In my world my races (Humans, Elves and Dwarves mainly) are almost intelligently designed (not quite created by a god in their image, but definitely 'created').
And this got me to thinking, are there any major defects in a human that you would expect not to exist if someone (or something) sat down to create the perfect humanoid?

The one that comes to mind for me is the crossing of our wind pipe with our digestive system, but while I know that is the reason why we can choke I'm not sure it's 100% a bad thing as I assume it also allows us to breath through our mouths (which presumably can be beneficial).

So the question is, are there any obvious ways to improve the basic humanoid body plan?

By improve I mean it should make some aspect of our bodies work better or remove a flaw (like the windpipe cross over mentioned above). The changes should also leave a human looking human (so adding wings or extra limbs isn't an improvement). They should make sense and be feasible (so you can't just add a back up brain or heart if there is no way the body could sustain them).


closed as primarily opinion-based by Mołot, Renan, RonJohn, Giter, Mindwin May 14 '18 at 14:14

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ This is an incredibly broad question, and unless you can define ‘improve’ it’s also opinion based... $\endgroup$ – Joe Bloggs May 14 '18 at 10:27
  • $\begingroup$ @JoeBloggs Fair point. I'll try to think of a way to narrow it down / provide more criteria. $\endgroup$ – adaliabooks May 14 '18 at 10:28
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    $\begingroup$ There wouldn't be a waste pipe running through a recreational area $\endgroup$ – Separatrix May 14 '18 at 10:31
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    $\begingroup$ @Seperatrix that’s only an improvement from a recreational point of view. From a waste management standpoint it’s considerably more efficient! $\endgroup$ – Joe Bloggs May 14 '18 at 10:42
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    $\begingroup$ I think it all depends on what their creator would consider to be an improvement. Maybe their creator is practical and would consider a full-body pelt a good protection from the weather; maybe it is vain and would consider any body hair unsightly. To define what it would consider an improvement, you'd have to tell us what their creator's personality is like. $\endgroup$ – Real Subtle May 14 '18 at 12:34

Don't bother fixing things that will make no difference for 99% of pop

Many of the previous answers are trying to remove stuff that are not useful. But, they are not really annoying either. I was never bothered by my caecum, were you? So if you remove it, you may save some small amount of energy/trouble for the body. But you could also later discover that, in the end, it had some purpose. Above all, you did something that will not make a noticeable difference in most of the cases.

Mostly they are things that are not optimal, but their correction will not make the human more able for anything. Do you think your life quality would increase significantly if we fix the path of your laryngeal nerve?

So what are the major defects in our bodies?

Well, it's what kills us. Let’s take the most frequent mortality causes (in Europe):

  • Heart diseases
  • Cerebrovascular diseases
  • Cancer (especially respiratory system)

So, if you could enhance humans, increase their resistance to these problems. For instance:

  • Stronger heart, maybe duplicated, or able to heal better
  • More resistant veins (especially in the brain)
  • Some mechanism that can clean the veins from cholesterol and other deposits
  • Immune system able to fight cancer
  • Make an immune system that would accept transplants more easily
  • And so on…

I guess it is less spectacular than removing wise teeth, but waaay more useful.

Last idea: remove addictions from humans. They will live longer and better. Tobacco, alcool, games, sugar, money, … Let them enjoy it, but don’t make them need it.

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    $\begingroup$ You mean no more SE addiction? $\endgroup$ – user9981 May 14 '18 at 14:10
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    $\begingroup$ Aren't "cancer fighting immune system" and "extra transplant tolerant immune system" mutually exclusive? $\endgroup$ – user28434 May 14 '18 at 14:37
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    $\begingroup$ @user28434 Don't know what kind of capability the OP has. Might be compatible with high enough tech/science/writing magic. $\endgroup$ – Legisey May 14 '18 at 15:23

Low hanging fruit

There are several glaring design errors, or "low hanging fruit", to use a bit of managementese, in human anatomy and physiology, which could be immediately corrected by an intelligent designer with minimal side effects. For example:

  • Move the photosensitive cells to the correct side of the retina -- for those readers who know about digital photocameras, our retinas work like old-school photographic sensors instead of more modern back illuminated sensors.

  • Straighten out the path of the recurrent laryngeal nerve; at present it follows a bizarre path which made sense in fish but is totally unsuitable for mammals.

  • Repair our defective mechanism for producing vitamin C, and in general reduce (or even eliminate) the number of essential amino acids.

  • Simplify the anatomy of our feet; as it is, our feet have the same structure as our hands, which made sense for quadrumanual monkeys but is overcomplicated for bipedal humans.

  • Fix the stupid way that the breathing reflex is triggered; as it is, breathing is triggered not by a lack of oxygen but by an accumulation of carbon dioxide, with the result that we can pass out due to hypoxia without noticing anything amiss.

  • Reduce the number of teeth; we have the same number of teeth as the other apes, but they have elongated muzzles whereas our tiny jaws lead to severe overcrowding.

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    $\begingroup$ Speaking of "low hanging fruit", the unprotected position of the testicles, while fine for our quadruped ancestors, is very poorly adapted for an upright stance. $\endgroup$ – Skyler May 14 '18 at 14:05
  • $\begingroup$ #5 is how people can die by carbon monoxide or sulfur hexafluoride asphyxiation -- the other (non-carbon-dioxide) gas displaces oxygen, but as we're still able to normally expel the carbon dioxide from our lungs we don't notice anything amiss, then simply pass out from lack of oxygen and, without external intervention, suffocate. $\endgroup$ – Doktor J May 14 '18 at 14:06
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    $\begingroup$ I'd also add continuously regenerating teeth (a la sharks or alligators), as opposed to simply having a "baby" set and an "adult" set. When the average lifespan of a human was 40 years it was fine, but as we've extended our lifespan, only having two sets of teeth is woefully inadequate in most cases. $\endgroup$ – Doktor J May 14 '18 at 14:07
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    $\begingroup$ @DoktorJ: Continuously regenerating teeth would be a massive change, but a third set of teeth may be feasible with minimal side effects. I wanted to put it in, but since my knowledge of human anatomy is limited to what I learned in high school a long time ago I was not sure that it could be done with minimal change to the existing system. Anyway, the list given in the linked WP article lists more such misfeatures, for example some our our sinuses drain upwards, which is rather silly. $\endgroup$ – AlexP May 14 '18 at 14:11
  • $\begingroup$ @DoktorJ, average lifespan is a misleading value without the consideration that the modal age of death was 0. If you survived childhood there was a good chance of making 70. $\endgroup$ – Separatrix May 15 '18 at 8:02

There are lots of ways humans are obviously not "intelligently designed". A such designed humanoid would, for example:

  1. Not have the genitals hanging outside the body
  2. Have a much better arrangement of organs/spine. We obviously came from walking on all fours in an earlier form and the curved spine was there as a way to support the weight of hanging organs. Now most of us end up with back issues at some point.
  3. No unnecessary organs (appendix)
  4. No strange pathways for nerves (recurrent laryngeal nerve)
  5. A bigger pelvis for the childbirth issue
  6. The eyes could do with a redesign, amazing as they are. Possibly remove the blindspot and maybe increase the visible spectrum available outside RGB.

Other minor possibilities. Many non-human animals can safely eat things that would kill us...fix that! Birds can eat hot chillis with no irritation.

  • $\begingroup$ This is the kind of thing I was thinking of, the spine in particular is an interesting one to consider. Thanks for the answer. $\endgroup$ – adaliabooks May 14 '18 at 12:33
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    $\begingroup$ Points 1) and 3) are actually important. E.g, keeping gametes cool/storing beneficial gut bacteria during infections $\endgroup$ – FoxElemental May 14 '18 at 12:33
  • $\begingroup$ @Anonymous there is no evidence that the appendix stores 'beneficial gut bacteria' during infections. What function it has - mainly as sampling point for the immune system - could just as well be done otherwise (most animals do not have an appendix). Same for the genitals: if gametes were designed for a higher optimum temperature, genitals could easily be internal, and more protected. $\endgroup$ – LSerni May 14 '18 at 12:40
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    $\begingroup$ Not have the genitals hanging outside the body -> Aren't testicles outside the body since sperms need a lower body temperature? $\endgroup$ – Liquid May 14 '18 at 12:46
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    $\begingroup$ @Liquid yes, but an "intelligent" design would either include a circulatory feature that is capable of carrying away and venting excess heat (so perhaps the scrotum would just be skin flaps, "frills" or the like, that dissipate the heat), or as LSerni suggested, gametes that can tolerate the higher temperatures of being inside the body. $\endgroup$ – Doktor J May 14 '18 at 14:14

Look into childbirth. It is a very risky process. Any proper design would not risk both the mother and child during the reproductive stage.

A really simple (to describe) change could be to have your fantasy races be egg layers. Egg laying is less risky because of the size/shape consistency of the egg compared to a live birth.

There's an interesting fluff piece here On Animal Biths. A lot of lower risk birthing comes down to adult/offspring size ratios.

Seahorses move the eggs to the father. I don't know a huge amount of the detail, but possibly "birth" is easier for the male as they eggs are in a more "external" area.

Many types of fish lay unfertilised eggs, which a male adds sperm to outside of a female. This means there's no risk to the parents, although the offspring are subject to predation unless looked after.

  • $\begingroup$ Hmmm, that's an excellent point. Not sure what exactly you could change though. $\endgroup$ – adaliabooks May 14 '18 at 10:28
  • $\begingroup$ Also if you could provide a bit more detail of what you could actually change to improve the situation that would help. $\endgroup$ – adaliabooks May 14 '18 at 10:34
  • $\begingroup$ That depends on the scope of your story. Egg laying might be a "simple" change. There's no reason your fantasy races have to be mammals given they are created. You could also consider something more extreme like recombination and splitting (two adults sacrifice themselves to create 3+ offspring), used in Stephen Baxter's "The We Who Sing". $\endgroup$ – Jontia May 14 '18 at 10:35
  • $\begingroup$ I think this is an excellent example of ‘improvement’ being a very hard term to define. Widening the pelvis or having the child born sooner would improve childbirth success rates, but would adversely affect the mother’s gait or infant mortality rates/development.. $\endgroup$ – Joe Bloggs May 14 '18 at 10:46
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    $\begingroup$ Childbirth is a very good choice for something that could be designed better, but "laying eggs" is not really a simple change, nor likely to be optimal for human development. Moving the birth canal forward to the lower belly would be a much simpler and more effective change. $\endgroup$ – Cyrus May 14 '18 at 14:22

I will address your initial question:

  • ... are there any major defects in a human that you would expect not to exist if someone (or something) sat down to create the perfect humanoid?

But let's formulate it in a bit different way:

  • Would we expect to be able to distinguish between designed and evolved life forms?

Yes, but not necessarily.

A thing which may distinguish designed lifeform from evolved life form is that the first one is bound by the realm of physics, chemistry and other processes affecting or theories describing ontogenesis of the life form.

Naturally evolved life form is not only bound to all mentioned above, but also by inheritance of previous life forms and their particular restrictions and environmental factors which did shape them(their ancestors) in the evolution process before it split to another branch which is a root for the life from we may investigate.

In that regard evolved life form is more constrained in choosing or refurbishing its inheritance and has history, the history behind each element of its existence.

The designed life form is more free in that regard, creators more free to implement different solutions as they are not bound by the necessity of one solution to transit in another solution they may choose solutions from all possible solutions and not care if such thing could evolve naturally, are there some problems in that evolving, is there problem in transiting from one state to another. In that regard flame throwing dragons most likely to be engineered solution. There are tricks to implement, creative solutions to create a system in the way and fashion evolutions won't work.

To ignite a flame - is it possible to use electricity, sure, piezo elements, sure it possible. will it emerge naturally? Not likely - each change in natural selection should be useful or neutral, or at least not that bad. But better are those which get something for the change.

It may be more difficult to detect the creation if creators are copycats. The life from they created may look natural, as it has pieces of the puzzle which may have recognizable historical meaning.

But also we should then take look at the whole ecosystem they exist in. The first question would be to ask if they are part of it and its historical evolution records. Then to see if their historical records belong to certain branch or multiple branches. Analyzing that data we can essentially tell if they are the probable result of the evolution of the ecosystem. Less probability, with a good understanding of the whole system and processes, higher are chances of their artificial creation.

As for specifics of improvements, it is a broad question and is opinion based part of it. Not all improvements are good in all environments, and they come with the cost of losing some options, because of fundamental limitations of blocks which are used. As an example - fur is good for the cold environment, but excessive one is limiting mobility in a hot climate. There are incompatible solutions, and more adaptations we may willing to have, higher chances to hit the wall of those incompatibilities.

We may expect a wider spectrum of parameters of environment they can live in - but it is not granted. And intelligent design may find different solutions around incompatible adaptations and each such trick decreases the probability to evolve naturally, so in a statistical sense, they can be well above average in the system, so we could suspect they are designed or it was a result of a unique situation. Taking into the account other data, we can say more precisely.

Things can be simple as everyone has blue eye's and 10-100 variations of the genes encoding that, depends how long in the past was the last correction.

very thing connection of certain aspects, as an example - not the blue eye, then died in a week or even born dead - it can be a sign of highly packed code, it can be a sign of design. Because naturally evolved life is more acceptable to mutations, more wiggle room for that, as it is a driving force for changes in their development and they are used to that. So very high mortality rate among mutants and very rare mutations can be a sign. They may look as a diverse system, but it may be static in the diversity and may have a higher mortality rate in newborns than usually average in the ecosystem system.

So there are ways to detect tampering or creation. They aren't guaranteed.

Hardest would be a good creation of a whole system from scratch trying to mask the fact of creation. A system probably can be created to be indistinguishable from a naturally evolved system. But we can test and try to determine how is the probability of the system to evolve naturally - there can be a difference in probabilities on the average in the galaxy, but we would not be able to catch the hand, just have a probability as a result.

as for improvement - add them more intelligence, the thing is not that much required for survivial, so hard to get too much of it in a natural way ...


The concept of designing a single new species to be outright better than humans needs an understanding of what humans are bad at... but all the things we are bad at have benefits in other areas. so if we were designing a species, then it would probably be for the express purpose of of filling a role that humans are less suited for. humans are not very strong on average, but can be, the problem comes from frequently very strong people have less ability to finely turn their strength, if a Brain surgeon puts a a couple grams more pressure on the scalpel they could cut something important underneath the bit they're working on and kill someone, a body builder can exert a force much much larger than an average human, but often finds it harder to judge the difference between 2 and 4 grams of weight pushing against a knife. both sides have benefits and both have drawbacks, but not in their chosen environments.

It would drastically depend on what you were designing them for, imagine a world like that of Blade Runner (original as well as sequel) but in this world they are genetically engineered humans rather than synthetic ones

there would need to be a purpose to them, if you wanted ones that worked all day every day within a coal mine, you'd probably want better ability to filter particles out of the air they breath, similar to the way the nose does but on a faster scale, and they would need to be stronger, and therefore a stronger heart to deal with the stronger muscles, but would they need to be intelligent? probably not, otherwise they might start to question "why am i doing this instead of the regular humans."

On the flip side if you wanted to design the perfect Doctor or brain surgeon (that may or may not one day be in a car crash and become a wizard...) then strength loses out to very fine and precise motor control and high intelligence, but maybe an increased immune system to deal with being around sick people all the time.

Humans are prone to genetic change, height size shape and characteristics can change significantly every generation, this is what allowed humans to evolve the way they have, but this also makes genetic disorders much more common, admittedly this tends to happen more to the male side of the species then the female, as is more common in the entire animal kingdom.

if you where designing a new species of human specifically to work in and around Radioactive areas, you would probably make the chance of a genetic mutation a lot lower, this would drastically reduce the risk of Cancers and other serious health risks.


In our bodies of evolved creatures we have the so called vestigial organs or functions, which are leftovers of previous features which we abandoned during the evolutionary path.

Some of these organs or functions are:

  • The human caecum is vestigial, as often is the case in omnivores, being reduced to a single chamber receiving the content of the ileum into the colon.
  • The plica semilunaris on the inside corner of the eye
  • The formation of goose bumps in humans under stress is a vestigial reflex: its function in human ancestors was to raise the body's hair, making the ancestor appear larger and scaring off predators

With an analogy, you could compare them to a car having leftovers of the horse attaching bars used in the chariots from which it evolved.

In a properly designed system (and I assume an intelligent designed species is such), no leftovers should be present.

  • $\begingroup$ I like my goose bumps :DDD I mean they have important part in the intelligence and perception of things and expression of things $\endgroup$ – MolbOrg May 14 '18 at 17:06

Well, to answer that question, we will have to use our imagination a little.

So, let's pretend that humans created a "new type" of human being. An improved human. How would this human look like? But would they work in a fantasy world? No. If you use a thing from science fiction on a fantasy world, it will probably not work out. So, what could you do to "improve" the human body?

To create an "improved" human body, we will not only need to compare them to normal humans, but to mythical creatures too. But, if you think about it, what would you change? It's not like we are perfect, but I think that if something needs to be changed it would be almost completely aesthetic.

I think that if you want to change something about the human body in your fantasy world, you are the only person that can really decide.

  • $\begingroup$ f you use a thing from science fiction on a fantasy world, it will probably not work out. Why not? But, if you think about it, what would you change? It's not like we are perfect, but I think that if something needs to be changed it would be almost completely aesthetic. Why? $\endgroup$ – nzaman May 14 '18 at 14:49
  • $\begingroup$ 'but I think that if something needs to be changed it would be almost completely aesthetic.' - actually a good point, we are grinded by evolution quite well. The rest are just perks or stuff we usually do not see. $\endgroup$ – MolbOrg May 14 '18 at 17:00

Intelligent design - no mouth. Mouth are not needed as food is digested through osmosis or photosynthesise (both ways working at once). You also don't need it for breathing as breathing through skin with ability of having gills-like skin. No speaking needed as telepathy would be a thing (something like Morse code by eyes but actually by changing your electro field). Also give the possibility to digest everything. Toadstool? No problem. No energetic value apart from that muscarine but that won't affect you.

why brain in skull? Keep much better eyes (like four of them) on a pole so they can see far and wide but keep brain in some extra cushion. Better even split brain functions and place their respective centers in different places in body. WITH extra replacement. So when one part of "brain" is destroyed it don't affect whole.

Regrown lost limbs. Like this is the worst. You're walking and suddenly elephant stomp on your foot. Man! So not cool. But you can easily cut it off as it will grow back in few weeks. You just need to osmosis some more energy and minerals.

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    $\begingroup$ both osmosis and photosynthesis are a large surface area to absorb the correct amounts of materials, human size and shaped animals do not have a large enough surface area they could point at the sun or submerge in whatever nutrients that are required. similary issues with Gills, but the eye pole thing could be of use in certain situtions and definately the limb regrowth $\endgroup$ – Blade Wraith May 14 '18 at 12:30
  • $\begingroup$ I doubt those changes would leave a generally human-looking being, as requested in the question. $\endgroup$ – Liquid May 14 '18 at 12:50
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    $\begingroup$ @Liquid That's a thing with intelligent design isn't it? When you try to make something intelligent you don't always end up with something looking aesthetic. $\endgroup$ – SZCZERZO KŁY May 14 '18 at 13:22
  • $\begingroup$ @SZCZERZOKLY Not sure of that. Anyway, it doesn't make your current answer any less out-of-scope (imho, at least). $\endgroup$ – Liquid May 14 '18 at 13:31

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