a structure and filling it with air means to depend on that (rather inflexible) structure. If war or other external threats (like earthquakes, volcanoes) threaten to damage or destroy your structures, being aquatic makes you more flexible and adaptable. Also if you want to attack an aquatic enemy it pays to be aquatic as well.

3. It's cheaper in the long run
Constructing a bio-dome may be cheaper than bio-engineering aquatic humans, but building thousands of bio-domes isn't. If you use bio-domes to colonize the universe, you have to build (at least) one for every outpost. If you bio-engineer aquatic humans, you only have to do it once and wait for them to reproduce.

4. We didn't mean to!
There is always the possibility of an accident. For instance, a gene-splicing-virus that was meant to cure a minor disease like cancer or something, but the intern made a typo and now we have 10.000 people who suddenly need water instead of air to breathe. We're lucky that they didn't die. Turning them back is far to risky, since we don't exactly know what went wrong, so we can only offer them a nice, watery habitat and hope they won't sue us.

Answer 2

Earth-like planets are mostly covered by water

If we assume that humans have the best opportunities to survive on planets as "earth-like" as possible, the majority of their surfaces will be covered by water. Humans who have been genetically modified to be amphibians, able to survive underwater and still breathe air, will be able to live on most of the surface area of such planets (excepting active volcanoes and brutally-cold regions such as the Antarctic interior, and even there with proper habitat modules people can survive).

People who can live underwater don't have to worry about having their homes destroyed by hurricanes, tornadoes, etc., and probably much less vulnerability to earthquakes, as underwater structures can be designed to freely move rather than be firmly attached to the ocean floor. Eventually, people could decide it's not worth it to invest in building all those shelters on dry land that are subject to the different kinds of destruction.

Answer 3

For science - just to see whether we can really do it or not

Making an air filled habitat for normal humans is boring. That would probably work if your technology is on a level like the one you described. But engineering a new race of humans that could live underwater without the need for such a special habitat? That sounds like an interesting project!

Humans are curious. Very curious. Finding out how such a race would develop would be incredibly interesting for most scientists. Just to see how evolution might progress with a certain set of differences introduced, like the ability to live underwater without any need for other structures.

It's also safer because the supporting structures cannot be destroyed - after all there are no such structures.

But the overall point is: People do things because they are interesting. We are very curious. Testing our limits and trying to go beyond is in our nature. To learn how this race would behave and how they would evolve over time and to to get new insights they might not get from normal humans adapting to a new environment would be more than enough reason to genetically engineer such a race.

Answer 4

We humans are a romantic people. We don’t want to merely survive on a world, we want to belong, we want to experience it, to be a part of it. What is the point of living on an ocean world in a pressurized tin can? We might as well be in a space station in orbit. No, we want to live in our world. To taste the oceans, feel the water on our skin, and get carried away by currents. We want to touch alien life with our own hands and hear it with our own ears. Why travel to some new, exotic, and far-away place to merely recreate the same environment we left? Especially when instead we can change ourselves to adapt and coexist with what nature has created.

When our options are to destroy and disrupt in the name of practicality versus creating a new human experience the choice seems clear.

Answer 5

Note the existence of CRISPR today, and add in technological advances sufficient for spaceflight; I don't see practical barriers to engineered humans, only social ones.

Now imagine a wild-west, under-policed period of expansion. Bad things happen on the frontier.

So, along comes a rich fella with a mermaid fetish. His motives are base, but who's going to stop him?

Answer 6

To aid space station habitation.

If a space station is filled with water, and not air, then humans can propel themselves by swimming. Air doesn't provide enough resistance, so an air-breathing astronaut can get stuck in the space station. Having that resistance also provides astronauts with exercise. Micro-gravity causes muscles to atrophy, so astronauts need extra exercise.

Water also serves as a radiation shield. Its density absorbs energy better than air does, so there is less radiation exposure.

It would cost more fuel to launch water into space over air, but in the case of a station not landing or launching from a planet, weight becomes a moot issue.

Answer 7

Fault Tolerance

If you rely an external, high-tech tools to allow you to survive underwater, then you will have to maintain those tools. If the life support system fails. you are screwed. If the power goes out, you are screwed. Regardless of the expense incurred in maintaining a habitat that isolates you from the natural environment, are you willing to bet that you can maintain 100% uptime forever?

If you're not, it makes sense to tweak the people so that they can survive when their technology fails. And if they can survive when the technology fails, it makes sense to then skip the expense and just ditch the technology.

Answer 8

Surviving problems and living space.

If you accept modifying humans it would be desirable to make them survivable in whatever environment they live. In a bubble city potential catastrophe is always just outside, in a mercity patching a leaky roof is probably not much more than an energy efficiency concern rather than an existential threat to the community.

I can pitch a tent to expand my living space or as temporary living space during repairs to my main dwelling. A temporary part of a bubble city would be nearly as expensive as the main thing. Outside my dwelling I can work all day fetching tools and food from inside as needed with little hassle using the same techniques as I learned in childhood and have practiced in daily life: using a hammer inside or outside a bubble would be completely different tasks.

Keeping or expanding a bubble is hard work. Living in the environment you where made for is easy: If humans were meant to live underwater they would have been born with gills and flippers.

Answer 9

Science aided evolution.

Who wouldn't like the ability to breathe under water? Hooray, now you can have it! What, you liked it so much down there, you don't want to go up? Ok, there is more work to do, but now staying underwater indefinitely won't affect your health. And look, there are other people here, just like you! Check out this girl, she is stunning! Didn't you always think that mermaid's tail is more attractive than legs?

Answer 10

Genetic modification is more versatile

When traipsing about planets looking for someplace useful to colonize, you never know what sort of hazards could be encountered until you get there. Maybe the planet is too hot for humans, but maybe it's too cold. Maybe there's no land, or the atmosphere is very thin. There are various ways an environment could be hostile to humans. Now, an enclosed system capable of supporting human life regardless of external conditions might be possible, but it would be bulky and heavy, and potentially very complex; difficult to transport or construct as-needed, especially if the mission plan was for a single vessel to colonize many planets during a long journey. On the other hand, if Genetic Engineering is capable of creating humans which can naturally survive in those hostile environments, then only the fixed hardware required to perform that genetic engineering en-route is needed for any number of colonizations.

For a mass colonization project, it's simply more efficient to adjust the colonists once you have more information than to carry along all the hardware needed to keep a single type of colonist thriving on a huge number of vastly different worlds.

Answer 11

Boredom. Technology takes away all meaning from some peoples lives, and they decide they want to experience something new, namely living as mer-people on an ocean world.

Answer 12

I came up with two things:

1st: There are some environmental changes which make it almost impossible to build on the ground.

For example quite fast tectonic activity which changes the ground rapidly so buildings would be destryed by nature within days.

Another environmental factor could be currents which make it very hard to build something.

2nd: As sad as it is, war was allways a main cause of inventions.

Answer 13

An army living under water could be a strategic benefit. (But amphibic people would be more useful than those needing water all the time).

Some sort of underwater mining could be a reason, but it is unlikely to be worth the effort.

A compelling reason would be the upcoming impossibility to live on ground, but a remaining possibility to live under water. Artificial air bubbles are a bad choice, as they are damageable, small, and it is very hard to set up an environment of refreshing air and food.

Imagine possibilities why mankind foreseeable cannot live on ground in near future, but still could under water.

• A nuclear war affects sea and continents, but maybe the deep sea is less affected? (I'm not sure).
• Attacks from enemies/aliens/outer space only go against grounders to conquer land, but they are not interested in the sea? (Though, maybe there is not enough time left for genetic science in this scenario).
• Some kind of poison in the air that does not get into water? (Though, water is always in exchange with air).
• Radiation from the sun burning live on ground, but filtered by salt water? (At least a reason without the need of war ...). Just increasing heat on surface could be a reason.

Answer 14

You could have a future society that takes eugenics to an extreme. Everybody has a job that is determined at birth, and are bred appropriately. Farmers are bread with strong backs and a tendency to be good with plants. Warriors are bred to be strong and aggressive. engineers are bred to be mechanically inclined. This all takes place down on the genetic level.

The next step is to have someone find some aquatic resource that is impractical to obtain with subs, suits, or living in a tin can under water. Maybe it's a particular strain of deep sea kelp that produces a compound necessary for easier genetic manipulation, or something that supercharges the brain of the ruling caste. The Genetic techs work overtime for a while to breed your merfolk. For the first few generations, everything goes swimmingly. Unbeknownst to the Masters on shore, the merfolk can breed...

Because it is difficult to have interactions between a pure air breathing society and a purely aquatic society, the merfolk drift away from the rest of humanity. They may maintain trade with the air breathers, but they will eventually slip the leash, so to speak.

Answer 15

It turns out that intelligent aquatic animals such as dolphins have skills that are very useful in colonizing planets.Maybe their nonverbal communication helps in interacting with alien species. Or they're good at finding new food sources. So they come along. A standard environment being desirable, it's easier to engineer humans to live in their environment than the reverse.

Answer 16

Colonization: A deep space civilization that has evolved in their own right discover they need to flee the system for some reason. Focusing on transportation they lack the time and resources to properly prepare for terraforming or base building. The nearest viable planet is a water world, which makes the logistics of supporting a colony even more problematic. They have the tech (perhaps from curiosity or boredom as was suggested), they have the colony ships and they have the destination. All that remains is to make the genetic modifications to the colonist en route to their new home world. Better that they are able to easily access the only available food source on the planet (under water). They can always return to the surface once the colony is established.

Answer 17

because merfolk are cheaper than robots and machines can travel faster than humans. imagine you want to colonize a planet that is 10 light-years away. first you send your generation ship, but it will take 1000 years to get there because the human body can't accelerate very fast without dying. meanwhile, you send a colonization kit at nearly light speed. it arrives in 20 years and starts building a space port for you.

unfortunately, you can't afford to send an entire space port, so you just send some robots that use the native resources to build a space port and stock it with food and other supplies. you also can't afford to send enough robots to do all the mining, smelting, constructing, farming, etc. so the first thing your robots do is build more robots. it turns out that on planets suitable for life, the most accessible resources to a tiny space probe are organic molecules. so the "robots" your probe builds are effectively tiny plants which generate the energy you need to fuel more complex machines. it then builds animals that are smart enough to build your space port. those animals are humanoid so they are easier to relate to, but they are aquatic so that when your descendants arrive they can colonize the land while the merfolk continue to live happily in the sea. indeed, you can even genetically program the merfolk to desire to build space ports but hate the idea of actually leaving the sea personally. it's like "brave new world" meets "a for andromeda"

Answer 18

Genetic Engineering is Common

A possible reason for your universe could be that your humans are especially advanced at genetic engineering in comparison to other sciences. If your humans commonly use genetic engineering as part of every day society (designer babies, counter diseases etc.) then the idea of genetically engineering a subspecies specifically for water environments is just an extension of what they do every day.

Answer 19

Its suprising no-one said climate change.

Climate change could easily drive us to have to live under the sea.

The climate changes, and the poles melt, and the world goes underwater ... so that's where we all need to live... there's your driver for mutation.