okay: http://www.nemoramjet.com/snduterus.html

I can't really remember where the skeletons were, but if you scroll down there are all sorts of categories.

Metal, you're thinking of Extraterrestrial, on The National Geographic Channel. I thought it was a more convincing and interesting speculation on extraterrestrial life than Alien Life because A) It takes place on two actual planetary bodies, compared to Alien Life which takes place on one made up planet. B) It used examples of convergent evolution, which allow us to know what biological traits are very likely to happen C) National Geographic Channel usually airs less dramatic sudo-science viewer-craving crap than the Discovery Channel does.

That said, let's stop talking about possible sources of information and actually using them.

PS: Read this! It's quite good - you'll learn a lot more than you will from one of the above mentioned TV shows.

aliens don't exist

deal w/ it

Well, they probably do, it's just that humans will probably never find them.

Wow, you guys really have to ruin the fun. Hyperkultra is right though, we may never make contact with aliens because of the vastness of the galaxy (not to mention the universe).

If we do, though, chances are it will be carbon based. Silicon based molecules are more fragile, and will be more unlikely of building the immense macromolecules required to sustain life. Though, other factors are almost certain to be different. For instance, the other lifeforms may have completely different nucleic acids, which would encode for different amino acids (the molecules that make proteins), different proteins, and so on, until the end result would be so entirely different from anything we know on Earth.

This way, everything would be different. The things imagined in the websites linked certainly have a chance of existing, and it's fun to think about. Plus, they have nice pictures.

I think there will be no planets that have birds as the dominant species, all life begins from simple micro-organisms so a totally avian planet is inconceivable really, nd birds can only grow so large before their mass and necessary wingspan become a major energy consumption problem (though as proven by pterodactyls the biggest size possible is relative to the size of the prey, and some pterodactyls were bloody huge).

"Advanced life" (brain equivalence to early tool using man or grater) would probably be generally slightly similar in appearance to humans, though I think the chances of being almost exactly similar are slim (would require similar gravity and environment). things most likely to be different are skeletal and muscle structure, nose and ears and hair growth.

also daman the chances of us being the only planet with life are incredibly unrealistic, unless of course you believe in god(s) (even though that would make it more likely to have alien life?)

I think there are almost certainly other alien civilizations; for us and only us to have developed in the entire universe would be unlikely, by my guess.
But they're probably pretty rare, even in an astronomical scale, so I doubt we'll be encountering or them soon, if at all.

A civilization either as or more advanced than us spreading their planet's life to other planets and letting it adapt from there seems entirely plausible, and that being the origin of earth life is logically plausible, but to think they had the one and only abiogenesis is about as likely as earth having the one and only abiogenesis, which would make us alone in the universe.

Why?

Everything I needed to know about the future of humanity, I learned from Issac Asimov.

True story.

but the thing is aliens don't exist so whats the point

I think life exists on planets other than our own, though the chances of it being sentient, living, and close are, close to none. There might be life on other planets, though unlikely, but it could just be bacteria. If there were sentient life forms, the chances of them still being alive is very, very slim. Even if either did exist, they probably are very, very far away. Though, the universe is a very big place.

Chances of other, alien life forms?
Likely.

Chances of our species ever meeting an alien, sentient or not?
Unlikely.

Hey there, I'd like to show another forum that deals with stuff like this...
Not only alien life they're speculating, but also extrapolations of evolution in the future and alternate evolutionary histories. Feel free to browse...

http://s1.zetaboards.com/Conceptual_Evolution/index/

You want alien speculation, go to Habitable Zone.
You want predictions on future evolution, go to Evolutionary Continuum.
You want alternate evolution, go to... well... Alternative Evolution.

Sorry to doppelpost, but I have something to say...



Yeah, I agree, the humanoid sentient alien idea is Star Trek and Star Wars' fault. I mean, it's hard to get a Shoggothy bundle of tentacles that acts in Hollywood.
What's not to stop the sentient aliens to be shaped like animated biscuits, for example? The possibility of life is endless, and there is a good probability of aliens existing. So we can't say they exist or not simply by saying we have no evidence of them... So we look to the stars, searching for evidence.

Life is basically something in a state of entropy that uses its surroundings to sustain that state of entropy as long as possible, and produce more copies of this same unbalanced chemical reaction that can also sustain themselves. Based off of this (probably wrong in at least one way) definition, life could exist and evolve in any condition that 1: was capable of making the self-replicating structures by means of random chemical reactions, as happened on earth, and 2: lived in an environment where it could sustain these. To sustain itself, life will need some sort of chemical reaction that makes energy, so basically any planet with the first condition which also had enough substances which, when reacted, would produce energy, would be a potential candidate. Although one might argue against this that plants, which are fairly self-sustaining, use photosynthesis to support themselves, the light reaction is only a catalyst to the entire reaction which gives energy to a plant; plants still have to use up chemicals to sustain themselves.

This means there are a ton of different possibilities for life on alien planets, but, like earth, to continue surviving, they will need some form of mobility, from walking, like most large animals, to being moved by its environment, like yeast, so they can continue to sustain themselves, and some method of absorbing things. The life that is successful will probably also, whether it reproduces with itself or a counterpart of the opposite gender, have some form of mutating its offspring, i.e evolution. Organisms with this trait will tend to beat out life that just copies itself, because it will be able optimize itself and outcompete its opponents.

Based on the natural order of things, predators will probably also develop on the typical alien planet, because there will be some forms of life which evolve sustain themselves by taking the already concentrated nutrients from other organisms, because the niche of gathering nutrients from the environment is already too full for them to develop in that direction. The prey will, in response, evolve to develop mechanisms like pain, increased mobility, and defense strategies. The predators and prey will continue evolving back and forth into more and more complex organisms until they are of a similar complexity to modern animals on earth. Because millions of years have selected for the most effective traits that modern organisms have, alien life will probably develop traits similar to these, traits which give as much information about the environment as possible. Alien animals may have some other senses, but they will probably be similar to the senses of animals on earth, sight, touch, taste, smell, and hearing are all senses which are not specifically useful to environment of earth, but would be useful to organisms in any number of environments.

As the complexity of the alien life increases, a third major niche, based on intelligence will form. These organisms will use their intelligence to manipulate the environment to their advantage, to kill prey, to defend themself, to gather supplies from their environment. As they develop, their body will change and focus more and more on manipulating their environment, they will develop some appendage along the lines of hands and arms so that they can build tools. Eventually they will take the path that ancient humans took, build cities, and civilize the world.

Pretty soon, there will not be enough room on their planet.

They need another planet to live on.

Only one light year away, they notice a small but promising planet called Earth...

By the time you have finished this post, it will be too late. We are coming.

by generally similar I meant having at least two eyes, a mouth, some form of grasping devices (hands &/ feet) and being generally bipedal. I do not think an alien would appear to be very human like (i.e the alien race in the new film avatar is probably extremely unlikely) I meant that an alien with knowledge comparable to humans would just be slightly similar in order to use their bodies to create mechanisms and tools... for example you need a good firm stance and grip in order to manipulate some human objects such as levers and some characteristics would make this impossible. I think the prawns from D9 are a good example of what I'm trying to say.