Sci-Fi's love of Humanoids

[Lt. Staplic]

I was thinking about this recently while working on a little side project. Is it really all that un-imaginative that most of the aliens we see in sci-fi are humanoid? Essentially the humanoid structure is a central chamber with which to store most vital organs, two upper appendages used for manipulation of the environment and two lower appendages used for locomotion, and a head. Essentially though this is what's required. Cephalization of the nervous system is very common evolutionarily because it allows for concentration of nervous tissue which eventually leads to large brains like ours. It also allows for sensory organs to be directed with velocity allowing for more apt understanding of the environment. Then we move onto the main body which again seems practical, to concentrate the vital organs in one place which can then be better protected from damage, as well as reducing the amount of work necessary to transport energy to these organs.

Manipulative arms are also necessary to gaining intelligence because without some way to manipulate your environment you cannot build tools, fire, etc and eventually get to the point where you reconstruct your environment to suit your needs. Finally locomotion is essential to finding food and mates.

So really out of the design the number of manipulative and locomotive limbs is easily changed. although I would also contend that adding limbs will increase the amount of calories an organism would need to intake without necessarily increasing the functionality of the creature.

So what do your thoughts?

[shran]

Out Of Universe it's a simple limitation on the Special Effects budget to keep things manageable. You wouldn't want 15 cave-troll sized jellyfishes in your main cast operated by 3 actors. That would be way too costly.
Also, the audience needs something recognizable. A starship captain falling in love with an Orion is simply better understandable than the captain falling in love with a 30 cm high locust-like creature.
Another tought is that the only succesful configuration is the Homo Sapiens. We know for sure this shape will work in our enviroment, so one assumes this will work in another enviroment as well, and there are no signs of viable alternatives being capable of intelligent thought and rising to our level of manipulation of the enviroment.

[GrahamKennedy]

What shran said. Part of it is just the FX limitations, and that's changing now that movies and even TV shows can put essentially anything they can think of onto the screen.

But also, the point of drama is to tell interesting stories that engage people, and for that you need characters people can identify with. If Mr Spock had been a squidlike creature that communicated through colour changes in his skin it would have been lovely and alien, but would people really have identified with him as a man torn between two sides of his nature? I think not.

As for whether humans are the "ideal shape"... well evolution almost by definition produces creatures which are ideally shaped for where and how they live, so it's a bit of a truism that we are indeed very well adapted for being intelligent tool users. But I'd say we just don't have enough data to be generalising on. There are plenty of humanoid species on Earth, monkeys, gorillas, etc, and none of them evolved into truly intelligent tool users, so we know at least that it's not true that this shape generally leads that way. Whether it's gone on other worlds the way it has gone here... who can say? We'll have to wait until we go and see, I guess.

[Tyyr]

It's a question of convergent evolution. Given a similar set of environmental conditions you would expect to see roughly similar looking creatures. For instance fish. I suspect that should we ever find life on a world with large bodies of water any creatures living in them will look a great deal like fish. They might have tentacles, or two mouths, or no eyes or three tails but they will be recognizable as fish. The need to move through liquid would preclude some outlandish designs and point toward hydrodynamically efficient shapes.

A similar thing could happen with humanoid aliens. The human form is relatively efficent given our conditions. However, imagine a world in which there are many powerful armored predators that are immune to most primative tools. Conditions might favor a more decentralized design with redundant organs to let them survive attacks by these beasts. In a high gravity environment with predominantly marshy terrain a creature with four or six or more legs might be favored to help distribute the load on the ground. And on and on.

Even within the humanoid form the big problem is that you wind up with lots of rubber forehead aliens. Within the basic humanoid patter there is a ton of permutations you could do. That ever alien comes SO close to humanity is the real problem.

Still, it all comes down to the limitations of visual FX and the use of aliens in a relatable way so it's highly unlikely to change. Things like the Nav'i in Avatar are on the far edge of what people will likely accept in terms of alieness while still being relatable.

[Mikey]

OOU - we see humanoids because you can get an actor to play a humanoid. Anything other than a humanoid requires a lot of your SFX budget a/o doesn't look quite "right." Secondly, we are more sympathetic to humanoids because we are humanoids. It's easier for us as an audience to relate to a humanoid rather than a giant talking slime mold. (Which natural reaction is, BTW, the centerpiece of a lot of SF - the Horta, e.g.)

Cephalization is pretty much necessary. Whether you call it a brain like ours or some sort of ganglion comprising whatever passes for nervous tissue, something of the sort needs to be present - there can't be any consciousness, and therefore sentience or sapience, without some sort of cortex (never mind tool use or suchlike.)

The number of limbs is pretty much a set point based on the point of vertebrate divergence on the world in question. On Earth, for example, all vertebrates have four limbs no matter the environment for which they evolved. The idea that more limbs requires a more energy-rich diet doesn't make sense, though... otherwise, octopi (twice the limbs we have, and proportionally far stronger) wouldn't be able to survive as predators. Conversely, giant pandas have only the four... but don't even take in enough energy to procreate properly. The caloric requirements of a given species are almost wholly dependent on that species' typical daily behaviors. For some great sci-fi treatments of non-humanoid intelligent races/species, see H. P. Lovecraft - the Elder Things and the Great Race of Yith especially; even more interesting based on the juxtaposition with humanoid species in his work.

Lastly, bear in mind the setting of your work - convergent evolution is a strong factor. It isn't chance that cetaceans and fish have come to be built so similarly. If your setting includes a planet that is remotely Earth-like, bear in mind that there's a better-than-average chance that local evolution would have ended up looking like ours even if based on a different phylum.

[GrahamKennedy]

It's a question of convergent evolution. Given a similar set of environmental conditions you would expect to see roughly similar looking creatures. For instance fish.

Not necessarily. Fish share the ocean with many creatures that look nothing at all like fish - from the octopus to the jellyfish and more besides. Evolution can produce similar creatures in similar environments, but there's nothing to say that it must.

A similar thing could happen with humanoid aliens. The human form is relatively efficent given our conditions.

Of course, sci fi generally restricts itself to planets that are also very similar to Earth for budget reasons, too. We may find intelligent life evolved in radically different environments elsewhere. Imagine what a being evolved on Venus or the depths of Jupiter might be like.

[Mikey]

Not necessarily. Fish share the ocean with many creatures that look nothing at all like fish - from the octopus to the jellyfish and more besides. Evolution can produce similar creatures in similar environments, but there's nothing to say that it must.

That's true - evolution can find different designs for the same environment, but anything off the norm tends to be a specialist design. The form of an octopus, for example, could never work for a creature that hunts in any way even minutely different from the way an actual octopus does. If we look at vertebrate life, then the field narrows much further, and we see the effect of convergent evolution across three different phyla. Yes, there are differences between cetaceans and fish; but the similarities are far stronger. There is considerably more outward structural similarity between manatees and groupers, for example, than between manatees and elephants (the closest relatives of the manatee.)

Of course, sci fi generally restricts itself to planets that are also very similar to Earth for budget reasons, too. We may find intelligent life evolved in radically different environments elsewhere. Imagine what a being evolved on Venus or the depths of Jupiter might be like.

Nigh unrecognizable, possibly. Obviously, the main factor in evolution in such disparate environments would be environmental pressure, not the journey to intelligence.

[RK_Striker_JK_5]

In the case of those two planets, literal pressure.

It's budget, most of the time. I accept it.