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Callisto
2004-Oct-04, 02:20 AM
We've seen what aliens might actually look like from a lot of movies over the years, but what do you think aliens look like?



http://fig.cox.miami.edu/~cmallery/150/astrobiol/ET/alien040.jpg

antoniseb
2004-Oct-04, 12:36 PM
Originally posted by Callisto@Oct 4 2004, 02:20 AM
what do you think aliens look like?
Mostly like bacillus bacteria.

eburacum45
2004-Oct-04, 03:04 PM
Absolutely. The most widespread form of life in the universe is probably deep crustal extremophile organisms of some sort.

But for an idea of what I think they might look like here are a couple of images...
Eburacum alien worlds (http://eburacum45.5u.com/alien_worlds.html)

wstevenbrown
2004-Oct-04, 06:55 PM
A critical juncture seems to be the invention of the cell wall. Most possibilities for "our" type of life vanish without it. Separation forced speciation, which forced competition. After competitive evolution came cooperative association (different types of cell hanging out together to use each other's products and/or wastes. See the writings of Lynn Margulies). The rest is history, as they say.

Back on topic, I think the default lifeform for the cosmos is pre-cell-wall. Hard to imagine a starfaring (on an intentional basis) race of that sort. Might be a sci-fi story in there somewhere-- how would we interact? :unsure:
Regards, Steve.

imported_Solaris
2004-Oct-05, 06:06 AM
Given that they are probably intelligent like our selves. They would most likely be bipedal, have numerous digits at their extremities, have some sort of stereo vision,are capable of storing energy; ie (food), and reproduce. I believe they would look a lot like us. Their facial features, skin texture, location, of their head, limbs, sexual organs, eyes ears etc., could be different.

Frisbee
2004-Oct-05, 08:54 AM
I figure they original poster was talking about what *intelligent* life would look like. I don't know about your, but all those bacteria look the same to me.

My take on it is that they would need to be mobile in order to go and get food. They wouldn't neccesarily have to be bipedal, IMO. Most mammals are quadrapes, aren't they? so we're certainly in the minority within our own mammalian class.

They would need some way of manipulating objects, tools, and food. Fine manipulators that are flexible and grip well in a stable grasp.

They would need to eat. There are various ways of absorbing stuff into the body, so I'm not sure a "mouth" per-se is a pre-requisite.

They would need to have some sort of metabolism, and produce waste products.

They would also need some means of observing the world around them. It doesn't neccesarrily mean that they would have "eyes", but they'd need to be able to determine distance, speed, recognise other individuals of their own kind.

And importantly, there isn't going to be much spaceship building going on if you can't communicate with one another.

That's about all I can think of that's a neccessity.

-Cheers

Frisbee

Sunstar
2004-Oct-05, 09:09 AM
Probably SETI porject can find one of them and we will all know how aliens may look like. It would be a real fun to find some of them and get to talk to them.

GOURDHEAD
2004-Oct-05, 04:01 PM
They would also need some means of observing the world around them. It doesn't neccesarrily mean that they would have "eyes", but they'd need to be able to determine distance, speed, recognise other individuals of their own kind.

And importantly, there isn't going to be much spaceship building going on if you can't communicate with one another.

That's about all I can think of that's a neccessity.

You didn't mention the effect of the natural selection process that continually filters the large number of "plans" attempted by the "change and test" forces of evolution. It is not only necessary that the mechanism function adequately; it must succeed in the competition with its "siblings". Bipeds with arms containing from 4 to 10 digits each, a face near the major organ of the central nervous system, and not encumbered with an awkward skin or skin covering will have significant advantages over those not so equipped. Watch out for the weasels and their kin! Natural selection is working with the same focus all over the universe and will produce critters all over the place that won't find each other too scary. The first "species" in a system to assess its survival a month or so in advance, by reasonably comtemplating the forces at play to terminate it, will rise to dominance and develop technology in order to be on their way to modifying the universe to suit themselves. Once galacticly established, its longevity will be asymptotic to perpetuity, an important term in the Drake equation.

Ola D.
2004-Oct-05, 08:00 PM
I don't care about how do they look as much as where and how to find them! :)

Well, i imagine them having larger brains and smaller bodies; similar to us but a bit mutated. Or maybe something else?! :huh:

Bridh Hancock
2004-Oct-06, 04:12 AM
[FONT=Times][SIZE=14][COLOR=purple]
Classifications of alien life: 1. lowlife (bacteria-like); 2. static (plant-like); 3. active (animal-like); and 4. highlife, from one or more of the other groups that we might communicate with. What else?--Sentient oceans and clouds?

I remember reading an article about aliens that are coming! and are coming here!! in that most something-or-other of intellectual and scholarly journals, the Weekly World News, which came complete with a photograph of ... dust mites. Oh well, ho-ho.

Distance is too wide, and space too cold, except for suns too hot; and so we really can only view and calculate prior to communicating. Meanwhile, on a roguish sort of planet-comet travelling around our sun are the Nibiru, preparing to return to Earth, while other secretive sentient entities, already here!, crush cryptic motifs into European wheat fields. What do these aliens of the 4th classification look like?--clowns?

Cheers and green cheeze to yezorl.

mark mclellan
2004-Oct-06, 08:46 AM
I also think that they will resemble us "loosely". I am assuming that mother nature is a universal lady and not localised to planet earth, therfore i am also assuming that the natural processes of evolution will end up with the most intellegent species of all planets being roughly similar to ourselves. I am assuming intellegence to mean capable of asking "why" and the capability to plan and explore space. :D :rolleyes: ;) :ph34r:

eburacum45
2004-Oct-06, 01:44 PM
Perhaps a few species of intelligent life will be upright bipeds; but with a radically different evolution to our own they will look bizarre and inhuman;

the quasi-humanoid species will probably be more disturbing than the non-humanoid species, in my opinion.

astromark
2004-Oct-08, 02:50 AM
:huh: "They will look bizarre and inhuman". Well of corse they will, they are. I have trouble believing the things I see in this forum. Where have you been? Do you read any of this stuff. You should. You might learn something... scroll back and read Mr gourheads and other postings in these colums... you will be enlightened. and dont get all prissy and affended, open your eyes and mind to the science. and continue to question and enquire. Its good for all of us.
:blink: The very thought that an alian might look like us is redicklyiouse ( silly ) The upright biped sentiant beings are probebly alone here on planet earth. Other intelagent beings capable of technoligies simular to ours may look very diferent indeed. Just looking around this planet we see other life forms that have developed comunitive skills and none of them look like us. Octipuse, whales, and Ants., get the idea....

rahuldandekar
2004-Oct-08, 07:31 AM
I'll answer why that is. Our upright stance, colour vision seeing only what we call as the visible spectrum - all have been developed to adapt to situations here on earth. The upright stance for surviving on the plains using our most sensitive organ, the eye. Colour vision ( development of the eye ) because the sun emits most of it's light in the visible part of the spectrum. I agree that the upright stance set the hands free that helped develop tools and civilisation, but the limbs themselves are an adaptation for walking on land.

That a certain adaptation was chosen by us does not mean it is the only one which makes intelligent life possible , for there might be infinite other pathways. That's the reason that I don't believe in alien incidents - The aliens in them have two eyes, mouth, two free hands and walk uprightly and bipedally. These adaptations have been developed by man for purposes other than intelligence and civilisation, and are surely not the only ones developed by aliens , who, on their planet, might have faced other situations, and developed something akin to an eye on their lower body, and might have some other combination of traits that made them as advanced as ( or superior than ) us.

suntrack2
2004-Oct-08, 12:42 PM
big head,small height, leisure rays in the eyes, having a sofware bound on the chest, walking style sometime like a robo, sometime like a hair,some time like a deer, sometime like a very fast jet, arms like solar panels, some 2-3 antenas mounted on head [this is the ultra modern alien] some other mold into verternary aspect like a neck like jiraff, the eyes like a frog, stomatch like ceal,and the tounge like a snake of 8 feet. legs are thin and small in height, the head and neck moves like a table fan but stopless, moving round totally. don't worry these are my ideas, finally they can be shape of birds like, but the head is of man over the body of bird, taking a take of like a giant flying container plane, some are small in sixe like a sparrow, having no head but the head is on the back, and expanding a large wings, then sparrow we can change into vulture...
we can imagine lot more aspects.still you wait when they [aliens]will meet then only how they look into appearence that only can be imagine later, i don't when they are reaching to earth, may be they are in the middle distance, or may be they are taking rest on different stars.....

sunil.

eburacum45
2004-Oct-08, 01:38 PM
all I am saying is that I am hopeful that many varied species of intelligent life live in our universe; but they are probably very distant from us, in every sense of the word. The closest intelligent upright biped species apart from ourselves might be hundreds of thousands of light years away.
And if we met them they certainly would not resemble humanity as much as Klingons seem to, or Cardassians, or Ewoks, or any of the alien species we see on TV or in the films.

I strongly believe in nonhumanoid aliens, as most of the posters here know; but there is no rule of the universe prohibiting upright bipeds.

isferno
2004-Oct-08, 01:54 PM
I've already read quite some good remarks here in this thread.

If you want to make a global assesment you can use the following:

- Must use limbs to handle tools.
Depending on the number of limbs, this will mostly lead to a bipedal lifeform.

- Must convey information in short time span
Signlanguage just does this, though out of sight communication is more probable. This implies hearing, and speech. Chemical/Biological exchange of information is just to slow.

- Must be able to gain information
Smell is also an important asset, as it warns about food, places etc. Of coarse, sight which reveals info nescessary for survival will be important to. Depending on the star, world, this might show some variations, and most probably will benefit lifeforms which live during daytime.

- Agility.
Exoskeletons are actualy quite heavy and limits the mobility. Larger insects (like Xindi in star trek serie) would have to have quite a thin exoskeleton, making them vulnerable.

- Land living
watercreatures have some drawbacks. Just imagine the invention of fire. Amphibians might do the trick, though over time, depency on swampy places will limit them and will probably make them less likely to go beyond a simple tool age.

- Omnivores
Both carnivores and herbivores lack interrest in one aspect of nature. Carnivores would not directly benifit from limbs which do not aid their hunt. And intelligence would only make them better use what they have, and not change their limbs into tool using objects.
Herbivores lack the possibility to remove dangers from their world.

- Management
Any large project requires that someone has the idea and others aid to accomplish it. This will always lead to some form of hiarchy.

- Clothing
Clothing for protection, (and surely for ceremonial wear), will be common.

Beyond this, almost everything is possible. Nature has a way of coming up with interresting ways to solve problems. Also psychological aspects will influence cultural traits. For example mating and nursing behaviour. As for missing a voicebox, which might lead to whistling and clicking for communication.

wstevenbrown
2004-Oct-08, 06:53 PM
I think that land creatures may be in the minority. Consider: whenever water is in adequate supply to form life, there is usually too much of it! Our own rock is only 23% land area (currently growing smaller). On a thalassian world, the most successful design, from the standpoint of promoting intelligence and tool use, is the cephalopod. Octopi, squids, and nautili all have the manipulating members, jet propulsion, and image-forming eye as well as adequate image-processing brain space. This last is a real puzzling case of so-called parallel evolution-- nobody can figure out how eyes which are essentially identical to our own evolved independently in such diverse creatures. The major difference is that our sclera is an elastic membrane, whereas in deep-sea creatures it is a sesamoid bone. I don't consider dolphins because most of their evolution took place on land. Intelligence in a fire-free environment may focus on other disciplines-- chemistry, electrophoresis, magnetohydrodynamics, metals science based on electroplating rather than forging/smelting. We can't really say how such an intelligence might approach interworld communication or travel-- the negatives here reflect only our own inability to achieve those ends by means presently known to us, in an environment we didn't "complete" our evolution in. That last sentence looks a little twisted, even to me, but I hope you all know what I mean. Steve

isferno
2004-Oct-08, 09:41 PM
By bypassing dolphins, you already admit yourself that, how strange it may seem, aquanautic creatures don't evolve beyond a certain point.

kashi
2004-Oct-09, 12:03 AM
I think they'd almost definitely be green.

isferno
2004-Oct-09, 01:40 AM
Green? http://www.universetoday.com/forum/style_images/1/icon8.gif

:P

Callisto
2004-Oct-09, 01:52 AM
I think they'd almost definitely be green.

yeah green, majority of people in this world imagine aliens green thanks to televison and movies. <_< I like green :)

Betelgeuse
2004-Oct-09, 08:25 AM
The truth - we don&#39;t know.

The thing is, if you take a movie like E.T, the alien has arms and legs just like us, and from what we can see breathes in the same way, however, that seems to me as though E.T is adapted to OUR planet. Therefore, the point I&#39;m trying to make is that differen&#39;t life forsm need different gasses etc to live and then adapt to look that way e.g a fish&#33;

But, I don&#39;t really know. The bacteria idea sounds pretty accurate. Can anyone give any feedback on my hypothesis?

mark mclellan
2004-Oct-11, 07:54 AM
Astromark,
"They will look bizarre and inhuman". Well of corse they will, they are. I have trouble believing the things I see in this forum. Where have you been? Do you read any of this stuff. You should. You might learn something... scroll back and read Mr gourheads and other postings in these colums... you will be enlightened. and dont get all prissy and affended, open your eyes and mind to the science. and continue to question and enquire. Its good for all of us.
The very thought that an alian might look like us is redicklyiouse ( silly ) The upright biped sentiant beings are probebly alone here on planet earth. Other intelagent beings capable of technoligies simular to ours may look very diferent indeed. Just looking around this planet we see other life forms that have developed comunitive skills and none of them look like us. Octipuse, whales, and Ants., get the idea....

Are we not all entitled to our own opinions? Who are you to assume the power of enlightenment ? The very idea that an alien (out of maybe millions) might look like us is not so ridicules to be silly at all&#33; So far it is the only form of life that we know of that has the ability to explore space &#33; Local communication between whales and ants does not answer a question about aliens because neither of those species can leave our planet, so i am guessing that we have less chance in being visited by an an ant from outer space than we have by some sort of humaniod.
Everybody keeping have your own thoughts and opinions...they are only silly if YOU know better :angry:

eburacum45
2004-Oct-11, 12:33 PM
Read Starmaker by Olaf Stapledon; it is an old book, written in a style unfamiliar to modern readers, but there has never been a better analysis of the possible shapes of intelligence;
he imagines intelligent bipeds, echinoderms, amphibians, centaurs; intelligent ships (seaships not spaceships); intelligent swarms of insectoids, birds, fish, bacteria; plantlike mobile organism, and symbiotes of various kinds.

if you are prepared to consider all the possible arrangements of mind, sensors and manipulatory equipment you will see that the incidence of anything resembling humanity except on a superficial level will be vanishingly small.

astromark
2004-Oct-11, 08:15 PM
:rolleyes: And I thought I was the only person to have read that book...
Thats where my ideas were stollen from...
The pasage of time will or may prove us wrong or write... but I dont think we will ever find alians.

Betelgeuse
2004-Oct-12, 06:56 PM
Originally posted by mark mclellan@Oct 11 2004, 07:54 AM
The very idea that an alien (out of maybe millions) might look like us is not so ridicules to be silly at all&#33;
This is an interesting point. Arguable, but interesting. I mean, like I said before, WE DON&#39;T KNOW&#33; For all we know, "aliens" could actually be splitting images of ourselves - there could be a "mirrored" wold out there somewhere where there are some sort of clones that resemble ourselves. We don&#39;t know. Could be true.

Nice point, mark mclellan&#33;

Rigel.

edwinksl
2004-Oct-21, 02:49 AM
Hm, I was thinking that aliens may be already out there, just that we cannot see them because our eyes can only detect the visible region of the EM spectrum. The aliens may be visible in other regions of the EM spectrum, but probably a small range like the visible range. :blink:

Betelgeuse
2004-Oct-21, 05:24 PM
edwinksl.

When you say "out there", do you mean out there in the universe or out there in our own world?

Rigel
:huh:

eburacum45
2004-Oct-21, 08:23 PM
by the way, objects that don&#39;t reflect light in the visible spectrum are black, not invisible.

astromark
2004-Oct-25, 06:12 AM
:rolleyes: There is no right or wrong here...and I was not being so presumptiouse as to sagest my humble opinion was better than all the others. I am only trying to provoke you and others to think a little more about the reason we look like we do.
My remark about ants and whales is valid if you concider that an ant like creature might develope a group intelagence and could develope technoledgy. While whales dont seem to aspire to space travel. You only need to go back 1000 years or so and we dident iether., and then you could concider that they never needed to build anything. Unlike us, they live in harmony with thier enviroment. Have you thought about the secret life of plants. That seem to sence danger and release chemicals to repair damage before it happens. Could you amagine a tree with a thought process. well no nor can I but its a thought a... and as for being able to space travel... Ha. the moon is very close. I could argue that its hardly space travel, only just. we are infants stepping into a very strange place, space. :blink:

suntrack2
2004-Nov-10, 04:33 PM
aunt like creatures and some reptile like, some are giant larger than elephant also, may be possible, and some like octopus also, aliens are aliens even we are aliens for them.

sunil

ynot
2004-Nov-16, 04:29 AM
Why should we assume that "they" look any different from us at all? The only real differences that might dictate a different shape would be chemical or gravity makeup of their planet. There&#39;s no reason not to assume that our own form is the generic result of an ideal set of criteria which hold true universally. Perhaps all biologic life strives for carbon-based, oxygen-burning chemistry, and to see by the visible light spectrum. There&#39;s no reason these laws should be any different on other planets, if the universe is composed of the same small number of elements, which seems to be the case.

No matter how they look physically, sentient beings will be the same psychologically as ourselves. They will behave well and badly, exhibit love and hate, rationality and irrationality, joy and shame as we do. The will share both our curiousity and paranoia. What bothers me is the manipulation of less developed beings by more socially or technically advanced ones (as was depicted numerous times on Star Trek). But that already happens right here on our own world.

My prediction: they look, act, think and feel amazingly like ourselves. In fact, we will quickly realize that they ARE the same as ourselves, our brothers in humanity. We always forget that, to them, WE are the "aliens". Why shouldn&#39;t we take ourselves as the most obvious model of what the universe would produce? Why should we look anywhere but in the mirror for "bizarre man-eating freaks"?

Our predictions of alien "monstrosities" are based more on our own subconscious projections, like in mythology or fairy tales, rather than outward objectivity. As for crop circles, I suspect they are physical phenomena emanating somehow from nature or even from within ourselves. But who&#39;s to say? Why couldn&#39;t there be space-travelling hooligans out there tagging our planet with their funky graffiti? Isn&#39;t that what we would do?

We are the "strangers", and they are the humans&#33;

antoniseb
2004-Nov-16, 04:17 PM
Originally posted by ynot@Nov 16 2004, 04:29 AM
My prediction: they look, act, think and feel amazingly like ourselves.
I can agree with your argument that they will act something like us. I think the argument that cooperation and understanding is a prerequisite for for technological advancement to the point of space-flight.

On the other-hand, I think that appearance is not something you can count on being that similar. I guess it&#39;s likely that they&#39;ll have spines and left-right symmetry. But after that who knows? Feathers, fur, scales, shells, marshmellow-like insulating buttons, eye-stalks... but on the theory that beauty is only skin deep, I&#39;m sure we&#39;ll grow to love them if we ever find them.

ulgah
2004-Nov-16, 10:32 PM
Since, as many posters are so fond of saying, "They will not have this and/or that, because that would look like us&#33;" They all must look like the "Blob." No matter which galaxy they are from. Hmmm, they all look alike&#33; Only we are different. LOL.

eburacum45
2004-Nov-17, 10:33 AM
Intelligent aliens (if they exist) will come in a myriad forms, and have a myriad different types of psychology;
to attempt to visualise them you have to disregard any preconceptions about the inevitable nature of the human form, and a reading of Stephen Jay Gould and Olaf Stapledon is highly recommended.

They certainly won&#39;t all look like blobs...
but some might.

damienpaul
2004-Nov-17, 10:47 AM
considering the vast arrangements of life that has and still does exist on the planet - I would not be surprised if ithe aliens were the odd socks making wormholes in our washing machines (just as a far out example).

eburacum45
2004-Nov-17, 12:57 PM
Mine escape from the tumble drier -
the static causes electrically charged regions of space which spontaneously connect with other parts of the universe;
some of these wormholes seem to mysteriously open out inside duvet covers which are in the cupboard.

Well, that is where I find my missing socks.

Strange old world...

ahrenjb
2004-Nov-20, 09:26 PM
:D It is completely ascenine to think that aliens would look anything similar to humans unless thier world was almost completely identical to ours, even then there would still be almost no possibility of similar traits because of an obcenely incredible amount of variables. Every event as small as the flapping of a butterflys wings would somewhat affect the evolutionary path of any creature. For an example here on earth, somewhere in the australian vincity there is an island that developed a land-locked lake due to a volcanic eruption. Among creatures that were trapped in the body of water, a variation of the man of war jellyfish. Over time it adapted to its new condioons and now, instead of cathing unwiling fish that just happens to come by it has evolved to eat a type of algae that grows on its dome.

My point is that any alien coming from any other inhabitable planet would be grossly different from any terrestrial life form. Challenge that&#33; If anyone has another view wiht reasonable back up please post it. :o

astromark
2004-Nov-21, 08:55 AM
:rolleyes: Common sence is allways the best answer... yes ahrenjb. I wouldent argue with your logic. :unsure: but I sort of hope someone does, just to make it entertaining. B) I think the science minded indaviduals would agree that the earth has expearanced some mass extiction avents. Distroying the dinosors made room for the spiecies we have descended from. I wonder what would have transpiered here if they had not. :ph34r: I would still be hidding and very frightened. :blink:
and thanks eburcom45. I rushed to my linnen coubord after reading your post, and have found all my missing socks. :P So what would life look like here if the dinosours had not been gazumped.?

Ola D.
2004-Nov-21, 03:29 PM
People always have the notion that aliens are scary ugly creatures. From a biological point of view, creatures try always to adapt to their environment and the surroundings. So I assume that aliens would have a similar appearance to humans or animals if they are found to be living in an environment and climate similar to ours. Changes in the surroundings would ultimately result with changes in the outer features and appearance of a creature, that is to adapt with the conditions it&#39;s living under.

suntrack2
2004-Nov-21, 04:24 PM
may be the machine aliens control by main server, may be snake like, may be deaf and dumb aliens [who don&#39;t know who is of whom], or may be impared of hearing, by limbs or so.

Darth Maestro
2004-Nov-21, 11:22 PM
I think we will find aliens that look as different as the differences between the millions of species that evolved on earth. Since we have travelled into space ... although not far ... we have seen different solar scenarios just from looking at the different planets and moons in our solar system. We know that life isn&#39;t on Venus or Mars ... not like it is here anyway. Since life did take hold on earth, we know the life causing ingredients were present in our solar system (i think they are everywhere) .... and our earth should be looked at like a big template.

(not to say there isn&#39;t any other life in our solar system)
Cheers

Candy
2005-Sep-28, 10:56 PM
I would think aliens have the same DNA as we do here on Earth. Layman here, but I hear basic DNA is the same for every genetic make-up of everything here on Earth. I don't see why the DNA wouldn't be the same elsewhere in the Universe.

Did I mention, I'm just a layman? Go gentle on me. ;)

eburacum45
2005-Sep-29, 04:40 PM
There are several types of nucleic acid that might be useful for genetic storage and transfer of information; tRNA, mRNA, aDNA, zDNA, even PNA. Three and four stranded varities sometimes occur.
It is possible that the variety which life on Earth utilises will predominate on many planets; it miight be the most suitable type for living creatures and will be selected by evolution on a biochemical level.
Even if this is true (and I don't think we can be sure yet) there are two mirror-image forms of DNA which are possible; we never encounter the mirror image L-DNA in nature as far as I know(as opposed to zDNA, which is completely different in form) but it could occur on other worlds.
Finally the code which the DNA contains could be entirely different in other worlds; it is only a code, after all, and this code is very likely to be different in other evolved biospheres. Apparently similar sequences of bases could code for very different proteins elsewhere, even for proteins not found on Earth.
This would make the alien DNA entirely different to, and incompatible with, our own, even if it was chemically similar.

Huevos Grandes
2005-Oct-01, 04:45 AM
Given that they are probably intelligent like our selves. They would most likely be bipedal, have numerous digits at their extremities, have some sort of stereo vision,are capable of storing energy; ie (food), and reproduce. I believe they would look a lot like us. Their facial features, skin texture, location, of their head, limbs, sexual organs, eyes ears etc., could be different.

Not really. Bilateral symmetry is just one of many body types. Hydras, plankton, even amoebae are equally possible like body types.

It's the height of hubris to suggest that everything we might meet (at least, those "intelligent" things) will look very much like us. I know it makes it easier to watch, but I have difficulty in believing that every race on "Star Trek" looks pretty much identical to humans, albeit with differently-colored skin, and some interesting bony forehead structurs.

Humans are hardly build well. Only two legs make us unstable, and our knees bend the wrong way to support fast movement, or the highest jumping.

+1 to the smart guy who said bacillus. "Life" is smeared all over the galaxy and universe, given the right conditions.

Thanatos
2005-Oct-01, 07:34 AM
I think they would look amazingly similar to some life form that evolved on this earth. Evolution weeds out the pretenders from the contenders. I believe most of the basics [DNA, etc.] would be astoundingly similar. Bipedal mammals with big brains would rise to the top of the food chain, IMO.

eburacum45
2005-Oct-01, 10:01 AM
There will be no true mammals on any other planet except Earth. If we find a world which has tetrapod creatures with fur and mammal-like jaws which suckle their young then we could perhaps label that class of animal 'mammal-like' or 'mammaloid'; but such worlds with classes of creatures similar to our own will be very few and far between.

In particular the evolution of the jaw in chordates was an evolutionary fluke, coming from an adapted gill-arch; most large mobile land heterotrophs on other worlds will evolve a different arrangement, probably based on pairs of independently mobile mandibles and maxillae.
If you were faced with a beast with a body like an antelope and a head like a grasshopper would you necessarily think of it as a mammal?

granolaeater
2005-Oct-01, 02:52 PM
If you want to make a global assesment you can use the following:

- Must use limbs to handle tools.
Depending on the number of limbs, this will mostly lead to a bipedal lifeform.


Wrong!
They only need some kind of appendage evolved for manipulation.
This appandage can have evolved from any movable body parts, including parts of the locomotory apparatus (limbs), feeding apparatus (mouth parts like lips or mandibles), respiratory apparatus (gills), or sensory apparatus (antennae).

Even if the are evolved from limbs this will only lead to a bipedal lifeform if the precursor is quadrupedal and the evolutionary pathway does nut include multiplication of body parts.
But there is no reason to think that most of the precursors have to be quadrupedal or that it is impossible for alien quadrupeds to develop an extra set of limbs.


- Must convey information in short time span
Signlanguage just does this, though out of sight communication is more probable. This implies hearing, and speech. Chemical/Biological exchange of information is just to slow.


Wrong!
Out of sight communication is more probable only if the non intelligent precursors have preadaptions that allow to develop such communication. For examle we could develop sound based speech because apes communicate by sound, too. If our ancestors would have been mute we would most likely have developed some kind of sign language.

Fast out of sight communication does not automaticly imply sound based language. An other way would be low frequency electromagnetic waves (radio communication). Some fish on earth show adaptions in this direction.

Chemical/Biological exchange of information is only to slow if there is faster competition, faster prey, or faster predators. This is not necessarily true on an alien world. Symbiotic carriers could largely increase the speed of such ways of communication.

Even sound based language could be coupled with organs very alien to us, since it has not necessarily to be created in connection with the respiratory system or the feeding apparatus. Some insects for example create sounds by using parts of their locomotory apparatus.



- Must be able to gain information
Of coarse, sight which reveals info nescessary for survival will be important to. Depending on the star, world, this might show some variations, and most probably will benefit lifeforms which live during daytime.


Wrong!
Optical sensors are only helpful in habitats with abundant light. Many intelligent species might have developed on the dark side of planets tidal locked to M-dwarfs or on the surface of worlds with huge atmospheres and cloud layers to thick to let light come through. Another possibility are subsurface habitats.
On all these worlds the word "daytime" would not make any sense.

An other possibility to get a representation of the world sufficient for tool use would be ultrasound.


- Agility.
Exoskeletons are actualy quite heavy and limits the mobility. Larger insects (like Xindi in star trek serie) would have to have quite a thin exoskeleton, making them vulnerable.


Wrong!
For their protective functions exoskeletons do not need to be heavier then the body armors of reptiles like crocodiles and lizards. These animals are not impaired in their mobility by their body armor.
For their skeletal functions only narrow areas have to be thicker to maintain the neeeded stability. These parts do not have to be heavier than an endoskeleton.

And again the necessety of agility is not absolute but dependent on the agility of competitors, prey, and predators.



- Land living
watercreatures have some drawbacks. Just imagine the invention of fire. Amphibians might do the trick, though over time, depency on swampy places will limit them and will probably make them less likely to go beyond a simple tool age.


On watercreatures I agree partially. At least our way of developing technology would be impossible under water. But of course this does not rule out other pathways I have not even thought about (perhaps including much more sophisticated biological adaptions to developing technologie than we have).

But on Amphibians quite the opposite could be true: Dependency on swampy places will press them to develop technologies to overcome this dependency and might trigger a much faster technological development then we had.



- Omnivores
Both carnivores and herbivores lack interrest in one aspect of nature. Carnivores would not directly benifit from limbs which do not aid their hunt. And intelligence would only make them better use what they have, and not change their limbs into tool using objects.
Herbivores lack the possibility to remove dangers from their world.


Wrong!
Carnivores could develop manipulatory appendages either for movement in a special habitat, for manipulating prey for easier feeding, or for searching hidden prey. Later they could develop intelligence and tool using to be able to broaden their spectrum of available prey and/or their spectrum of habitats.
Carnivores could be very interested in plant like organisms because the find their animal like prey between or even in them or because they need them for building nests or using them for camouflage.

Herbivores could develop manipulatory appendages either for movement in a special habitat, for manipulating plant like organisms for easier feeding, or for searching hidden food. Later they could develop intelligence and tool using to be able to broaden their spectrum of available food and/or their spectrum of habitats or for protection against predators.
Herbivores could be very interested in animal like organisms because the could be potential predators or potential protectors against predators.
Herbivores could gain intelligence to develop the ability to remove dangers from their world.



- Management
Any large project requires that someone has the idea and others aid to accomplish it. This will always lead to some form of hiarchy.


Wrong!
Large projects require some kind of social cooperation. But this is not necessarily a hierachical organisation of individuals. Ants can accomplish large projects, too.

We did not develop our hierarchical social structure in order to be able to accomplish large projects, but we simply inherited this structure from our apelike ancestors.

The less individual the aliens are and/or the more communication oriented, the less need for hierarchical structures they would have. On the other end of the spectrum there would be a hive-mind composed of completely equal organisms.



- Clothing
Clothing for protection, (and surely for ceremonial wear), will be common.


Why?

Since even some human cultures do not use clothing, even anthropozentrism would be a too broad term for this blatant prejudice.

granolaeater
2005-Oct-01, 04:46 PM
People always have the notion that aliens are scary ugly creatures. From a biological point of view, creatures try always to adapt to their environment and the surroundings. So I assume that aliens would have a similar appearance to humans or animals if they are found to be living in an environment and climate similar to ours. Changes in the surroundings would ultimately result with changes in the outer features and appearance of a creature, that is to adapt with the conditions it's living under.


Scary or ugly are no absolute categories. People tend to consider creatures scary or ugly that are very different in appearance from what they are used to.

From a biological point of view, such an unusual appearance of aliens is very likely.

The appearance of organisms is not only dependent on their physical environment (and even this might vary over a wide range on different alien worlds).

First different organisms can find very different solutions to the same physical problem (just consider the different wings of bats, birds, and insects).

Second evolution can not create arbitrarily any design from scratch. Adaptions are created by modifying existing structures. On this way evolution produces inner constrains that stabilise certain body plans. But according to initial random variations these constrains could be very different on different worlds even with similar physical conditions.

Third organisms are not only adapted to their physical environment but to their biological environment, too. So initial differences in the environment on different planets will be greatly enhanced by evolution of different ecosystems.

Ilya
2005-Oct-01, 05:35 PM
People always have the notion that aliens are scary ugly creatures. From a biological point of view, creatures try always to adapt to their environment and the surroundings. So I assume that aliens would have a similar appearance to humans or animals if they are found to be living in an environment and climate similar to ours.
First, something similar to, but not quite like human IS scary. The term for that is "monster." Second, similar environemtn forces similar appearance only in some special cases. Sharks, dolphins and ichthyosaurs all look alike, but that's because a) fast hunting underwater imposes unusually limiting restrictions, and b) because they all are vertebrates, thus sharing the same body plan to begin with. Squid are also aquatic predators, and are similarly streamlined, yet no one would mistake a squid for a dolphin.

If you look at history of life on Earth you will see some adaptations (camera eyes, sonar, poison, flight, chewing, one-way digestive tract) which evolved independently and a number of times, and some others (quadrupedal body plan, vertebrate jaw, feathers, inner ear, Hymenoptera tail stinger) which appeared only once. I think it is a good bet that the former are "universals" likely to exist in completely unrelated biospheres, while the latter are "parochials", unique to Earth. Animals on other planets will almost certainly have some mechanism to break food into small chunks for faster processing, but that mechanism may look nothing like our jaws. Aquatic hunters will look like torpedoes with fins, but will not necessarily have brain in front, or squid tentacles either.

KingNor
2005-Oct-01, 06:36 PM
what if the life form was on a much MUCH diffrent size scale than us? or a species that grows indefinately over several hundred years.

something that is born the size of a dog, and grows and grows forever :-0

granolaeater
2005-Oct-01, 07:04 PM
I think on size scale there are some physical constrains for intelligent tool users.

On the short end you have to deal with brain size. An alien brain might be much more efficient in size to complexity ratio then ours (even birds brains are). But due to things like electrical resistance of organic insulators, capacity between organic wires and similar variables there will be a minimum possible size of an intelligent brain due to physical reasons. If you have minimum brain size, you have also minimum body size to nourish that brain.

On the big end you will get problems with the speed of signal transport through the body.

so I don't think you will find many intelligent aliens much shorter then 10cm or much bigger then 100m.

Izunya
2005-Oct-01, 08:41 PM
First, something similar to, but not quite like human IS scary. The term for that is "monster."

Well, it depends on your definition of "monster." In all the mythology books I've ever read, Scylla is considered a monster, and she wasn't shaped very much like a human, according to the stories: six vaguely doglike heads on six snaky necks, either sessile or very territorial, since she was always found in a cave right across from Charybdis . . . and, of course, there's the Kraken. Me, I think the definition of a monster is more like, "a creature that is very dangerous to humans, possibly using some power we don't understand or appearing in some way 'unnatural.'"

So there are several reasons why aliens might conceivably be considered monsters. First, they could be actively dangerous to human beings. (Which could be deliberate or not-deliberate. Imagine an amphibious or aquatic race that communicates by electrical pulses, the sort an electric eel or catfish uses. Or a sonar-using race that utilizes really loud ultrasound . . .) Second, they could look like something we generally perceive as dangerous. A being that reminds most humans of a large spider is going to get an interesting reception among the general population. Hopefully we would be mature enough to judge it by its character rather than its shape. Third, the being could use some sort of ability we don't understand, or appear somehow deeply wrong to the human eye. The spider-ish example above might fit this, as well; it might not really have much in common with an arachnid beyond "lots of legs," but the human brain insists (quite rightly) that giant bugs "just ain't right." Anything that appears to have several heads would qualify, as well.



If you look at history of life on Earth you will see some adaptations (camera eyes, sonar, poison, flight, chewing, one-way digestive tract) which evolved independently and a number of times, and some others (quadrupedal body plan, vertebrate jaw, feathers, inner ear, Hymenoptera tail stinger) which appeared only once. I think it is a good bet that the former are "universals" likely to exist in completely unrelated biospheres, while the latter are "parochials", unique to Earth. Animals on other planets will almost certainly have some mechanism to break food into small chunks for faster processing, but that mechanism may look nothing like our jaws. Aquatic hunters will look like torpedoes with fins, but will not necessarily have brain in front, or squid tentacles either.

True enough. It does beg the question, of course, of how many times sapience itself is likely to evolve. I've read some interesting arguments on both sides of the question.

Izunya

Ilya
2005-Oct-02, 08:17 PM
what if the life form was on a much MUCH diffrent size scale than us? or a species that grows indefinately over several hundred years.

something that is born the size of a dog, and grows and grows forever :-0
I believe it is called a "tree"...

Oh, you meant something that actually moves? Only possible under water, or in some other fluid. On land gravity and square-cube law eventually put a stop to growth.

Sock Munkey
2005-Oct-17, 02:38 PM
Body size, the square-cube law, and the gravity of the planet in question could have a significant effect on what technologies a land-dweling species might develop as well.
Take flight and/or space travel for instance.
If gravity is low or the species is significantly smaller than us they could achieve flight at a lower level of technology than we did.
A chimp could probably fly a half-size version of DaVinci's wings assuming you could teach one to do so.
Conversely, an elephant-sized sentient probably wouldn't have manned air vehicles untill nearly at our level of tech.

dgoodpasture2005
2005-Oct-17, 02:43 PM
i would speculate... they could be totally outlandish... solar powered... use solar energy for food (why not... plants can!) who knows how they evolve. The imagination is awesome though :)

Eric Vaxxine
2005-Oct-17, 04:25 PM
ESA published a picture of green slime/algae/something living in a canyon on Mars? You can see it on this home page...middle right.
http://www.esa.int/SPECIALS/Mars_Express/

zebo-the-fat
2005-Oct-18, 10:29 PM
All aliens must look like humans with rubber stuck on their faces, and they will all speak english with strange accents!

Candy
2005-Oct-18, 10:35 PM
All aliens must look like humans with rubber stuck on their faces, and they will all speak english with strange accents!
That's an American, silly.

zebo-the-fat
2005-Oct-18, 10:38 PM
That's an American, silly.

:razz::razz:

eburacum45
2005-Oct-20, 08:22 AM
i would speculate... they could be totally outlandish... solar powered... use solar energy for food (why not... plants can!) who knows how they evolve. The imagination is awesome though :)
Solar powered animals exist on this planet- see here.
http://www.seaslugforum.net/factsheet.cfm?base=solarpow
These sea slugs obtain part of their sustenance from the algae which grow symbiotically within their tissues. Additionally many single celled motile organisms are photosynthetic.
But the energy collected from solar power is not enough to fully sustain an active mobile multicellular animal; to sustain a human you would need many tens of square metres of collection area. So photosynthesis can only supply part of an animal's needs.
No reason why a mobile life form couldn't photosynthetise; but it would need to eat in order to obtain the greater part of its energy.

ASEI
2005-Oct-23, 03:52 AM
they never needed to build anything. Unlike us, they live in harmony with thier enviroment. I know whales live in "harmony" with their environment. But why is this considered some sort of virtue or superior state? Do you realize what would happen to humans if we attempted to "live in harmony with our environment?" We'd all die. Our largest, and near only survival advantage is our brain - the ability to alter our environment to suit us, rather than deal with it through blind strength or natural abilities.

Maybe one of the driving forces for the evolution of intelligence is the need to hunt or continually outwit something, and a near lack of other abilities to do it with. Without playing the survival game with handicaps, maybe we wouldn't have gotten so good in this respect?


to sustain a human you would need many tens of square metres of collection area. So photosynthesis can only supply part of an animal's needs.
Maybe around a hotter star, or a star with a greater ultraviolet component to it's radiation? That way, more of the star's energy could be used for photosynthesis purposes. Of course, the solar powered organism would probably only be able to sustain mobile activity during the day, or something.

ASEI
2005-Oct-23, 04:08 AM
An interesting sci-fi-ish idea: What if two species evolved intelligence simultaneously in competition with each other? Either via predator/prey interactions, or just resource competition. Though it was the case on our planet that we wiped out the other proto-humans, perhaps there doesn't have to be only one?

Candy
2005-Oct-23, 10:05 PM
An interesting sci-fi-ish idea: What if two species evolved intelligence simultaneously in competition with each other? Either via predator/prey interactions, or just resource competition. Though it was the case on our planet that we wiped out the other proto-humans, perhaps there doesn't have to be only one?
If one of those species were human-like, wouldn't we merge with them? Knowing the distasteful breeding practices of mankind (you know what I mean about "~breeding with animals"), I'm pretty sure we'd mesh well with aliens. ;)

astroscope
2005-Oct-25, 11:39 PM
We've seen what aliens might actually look like from a lot of movies over the years, but what do you think aliens look like?

I think they look like this :

http://booch.servehttp.com/photos/alien.jpg

Candy
2005-Oct-25, 11:57 PM
I think they look like this :

http://booch.servehttp.com/photos/alien.jpg
OMG!

RBG
2005-Oct-26, 04:52 PM
I disagree. The environment the organism evolves in has a far bigger impact on the form it takes than some once-off, insignificant event around it.

Here is an example: Dolphins were at one time land-dwelling four-legged terrestrial-moving animals. "Put" them in the ocean and - what do you know - they evolve to look and act much like a fish. All the flapping butterflys in the world were not going to change that. (So if there is an ocean harbouring creatures on some other world, guess what one life form would very likely look like.)

The same principle could apply to an alien world where savannah-like, forest-like and predator-like (etc.) conditions exist to continuously produce evolutionary pressures favouring an organism to adapt in a most ideal way to that environment. Including human-like form on land; fish-like form in the sea.

RBG


:D It is completely ascenine to think that aliens would look anything similar to humans unless thier world was almost completely identical to ours, even then there would still be almost no possibility of similar traits because of an obcenely incredible amount of variables. Every event as small as the flapping of a butterflys wings would somewhat affect the evolutionary path of any creature. For an example here on earth, somewhere in the australian vincity there is an island that developed a land-locked lake due to a volcanic eruption. Among creatures that were trapped in the body of water, a variation of the man of war jellyfish. Over time it adapted to its new condioons and now, instead of cathing unwiling fish that just happens to come by it has evolved to eat a type of algae that grows on its dome.

My point is that any alien coming from any other inhabitable planet would be grossly different from any terrestrial life form. Challenge that! If anyone has another view wiht reasonable back up please post it. :o

Relmuis
2005-Nov-16, 08:31 PM
I think that many alien intelligent species (perhaps 2 or 3 percent of them) would look humanoid. But there would be variations. The closer you would want your alien to resemble humans, the farther you would need to travel to find him.

Earthlike worlds with slightly more gravity would tend to produce centauroids. Also with variations. The nearest centauroid might look like the uper part of a gorilla transplanted on the body of a donkey, for example. And its two eyes might be above each other, rather than side by side.

Earthlike worlds with slightly less gravity would tend to produce flying aliens. Some might look like bats, others like octopoi with a balloon-like body, yet others like living monoplanes, with their manipulative extremeties tucked away inside their mouths. In a dense atmosphere a lifeform might look like a living umbrella, which keeps aloft by opening and closing itself.

Earthlike worlds with vast tracts of level ground might have inhabitants which look like giant wheels. The outside of the wheel might be covered with tiny mouths used for grazing.

Blob-like or balloon-like aliens might be found in the atmospheres of gas giants.

Ilya
2005-Nov-17, 02:15 AM
Dolphins were at one time land-dwelling four-legged terrestrial-moving animals. "Put" them in the ocean and - what do you know - they evolve to look and act much like a fish. All the flapping butterflys in the world were not going to change that. (So if there is an ocean harbouring creatures on some other world, guess what one life form would very likely look like.)

The same principle could apply to an alien world where savannah-like, forest-like and predator-like (etc.) conditions exist to continuously produce evolutionary pressures favouring an organism to adapt in a most ideal way to that environment. Including human-like form on land; fish-like form in the sea.

I posted this before, but it bears repeating: similar environment forces similar appearance only in some special cases. Sharks, dolphins and ichthyosaurs all look alike, but that's because a) fast hunting underwater imposes unusually limiting restrictions, and b) because they all are vertebrates, thus sharing the same body plan to begin with. Squid are also aquatic predators, and are similarly streamlined, yet no one would mistake a squid for a dolphin.

If you look at history of life on Earth you will see some adaptations (camera eyes, sonar, poison, flight, chewing, one-way digestive tract) which evolved independently and a number of times, and some others (quadrupedal body plan, vertebrate jaw, feathers, inner ear, Hymenoptera tail stinger) which appeared only once. I think it is a good bet that the former are "universals" likely to exist in completely unrelated biospheres, while the latter are "parochials", unique to Earth. Animals on other planets will almost certainly have some mechanism to break food into small chunks for faster processing, but that mechanism may look nothing like our jaws. Aquatic hunters will look like torpedoes with fins, but will not necessarily have brain in front, or squid tentacles either. Savannah dwellers will have good protection from desiccation and ultraviolet light*, but not necessarily four limbs, let alone two arms and two legs.

*And even that is unnecessary if the planet orbits a red or orange star.

Relmuis
2005-Nov-17, 12:35 PM
I have often asked myself how many shapes are actually possible? This might be a large number, but it will not be infinite, I think.

Take, for example, the number of major appendages (heads, arms, legs, wings, tentacles, whatever). This must be a whole number: zero, one, two, three, four, five, six, etc. We have five major appendages (one head, two arms, two legs). It is doubtful whether any aliens would have more than, say, fifty appendages. (What would be the use of having such a large number?) So, the fraction of alien shapes with five appendages like us would likely be small, but not vanishingly small.

Then there is size. Because matter is made up of atoms, an intelligent being must exceed some minimum size. There is likely also some maximum size which can be exceeded only in very special circumstances (such as Larry Nivens Smoke Ring).

Reasoning on in this way we may map out a certain finite area of possible shapes for intelligent lifeforms.

One might call two shapes the same if they are not readily discernable from one another, or if their individual variation spectra overlap. (Consider that the human variation spectrum includes, for example, pigmies.) Now the potential infinity of shapes has been constrained to fall within a certain area of possibilities, and a certain grainyness has been imposed on this area by lumping together nearly indiscernable shapes. A finite amount of these grains must then remain. Perhaps there are one billion of them, but not all of them will be equally common: perhaps there are only one million which occur more than once in a particular galaxy.

Somehow I feel that our own general shape is not wildly improbable, and so would belong to the one million grains which recur more than once.

Now, there are at least a hundred billion stars in our galaxy, and if intelligent life is produced just at one in ten thousand stars, then eventually our galaxy will have produced ten million alien civilizations. This suggests that two or three species of intelligent beings will arise (though none might be extant today) whose members would look like human beings at least in a fuzzy photogramme.

And if there are billions of galaxies, these will produce some species which would look almost exactly like us; that is: the difference would only show up in a medical examination.

This does not mean that we might be able to breed with them (we certainly would not be able to!) or that we would have the same number of internal organs, or the same lifespan, or the same kind of emotional life. It just means that they would look like us from the outside.

Byron Cleveland
2006-Mar-08, 08:18 PM
Have anybody read all Harry Potter's book

Byron Cleveland
2006-Mar-08, 08:23 PM
I have suspected to know alot about Aliens and UFOs coming around and we could see them. But if they are real why would they just come to earth to take over. They have all the things to do what ever they want.

Ilya
2006-Mar-09, 12:51 AM
Then there is size. Because matter is made up of atoms, an intelligent being must exceed some minimum size. There is likely also some maximum size which can be exceeded only in very special circumstances (such as Larry Nivens Smoke Ring).
While Niven's Smoke Ring is about as "special" a circumstance as one can think of :), there is nothing particularly special about lack of weight. Every animal is weightless under water, which is why blue whales are as big as they are. IIRC, a 150-ton filter-feeder is just at the limit of what ocean ecosystem can support; a cold-blooded filter-feeder could be bigger, but not by much -- maybe 200 tons. But the limiting factor is food supply, not weight.

Relmuis
2006-Mar-09, 02:52 PM
Under water, the body as a whole may be weightless, but dense structures (such as bones) are still pressing upon more tenuous structures.

I once read a story where experiments were done in launching humans in water-filled space capsules. The author suggested that this way the humans might withstand extremely high gee-forces. (They would of course have to wear wetsuits, or something similar.)

But I think that a limit would be reached where bones would start to crush the underlying flesh. I expect that the ribcage would prove to be the weakest link in this experiment. If the lungs could be filled with some oxygenating fluid, the skull would likely become the next weakest link.

There is also the issue of blood pressure. In a gravity field, a large animal must cope with hydrostatic pressure differences between liquids in the upper and lower regions of its body, preventing cavitation in the upper regions and rupture in the lower ones. (Which is why astronauts must assume a horizontal position during launch. They would still have to do this if they were immersed in water.)

Byron Cleveland
2006-Mar-09, 07:47 PM
What do any one thanks what a Alien really looks like.

Byron Cleveland
2006-Mar-09, 08:18 PM
are you sure about that

zebo-the-fat
2006-Mar-09, 08:41 PM
They look like me when I remove this Human Suit!:eek:

trinitree88
2006-Mar-10, 12:22 AM
[QUOTE=Relmuis]Under water, the body
But I think that a limit would be reached where bones would start to crush the underlying flesh. I expect that the ribcage would prove to be the weakest link in this experiment.

If the lungs could be filled with some oxygenating fluid, the skull would likely become the next weakest link.

Point. The lungs could be filled with dimetylsulfoxide which will carry enough oxygen to enable a mammal to "breathe"...it's effects on the physiology?...hmmm....:shifty:

Plat
2006-Mar-10, 03:32 AM
- Clothing
Clothing for protection, (and surely for ceremonial wear), will be common.


Yeah, I completely forgot about clothing...I dont know but I dont think they would be walking around naked.

Relmuis
2006-Mar-10, 10:31 AM
Why not?

Perhaps there are fallen and unfallen civilizations, and clothes are only used by the first kind. Though protective clothing (such as space suits) might be in use everywhere.

Byron Cleveland
2006-Mar-10, 07:45 PM
But what if they wear our kind of clothes and look normal

umop ap!sdn
2006-Mar-11, 11:03 PM
Most aliens likely wouldn't breathe oxygen IMO. It was a while before the stuff came to be made here on Earth, and IIRC when it did it wiped out almost everything. Nasty stuff if your biochemistry isn't geared to it. That's why, though they would likely be toxic to us, we would almost certainly be toxic to them.

It seems to me that we got to be vertical bipeds because early humans had to peer out over the grassy savannahs to check for signs of predators. But how about a world where there are no grasses. The Earth was this way back in the Mesozoic, and though there were bipedal dinosaurs (mostly the predatory type) they kept their spines parallel to the ground. On a planet where the sedentary life (i.e. similar to our vegetation) is either sparse or tree-like, there would be little or no pressure to evolve a vertical stance. Thus starting with a tetrapodal form we might see bipeds that are shaped more like a Velociraptor than a human.

On the other hand, such a body plan might prove cumbersome for a technologically advanced species. Though having arms directly under the front half of the body seems to work well for predation, what about for soldering a circuitboard or handling a container of potentially volatile chemical? I think what might develop in that case is essentially a bulb with the "head" (brain and key sensory organs) and neck sticking out of the top, and the digestive system down in the bulb part. The arms would simply protrude from the front of the bulb, and the mouth may be above, below, or even between them (especially if the lips are vertical or in a more complex arrangement).

The nice thing about this is that it works for hexapods too... they'd go through a centaur phase and then become a bulb with 4 legs instead of 6. Odd numbers of legs could result if a preexisting tail is adapted for locomotion. I'm not sure though how radial forms (e.g. starfish shape) would develop; they'd likely follow a much different path.

Well, that's one possibility anyway. :D

parallaxicality
2006-Mar-12, 01:57 PM
Ilya:

The tetrapod form may be "parochial" but I think to label it that misses the point; we are, as far as we can see, the only lifeform our world has yet produced in 4 billion years of trying that has the capability to communicate with and observe other worlds. Given that, it is very likely that we are highly atypical in evolutionary terms, and that a series of "parochial" and highly improbable events must occur in order for us to exist. If that is correct, the same would hold for alien biospheres, meaning that while life itself may be common, intelligent life is very rare. The question is not how likely such adaptations as the tetrapod form are, but how necessary they are to creating our intelligence. If, for instance, our tetrapod shape, upright posture and binocular vision (all of which we developed long before our brains got big) were necessary for us to attain the level of technological development we have, then we would expect a being of a similar level of technological development to have followed along similar lines. It may very well be that those planets that don't follow these "parochial" paths never develop intelligent civilisations; evolutionary unlikelyhood would therefore not determine the variety of intelligent life in the galaxy, but the frequency of it. We followed this highly parochial evolutionary path, so we became intelligent. Others didn't, so they didn't.