I am considering a human-like species that has a consciously controlled womb- like organ. These beings would be able to gestate and give birth to any smallish creature that fitted their purpose. Naturally, matter doesn't appear out of nowhere; they have to ingest enough food in order to do this. The creatures they create might not be able to breed, or lack other features. This skill would need practice, and these beings would produce specially designed warriors, livestock, or other animals this way instead of breeding them. They could give birth to them in the form of young to minimize energy requirements. The system could also be used to directly create objects they required out of bone, skin, or fur. The system could even still function as a womb and allow them control over the bodily form of their babies.

In short is it possible for a creature to have a sort of all-purpose bio-fabricator, how might it come about and how would it be used? The closest real example I can think of is a queen bee producing worker bees. However, the worker bees are relatively similar in form to the queen, and the queen can't consciously alter the design. This is my first question.

EDIT: This organ would work like a womb producing a baby except that the muscle, bone, skin getting placed/grown would be a conscious decision, not a biologically hard coded one.

So the person would be able to create a small "helper" creature which could find food or warn of danger, would obey simple instructions from the parent and would have a body plan suited to helping the person survive. Such "helper" organisms already exist, (bees) but their body plan is biologically hard coded.

EDIT 2: Any talk of how this could be exist mention DNA editing capabilities. What if the system involved sacks of skin, muscle and bone cells in solution. A coagulating agent, and a trunk like appendage capable of squirting them out, in a manner similar to 3D bioprinters. This method doesn't need DNA to be designed, and all the control is muscular. it also doesn't need any cells to grow, so could be very fast.

  • $\begingroup$ Is nanotechnology an option? Or do you want this "bio-fabricator" to be sentient, not a tool? Even then, the nanites could also have a governing AI which could make decisions, etc. Otherwise, I'm not sure nature could explain away something that biologically versatile. $\endgroup$
    – AndreiROM
    Commented Feb 12, 2016 at 16:19
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    $\begingroup$ I would give birth to a dragon and die happy. $\endgroup$ Commented Feb 12, 2016 at 16:31
  • $\begingroup$ The bio fabricators are evolved organs $\endgroup$ Commented Feb 12, 2016 at 16:52
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    $\begingroup$ @DonaldHobson, +1 very cool idea. They could even travel the stars, seeking out new life to ingest and add to its DNA library. I've seen this kind of thing mentioned before in fiction (the hive queens of Mccaffrey's Talents series), but just as a side character. As a central character, either protagonist or antagonist, your bio-fabricators a comparable to the Predators or the Aliens in complexity and story value. Good luck with them! $\endgroup$ Commented Feb 12, 2016 at 17:02
  • $\begingroup$ Welcome to WorldBuilding.se! Great first question. $\endgroup$ Commented Feb 12, 2016 at 17:14

6 Answers 6


If you include intelligent intervention in your definition of evolution, then your bio-fabricator could definitely "evolve".

Start with something similar to human evolution, a path that leads to a self-aware and intelligent species.

Now, in a manner similar to our embrace of the physical sciences, have this intelligent species embrace biological sciences. Have them start enhancing their bodies for different tasks and after a time, have them master genetics such that they can make those enhancements inheritable.

So far, what you have accomplished is comparable to our industrial revolution. Your biologically adaptive beings have not only developed their own version of tool-use, but they have industrialized the production of those tools using the reproductive capabilities of their own bodies.

The next "natural" step would be a biological equivalent to our computer revolution; converting their internal factories from hard-wired processes which generate only a single end-product, to a general purpose, programmable tool which produce a variety of solutions and end-products.

Your bio-fabricator is the "natural" result of an intelligent species mastering biological and genetic sciences, instead of our physical and electronic equivalents.

  • $\begingroup$ +1, this was my thought process as I wrote my answer. "Intelligent intervention" is definitely the way to go here for such a phenomenon. $\endgroup$ Commented Feb 12, 2016 at 17:52

The feature you're asking for cannot reliably come about by evolution.

First off, to create all the organ systems of the animal, you require the elements and compounds that make up those organ systems of the organism you're creating. That's just a given. And because you're not processing and passing on those compounds through excretions out of your body, you're building up potentially toxic levels of those very same elements and compounds.

Second, I can think of no environment or situation where it would be biologically advantageous to have a component that is a factory for every type of creature. You also face a lot of problems like choking to death on bone, or becoming hypercalcemic or hyperphosphatemic because of raw calcium/phosphorus sitting and being absorbed in the host organism's blood.

You -could- have a factory that sits inside of a body, and the factory itself can be made by an intelligent species (on our planet, humans) and address all the problems with rejection. You could rewire a biological host to contain nanotechnology and barriers that stop raw elements from being absorbed in the body and leading to diseases or other problems.

However, at that point, why does it need to sit in the host?

You're better off conjuring an animal that creates offspring similar to it (asexually) or little slave organisms made by easy, accessible elements. I'm thinking of something like a jellyfish, which could conceivably be created in a host that isn't a jellyfish. Simplistic and elegant. Instead of creating any small creature, it can be very good at creating one, specific creature.

Perhaps your sapient species can get away with that. Something with a lot of water content and a realistic amount of compounds. I'm thinking a host that spits out bioluminescent jelly-like fireflies.

That would make for a great story.

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    $\begingroup$ creating little slave organisms is exactly what I was asking about. $\endgroup$ Commented Feb 12, 2016 at 17:07
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    $\begingroup$ This makes no sense. Why would the elements and compounds that make up the created organism be toxic to the "mother"? Mammals already provide those things for their own offspring in utero—the only difference being that those nutrients are self-organized according to the organism's own genetic code, rather than externally-organized. If there are great barriers to the questioner's hypothetical, they certainly do NOT lie in toxicity, choking on bone, hypercalcemia, hyperphosphatemia, and so on! That's just a matter of speed. Remember, it takes 9 months for a human to make an 8-pound baby... $\endgroup$
    – ErikE
    Commented Feb 12, 2016 at 19:52
  • $\begingroup$ @ErikE Your issue with my answer disagrees with the spirit of the question (and even some explicit statements). It's a creature factory with utility that involves spitting out a significant number of (or significantly useful) creatures of any type or shape, not specifically a mammal, nor one that specifically slowly creates one creature (or one of its own species). The matter has to come from somewhere, and if I interpreted the question's spirit appropriately, the ingestion required to satisfy a slave colony does bring up some questions. $\endgroup$ Commented Feb 12, 2016 at 20:24
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    $\begingroup$ I agree there are some questions about just how the materials acquisition and transfer works, but I still maintain that you're overstating the case about how difficult the process would be. The questioner didn't explicitly state the time-period that is required to build these small helpers, and even said they could be created "in the form of young". Perhaps the mother organism has the ability to store materials differently. It could even "unmake" one formless "baby", stealing its materials to make another, formed and useful one. $\endgroup$
    – ErikE
    Commented Feb 12, 2016 at 20:33
  • $\begingroup$ @ErikE It's the fact that the question-asker is asking about utilitarian colony-like offspring. In fact, OP describes "warriors" and "livestock," which historically are considered to be most useful in abundant supply. With an abundant supply combined with the fact it must create everything, one could reasonably assume that time is of the essence, and that the ingested resources could be toxic. Being the mother doesn't make them immune. This is a problem for evolving to be such a creature. If you imagine it already evolved, it isn't a problem. However, OP asks, "How may it come about?" $\endgroup$ Commented Feb 12, 2016 at 20:39

It'd take some creativity, but I think it could happen. However, I'd like to make some tweaks. In particular, the direct construction of bone, skin, and fur is going to be very difficult to fit in with what a womb needs to do. Fortunately, I think there's a way to get a lot of those constructs more, well, traditionally.

Bone and skin and fur are typically created when stem cells differentiate into bone and skin and fur cells. From there, they grow according to how the body shapes them Managing this process is a beautiful art. The bones don't get grown from one side to the other, they expand from within, growing with the baby's body.

If we want to have a womb that can construct these things, we should probably tap into this powerful force. What if the creature could consciously communicate with the workers (cells running algorithms) making the baby grow, get information from it and then give instructions for how to shape things.

This would have obvious implications of permitting the construction of custom tailored creatures to work for your alien. It also is something that would require skill to master. Working in harmony with your little unborn creature is not easy. A poorly placed tumor growing a bone spike uninhibited could be fatal! It would also permit the construction of inanimate objects. Instead of the womb producing it directly, the creature would gestate a new baby helper who would be guided to produce the correct shape. Then, once it's completed, a conscious signal would tell the unborn creature to cease trying to be born, and release its resources to the parent (wow, that's a pretty delicate euphemism to try to write!). What would be left is whatever inanimate structure you wanted.

This could come up from any species whose conscious awareness of what they need to be as a species rises above their biological awareness. It would take some genetic manipulation, or perhaps some careful breeding, but eventually you could create a embryo similar to that of a bee in its ability to be many things. It would likely be used to generate very precise structures. It can't make things fast (generating a lot of bone fast is a very specialized activity), but it can make "the right thing." There would be a lot of gurus who specialize in having a mostly complete small creature stored away, ready to be specialized at a moments notice. These individuals would see magical, for it would appear they can gestate faster than others.


In response to your edit 2, "bioprinted" bone and skin and fur would be very ineffective. The fur might be effective (I don't know enough about the process we use to make hair), but bone in particular is highly dependent on structure. It is an ideal material to be grown slowly while subject to loads, because that helps the bone align its structure properly. Trying to grow it quickly in arbitrary printed shapes would make it very difficult to achieve bone's superior qualities.

This is why the modern biomedical printing community typically 3d prints the substrate, and then lets the tissue grow on it at the tissue's rate.

A bioprinter that can print bone like that would almost certainly never evolve. Nature is no where near that wasteful. It would optimize the material it prints with for the task. You would see printing done with compounds designed to be printed, not recycled concepts from cellular growth.


Thinking about all these implications is rather "icky" but here is my first answer ever in stack exchange.

As others have said I doubt if this sort of feature would arise from the randomness of natural processes. If these people where the product of extensive tinkering or genetic manipulation it 'might' be possible.

The provided processes of a host growing an organism of its choosing by manipulating the form during development seems a tad backwards. A "womb" is a safe nutrient providing environment for an organism to self-assemble based off its genetic structure. The host body may be key in some steps by providing resources or trigger hormones at key times but the organism itself is seeing to its own form.

What maybe possible is a being whom has a special set of reproductive organs that have the ability to manipulate the genetic structure of the organism. I suppose it would spit out a zygote at this point since it is asexually producing these divergent organisms, the host would then need to provide hormones or resources appropriate to the form they are producing.

"Growing a perfect killing machine?" "Code a humanoid form with simple brain structure and heavy musculature and dense bones: make sure you have lots of protein, calcium, and Cortisol in your womb." Then when the organism is viable enough eject it from the womb care for it; watch it grow into the killer you want it to be.

It seems there would be drawbacks to this approach.

  • The host's base genetic structure is the starting point and it would seem until you are highly skilled at creating the code most "creations" would be tantamount to cloned children with minor differences. The time of gestation and rearing these creations would be long and undoubtedly emotional.
  • The host's base genetic structure is the starting point and it would seem until you are highly skilled at creating the code most "creations" would be tantamount to cloned children with minor differences. The time of gestation and rearing these creations would be long and undoubtedly emotional.
  • It also would appear that the "simple" forms of just bone or leather (skin really) or fur (hairy skin) would be the most difficult to achieve as the "purity" of just these structures would be hard to code genetically (and have self assemble).
  • Another potential pit fall would be if the manipulated code is too different from the host, a natural rejection might occur causing the host's immune system to remove the offending material.

Some of those problems and other moral and emotional ones wash off when you eliminate the idea of a womb all together and you have a more insect like approach.

Have the "Queen Mothers" use the genetic manipulation to create fertilized egg sacks that gestate and go through larval cycles where the "Queen" is only responsible for dropping the base material and letting the pupa do the rest "You know, throw them a couple of dead bodies to eat and in a few months BAM! full grown dragon clone baby thing."

  • $\begingroup$ +1 the use of eggs would also allow the "Mother" to produce more than one offspring at a time. Design once, then lay multiple eggs. $\endgroup$ Commented Feb 12, 2016 at 18:53
  • $\begingroup$ Nice answer! Welcome to the site. $\endgroup$
    – Quiquȅ
    Commented Feb 12, 2016 at 20:23

I doubt something like that could be completely biological. Some manipulation could have happened implanting a Molecular Assembler in a few individuals and overtime the two became more and more integrated. One could suppose these individuals lived for long time for that to happen and that they are very few to not lead to destruction of resources. At a certain level of integration they went on with self-replication, which would take place of regular reproduction due the small number of these individuals, and would be highly regulated. In replicated offspring the molecular assembler is so integrated that can be considered more of an organ than an implant and at that point you can bring in an evolution in the organ.


Consider the organism is in an environment such as "food web". The birthing machine is isolated from the environ, similar to problems that have been considered on TedTalks such as producing Coral. Yes, you can make a coral incubator in which the progeny are protected from ingestion by species higher up the web and result in increased coral.

Biology is the science of Life, and that means genetic information, no way around that. To create a Lego Genetic machine would not be possible today. Perhaps once you have organisms genetically sequenced with Next Gen sequencing technology, such as I saw on Documentary it is possible to sequence human genome now in 7.4 seconds (amazing considering the initial input of TIME)...

There is no getting around the egg/sperm problem other than creating "Dolly". Interesting question of "Hybrids" being sterile...such a concept would eliminate the factor of FERTILITY and also factors such as Darwinian competition for survival.

If you are looking at making "Cocoon" like incubator for multiple species progeny there are too many factors to consider. Start with the fertilized egg of any species and look at the controlled variables necessary.

Perhaps you could start with the most simplistic cocoon and make a list of the required conditions, even that would be a feat.

Why not try to grow a human central nervous system in isolation that is absent body components...perhaps this "brain" could be made to survive floating about the International Space station for hundreds of years...floating around in an artificial environment of "sustainability"==nutrition AND a way of getting rid of "metabolites"==waste (such as what an artificial kidney would supply). This would require continual output and excrement--you could just dump the excrement into space...ha. Bye.

Still trying to couple human neurons to silicon (Didn't MIT build an "artificial eye" couples to the vision portion of the CNS? Who needs taste if the inputs are through artificial vessels? But then again these vessels are subject to "aging" by oxidation etc. You would need to be able to grow CNS tissue on an artificial scaffold which would provide nutrients couple with a filter for excretion...this would be a continuous "pump".

Solve this problem in SPACE and who needs the "food web" to provide food to a human mouth? Seems like the solution would be to somehow couple genetic information with directed nanotech.

Philosophical questions galore. What is life? They seem to have decided "end of life" is "absence of neuronal activity". It could therefore be derived by the science of LOGIC that the beginning of LIFE is neuronal activity==if humans are to decide this question at all. Following the definition above, human life would begin at the moment nanotechnology or the limits of what "humans" are capable of detecting as neuronal activity. As these limits progress to an earlier and earlier stage it is self-evident that LIFE will begin at "conception"...we just can't measure it yet. It is obviously self-evident that the time frame will become less and less.

This whole argument reminds me of the famous question by Aristotle " how many hairs does it take to make a beard?" Ha. We had a kid in 7th grade who let 5 hairs grow on his chin and we joked "nice beard". If it "looks like" a beard is it in fact a beard? Breeching the subjective vs objective. Then we had my "girlfriend" or wanna be girlfriend who was attracted to beards and she commented about "Joe"--what a "nice full beard he has"...I was not capable of this as my testosterone just wasn't there. Bye.

  • $\begingroup$ The human quest for immortality. Trying to escape limitations. Ultimate quest for "power". Pope Francis. You are corruptible. End. $\endgroup$
    – guest
    Commented Feb 12, 2016 at 23:45
  • $\begingroup$ Big! Block! Of! Text! $\endgroup$ Commented Feb 12, 2016 at 23:48

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