- #71
kuzao
- 18
- 0
totally agreed :)
We are trying to define life. That means we cannot refer to life processes as definors.kuzao said:we are talking about viruses and life here of course taht implies that we talk biology here.
Only in a biological context. And an Earth biological context at that.kuzao said:do you realize that transcription and translation are synonymes for the presence of rna and dna?
Transcription is the process of copying something from one medium to another.kuzao said:if your point would be valid that woul mean that you need life to define transcription and translation. but you dont.
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.kuzao said:translation and transcription are chemical processes. you do not have to use 'life' to define them.
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.kuzao said: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?
You could have made it absolutely clear by putting it in your definition anytime after post 52!kuzao said:ok maybe i assumed too much.
let me make it absolutly clear: whenever i talk about translation and transcription i mean the biological transcription and translation which is a) copying dna to rna and b) rna to poly peptide.
kuzao said: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.
kuzao said:let me make it absolutly clear: whenever i talk about translation and transcription i mean the biological transcription and translation which is a) copying dna to rna and b) rna to poly peptide.
kuzao said:life is what performs transcription and translation
CRGreathouse said:So life is that which
- Copies DNA to RNA
- Copies RNA to polypeptides
So a virus, which performs neither, is not alive by your definition. A genetics lab which performs ligation and transcription would be alive.
This argument could apply to anything you want.CRGreathouse said:A genetics lab which performs ligation and transcription would be alive.
DaveC426913 said:This argument could apply to anything you want.
"Life makes copies of itself."
"A lab can do that so it must be alive."
I think it's safe to say that "a bunch of humans performing roles that model the mechanisms of life" is disqualified as being an example of life itself.
DaveC426913 said:This argument could apply to anything you want.
"Life makes copies of itself."
"A lab can do that so it must be alive."
I think it's safe to say that "a bunch of humans performing roles that model the mechanisms of life" is disqualified as being an example of life itself.
Phrak said:DaveC, what's your definition of life? This is very long thread, so if you stated it already, it's worth repeating.
Mine had been: A self replicating, adaptable system.
This leaves out crystals, and includes viruses. I'd want to have prions in the ambiguous middle, but it excludes them entirely.
sokrates said:Well put. I agree with this. I am just curious though, what are the adaptation mechanisms of a virus?
kuzao said:but self replication is quite dangerous that would leave all strile organisms out of the definition so many crops would count as life anymore so many sterile organisms etc tehy can only grow on their own thei can't replicate.
you could get around that at least a bit by saying you apply the definition only to cell sized entitys but still i would say excluding annything what can't grow anymore is a bit difficult
sokrates said:After all those useless points (circular arguments, discussions on semantics, stating big remarks on how definitions narrow generalities), is this your definition of life: anything but "a bunch of humans performing roles that model the mechanisms of life".
I thought you were defending the view that it all depended on the definition... Based on what you complain in this thread without stating your own take on the issue, this example is a perfect satirical example of "life"...
CRGreathouse said:Fair enough. Do you have an alternate definition?
DaveC426913 said:You have not been following the discussion. You are interpreting my post in a vacuum.
Read https://www.physicsforums.com/showpost.php?p=2283100&postcount=77" (in particular, the last line) where CRG makes a satirical example of life based on kuzao's definition.
Then skip to https://www.physicsforums.com/showpost.php?p=2283234&postcount=80", where I demonstrate that CGR's satirical example is itself invalid, since it is so broad that anything could be defined that way.
kuzao said:any thougs about this definition?
kuzao said:a group of similar organisms / entitys with the ability to metabloize and mechanism to ensure (or is promte a better choice?) the groups continued existence
kuzao said:but self replication is quite dangerous that would leave all strile organisms out of the definition so many crops would count as life anymore so many sterile organisms etc tehy can only grow on their own thei can't replicate.
you could get around that at least a bit by saying you apply the definition only to cell sized entitys but still i would say excluding annything what can't grow anymore is a bit difficult
CRGreathouse said:I think it's an improvement over the more specific earlier one.
I do have some problems with it, though. What is "metabolize"? I think it's hard to define that without reference to life. (Feel free to disagree, with a definition!) Also, the more I think about it, the more difficulties I have with "similar". Not only is this abstract, but it also causes problems with symbiosis. What about humans and our symbiotic bacterial cultures? Worst, what about our mitochondria? How do we draw the line so those are includes but other symbiotes are not?
Phrak said:Self-similar replicating system. What system would include crops that cannot reproduce or the product of a horse and a donkey? Individual organisms without reference to a group would not qualify--but as elements of a group structure, do. For instance, sexual reproduction takes two. In isolation, an individual person doesn't normally reproduce.
Many things such as mules and certain crops are unable to reproduce, yet are very much alive.kuzao said:im sorry but i don't understand your argument. could you elaborate?
DaveC426913 said:Many things such as mules and certain crops are unable to reproduce, yet are very much alive.
DaveC426913 said:Many things such as mules and certain crops are unable to reproduce, yet are very much alive.
kuzao said:im sorry but i don't understand your argument. could you elaborate?
Phrak said:I'm not sure I can, unless you can tell me what you want elaborated. After being unsuccessful at defining what is living vs. not-living in terms of individual organisms, I attempt to define life as more than one organism. This is what I've called a system. Living things are then part of a living system whether they can self-similarly replicate, or not.
It would be a good to define what I've been calling a 'system' in solid terms, otherwise, it's philosohpy, as you've called it. A very good point. I don't have an answer. I was hoping someone with more insight than I could identify it.
Yes.kuzao said:dave do you think he/she meant that?
I wouldn't say not 'useful', I would say not unilateral.kuzao said:then it would back my argument that reproductions isn't a usefull thing to inculde in a dfinition of life, or?
kuzao said:ah ok i understand :)
that would be a similar approach as in post 89, or?