I was reading an article on Earth-like extrasolar planets and watching Star Trek at the same time when I got the idea. Could intelligent aliens look like humans? Supposibly Earth-like extrasolar planets might be very commen (some even believe that 25% of all planets in the galaxy are Earth-like). Conditions on those planets would be very similer to those on Earth, hence the name. One could imagine a near copy of the sun with a planet the size of Earth in the habital zone, would have a very similer climate and geographical formations to Earth. Could'nt humanoid beings develope there? When you think about it, it would'nt be that hard to imagine something like Cardassians or Klingons developeing. Some of these humanoid spices might have strong ties to reptile DNA, and look like the Cardassians or Xindi from Star Trek. Something like Klingons might be a more robust, primitive version of us. So my question to you is this: Would you be suprised if most intelligent beings in the galaxy are humanoid?

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:unsure: It largely depends on the broadness of your definition of humanoid. Of course we don't know and won't know even after we have seen a few of them. My guess is that brain energies and efficiencies will drive the configuration of sentient species to 2 locomotion appendages, 2 manipulation appendages, seeing, hearing, touching, and smelling organs/systems, and regulated blood temperature. Statue and facial features won't necessarily be constrained to resemble humans. They will be physical and constrained to the 3 dimensions of space and one of time and won't flit about in any other dimensions. :unsure: :unsure:

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

I imagine a race would have to evolve through the stages of technology... limbs to use tools, having whatever area containing the brain expand to accomodate greater intelligence, etc.

It also depends on the habitat of the planet, assuming they are still living on the planet on which they evolved (and not on a moon or other planet). Perhaps severe changes in altitude make for civilizations with different abilities to breathe the atmosphere, or rocky/volcanic conditions make for the ability to resist heat or climb mountains.

If their sun has become a red giant over the last few million years, and they moved to a safer planet or somehow managed not to die out, their vision might extend into the infrared spectrum more than ours. Perhaps they did not evolve to use sound, or their sense of smell is sensitive enough to act as vision.

I rather think they would probably NOT look really humanoid... who knows what ecological niche a species must fill in order to become the dominant intelligent race... what if it's a watery world...

Polarbeast

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I do not know how likely or unlikely it will be. I think we will be surprised by the variety of life and places life can exist. Life we recognize as life. I wonder if sentient life forms that have evolved in very different environments would even be able to recognize each other as "alive". I am sure there must be science fiction written about this. I imagine things like photovoltaic life forms, gaseous life forms, etc. I am reading a book now called "Hidden Empire" where a advanced civilization in a gas giant went unrecognized until humanoids ignited the planet to form a new sun.

I did want to interject that there may be true commonalities in life on various planets and other environments if theories like panspermia turn out to be valid, even if the shape these life forms take are not 'humanoid'.

I have also wondered about how realistic it is to think we would be able to settle an 'earth-like' planet. There is a lot of science fiction out there that considers such things as common/conflicting proteins in a similar but alien environment. The DNA may have a common origin but the proteins it makes on a different planet may be deadly to us. We may be poison to other life forms on earth-like planets.

I think Star Trek's plethora of sentient humanoid life forms filling the universe is too human-centric to be real. :-) I think it is necessary for reasons of plot and so forth. Also, we don't have to many other models.

I think life is unfathomable. Could it be that we are even just a small barely sentient part of what is aware and alive about earth. Ghia, anyone?

Fun topic.

There are tasks that intelligent life needs to perform, like manipulating, communicating and sensing, but there are loads of way these are done on earth, let alone on other planets. Just look at the octopus, compound eyes, fire flies, dolphins etc. I don't think it's difficult to imagine aliens based on even more outlandish forms than these.

I think Star Trek used humanoid aliens to save on special effects and to make the communicating easier. There were some exceptions, like the nanobots from the Next Generation and the sentient rock from the original series. But these tended to follow a simple story of: Alien causes trouble, debate whether it is alive or not, managed to establish communication, all ends happily ever after.

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I think the humanoid form is a somewhat efficient design of evolution in responce to the needs and conditions that are specific to our gravity, temperature and other environmental factors here on earth. Provided such similar factors are present on other earthlike worlds, I beleive the process of evolution would eventually come back around to the same or similar humanoid design. But since evolution can be a very slow process (in our perception of time) the likely hood of our finding other humanoid life is probably going to be a lot smaller than the likely hood of our finding other earth like planets.

I wonder how things would evolve on an earthlike world with gravity more similar to our underwater environments? I also wonder whether evolution would also create other forms of life like we have on this planet (cats, dogs, rodents, fish, etc) and what they would look like.

To answer the question...yes, I would be a little surprised if we discovered that there was an abundance of humanoid life in space, however I'd be even more surprised if we ever discovered a way to cheaply and efficiently get off this planet and reach warp like speeds that enabled us to do more exploration of space than what we do now.

It´s all about symetry. We humans have what is called a lateral (don´t know if this is the correct term in english) symetry. But there are life forms on Earth with other kinds os symetry. A sea star has what is called a radial symetry. I agree that our "configuration" gives us very usefull habilities (as posted previously) but don´t forget that we are as we are because of the conditions thru out our evolution on this planet (and all the consequences that come from that)

having just read Michio Kaku's interview about what scientists hypothesize about Type 2 and 3 civilizations, he says that these beings will be able to manipulate space-time the way you or i would manipulate a wet washcloth... so i would imagine these Type 2 beings would be able to materialize when they are on planets that have a specific gravitational pull, and when they are travelling between universes they would naturally dematerialize and let their minds control and navigate any "space craft" they might be travelling in. maybe they'd have "2 legs" or "2 eyes" when they assumed a terrestrial form, or maybe they'd be able to shape themselves into something that would not look out of place to a native of some exotic unexplored planet by taking in soil and atmospheric samples, and running them thru some kind of analyzer. then Type 3s would basically be shapeshifters and could assume any size or shape they needed to be depending on which kind of environment they happened to be in and they wouldn't use handheld tools to accomplish these feats, they would just have to think about them and *voila* they've morphed again, like interplanetary chamaeleons...

just rambling and imagining .. hi all..i'm new here.

While it may be nice to think that we are a foregone evolutionary conclusion, I think it is a little human-centric to assume that the same path would be followed anywhere else. The Dinosaurs ruled Earth for much longer than we have. If it weren't for them being wiped out, we probably wouldn't be here to talk about it.

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The difference between us and the dinosaurs is that they had all that time and didn't develop speech, writing, tools, technology etc. Now it's arguable whether we've done "better" but we've definitely done more.

But I think the speed of our development is a double-edged sword. We'll either burn up fast, die young and leave a good-looking extinct species; or we'll make all these amazing advances that we're speculating about. What I don't think will happen is that in 1000 generations we'll be anything like we are today.

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Spike
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Well, I think we are just an experiment with nature...and we are the first experiment to turn loose on the experimenter.

Just one thing: if there were an advanced civilization on Earth anywhere from 5.4 Billion years ago to six hundred million years ago, what are the chances we'd find out about it?

About one in 10 to the 56.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

We have a hard enough time finding the remains of our civilization from 8000 years ago. I think that it would be difficult to find remains of civilization that is any older than a million years or so. If a civilization did exist though, there is no reason I could think of that it would completely die out. Even nuclear war wouldn't completely wipe out civilization, just rough it up a bit.

As for the humanoid thing - dolphins look a lot like fish even though they came from a completely different spot on the evolutionary tree. I wonder how much necessity will constrain how an organism will develop in these cases. I would guess that with earth like gravity, and a terrestrial (rather than oceanic) habitat, our intelligent lifeforms will have at least four limbs (two manipulating, two for walking). Other than that, anything goes.

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I agree with ASEI anything does go, just imagine a creature which evolved in a liquid medium. It would need to travel in a “Space ship” filled with a liquid, it would need to communicate through liquid a so forth. What weird and interesting adaptions would result from such an evolution. This creature would have to discover countless other technologies just to survive. Then the question arises, would we even recognize such a creature. :huh:

You mean like us?

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Well I was actually referring to species still in a liquid medium ^_^

I don't think an advanced liquid-dwelling lifeform could evolve. In a liquid, you can't have fire, which means no metallugy, which means no electricity. Maybe they'll find ways around it, but it seems unlikely.

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Perhaps you underestimate the power of evolution to drive them out of the liquid.


Evolution is very wasteful at first until it produces sentients capable of technology development. Whatever is not prohibited by the laws of physics will be tried in many places more than once.

Europa is a likely example of a water world in which life could evolve with little hope of crawling out onto dry land but mindless evolution cares not a whit. It could produce critters which would use instinctive biological functions to build hermetically sealed calcate/silicate (or other material depending on what's prevalent) modules thus creating totally submerged dry land for their descendants or others to evolve dry land relevant technology. As intelligence increases it will produce curiosity which will lead them to break through the icy shell which at first will cause great trauma and even death for some of them. They will solve this dilemma and establish outposts on the surface of Europa and begin to contemplate the universe as we do. Prior to this their view of the universe would have been very myopic. These critters will probably have a crablike or scorpionlike appearance; however, we should not rule out reptilian nor mammal like creatures with breathing apparatuses greatly extrapolated from gill-like structures. Evolution can also provide bio-lights and even bio-torches (hypergolic processes useful to tunnel through the icy shell ) as well as capabilities we (I) haven't thought of.

Soup up your imagination; join me in dreaming up a practical biota for Europa, Ganymede, Titan, and Callisto. Assume the energy source is a combination of gravitational flexing and radioactive element decay heat.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

I'm guessing, because of evolution, they could look somewhat like us. But, you can bet, they'll not be a vertebrate.

They will almost certainly look nothing like humans; even the bipedal bilaterally symetrical ones with a distict head will look incredibly outlandish compared to anything on Earth, as they will share no common ancestor.

Other species will look entirely alien...

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I think it is naiave of us to think that creatures on another planet would become humanoid in shape. How much of our biological structure is due to our gravity, and the gasses present in our atmosphere . If the earth had been 5 degrees hotter when we made that special leap from small mammals to larger mammals, we would have needed to develop a better circulatory system to enable us to be more efficient in cooling ourselves, either by producing baggy skin (such as the elephant) or to remain much smaller as to not produce as much body heat. Minor differences in our history could have had drastic effects on our evolution. Other species may breath through their skin, rather than have a respiratiry/circulatory interchange like humans, leading to completely different anatomical design. If Gravity had been 15ms^-2 instead of 9.8, would we have made the transistion from walking on all fours to standing upright, we would most definately not have an average height of 175cm (approx).

P.S. GOURDHEAD, I like your prediction for life on europa, nice work.