Are viruses life?


by SpaceGuy50
Tags: life, viruses
kuzao
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#55
Jul23-09, 12:03 PM
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hmm i wonder what non living things you are refering too when you say there are some which transcribe and translate?
DaveC426913
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#56
Jul23-09, 01:46 PM
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Quote Quote by kuzao View Post
hmm i wonder what non living things you are refering too when you say there are some which transcribe and translate?
Computer programs for a start.
junglebeast
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#57
Jul23-09, 02:27 PM
P: 462
Quote Quote by kuzao View Post
are you unsatisfied with the grammar of my statement? should i rather say any entity that contains dna and rna at the same time is to be called life?
Understanding the function of DNA makes it obvious that DNA itself is not necessary for life. It's role is simply to store information in a way that can be copied to allow evolution to occur. DNA is certainly not the only molecule that could potentially fill this purpose.

I believe there has been at least one organism identified on Earth that does not use DNA, although I can't remember the name of it. Anyway, life on other planets almost certainly will not use the exact form of DNA as here on Earth. Moreover, there is no fundamental reason why life must be molecular at all. Life could theoretically be formed out of sub-atomic particles, or even out of virtual building blocks in a computer.
DaveC426913
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#58
Jul23-09, 02:35 PM
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Quote Quote by junglebeast View Post
DNA is certainly not the only molecule that could potentially fill this purpose.
...
Anyway, life on other planets almost certainly will not use the exact form of DNA as here on Earth. Moreover, there is no fundamental reason why life must be molecular at all. Life could theoretically be formed out of sub-atomic particles, or even out of virtual building blocks in a computer.
All of which I would agree with, if he hadn't qaulified it by saying Earth life.
BoomBoom
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#59
Jul23-09, 05:04 PM
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Quote Quote by junglebeast View Post
Understanding the function of DNA makes it obvious that DNA itself is not necessary for life. It's role is simply to store information in a way that can be copied to allow evolution to occur.
That is most certainly not the only function of DNA. DNA is essential to cellular function.


Anyway, life on other planets almost certainly will not use the exact form of DNA as here on Earth.
How can you be so certain? The "central dogma" could very well be universal.....across the universe. Until we actually find extraterrestrial life, the words "almost certainly" has no substance to it whatsoever.
junglebeast
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#60
Jul23-09, 05:33 PM
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Quote Quote by BoomBoom View Post
How can you be so certain? The "central dogma" could very well be universal.....across the universe. Until we actually find extraterrestrial life, the words "almost certainly" has no substance to it whatsoever.
The same way you can be certain than 10 = x + y has multiple solutions. No experiments are necessary once you understand addition...
kuzao
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#61
Jul23-09, 06:29 PM
P: 18
@ dave
while we seem to agree on the answer our way of comming ot that conclusion seem to be different.

no offense meant but could it be that it is a while ago since you studied molecular biology?

as for transcription and translation, i used these as biological terms. they are defined as coppying dna to rna and then making poly peptides out of rna.
this means that there are actually no artificial 'things', entitys or what ever who translate and transcribe.

@ jungle beast

im not aware of any organism who doesnt contain dna. could you find the name? im curious.

Understanding the function of DNA makes it obvious that DNA itself is not necessary for life. It's role is simply to store information in a way that can be copied to allow evolution to occur. DNA is certainly not the only molecule that could potentially fill this purpose.
first: of course its not the only molecule but its is certainly the only for EARTH based BIOLOGICAL (some call it organic) life. and that was as, dave pointed out, exactly what i said. are we trying to define what we have here based on 'hard' definitions or are we trying to be philosophical? there is nothing wrong with that, but then the defintion would be so much longer and 'softer'.



second: again there is no offense meant when i say: you didnt had any molecular biology classes, or?
boomboom is right when he says that dna's task are many and not limited to only storing information. expression regulation by dna folding, dna binding and many more ways is big topic in mole. bio.

i do not totaly agree with boomboom on his 'central dogma' theory.
yes it MIGHT. but it might also NOT. we cant say and i proclaim we will never find out because that would require to locate and analyse ALL life (and i mean ALL! not only on earth or in this galaxy) hencefore this is a irrelevant point and futile to discuss.


one thing we should have a common understanding of is the term 'definition'. do we want something which desribes the essence, the principle of life or do we want a definition as lawyers tend to make them ^^ loooong, wound in strange shape so that every possible and impossible exeption is included and useless? (this time the offense to lawyers is intended :P )

alex

p.s. sry for the typos. being dyslexic AND tired is fatal ^^
DaveC426913
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#62
Jul23-09, 06:47 PM
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Quote Quote by kuzao View Post
as for transcription and translation, i used these as biological terms.
Which is a circular argument.

Basically your argument boils down to "life is that which performs biological functions".
DaveC426913
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#63
Jul23-09, 06:51 PM
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Quote Quote by BoomBoom View Post
How can you be so certain? The "central dogma" could very well be universal.....across the universe. Until we actually find extraterrestrial life, the words "almost certainly" has no substance to it whatsoever.
Because amino acids can form a nearly infinite variety of proteins. For DNA to arise the same twice - let alone common - is astronomically unlikely.

Personally, I think it will be very similar, but not the same.
kuzao
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#64
Jul23-09, 06:55 PM
P: 18
@dave

oh far from beeing true. my statement could be read as 'life is what is based on these two functions' (still doesnt sound flashy)

one could see it as a circular argument IF these were the only functions present in organism and thus they could be called the only biological functions.

maybe i should have explained more.
transcription and translation are terms closely realted to presence of rna and dna. thus saying transcription and translation is defining life means presence of dna and rna is defining life.

does this make it more clear to you? do you see now that this is not a 'soft' argument but a very ahrd one? and also not a circular one?
kuzao
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#65
Jul23-09, 07:02 PM
P: 18
Quote Quote by DaveC426913 View Post
Because amino acids can form a nearly infinite variety of proteins. For DNA to arise the same twice - let alone common - is astronomically unlikely.

Personally, I think it will be very similar, but not the same.

first i think its futile to find a defintion for something we dont even know about yet. thats just discussing because we like to read our on writings...

however i agree on the point that it is unlikely. to be exactly the same. but how exactly the same does it has to be to be still called dna? what if it incorporates uracil instead of thymine. could i then still be called dna?

i assume dave then would argue that its not the same thus he was right while boomboom would say hey look it basically the same?

lets dont wander into that realm. there is no merit there.
DaveC426913
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#66
Jul23-09, 07:13 PM
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Quote Quote by kuzao View Post
@dave

oh far from beeing true. my statement could be read as 'life is what is based on these two functions' (still doesnt sound flashy)

one could see it as a circular argument IF these were the only functions present in organism and thus they could be called the only biological functions.


maybe i should have explained more.
transcription and translation are terms closely realted to presence of rna and dna. thus saying transcription and translation is defining life means presence of dna and rna is defining life.


does this make it more clear to you? do you see now that this is not a 'soft' argument but a very ahrd one? and also not a circular one?
No and no.

Translation and transcription do not define life. There are non-living things that translate and transcribe that have nothing to do with DNA or RNA. It is too general.

Your argument is the equivalent of:

All cars have motors. Therefore, the definition of a car is that which has a motor.
kuzao
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#67
Jul23-09, 07:33 PM
P: 18
as i said before transcription and translation are terms of molecular biology and in this context i used them.

do you understand what translation and transcription means?

there are no things which can translate and transcribe and are artificial (at least to my knowledge and if you dont purposly trying to ridicule my argument by saying that a vial where you put in some dna, rna, polymerase and other things should then be called life)

your car argument is a faulty one. if you understand the meaning of transcription and translation you will understand that all things which inherit these two abilities are life. while not all things inhereting a motor are cars.

if you define life via rna and dna or translation and transcription you will as a result get all the things who can 'do' the 'things' most people asscociate with life. like proliferation, metabolism and so on. which is in my opinion a reason to chose this defintion because it avoids to define something by some 'effect' but instead defines by source / reason.

alex
DaveC426913
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#68
Jul23-09, 07:47 PM
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Quote Quote by kuzao View Post
as i said before transcription and translation are terms of molecular biology and in this context i used them.
OK, so let's make that context explicit.

"Life is that which performs biological transcription and translation."

That is circular.
kuzao
kuzao is offline
#69
Jul23-09, 08:00 PM
P: 18
we are talking about viruses and life here of course taht implies that we talk biology here.

do you realise that transcription and translation are synonymes for the presence of rna and dna?

how can chosing the two elemental functions of an organism as lifes definition be a circle argument?


if your point would be valid that woul mean that you need life to define transcription and translation. but you dont.

translation and transcription are chemical processes. you do not have to use 'life' to define them. so how can this definition then be a circular argument?

by the way i feel sorry for the other discussion participants because we take up to much space. should we continue this conversation in skype or via email?

alex
BoomBoom
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#70
Jul23-09, 08:15 PM
P: 293
Quote Quote by kuzao View Post
i do not totaly agree with boomboom on his 'central dogma' theory.
yes it MIGHT. but it might also NOT. we cant say and i proclaim we will never find out because that would require to locate and analyse ALL life (and i mean ALL! not only on earth or in this galaxy) hencefore this is a irrelevant point and futile to discuss.
Well, I wasn't claiming that is was for sure, I was making the point that it could be...in order to counter the assertion by JB that it is "almost certain" that DNA from another planet would be different.

The true answer is we don't know, nor can we know until we find some...then we could start to make some educated assumptions perhaps.
kuzao
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#71
Jul23-09, 08:20 PM
P: 18
totally agreed :)
DaveC426913
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#72
Jul23-09, 08:27 PM
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Quote Quote by kuzao View Post
we are talking about viruses and life here of course taht implies that we talk biology here.
We are trying to define life. That means we cannot refer to life processes as definors.

Quote Quote by kuzao View Post
do you realise that transcription and translation are synonymes for the presence of rna and dna?
Only in a biological context. And an Earth biological context at that.

All I am requiring is that you create your life definition without referring to life processes in doing so.


Quote Quote by kuzao View Post
if your point would be valid that woul mean that you need life to define transcription and translation. but you dont.
Transcription is the process of copying something from one medium to another.

Translation is more broad, and involves moving something from one place to another, and several other definitions.

If you wish to further define or qualify those, do so. If you qualify those words in the context of the very thing we are trying to define, you will end up with a circular argument.

Quote Quote by kuzao View Post
translation and transcription are chemical processes. you do not have to use 'life' to define them.
Now you're getting closer to a valid definition. You've removed the reference to biology (life - the circular reference), and are defining it on terms of chemistry. That is not how you were contextualizing it previously.

That is what I was asking for.

"Life is that which performs chemical transciption."


Quote Quote by kuzao View Post
by the way i feel sorry for the other discussion participants because we take up to much space. should we continue this conversation in skype or via email?
They are quite capable of jumping in when and if they wish. It's not like walkie-talkies, where they have to wait for us to finish.


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