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Author Topic:   What is Life?
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 91 of 268 (593101)
11-24-2010 10:54 AM
Reply to: Message 90 by Jon
11-24-2010 10:09 AM


Re: It is What we Make It
The importance of the differences between life and non-life is the same as the importance of the differences between a rock and a mountain. And where does a rock begin and a mountain end?

A good example --- because in geology there is no formal definition telling us when we're looking at a mountain and when we're looking at a big hill.

And a bad example --- because there we're dealing with a continuous quantitative scale (height). The case is different with life. A bacterium doesn't just have more of some quality than (for example) a grain of sand. It has different qualities.


This message is a reply to:
 Message 90 by Jon, posted 11-24-2010 10:09 AM Jon has responded

Replies to this message:
 Message 96 by Jon, posted 11-25-2010 2:33 AM Dr Adequate has responded

  
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 92 of 268 (593102)
11-24-2010 10:57 AM
Reply to: Message 89 by Dr Jack
11-24-2010 7:53 AM


Re: Viruses Again
No, because the study of viruses is necessarily linked to the study of the living host of viruses. You cannot understand a virus without also understanding certain aspects of their hosts.

What if all he studies is their taxonomy through molecular phylogeny? Or the self-assembly of their protein coats? (I suppose in the second case there is a case that he's just a biochemist. But in the first case, not so much.)


This message is a reply to:
 Message 89 by Dr Jack, posted 11-24-2010 7:53 AM Dr Jack has responded

Replies to this message:
 Message 98 by Dr Jack, posted 11-25-2010 11:10 AM Dr Adequate has not yet responded

  
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 93 of 268 (593103)
11-24-2010 11:01 AM
Reply to: Message 88 by Stephen Push
11-24-2010 7:31 AM


Re: Life?
The prevailing theory of prion replication involves "autocatalytic protein misfolding." Why wouldn't that fall within your definition of "life"?

Because it doesn't say "autocatalytic protein mis-synthesis".

Recent research also shows that, although they lack nucleic acids, prions undergo Darwinian evolution, including mutation and natural selection.

Interesting, I'd like to look at that research, if you have a link. Thanks.

But my feeling is that they aren't really performing reproduction as such.

Question: is it possible to come up with a simple definition which includes prions but excludes the growth of crystals in solution?


This message is a reply to:
 Message 88 by Stephen Push, posted 11-24-2010 7:31 AM Stephen Push has responded

Replies to this message:
 Message 95 by Stephen Push, posted 11-24-2010 9:51 PM Dr Adequate has not yet responded

  
Blue Jay
Member (Idle past 808 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 94 of 268 (593123)
11-24-2010 1:04 PM
Reply to: Message 60 by AlphaOmegakid
11-23-2010 9:19 AM


Re: Sad Sad Sad
Hi, AOk.

AlphaOmegakid writes:

I hire employess. A requirement in certain positions is a high school doploma or GED. Completing 12 grades with no diploma is not necessarily any better than completing 10 grades with no diploma. But a diploma does have meaning.

First, you can't really complete 12 grades without getting a diploma: if you didn't get a diploma, it means you didn't complete at least 1 grade.

Second, if people who've completed 12 grades are not necessarily more capable of handling the job than people who've only completed 10 grades, then there is no meaning to completing 12 grades beyond that arbitrarily assigned to it by the arbiter. That is, the diploma holds meaning only because you, the employer (or the law that you're abiding by), say it does.

Likewise, in defining life, we're not just looking for something to which we can assign meaning: we're looking for something that has meaning beyond what we assign to it. Clearly, the diploma has no such meaning in your example, so it is not a good analogy for things that actually hold meaning.

-----

AlphaOmegakid writes:

A brick is a buiding block of a brick house. But it is far away from the definition of a brick house. You can organize bricks and make a fireplace with bricks and mortar. This is closer to the definition of a brick house, but it still does not meet the definition of a brick house.

At what point does a pile of bricks become a brick house?
When the last brick is put into place?
When the mortar dries?
When the electrician approves the wiring and the water main is turned on?

If you were showing off your 75%-completed house, and you said to your friends, "look at my new house!"---would you be justified in using the term "house"? I wouldn't make a fuss about it.

And then, when the brick house is completed, how many bricks have to fall out of the west wall before we have to stop calling it a brick house?
If a tornado took a chunk out of the garage, would you have to revert to calling it an "organized pile of bricks"?

"Brick house" is not all that clearly defined in relation to "pile of bricks," so this is yet another example of a pair of terms that are only distinguished insomuch as we choose to distinguish them.

-----

AlphaOmegakid writes:

Bluejay writes:

What do you do with things that match five of the seven pillars, or four, or six?

You give them a special scientific name. Something like "virus". And you recognize that they meet 5 of the 7 criteria, but they do not meet the full criteria.

And then what? Treat them like "not life"? Consider them the equivalent of rocks and sand? Or acknowledge that they fit somewhere between rocks and "life," and thereby reject the idiot classification that has us claiming that "life" is discreetly and distinctly different from "not life"?

Actually, virologists treat viruses just as if they were "life." They study their behavior as if they were "life." They study their physiology and genetics as if they were "life." They study their evolution as if they were "life." In fact, biologists consider people who study viruses to be a type of biologist.

This raises the question of why we defined "life" to exclude viruses in the first place. Clearly, that definition hasn't had much effect on how we treat them; also clearly, that definition doesn't prevent them from being more like "life" than like other things that are "not life."

This is what a biologist means when they argue about the definition of "life" being unclear: not that it's impossible to cobble some things together into a workable definition, but that the definition doesn't really hold much meaning in terms of how things function, behave or evolve.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 60 by AlphaOmegakid, posted 11-23-2010 9:19 AM AlphaOmegakid has responded

Replies to this message:
 Message 102 by AlphaOmegakid, posted 11-29-2010 9:44 AM Blue Jay has responded

  
Stephen Push
Member (Idle past 2970 days)
Posts: 140
From: Virginia, USA
Joined: 10-08-2010


Message 95 of 268 (593197)
11-24-2010 9:51 PM
Reply to: Message 93 by Dr Adequate
11-24-2010 11:01 AM


Re: Life?
Dr Adequate writes:

Interesting, I'd like to look at that research, if you have a link. Thanks.

Darwinian Evolution of Prions in Cell Culture. Science, 12 February 2010: 869-872.

That page also contains links to two critical responses to the research paper and a rebuttal from one of the paper's authors.

But my feeling is that they aren't really performing reproduction as such.

Although the requirement of synthesis in your definition excludes prions, why isn't the method by which prions replicate themselves a form of reproduction?

Question: is it possible to come up with a simple definition which includes prions but excludes the growth of crystals in solution?

Life is any chemical entity that replicates itself and evolves by means of mutation and natural selection.

OR

Life is any entity composed of organic molecules that replicates itself.

Assuming the prion evolution theory holds up, I would prefer the first definition, since it would have the advantage of admitting extraterrestrial life that may not be based on organic chemistry.

Edited by Stephen Push, : No reason given.


This message is a reply to:
 Message 93 by Dr Adequate, posted 11-24-2010 11:01 AM Dr Adequate has not yet responded

  
Jon
Inactive Member


Message 96 of 268 (593208)
11-25-2010 2:33 AM
Reply to: Message 91 by Dr Adequate
11-24-2010 10:54 AM


Re: It is What we Make It
A bacterium doesn't just have more of some quality than (for example) a grain of sand. It has different qualities.

If you say so.

Jon


Check out Apollo's Temple!
Ignorance is temporary; you should be able to overcome it. - nwr

This message is a reply to:
 Message 91 by Dr Adequate, posted 11-24-2010 10:54 AM Dr Adequate has responded

Replies to this message:
 Message 97 by Dr Adequate, posted 11-25-2010 8:04 AM Jon has responded

  
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 97 of 268 (593217)
11-25-2010 8:04 AM
Reply to: Message 96 by Jon
11-25-2010 2:33 AM


Re: It is What we Make It
If you say so.

Do you disagree? Otherwise we could both say so.


This message is a reply to:
 Message 96 by Jon, posted 11-25-2010 2:33 AM Jon has responded

Replies to this message:
 Message 99 by Jon, posted 11-25-2010 11:17 AM Dr Adequate has responded

  
Dr Jack
Member (Idle past 215 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 98 of 268 (593228)
11-25-2010 11:10 AM
Reply to: Message 92 by Dr Adequate
11-24-2010 10:57 AM


Five Clumsy reasons why viruses are not alive
I found a rather good blog post arguing against a 2009 paper that argued viruses are not alive. It seems pertinent.
This message is a reply to:
 Message 92 by Dr Adequate, posted 11-24-2010 10:57 AM Dr Adequate has not yet responded

  
Jon
Inactive Member


Message 99 of 268 (593229)
11-25-2010 11:17 AM
Reply to: Message 97 by Dr Adequate
11-25-2010 8:04 AM


Re: It is What we Make It
quote:
Adequate in Message 91:

A bacterium doesn't just have more of some quality than (for example) a grain of sand. It has different qualities.


Jon writes:

If you say so.

Do you disagree? Otherwise we could both say so.

It doesn't matter. They are obviously different; but so is anything that is different. Their differences aren't important, however, to anyone but us. Our agreement would not change reality; I see no reason to comment on that issue.

Jon


Check out Apollo's Temple!
Ignorance is temporary; you should be able to overcome it. - nwr

This message is a reply to:
 Message 97 by Dr Adequate, posted 11-25-2010 8:04 AM Dr Adequate has responded

Replies to this message:
 Message 100 by Dr Adequate, posted 11-25-2010 11:27 AM Jon has responded

  
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 100 of 268 (593230)
11-25-2010 11:27 AM
Reply to: Message 99 by Jon
11-25-2010 11:17 AM


Re: It is What we Make It
It doesn't matter. They are obviously different; but so is anything that is different.

Yes, but quantitative and qualitative differences are also different.

The way in which a small piece of cheese differs from a big piece of cheese is different from the way in which it differs from a small piece of chalk.

Their differences aren't important, however, to anyone but us.

Oh, you could say that of anything. But I shall still go on using different nouns for different things.


This message is a reply to:
 Message 99 by Jon, posted 11-25-2010 11:17 AM Jon has responded

Replies to this message:
 Message 101 by Jon, posted 11-25-2010 2:02 PM Dr Adequate has not yet responded

  
Jon
Inactive Member


Message 101 of 268 (593243)
11-25-2010 2:02 PM
Reply to: Message 100 by Dr Adequate
11-25-2010 11:27 AM


Re: It is What we Make It
Oh, you could say that of anything. But I shall still go on using different nouns for different things.

Good; that's probably the smart thing to do.

Yes, but quantitative and qualitative differences are also different.

A difference is a difference. Our distinction of different differences is our own.

Jon


Check out Apollo's Temple!
Ignorance is temporary; you should be able to overcome it. - nwr

This message is a reply to:
 Message 100 by Dr Adequate, posted 11-25-2010 11:27 AM Dr Adequate has not yet responded

  
AlphaOmegakid
Member (Idle past 986 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 102 of 268 (593764)
11-29-2010 9:44 AM
Reply to: Message 94 by Blue Jay
11-24-2010 1:04 PM


Re: Sad Sad Sad
First, you can't really complete 12 grades without getting a diploma: if you didn't get a diploma, it means you didn't complete at least 1 grade.

Well, first off your premise is wrong. Diploma's are base on credits nowadays, not the completion of grades. You can complete twelve grades, and not complete the credit requirements. And you don't graduate.

Second, if people who've completed 12 grades are not necessarily more capable of handling the job than people who've only completed 10 grades, then there is no meaning to completing 12 grades beyond that arbitrarily assigned to it by the arbiter. That is, the diploma holds meaning only because you, the employer (or the law that you're abiding by), say it does.

Again, the diploma holds meaning in a variety of contexts outside of hiring. Completing a job assignment is irrelevant. The main meaning has nothing to do with education or intellect. It has to do with understanding and completing a goal. That's why the goal is defined and has meaning.

Likewise, in defining life, we're not just looking for something to which we can assign meaning: we're looking for something that has meaning beyond what we assign to it. Clearly, the diploma has no such meaning in your example, so it is not a good analogy for things that actually hold meaning.

Baloney! We ARE looking for something we can assign meaning. The living organisms are distinctly different from those which are non-living. Including viruses.

All life, 100%, meets the seven pillars definition given. Other things do not. That's why definitions are good and logical. We can't discuss them logically without definitions.

At what point does a pile of bricks become a brick house?
When the last brick is put into place?
When the mortar dries?
When the electrician approves the wiring and the water main is turned on?

At the point the contractual obligations are met. There is a plan. A design. There is a requirement to meet the plan. It is the plan and the legal requirements (laws) that define the house.

Even in building a hut, there is a plan. There may not be any building requirements, but there is a plan. It is the designer or owner who decides the definition of their house. That doesn't mean it cannot be defined.

If you were showing off your 75%-completed house, and you said to your friends, "look at my new house!"---would you be justified in using the term "house"? I wouldn't make a fuss about it.

Of course, but this language assumes the planned end result doesn't it? If construction stopped and we came back ten years later, you wouldn't be using this language now would you?

And then, when the brick house is completed, how many bricks have to fall out of the west wall before we have to stop calling it a brick house?
If a tornado took a chunk out of the garage, would you have to revert to calling it an "organized pile of bricks"?

You do realize there are definitions for this as well. Houses are condemned for certain levels of damage. I loose hair all the time. That does not disqualify me from being a living human. But at some point, I will no longer be breathing and I will have no more hair. I will be dead. You see. It can be defined.

"Brick house" is not all that clearly defined in relation to "pile of bricks," so this is yet another example of a pair of terms that are only distinguished insomuch as we choose to distinguish them.

Ummmmmm.....yeah! We choose to distinguish them via definition.

And then what? Treat them like "not life"? Consider them the equivalent of rocks and sand? Or acknowledge that they fit somewhere between rocks and "life," and thereby reject the idiot classification that has us claiming that "life" is discreetly and distinctly different from "not life"?

Treating them as not life is a "vital" step in understanding what they are. Viruses predominantly destroy life.

No they are not equivalent to rocks and sand. We know this, because rocks and sand have definitions. And viruses don't meet those definitions.

Why would you say "the idiot classification that has us claiming that "life" is discreetly and distinctly different from "not life"?" Do you have some sort of definition for idiot?

Actually, virologists treat viruses just as if they were "life." They study their behavior as if they were "life." They study their physiology and genetics as if they were "life." They study their evolution as if they were "life."

Nope. Nope. Nope. and Nope.

In fact, biologists consider people who study viruses to be a type of biologist.

That's because virologists study how viruses effect/destroy life.

This raises the question of why we defined "life" to exclude viruses in the first place.

So you agree that there is a definition and it excludes viruses. That sort of negates your whole argument doesn't it?

Clearly, that definition hasn't had much effect on how we treat them; also clearly, that definition doesn't prevent them from being more like "life" than like other things that are "not life."

Well actually we mainly treat the living, who have the virus. We haven't learned too much about treating viruses yet. And no, I agree with you that they are more like the living than the non living, but only when they, like all the living things gain their "life" from the living...LOB. Virions, by themselves aren't anywhere close to life.

This is what a biologist means when they argue about the definition of "life" being unclear:

Oh I disagree. Biologists argue that the definition of life is unclear ONLY for the reason of allowing equivocation in abiogenesis.

not that it's impossible to cobble some things together into a workable definition,

Yes, you are right. It is possible to define life. It is in every biology textbook and in the paper I cited. It wasn't cobbled up though.

but that the definition doesn't really hold much meaning in terms of how things function, behave or evolve.

Oh contraire! The main aspects of the definition of life have to do with how things function, behave, and evolve.


This message is a reply to:
 Message 94 by Blue Jay, posted 11-24-2010 1:04 PM Blue Jay has responded

Replies to this message:
 Message 103 by Panda, posted 11-29-2010 10:25 AM AlphaOmegakid has not yet responded
 Message 104 by ringo, posted 11-29-2010 10:30 AM AlphaOmegakid has not yet responded
 Message 105 by Dr Adequate, posted 11-29-2010 11:02 AM AlphaOmegakid has not yet responded
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Panda
Member (Idle past 1823 days)
Posts: 2688
From: UK
Joined: 10-04-2010


Message 103 of 268 (593770)
11-29-2010 10:25 AM
Reply to: Message 102 by AlphaOmegakid
11-29-2010 9:44 AM


Re: Sad Sad Sad
kid writes:

Treating them as not life is a "vital" step in understanding what they are. Viruses predominantly destroy life.


Since viruses do not predominantly destroy life, treating them as not life is obviously not "vital" in understanding what they are.

In fact, scientists have understood what they are for quite a while and haven't needed to categorise them as 'life' or 'not life'.
All they actually needed to do was study them.

I also note that you have abandoned your falsehood about people not attempting to define life.
Having Dr. Adequate list the 6 definitions in this thread alone must have been enough for you to realise that you were completely wrong.
Apology accepted.


This message is a reply to:
 Message 102 by AlphaOmegakid, posted 11-29-2010 9:44 AM AlphaOmegakid has not yet responded

  
ringo
Member
Posts: 16362
From: frozen wasteland
Joined: 03-23-2005
Member Rating: 3.4


(1)
Message 104 of 268 (593771)
11-29-2010 10:30 AM
Reply to: Message 102 by AlphaOmegakid
11-29-2010 9:44 AM


AlphaOmegakid writes:

It is the designer or owner who decides the definition of their house. That doesn't mean it cannot be defined.


Where you're going wrong is in assuming that there's only one definition. The designer and owner may or may not have the same definition. The designer may define it as a house as soon as the drawings are complete. The owners may be showing people "their house" when it's just a foundation and a pile of lumber. The city government has its own definition - it's a house when it meets all of the building codes and becomes taxable.

It's naive to pretend that one definition will work in all situations.


"It appears that many of you turn to Hebrew to escape the English...." -- Joseppi
This message is a reply to:
 Message 102 by AlphaOmegakid, posted 11-29-2010 9:44 AM AlphaOmegakid has not yet responded

  
Dr Adequate
Member
Posts: 16094
Joined: 07-20-2006
Member Rating: 8.2


Message 105 of 268 (593773)
11-29-2010 11:02 AM
Reply to: Message 102 by AlphaOmegakid
11-29-2010 9:44 AM


Viruses Redux
Treating them as not life is a "vital" step in understanding what they are.

Well, no. I can know exactly what a virus is and how it works whether or not I choose to call it "life".

I referred you earlier in this thread to an article by Nobel Laureate David Baltimore in which he wrote: "I think theyre about as alive as anything". Now he got his Nobel Prize for discovering reverse transcriptase, an essential part of the life cycle of retroviruses. The fact that you and he disagree on whether they should be classed as "alive" didn't prevent him from making his discovery; and, I will wager, your stance has not enabled you to make a single discovery in virology.

Viruses predominantly destroy life.

This is something of a non sequitur. A carnivore like a lion, an insectivore like a shrew, or a sufficiently nasty bacterium such as Yersinia pestis also make their living by "destroying life". This has no bearing on whether they are alive.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 102 by AlphaOmegakid, posted 11-29-2010 9:44 AM AlphaOmegakid has not yet responded

Replies to this message:
 Message 106 by RAZD, posted 11-29-2010 10:21 PM Dr Adequate has not yet responded

  
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