Humanoid Aliens?

[Moontanman]

What would aliens look like? Many people seem to think they would be more less human in appearance, "humanoid" is the term often used. But what does that mean and how likely is an alien to be "humanoid"? 

I guess defining humanoid is the best way to start, a head, a torso, two arms, two legs? By that definition a gorilla is humanoid. 

Stephen Jay Gould, is his book "Wonderful Life" Gould suggested that rerunning the "movie" of life would not result in the same organisms we are familiar with, even something as basic as vertebrates might not exist if the tape of life was rerun. 

This would suggest that aliens that resemble us at all would be highly unlikely. However there is the idea of Convergent evolution where vastly different creatures that occupy similar ecological niches often look like each other. Sharks, Ichthyosaurs, and dolphins are often cited as examples. Would this process be likely to produce alien creatures that look like us, ie humanoid?   

Should we expect intelligent aliens to resemble us? If so how closely?  

[mistermack]

The only creatures on Earth that I can think of, that have, or have had, a humanoid form, are related to us pretty closely through having a common ancestor not long ago, in evolutionary terms. 

So even here on Earth, there has only been one line of creatures that evolved in that way. 

So the chances of a similar form evolving on an alien world and developing to our level are truly tiny. You would need a planet like Earth, with all it's special features, in the goldilocks zone, protected by a magnetic field, and you would need photosynthesis to evolve, and produce forests of tree-like things on dry land. And for that planet not to be hit too often by meteorites while the aliens were evolving. And not too much volcanism. And similar gravity, and a similar greenhouse gas atmosphere. With plenty of water in oceans. 

Basically, you need another Earth for aliens who look like us. 

[Genady]

Chances are that they are headless. The brain should be better protected and insulated than ours. More like our heart, lungs, etc.

[swansont]

Dolphins are quite intelligent but don’t look like humans.

But aliens would be any species not from earth. There are millions of animal species here, with varying degrees of intelligence, and most are not humanoid. No reason to expect things would be markedly different elsewhere.

[Ken Fabian]

32 minutes ago, Genady said:

Chances are that they are headless. The brain should be better protected and insulated than ours. More like our heart, lungs, etc.

I think the advantage of tool making problem solving is that it overcomes physical limitations. Perhaps a mutant line of them needed head protection to overcome the vulnerabilities of an enlarged brain with thinned brain case to survive at all but the invention allowed them to survive where their hard headed cousins could not. A bit the way humans need clothing and shelter and fire to overcome lack of insulating fur and the products of invention allowed them to colonise environments even their furred relations could not tolerate.

[swansont]

38 minutes ago, Genady said:

Chances are that they are headless. The brain should be better protected and insulated than ours. More like our heart, lungs, etc.

Insulated is not necessarily a good idea. Keeping our brains cool is important.

[Moontanman]

1 hour ago, mistermack said:

The only creatures on Earth that I can think of, that have, or have had, a humanoid form, are related to us pretty closely through having a common ancestor not long ago, in evolutionary terms.

So even here on Earth, there has only been one line of creatures that evolved in that way. 

How do you define humanoid? 

1 hour ago, mistermack said:

So the chances of a similar form evolving on an alien world and developing to our level are truly tiny. You would need a planet like Earth, with all it's special features, in the goldilocks zone, protected by a magnetic field, and you would need photosynthesis to evolve, and produce forests of tree-like things on dry land. And for that planet not to be hit too often by meteorites while the aliens were evolving. And not too much volcanism. And similar gravity, and a similar greenhouse gas atmosphere. With plenty of water in oceans. 

Basically, you need another Earth for aliens who look like us. 

None of that would necessarily come about because the planet was identical to Earth. Gould suggested that even vertebrates wasn't a sure thing, in fact eukaryotes aren't a sure thing. Eukaryotes are thought to have come about by a symbiosis between vastly different organisms with no guarantee of similar results on any planet.  

1 hour ago, Genady said:

Chances are that they are headless. The brain should be better protected and insulated than ours. More like our heart, lungs, etc.

Interesting idea but odd that nothing like that on a large scale has been found on Earth even in the fossil record. 

37 minutes ago, swansont said:

Dolphins are quite intelligent but don’t look like humans.

But aliens would be any species not from earth. There are millions of animal species here, with varying degrees of intelligence, and most are not humanoid. No reason to expect things would be markedly different elsewhere.

I'm not sure I understand what you are saying. I would assume that on any world with life you would get a myriad of species on at least the microscopic scale ie bacterial level. But once you get to the stage of microbes... what determines where you go from there? 

39 minutes ago, Ken Fabian said:

I think the advantage of tool making problem solving is that it overcomes physical limitations. Perhaps a mutant line of them needed head protection to overcome the vulnerabilities of an enlarged brain with thinned brain case to survive at all but the invention allowed them to survive where their hard headed cousins could not. A bit the way humans need clothing and shelter and fire to overcome lack of insulating fur and the products of invention allowed them to colonise environments even their furred relations could not tolerate.

A separate head and body was already well established in mobile animals in the Cambrian well before anything like a "enlarged brain" evolved.  

41 minutes ago, swansont said:

Insulated is not necessarily a good idea. Keeping our brains cool is important.

That depends on the environment and on Earth life has struggled with both hot and cold temps.  

I think maybe I asked the question in a wonky fashion. Possibly we should be thinking about "is the humanoid form needed to make tools, hunt, process meat and hides, build shelters and such" I am open to suggestions but if this form is needed then our civilization becomes dependant on some wildly unlikely scenarios.   

[mistermack]

31 minutes ago, Moontanman said:

How do you define humanoid?

Very loosely for the purposes of discussing aliens. I would start with a body of sixty plus kilos, with four limbs (very common) no tail (pretty common), thin neck with big head (pretty rare), and habitually bipedal (extremely rare). 

38 minutes ago, Moontanman said:

None of that would necessarily come about

I'm not saying it's likely. It's very unlikely. I'm just speculating what conditions would be needed for human-like aliens to evolve.

 

[TheVat]

51 minutes ago, Moontanman said:

I think maybe I asked the question in a wonky fashion. Possibly we should be thinking about "is the humanoid form needed to make tools, hunt, process meat and hides, build shelters and such" I am open to suggestions but if this form is needed then our civilization becomes dependant on some wildly unlikely scenarios. 

I've wondered if certain lines of development (body morphology in particular) are more likely paths to a spacefaring tech society.  One guess is that you need to be able to make tools and so there's a minimum requirement of articulated appendages, and tech progress is more likely if you're land-dwelling and have a need to make fire.  That still allows a vast range of possible forms.  I liked the speculation in "Arrival" that the aliens were completely unlike humans but did have articulation at the ends of their tentacles.

BTW, some amusing visualizations of aliens are to be seen in

https://en.wikipedia.org/wiki/Barlowe's_Guide_to_Extraterrestrials

 

[swansont]

1 hour ago, Moontanman said:

I'm not sure I understand what you are saying. I would assume that on any world with life you would get a myriad of species on at least the microscopic scale ie bacterial level. But once you get to the stage of microbes... what determines where you go from there? 

There are multiple species of intelligent life on earth. How many depends on where you place the bar. So it’s too simplistic to wonder what alien intelligence would look like, as if only one species has intelligence.

[Moontanman]

15 hours ago, swansont said:

There are multiple species of intelligent life on earth. How many depends on where you place the bar. So it’s too simplistic to wonder what alien intelligence would look like, as if only one species has intelligence.

Good point, another flaw in my question, I was asking about more than just intelligence, I was aiming for technologically advanced as part of the requirements as well as form and intelligence.  

[swansont]

2 hours ago, Moontanman said:

Good point, another flaw in my question, I was asking about more than just intelligence, I was aiming for technologically advanced as part of the requirements as well as form and intelligence.  

That would require tool-making. Human precision grip aids with this, which suggests bipedalism, but it might not be required.

 

[Genady]

3 hours ago, swansont said:

That would require tool-making. Human precision grip aids with this, which suggests bipedalism, but it might not be required.

 

Could help to have more than two pairs of appendages. E.g., insects.

[mistermack]

1 hour ago, Genady said:

Could help to have more than two pairs of appendages. E.g., insects.

https://static.wikia.nocookie.net/powerlisting/images/2/29/GAN21961.jpg/revision/latest?cb=20201016181456  

[Genady]

On 9/26/2023 at 6:22 PM, Moontanman said:

Interesting idea but odd that nothing like that on a large scale has been found on Earth even in the fossil record.

Squid:

[Genady]

11 hours ago, mistermack said:

https://static.wikia.nocookie.net/powerlisting/images/2/29/GAN21961.jpg/revision/latest?cb=20201016181456  

That URL does not work for me, but this does:

https://static.wikia.nocookie.net/powerlisting/images/2/29/GAN21961.jpg/revision/latest

Edited September 28, 2023 by Genady

[Moontanman]

12 hours ago, Genady said:

Squid:

I'm not sure what you mean, a squid has a head, that head contains the eyes, the brain, and the mouth... and feet or arms but no braincase! 

17 hours ago, Genady said:

Could help to have more than two pairs of appendages. E.g., insects.

True, a praying mantis is almost the poster child of such an idea. 

[Genady]

1 hour ago, Moontanman said:

I'm not sure what you mean, a squid has a head, that head contains the eyes, the brain, and the mouth... and feet or arms but no braincase! 

I am not sure why to call this a head. I'd say it has its eyes, brain and the mouth in its torso.

[Moontanman]

21 hours ago, Genady said:

I am not sure why to call this a head. I'd say it has its eyes, brain and the mouth in its torso.

I've cut up large numbers of squid, I like to catch and eat them, the arms are arranged around the head... hence the name cephalopod. When you cut one up the head becomes obvious but if there are any experts here I would appreciate a call on this... do squids have a distinct head? Personally I'd say an octopus comes closer to your idea but both squid and octopus are highly derived snails. 

[dimreepr]

20 hours ago, Moontanman said:

do squids have a distinct head?

Define head?

For instance, a human head is the center of our intelligence, while a squid head is only, roughly, the center of it's body.

As for the topic, humanoid alien's are a human concept/conceit; the chance that equivelent intelligent life is our doppelganger, is astronomically (pun intended) small... 

[Moontanman]

4 hours ago, dimreepr said:

Define head?

For instance, a human head is the center of our intelligence, while a squid head is only, roughly, the center of it's body.

As for the topic, humanoid alien's are a human concept/conceit; the chance that equivelent intelligent life is our doppelganger, is astronomically (pun intended) small... 

I agree, in fact I would say that "humanoid aliens" is the biggest flaw in the whole "UFO Aliens" phenomena, they look far too much like us to have come from anyplace other than inside our minds.  

A squid is an example (octopus or cuttlefish is a better example) of an animal with a body plan vastly different than vertebrates. Since there is no reason to think vertebrates are inevitable in the process of evolution, in fact IMHO vertebrates are a fluke and could have easily been passed over by natural selection or simply failed to evolve at all, vertebrates evolved from invertebrates and not the other way around there is no reason to think that the evolution of vertebrates is inevitable or even likely.  

Edited September 30, 2023 by Moontanman

[Moontanman]

Would a Centaur like creature be considered humanoid if the raised portion of the creature, human part in mythological centaurs, was indeed more or less human in appearance would that be considered humanoid? John Varley raised this question, IMHO, in his books Titan, Wizard, and Demon. The aliens are so human in appearance that we found them sexually attractive and could mate with them but they were centaurs with three sexes but only two individual sexes were readily apparent. But Gorillas are humanoid but not exactly sexually compatible with us fragile humans. Would sexual attraction cause less than humanoid aliens to be considered humanoid?   

[mistermack]

Of course, humanoids wouldn't be new. Jesus of Nazareth was half man half alien, two thousand years ago. He looked human, but had very alien powers, including walking on water, turning water into wine, and multiplying solid objects like loaves and fishes. And regeneration after apparent death.

The Greeks had gods that were humanoid too, but they were just superstitious stories. 

[Moontanman]

17 hours ago, mistermack said:

Of course, humanoids wouldn't be new. Jesus of Nazareth was half man half alien, two thousand years ago. He looked human, but had very alien powers, including walking on water, turning water into wine, and multiplying solid objects like loaves and fishes. And regeneration after apparent death.

The Greeks had gods that were humanoid too, but they were just superstitious stories. 

Well gods, like aliens, are created by humans in their own image. 

[swansont]

On 9/26/2023 at 5:09 PM, Genady said:

Chances are that they are headless. The brain should be better protected and insulated than ours. More like our heart, lungs, etc.

I recently read a comment about this, arguing that it makes sense for the brain to be close to the sensory input of the eyes, ears and nose. Sight perhaps the most important, since visual reaction times can be crucial to survival.