What might an alien creature really look like?

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Profile Andy Westcott
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Message 435714 - Posted: 13 Oct 2006, 18:34:08 UTC - in response to Message 435590.  

Chuck, an interesting read - thanks.
Regarding my reference to the T-Rex, and your comment:
"It is no suprise at all that a T Rex has the same bones humans do. We both evolved from a common ancestor millions of years ago...."

My point here is that if 'panspermia' is a feature of our galaxy, or even universe, the DNA involved in an alien intelligence could have certain parts of the code in common with ours, which could cause them to have certain similarities to us in the same way that the T-Rex has. We could all have a common ancestor. If this is the case, then I would expect evolution would add its own honing of the species for its own particular requirements, but even then the creature could still possibly have recognisable anatomical features.

Perhaps this discussion ultimately comes down to whether there could be such a phenomenon as panspermia.
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Message 435755 - Posted: 13 Oct 2006, 20:43:10 UTC - in response to Message 435714.  

Chuck, an interesting read - thanks.
Regarding my reference to the T-Rex, and your comment:
"It is no suprise at all that a T Rex has the same bones humans do. We both evolved from a common ancestor millions of years ago...."

My point here is that if 'panspermia' is a feature of our galaxy, or even universe, the DNA involved in an alien intelligence could have certain parts of the code in common with ours, which could cause them to have certain similarities to us in the same way that the T-Rex has. We could all have a common ancestor. If this is the case, then I would expect evolution would add its own honing of the species for its own particular requirements, but even then the creature could still possibly have recognisable anatomical features.

Perhaps this discussion ultimately comes down to whether there could be such a phenomenon as panspermia.


Panspermia is certainly possible, but any nearby supernovae providing the raw materials in Earth early history would be lone gone by now.

It could have provided a short cut. Providing that all conditions are appropriate, I see no reason why it can't or couldn't have worked, but I think it is unnecessary to use it to explain how life arose on Earth, when all the materials and conditions existed to create life anyway.

A methane and ammonia atmosphere is quite capable of creating amino acids and other CHN based products in the presence of lightning, and with countless billions of molecules in all kinds of environments, some could combine to produce primitive molecules, evolve self replication and ultimately into more complex lifeforms.

My feeling is that life actually evolved independently on Earth, and a common ancestor between us and any other beings are the laws of physics and chemistry.

If life arises on a similar planet to Earth, then I would expect to see recognizable lifeforms similar in form to that of Earth's because what we see now are the best results of a 4 billion year experiment in creating lifeforms supremely adapted to their environments.
This could of course be completely wrong and a better arrangement could have arose, but trial and error and nature finds the most efficient forms. Here on Earth the pentadactyl form arose before the dinosaurs and proved to be the most successful.
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Message 435947 - Posted: 14 Oct 2006, 5:25:37 UTC - in response to Message 435590.  

A number of posts in here show that many people don't understand evolution and its random aspects.


Precisely the point I was trying to put over in my postings, Chuck.

Evolution is random.
Random mutations of DNA result in changes, sometimes subtle, sometimes radical. IF one of these changes results in a life form that is better adapted to the current environment, that mutation will flourish.
As the environment changes, mutations have to occur that provide an organism with the best possible chance of survival. Therefore, life on various planets will evolve differently, according to local conditions.
The notion that human form is the most efficient is a little arrogant. Life on other planets, if it is based on DNA, has the opportunity to evolve in totally different lines to life on Earth.
A good example of this is my home country of Australia. One continent separated from the rest of the major land masses, and millions of years later, life forms totally different to those found on any other continent have evolved.
If that can happen to ONE landmass on ONE planet, then it is clear life on other planets is likely to be entirely dissimilar to life on Earth.
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Message 436013 - Posted: 14 Oct 2006, 10:45:30 UTC - in response to Message 435947.  

A number of posts in here show that many people don't understand evolution and its random aspects.


Precisely the point I was trying to put over in my postings, Chuck.

Evolution is random.
Random mutations of DNA result in changes, sometimes subtle, sometimes radical. IF one of these changes results in a life form that is better adapted to the current environment, that mutation will flourish.
As the environment changes, mutations have to occur that provide an organism with the best possible chance of survival. Therefore, life on various planets will evolve differently, according to local conditions.
The notion that human form is the most efficient is a little arrogant. Life on other planets, if it is based on DNA, has the opportunity to evolve in totally different lines to life on Earth.


Can't disagree here, though not all mutations are inherited!


A good example of this is my home country of Australia. One continent separated from the rest of the major land masses, and millions of years later, life forms totally different to those found on any other continent have evolved.
If that can happen to ONE landmass on ONE planet, then it is clear life on other planets is likely to be entirely dissimilar to life on Earth.


I disagree that lifeforms in Australia are totally different. They may look different, and hop instead of run, but they all basically variations on the same pentadactyl theme - as other animals elsewhere in the world - five finger/toes, four appendages, one head, two eyes, breathe oxygen, expire CO2 etc.

Question is, how dissimilar do you judge other lifeforms to be? Of course they would be a product of their environments, but the most successful adapted forms will arise, and I would guess that they would at least have two eyes, heads for processing and some form of locomotion, and in that way be similar.

Andy.
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Message 439165 - Posted: 18 Oct 2006, 14:09:18 UTC

Here on Earth the pentadactyl form arose before the dinosaurs and proved to be the most successful.


This is in error - the form did indeed arise in the early Cambrian - as the Burgess shale shows, from a time before the form was favored. I disagree that it PROVED to be the most successful - it isn't necessarily so; it may have just happened to be the lucky survivor.

We don't know, and we have no immediate way of knowing whether the pentadactyl form is superior. Steven J Gould himself says that there is no discernable advantage to any of the dissimilar forms found in the Burgess shale - for him, the history of lifeforms could have gone in any direction, and indeed, we can imagine an alien ocean populated by exactly the same forms (which of course it wouldn't be), where another type dominates instead.

If we want a better example of animals being homologous, look to dolphins, sharks, and icthyosaurs; mammal, fish and reptile, respectively. All of them facing the same engineering problem: how to have speed in water. All of them looking more similar than dissimilar. This is convergent evolution.

I am sure that C based lifeforms will be analogous, but I don't suppose for one instant that they will actually look even vaguely alike at all.
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Message 441105 - Posted: 21 Oct 2006, 9:08:04 UTC - in response to Message 436013.  
Last modified: 21 Oct 2006, 9:43:31 UTC

A good example of this is my home country of Australia. One continent separated from the rest of the major land masses, and millions of years later, life forms totally different to those found on any other continent have evolved.
If that can happen to ONE landmass on ONE planet, then it is clear life on other planets is likely to be entirely dissimilar to life on Earth.


I disagree that lifeforms in Australia are totally different. They may look different, and hop instead of run, but they all basically variations on the same pentadactyl theme - as other animals elsewhere in the world - five finger/toes, four appendages, one head, two eyes, breathe oxygen, expire CO2 etc.

Question is, how dissimilar do you judge other lifeforms to be? Of course they would be a product of their environments, but the most successful adapted forms will arise, and I would guess that they would at least have two eyes, heads for processing and some form of locomotion, and in that way be similar.

Andy.


The pentadactyl plan, while important, is not the only yardstick we use to compare life forms. Only one of many, and applicable only to land-dwelling vertebrates, plus a few ocean-dwellers.

Australia's unique life forms include two species of monotreme. The echidna, (tachyglossus) also known as the spiny anteater, and the platypus. Both of these creatures are mammals, but there mammary glands developed from different secretion glands than other mammals, and they LAY EGGS!!!

Thus, evolution has followed different paths on one planet, due to environmental differences. The likelihood is that environmental conditions on a different planet, along with random factors we can only guess at will produce life in forms we could only consider bizarre.

Differences in oxygen/nitrogen ratios in the atmosphere, length of seasons (if any) gravity, orbital eccentricity and a myriad of other variables would, I believe, produce some interesting results.

I for one, will be extremely surprised if ET life includes human forms, or even close. (Always assuming of course, that I am still around when we find ET)

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Message 441108 - Posted: 21 Oct 2006, 9:32:49 UTC

Asimov postulated the Convergent, and Divergent Hypotheses (Theories?) of Humanity. The Divergent Hypothesis says Humanity began independently on many planets, the natural result of Evolution. The Convergent Hypothesis states Humanity traces back to Terra. The question remains unresolved in Asimov.
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Message 441615 - Posted: 22 Oct 2006, 5:20:32 UTC - in response to Message 439165.  

This is in error - the form did indeed arise in the early Cambrian - as the Burgess shale shows, from a time before the form was favored. I disagree that it PROVED to be the most successful - it isn't necessarily so; it may have just happened to be the lucky survivor.


Chuck,

I tend to agree!

It is possible that other plans existed, but the precursor-creature that first used the pentadactyl plan had other features that allowed it to out-compete creatures based on other plans. (If that makes sense). This means the pentadactyl plan became predominant by ACCIDENT.

This is only a posssibility, and would take a helluva lot of proving/disproving. However, I think you are making a very good point.

Much of evolution is due to chance. Best example I can think of is the "mass extinctions" that occurred several times in the past, and which were probably due to comet or asteroid impact. All sorts of life forms were wiped out, many of which may well have been more competitive, if not for the catastrophic damage to their environment.

It's a long stretch, but who knows? Maybe a dinosaur would have developed intelligence, given some exrta time?

And THAT leads me to the thought there may be a reptilian ET somewhere.

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Message 442265 - Posted: 22 Oct 2006, 23:53:58 UTC

I kindof doubt an ET could be classified as "reptile", or "mammal", or "insect".
Each planet may have their own unique animal classifications that probably incorporate many elements of different animal-classes on Earth. *shrug*
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Message 442313 - Posted: 23 Oct 2006, 1:19:14 UTC - in response to Message 441615.  

Maybe a dinosaur would have developed intelligence, given some exrta time?


There is still time!

Evolution hasn't finished, there are still perhaps another 5 billion years left to run on the Earth's clock, and perhaps human intelligence is an evolutionary dead end. Perhaps one day reptilian palaeontogists will pick through our fossils and make wild guess about our lifestyle.

Humans seem to have such a myopic and parochial perspective, but they only rent the briefest instant in time!

http://news.bbc.co.uk/2/hi/uk_news/6057734.stm
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Message 442366 - Posted: 23 Oct 2006, 4:38:48 UTC - in response to Message 442265.  

I kindof doubt an ET could be classified as "reptile", or "mammal", or "insect".
Each planet may have their own unique animal classifications that probably incorporate many elements of different animal-classes on Earth. *shrug*


Point taken, and it is pretty much what I've been driving at in this thread, Airbuster.
Just because evolution has taken certain turns here doesn't mean it will do the same elsewhere.
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Message 442376 - Posted: 23 Oct 2006, 5:13:09 UTC
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If we survive long enough to "Leave the Nest", when our home planet is returned to dust, Interstellar travel will be common place for our species. Assuming we have survived this long, and ventured into the galaxy to find suitable habitats for ourselves, time travel will inevitably be reached by this point and when we return to study ourselves then the ALIENS will look like an Evolved US!

Intergalactic Travel will be the Main Concern for us in the Future!
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Message 442466 - Posted: 23 Oct 2006, 13:42:31 UTC - in response to Message 442376.  

If we survive long enough to "Leave the Nest", when our home planet is returned to dust, Interstellar travel will be common place for our species. Assuming we have survived this long, and ventured into the galaxy to find suitable habitats for ourselves, time travel will inevitably be reached by this point and when we return to study ourselves then the ALIENS will look like an Evolved US!



Can you say that again, slowy please? lol
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Message 442529 - Posted: 23 Oct 2006, 17:10:26 UTC - in response to Message 442466.  

Quote:
"Perhaps one day reptilian palaeontogists will pick through our fossils and make wild guess about our lifestyle."

I actually doubt it, simply because of mankind's destructive tendencies. We just wouldn't allow another species to develop to that stage - heck, we struggle allowing other races within our species to develop!!

The exception would be a planetwide disaster, mass extinction class, which destroyed all humans and left the arena clear for a newcomer.
It's apparently happened before with other species....
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Message 442652 - Posted: 23 Oct 2006, 21:29:47 UTC
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It is possible that other plans existed, but the precursor-creature that first used the pentadactyl plan had other features that allowed it to out-compete creatures based on other plans. (If that makes sense). This means the pentadactyl plan became predominant by ACCIDENT.


Forgive me, but there are contradictions in here, and a few errors.

First it isn't possible that other plans existed - the Burgess Shale shows that in at least one tiny part of the world (Canada, in fact,) other plans DID exist! Plans which belong to no known biological phylum today! Great diversity by phylum, not by mere family!! Please read 'Wonderful Life' by Steven J. Gould

The penta-plans of the Burgess did NOT appear to be any better at competing with non-pentas. It may be that they did have an advantage that is unclear at the moment, or it may be that some few pentas simply were in an evolutionary niche that happened to escape some particular disaster that wiped out other forms. The disaster could have been some other type that would have preferentially wiped out PENTAS, and then there would be an intelligent - multi-pseudopodded wormLIKE form thinking about the poor extinct Penta-seastars who were maladapted and of course got wiped out. (What would be their descendants?! An intelligent giant seastar, typing on a touchpad with his tubefeet?!? How ridiculous! Of course they died out!!!)


This shows the prejudice and parochial distortion humans view themselves with, as Andy pointed out.


BTW, intelligent dinosaurs might yet re-inherit the planet. If humans die out, the birds might take our place. And they are only evolved and modified dinosaurs.
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Message 442821 - Posted: 24 Oct 2006, 4:06:36 UTC - in response to Message 442652.  

It is possible that other plans existed, but the precursor-creature that first used the pentadactyl plan had other features that allowed it to out-compete creatures based on other plans. (If that makes sense). This means the pentadactyl plan became predominant by ACCIDENT.


Forgive me, but there are contradictions in here, and a few errors.

First it isn't possible that other plans existed - the Burgess Shale shows that in at least one tiny part of the world (Canada, in fact,) other plans DID exist! Plans which belong to no known biological phylum today! Great diversity by phylum, not by mere family!! Please read 'Wonderful Life' by Steven J. Gould

The penta-plans of the Burgess did NOT appear to be any better at competing with non-pentas. It may be that they did have an advantage that is unclear at the moment, or it may be that some few pentas simply were in an evolutionary niche that happened to escape some particular disaster that wiped out other forms. The disaster could have been some other type that would have preferentially wiped out PENTAS, and then there would be an intelligent - multi-pseudopodded wormLIKE form thinking about the poor extinct Penta-seastars who were maladapted and of course got wiped out. (What would be their descendants?! An intelligent giant seastar, typing on a touchpad with his tubefeet?!? How ridiculous! Of course they died out!!!)


This shows the prejudice and parochial distortion humans view themselves with, as Andy pointed out.


BTW, intelligent dinosaurs might yet re-inherit the planet. If humans die out, the birds might take our place. And they are only evolved and modified dinosaurs.


Chuck, read my previous postings. You'll find this is exactly what I've been trying to drive in this thread... the thought that human form is the likeliest intelligence in the Universe is seriously flawed.

Star Trek only shows humanoids to be predominant because of the strange shortage of non-human actors. (Although that mutt from "Frasier" appears smarter than a lot of people I have met)
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