Humanoid Aliens

[Draconis]

To me it seems reasonable to postulate that there are aliens out there in the universe, although whether they have actually come visiting is an open question.

But, in the supposed visits that are on record, they seem to be remarkably, perhaps even suspiciously, humanoid. I was wondering if convergent evolution would work elsewhere in the universe (I think very probably), or else perhaps otherwise said aliens would be very unlikely to be like us (bug eyed monsters with tentacles?) on the basis that the events that occured here would have to be pretty much the same elsewhere to produce a similar result.

Perhaps it's merely a case of our proposed alien needing to have a set of basic features or capabilities, such as forward facing eyes, hands, large brain, etc, with the business of exactly how the species acquires such features being irrelevant; similarly there could be extra features that have no bearing on whether a species dominates a planet (eg human appendix). Would it matter if humans had scaly skin or a tail?

Is having two legs, two arms, a body and a head idea the best layout for a dominant species? It would be rather boring if it where.

 

[rousseau]

Assuming that there is a set of constant conditions needed to produce the material phenomena that we call 'life', if other 'life' exists elsewhere it's likely anatomically similar to life on our planet.

The appearance of living things isn't really random, it's a result of physical variables that are likely unchanging throughout the universe.

The only other alternative I can think of is if there is another 'life-like' material phenomena, that's not life, but can produce refined behaviour like space travel. But then, life on this planet is only interested in other life visiting us, isn't it?

 

[whichphilosophy]

There seems to be a mathematical possibility of live existing elsewhere besides earth. What we are learning is life on earth can exist in places we once though impossible such as high and low temperatures.

 

[Bomb#20]

But, in the supposed visits that are on record, they seem to be remarkably, perhaps even suspiciously, humanoid. I was wondering if convergent evolution would work elsewhere in the universe (I think very probably)...

Perhaps it's merely a case of our proposed alien needing to have a set of basic features or capabilities, such as forward facing eyes, hands, large brain, etc, with the business of exactly how the species acquires such features being irrelevant;...

Is having two legs, two arms, a body and a head idea the best layout for a dominant species? It would be rather boring if it where.

Well, if we assume that an intelligent alien would have to have a brain in a head with eyes, and hands on arms that don't need to be specialized for walking so they're free to be used for manipulation, well, convergent evolution has already created that design several times right here on Earth.

Species like us, walking around upright, are in a distinct minority just on this planet. So I'd have to bet against any aliens we encounter being even vaguely humanoid.

 

[Draconis]

There seems to be a mathematical possibility of live existing elsewhere besides earth. What we are learning is life on earth can exist in places we once though impossible such as high and low temperatures.

I'm currently wondering if the Great Oxygen Crisis was inevitable, or perhaps if on another planet it might not have occured at all; hence those organisms for which it is poisonous would still be around. If they did the things that happened here, then the multicellular life they produce might be very different.

What sort of environment would prevent or drastically reduce photosynthesis? Perhaps a really dim sun and/or very cloudy atmosphere? Or else have lots more iron in the planet's crust, which would soak up lots of oxygen? We have only 5% iron in the earth's crust.

 

[Draconis]

Species like us, walking around upright, are in a distinct minority just on this planet. So I'd have to bet against any aliens we encounter being even vaguely humanoid.

Yes, but if they got a large brain, they are in with a shot of dominating the planet, creating advanced technology and perhaps even going for a jaunt around the galaxy.

But I do share your scepticism as to whether they will look pretty very much the same as us. They might have furry or scaly skin.

As far as the types of Aliens that have allegedly visited Earth, two types stand out. The Greys, which are arguably different enough to consider that they evolved under different circumstances than ours. Then there's the "Nordics" which look very suspiciously humanoid: tall and blonde haired. In terms of abductions, the Greys are marginally less likely to be the result of an alleged abductee's imagination than the Nordics, especially in view of the fact that Nordic sightings are more common in Europe. I'm more than tempted to think that the "Nordics" are simply peoples' imagination gone wild.

Or it all might be imaginary.

 

[Tom Sawyer]

I think that if you're in Europe and some tall, blonde guy anally probes you, that's just called "Friday night" and isn't due to alien abductions.

 

[Loren Pechtel]

Actually, when you look at it you would expect to find roughly humanoid aliens.

1) Bilateral symmetry is the simplest from an evolutionary standpoint.

2) Extra limbs use lots of energy, it would be hard for them to provide enough advantage to be worth having.

3) From an evolutionary standpoint it's much easier to go from a quadruped to an upright walker than to develop extra limbs to become a quadruped with arms.

4) We want our vision sense to be placed as high as possible both for locating food and for self defense.

5) Nerve speeds matter, we want our sensory and processing organs as close together as possible. Hence the head.

6) While there is no advantage (and some disadvantage) to having our food intake on the head it's easier from an evolutionary standpoint as we start out as flesh wrapped around a digestive system--hence the end result is likely flesh wrapped around digestive system with appendages.

7) Having our breathing intake on the head does help with swimming--you need the intake as high as possible. (Note: Whales and dolphins have shifted to a horizontal life--the upper back is the top for them. Hence they are not a rebuttal of this.)

Add all this up and what do you get? Something remarkably like a human.

 

[Angra Mainyu]

I'm not sure about that. Leaving aside other potential issues:

2) Extra limbs use lots of energy, it would be hard for them to provide enough advantage to be worth having.

But that seems to depend on the environment. Insects, arachnids, octopuses, squid, etc., do just fine with them. And plenty of monkeys and lemurs kind of added another limb of sorts. So did elephants.

3) From an evolutionary standpoint it's much easier to go from a quadruped to an upright walker than to develop extra limbs to become a quadruped with arms.

Maybe so, but what about going from a six-legged thing to a four-legged thing with two arms, or from an eight-legged thing to a six-legged thing with two arms, and then perhaps to a four-legged thing with four arms?
Alternatively, how about going from a 8-tentacled thing to a thing with two arms (or arm-like tentacles) and 6 legs?

There is also the question of genetic engineering. Advanced star-faring aliens may well be the result of, say, millions of years of that, so who knows?

 

[Loren Pechtel]

I'm not sure about that. Leaving aside other potential issues:

But that seems to depend on the environment. Insects, arachnids, octopuses, squid, etc., do just fine with them. And plenty of monkeys and lemurs kind of added another limb of sorts. So did elephants.

3) From an evolutionary standpoint it's much easier to go from a quadruped to an upright walker than to develop extra limbs to become a quadruped with arms.

Maybe so, but what about going from a six-legged thing to a four-legged thing with two arms, or from an eight-legged thing to a six-legged thing with two arms, and then perhaps to a four-legged thing with four arms?
Alternatively, how about going from a 8-tentacled thing to a thing with two arms (or arm-like tentacles) and 6 legs?

There is also the question of genetic engineering. Advanced star-faring aliens may well be the result of, say, millions of years of that, so who knows?

Much of what you're talking about is small stuff. Square-cubed law: Those extra pieces mean a lot less when the critter is small enough.

 

[braces_for_impact]

I've wondered if there's perhaps a selection bias that would make for somewhat similar body plans among space faring species. After all, regardless of what species take to the stars, they are going to need to use tools that require very fine manipulation. At least, I can't think of another way. Of course my failure of imagination doesn't make it so. I mean, suppose dolphins and elephants were even smarter than we. What good would that do without the ability of very fine manipulation that our hands give us? I'm trying to imagine an elephant or dolphin technology, and I'm not having much luck. I could see a cephalopod mollusk type being with each arm ending in 5 or 10 very fine tentacle-like structures being used for very fine manipulation perhaps. It could evolve to perhaps only have 4 arms, two which function with "hand-tentacles" and two which resemble "feet".

I wonder if such a selection bias would result in many species having similar technology as well? Silicate based electronics and so on. I had thought of an organic type of technology, but it seems to me that such a technology would require fine manipulation on the genetic level of some type anyway, so back to square one.

Fun questions to ponder!

 

[PyramidHead]

Actually, when you look at it you would expect to find roughly humanoid aliens.

1) Bilateral symmetry is the simplest from an evolutionary standpoint.

2) Extra limbs use lots of energy, it would be hard for them to provide enough advantage to be worth having.

3) From an evolutionary standpoint it's much easier to go from a quadruped to an upright walker than to develop extra limbs to become a quadruped with arms.

4) We want our vision sense to be placed as high as possible both for locating food and for self defense.

5) Nerve speeds matter, we want our sensory and processing organs as close together as possible. Hence the head.

6) While there is no advantage (and some disadvantage) to having our food intake on the head it's easier from an evolutionary standpoint as we start out as flesh wrapped around a digestive system--hence the end result is likely flesh wrapped around digestive system with appendages.

7) Having our breathing intake on the head does help with swimming--you need the intake as high as possible. (Note: Whales and dolphins have shifted to a horizontal life--the upper back is the top for them. Hence they are not a rebuttal of this.)

Add all this up and what do you get? Something remarkably like a human.

Or like an ostrich with arms. Our forward-bending knees are a bit of an oddity in the animal kingdom, as are our flat faces.

 

[Terrell]

I think it's a pretty interesting thing. I'd suspect that there will at least be some cases, either current, future, or past where there have evolved intelligent creatures that are humanlike in appearance. 2 arms, 2 legs, head with sensory organs, etc. or their equivalents. It wouldn't surprise me though if some creatures had something akin to tentacles or trunks for manipulation of objects in lieu of hands. No idea what they may have in lieu of legs, but that's probably due to a lack of imagination on my part. If they're able to make tools, I'd think they'd simply design them with their way of manipulating objects in mind.

I think it would be based on what was both lucky and useful wherever they evolved.

 

[Tom Sawyer]

As long as they have compatible sexual organs, it doesn't really matter what they look like.

 

[Loren Pechtel]

Actually, when you look at it you would expect to find roughly humanoid aliens.

1) Bilateral symmetry is the simplest from an evolutionary standpoint.

2) Extra limbs use lots of energy, it would be hard for them to provide enough advantage to be worth having.

3) From an evolutionary standpoint it's much easier to go from a quadruped to an upright walker than to develop extra limbs to become a quadruped with arms.

4) We want our vision sense to be placed as high as possible both for locating food and for self defense.

5) Nerve speeds matter, we want our sensory and processing organs as close together as possible. Hence the head.

6) While there is no advantage (and some disadvantage) to having our food intake on the head it's easier from an evolutionary standpoint as we start out as flesh wrapped around a digestive system--hence the end result is likely flesh wrapped around digestive system with appendages.

7) Having our breathing intake on the head does help with swimming--you need the intake as high as possible. (Note: Whales and dolphins have shifted to a horizontal life--the upper back is the top for them. Hence they are not a rebuttal of this.)

Add all this up and what do you get? Something remarkably like a human.

Or like an ostrich with arms. Our forward-bending knees are a bit of an oddity in the animal kingdom, as are our flat faces.

Change the knees and face and we still have something that's basically humanoid.

An ostrich with arms in place of it's vestigial wings would still be approximately humanoid.

- - - Updated - - -

As long as they have compatible sexual organs, it doesn't really matter what they look like.

And what makes you think interspecies sexual attraction would occur?!?! It's based on some pretty subtle factors between humans, an alien that matched them would be exceedingly unlikely.

 

[Tom Sawyer]

Dude, if humans ever run into aliens, we are so going to nail them. It's 90% of the rationale behind the entire space program. Who cares if we find them attractive? Put a bag over each of their heads and do your business.

 

[Keith&Co.]

Dude, if humans ever run into aliens, we are so going to nail them. It's 90% of the rationale behind the entire space program. Who cares if we find them attractive? Put a bag over each of their heads and do your business.

That's why the Pioneer 10 and 11 spacecraft were adorned with pictures of naked people. Come here and sex us, we're ready is the message we're sending.
All the best fanfiction involves fucking something that's not entirely (or even peripherally, in some cases) human. Imagine when we can move some of that from the fiction to the 'amateur' portions of the porn library.

 

[Angra Mainyu]

I'm not sure about that. Leaving aside other potential issues:

But that seems to depend on the environment. Insects, arachnids, octopuses, squid, etc., do just fine with them. And plenty of monkeys and lemurs kind of added another limb of sorts. So did elephants.


Maybe so, but what about going from a six-legged thing to a four-legged thing with two arms, or from an eight-legged thing to a six-legged thing with two arms, and then perhaps to a four-legged thing with four arms?
Alternatively, how about going from a 8-tentacled thing to a thing with two arms (or arm-like tentacles) and 6 legs?

There is also the question of genetic engineering. Advanced star-faring aliens may well be the result of, say, millions of years of that, so who knows?

Much of what you're talking about is small stuff. Square-cubed law: Those extra pieces mean a lot less when the critter is small enough.

Elephants are big. And some monkeys and lemurs aren't so small.
But that aside, you're thinking too much about present-day conditions on Earth and out of the ocean.
For instance:
1. Some octopuses and squid are a lot bigger than humans.
2. Some arthropods were huge during the Carboniferous (Arthropleura is the biggest known).
3. The alien planet may well have (for example) lower gravity than Earth, but higher atmospheric pressure, resulting in very different conditions for evolution.
4. The extra limbs may be useful in a very low gravity environment in space, and genetic engineering is an option.

 

[Peez]

 

[untermensche]

Who knows?

What are the odds the cell will evolve?

Maybe greater than the number of planets in the universe and the Earth just beat the odds.