Is ET Out There?

Yea, you're right...........Come to think of it, I haven't seen to many "happy" tuna fish out there lately have you??? I guess it's the potential confinement in those tuna cans that makes them depressed.........

Atta Boy

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I wanted to give an evolutionary biologist's perspective on this discussion.

1) Evolution has no progressive direction. That means that intelligence is not some inevitable evolutionary outcome. Evolution by natural selection means that whatever will optimize genetic representation in the next generation will be favored. In our species' history, that meant intelligence, but this is not the case for almost every other earthly species.

2) We simply don't know if there were intelligent dinosaurs. There certainly appears that there was some sociality in some dinosaur species, as well as child care, which implies levels of intelligence somewhat equal to cows. However, there were thousands of dinosaur species, therefore there was a range of dinosaur intelligences, and the upper range for a dinosaur species could have been as high as a dolphins.

3) Unless panspermia is correct (personally I believe it's possible for life to travel between the planets, but it's unlikely to be the source or seed for the development of life on earth) there will not be any earth organisms on any other planets. There won't be bacteria, virus, mammals, fish, plants, protozoa, etc. These life forms are endemic to earth and will not be found elsewhere in the universe.

4) I agree with Dinosaur and crazymikey that where ever life can occur, it will occur. I also think this will be shown to be true in our lifetimes when evidence for Martian life is found. We can speculate about E.T. life characteristics. We can be pretty sure it will be carbon based, and probably protein based. There will be phospholipid membrane bound cells, and probably multicellular and unicellular forms. I'm not convinced that DNA/RNA will be the replicating and info storage molecule, but it will be some carbon molecule and it may be similar to DNA/RNA or perhaps protein based.

5) Many species attributes and/or characteristics are of historical origin and not necessarily selective origin. Vertebrates are quadrapeds because of phylogenetic history, not because 4 limbs is the optimal selective number.

 

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I think most dinosaurs and dolphins would agree with you........I'm not to sure about the tuna fish...........

Atta Boy

 

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Actually i think intelligence is inevitable. Not only in humans, but in many classes of animals.

 

We're all looking forward to the day when either the Spirit and/or Oppourtunity rover finds an ancient empty martian beer can or bottle buried in the sands of Mars.........Should answer a lot of questions I would think.................

Atta Boy

 

If life ever did get started on Mars, when the planet's environment was a lot more clement, it is almost certainly still there. Living organisms, especially the simplest ones, are remarkably adaptable. Some Earthly extremophilic bacteria can survive and breed in simulated Martian environments.

That's not to say that Martian life ever got further than the microbial stage.

@ Paulsamuel: thankyou for your intelligent post. I agree with most of your points; except that, if life is discovered on other planets, the classifications of "viruses," "bacteria," and "plants" are almost certain to be applicable. Any conceivable planetary biosphere will have single-celled organisms and non-cellular parasitic ones, even if the specific biochemistry is quite different; larger autotrophs which photosynthesise, or maybe thermosynthesise, would be analogues of what we call plants, especially if they are immobile and act as the basis of a food chain.

 

1) virus, bacteria, plants are taxonomic groups. taxonomic groupings require commonality by descent (i.e. they share characteristics because they were derived from a common ancestor). that would be impossible for E.T. life.

2) we have many "single-celled organisms" right here on earth that we don't call bacteria. i see no reason why a single-celled organism would be called bacteria somewhere else.

3) i agree autotrophs are necessary, but to replicate the same events that led to plants here, i.e. endosymbiotic source of mitochondria AND chlorplasts is probably very unlikely. in fact, the protein chlorophyll is unlikely to arise somewhere else, how they gonna make chloroplasts?

I'm not saying that there will not be analogues for basic ecological requirements, I'm saying those analogues will not be bacteria, plants, and virus. This is merely a clarification of my own speculation.

 

Perhaps we will have larger ecological classification schemes for multi-planetary taxonomy: something like "Exoplants" or "Pseudobacteria"?

If humans colonise an Earthlike world covered in green autotrophic vegetation, I imagine that the colonists would refer to those organisms as "plants" on a day-to-day basis - rather than repeating some cumbersome phrase which reflects their separate origin from Earth flaura.

 

A rose by any other name, is still a rose. (grins)

Is ET out there?

Out there, down there, around there, their everywhere, their everywhere
Some you may want for neighbors, and some you would probably tar, feather, and run out of town on a rail.

 

To another lifeform in another solar system, we're considered ET too.......Nothing special about us........Just another evolved carbon based lifeform that supposedly exhibits some degree of intelligence.....Maybe!!!

Atta Boy

 

Not strictly speaking: "ET" is short for extra-terrestrial, and the word terrestrial relates specifically to OUR planet. We're just terrestrial

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... or, to Mr. Spock's dad, we might be EV (extra vulcanoid...)

 

Quick clarification - Are all viruses really descended from an original ancestral virus (we'll exclude artificial viruses for now)? What's the chances of viruses developing independently?

I notice you didn't mention prions... could a prion become a virus?

 

How about right there?

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Interesting Reading

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well, that's the implication. the alternative is that viruses arose more than once, and i can't see that happening. for viruses to arise more than once implies that they are some endpoint in evolution given certain conditions.

I don't a lot about prions but:
" Evidence suggests that a prion is a modified form of a normal cellular protein known as PrPc (for cellular), a normal host protein encoded by a single exon of a single copy gene. This protein is found predominantly on the surface of neurones attached by a glycoinositol phospholipid anchor, and is protease sensitive. Thought to be involved in synaptic function.
The modified form of PrPc which may cause disease i.e. the prion is known as PrPsc (for scrapie) which is relatively resistant to proteases and accumulates in cytoplasmic vesicles of diseased individuals.

It has been proposed that PrPsc when introduced into a normal cell causes the conversion of PrPc into PrPsc. The exact nature of the process is unknown but it could involve a chemical or conformational modification."
from: http://www-micro.msb.le.ac.uk/3035/prions.html

Since prions are modified versions of one's own protein, and that Viruses are RNA or DNA based, then no, there's no way for prions to become viruses, as far as we know.

 

I have referred to it before, but why not once more. Of course this is just the opinion of a certain subset of virologists.

Res Microbiol. 2003 May;154(4):231-6. Related Articles, Links

Do viruses form lineages across different domains of life?

Bamford DH.

 

thanks!

i'm definately reading that one. did you read it?

 

Holy crap! The whole issue is dedicated to the origin and evolution of viruses!
Look at these!!

Research in Microbiology
Volume 154, Issue 4, Pages 223-313 (May 2003)

1. The great virus comeback––from an evolutionary perspective, Pages 223-225 Patrick Forterre

2. The view from Les Treilles on the origins, evolution and diversity of viruses, Pages 227-229 Henry M. Krisch

3. Do viruses form lineages across different domains of life?, Pages 231-236
Dennis H. Bamford

4. The role played by viruses in the evolution of their hosts: a view based on informational protein phylogenies, Pages 237-243 Jonathan Filée, Patrick Forterre and Jacqueline Laurent

5. Bacteriophage observations and evolution, Pages 245-251 H. -W. Ackermann

6. Bacteriophages with tails: chasing their origins and evolution, Pages 253-257 Roger W. Hendrix, Graham F. Hatfull and Margaret C. M. Smith

7. The diversity and evolution of the T4-type bacteriophages, Pages 259-267
Carine Desplats and Henry M. Krisch

8. Myoviridae bacteriophages of Pseudomonas aeruginosa: a long and complex evolutionary pathway, Pages 269-275 Victor Krylov, Elena Pleteneva, Maria Bourkaltseva, Olga Shaburova, Guido Volckaert, Nina Sykilinda, Lidia Kurochkina and Vadim Mesyanzhinov

11. Evolutionary insights from studies on viruses of hyperthermophilic archaea, Pages 289-294 David Prangishvili

12. Relationships between fuselloviruses infecting the extremely thermophilic archaeon Sulfolobus: SSV1 and SSV2, Pages 295-302
Kenneth M. Stedman, Qunxin She, Hien Phan, Hans Peter Arnold, Ingelore Holz, Roger A. Garrett and Wolfram Zillig

14. Haloarchaeal viruses: how diverse are they?, Pages 309-313
Mike Dyall-Smith, Sen-Lin Tang and Carolyn Bath

 

He works in almost the same building and I had to listen to him during an 'evolution of viruses' course. I just skimmed trough the article some time ago.

I can remember making some comments on the cladogram but I can't remember what. Maybe if I look at it again.

 

Enough about virusses!

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We al have our share!

Let me point out at this stage in the discussion, that UFO's have been filmed by the mexican military last march.

Last thuesday, it was on their news program.

And OUR newspaper found it worthy enough to mention it,....it's in dutch, but it reads similar like english.

here's the link,..
Click here

and here's the link to a video of the scene, it's in German, but you won't find it difficult to understand. Are they here????

Here they are!

 

your links don't appear to be working, however, even if they were, i wouldn't believe it. we've been burned too often with fraudulent UFO and alien reports.

i have a friend in Mexico (a biologist who's a professor and researcher at a Mexican university) and if real aliens and ufo's were discovered in Mexico, he would notify me.