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Author Topic:   Life - an Unequivicol Definition
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 31 of 374 (772461)
11-14-2015 1:17 PM
Reply to: Message 26 by Blue Jay
11-13-2015 12:03 PM


Perhaps this is a nitpick, but the simplicity of your definition is an illusion. All you've really done is obscure the complexity of it behind a footnoted definition for "evolution." In all fairness, you should include the footnote as part of your definition, because without it, languages and stars,, which are also said to "evolve," can also be considered "life."

Sorry, I figured that "biological evolution" is understood on this forum when talking about evolution, and I thought to footnote clarified that. So you can add "biological" to my definition:

... anything capable of biological evolution. (cue definition of evolution ^(1)... ).

If we look a little closer, we can see that "hereditary" presupposes reproduction, and "traits" presupposes organization. "Reproduction" and "organization" are two of the classical characteristics of life. So, "hereditary traits" is sort of just a glossed-over paraphrasing of a more substantive definition.

And you can add "responds to stimulii" as well. To me the fact that you can extract "the classical characteristics of life" demonstrates the power of this definition to accurately describe life ... without falling victim to the shortfalls of the classical description\definition\characteristics (not all the elements can be applied all the time to all forms of life as we know it), rather it defines how they need to operate in order to have life.

In fact, we can further evaluate your entire definition and conclude that it's basically just an obscurantist repackaging of the "classical" description of life:
Life is organized; it responds to stimuli, metabolizes energy, grows, reproduces, and adapts.

Curiously I prefer to think of it as more of a koan rather than obscurantist repackaging. My premise\argument is that evolution requires life to exist (hence the origins of life is not part of evolution, something I believe we agree on), but also that life requires evolution. You could argue that this is circular, but I see it as recognizing the threshold between life and non-life. A yin\yang kind of thing.

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
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NoNukes
Inactive Member


Message 32 of 374 (772473)
11-14-2015 2:12 PM
Reply to: Message 30 by RAZD
11-14-2015 12:49 PM


Skin cells reproduce skin cells with modifications, same with other organs, same with gut bacteria.

Is a mule's skin being alive that enough to make a mule alive? Your observation seems to be that the mules skin is alive, which is not something under question.

it means that heritable traits are passed from one generation of cells to the next, and that process maintains the ability of the mule to live

Mules do not possess inheritable traits. I think you are stretching your definition passed breaking. Mules do not evolve.

Let's take it further. Would a single cell creature with the ability to reproduce without error or mutation be alive? Such a creature could not evolve.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King

If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams


This message is a reply to:
 Message 30 by RAZD, posted 11-14-2015 12:49 PM RAZD has responded

Replies to this message:
 Message 33 by RAZD, posted 11-14-2015 6:08 PM NoNukes has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 33 of 374 (772484)
11-14-2015 6:08 PM
Reply to: Message 32 by NoNukes
11-14-2015 2:12 PM


Is a mule's skin being alive that enough to make a mule alive? Your observation seems to be that the mules skin is alive, which is not something under question.

That was but one example, others would be the cells that form specific organs inside the body, each reproducing after their kind\clade ... all the elements that make up the mule are alive in this sense.

Certainly when we look at organ transplants, the body may be 'legally dead' but the organs are still living and can be transplanted into people that need them -- dead organs from cadavers don't do it.

You are confusing the life of the mule with the life of the individual cells that form the mule colony ...

Mules do not possess inheritable traits. I think you are stretching your definition passed breaking. Mules do not evolve.

Wrong on two counts: (1) they posses inheritable traits even if they do not have a means to convey those traits to offspring, and (2) their individual cells that all go to make up the entity called "mule" have inheritable traits that they pass to their offspring so long as the "species" (the mule) exists and does not go extinct (the mule dies).

Let's take it further. Would a single cell creature with the ability to reproduce without error or mutation be alive? Such a creature could not evolve.

No. Can you show me evidence of one?

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 32 by NoNukes, posted 11-14-2015 2:12 PM NoNukes has responded

Replies to this message:
 Message 34 by NoNukes, posted 11-15-2015 12:22 PM RAZD has responded

  
NoNukes
Inactive Member


Message 34 of 374 (772522)
11-15-2015 12:22 PM
Reply to: Message 33 by RAZD
11-14-2015 6:08 PM


No. Can you show me evidence of one?

Even without being able to show evidence of such a creature, the question is enough for me to find your definition unsatisfying.

That was but one example, others would be the cells that form specific organs inside the body, each reproducing after their kind\clade ... all the elements that make up the mule are alive in this sense.

I accept that a mule is alive, the question is whether the definition you put forth works to tell me such a thing. Let me repeat your definition here:

RAZD writes:

Mine is simpler: anything capable of evolution.

Mules are not capable of evolution by the accepted definition of biological evolution. A population of mules does not reproduce and accordingly there are no following generations of mules to even discuss whether there are changes in alelle frequency from generation to generation of mules. If a mule has a feature that helps it survive better than other mules, those traits cannot be passed on to any offspring to increase those traits in the population. You would have to redefine evolution somehow to make this stuff work. But you said that you were using evolution to mean biological evolution as currently understood.

What you are doing here is changing your original definition of life to talk about changes in the organs of a mule during a mules lifetime. However, said changes are not even inheritable by other mules. So yeah, the mule has living organs. But is a mule alive? Not according to your original definition.

Edited by NoNukes, : Small punctuation changes.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King

If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams


This message is a reply to:
 Message 33 by RAZD, posted 11-14-2015 6:08 PM RAZD has responded

Replies to this message:
 Message 56 by RAZD, posted 11-18-2015 5:06 PM NoNukes has responded

  
Pressie
Member
Posts: 2074
From: Pretoria, SA
Joined: 06-18-2010
Member Rating: 2.7


Message 35 of 374 (772565)
11-16-2015 6:02 AM
Reply to: Message 1 by AlphaOmegakid
11-12-2015 10:32 AM


AlphaOmegaKid writes:

So, at a minimum, a cell must be self contained, must metabolize, and must be a "protein factory"

This then will exclude Tasmanian Tiger Cancer from being alive.

What those guys do is to be part of a Tassie Tigers as cells (they come from Tassie Tigers, they are self-contained, they metabolize and are a protein factory), then can't do most of those things when leaving; then they infect another Tassie tiger by air and they do it all again. Are they dead or in between?

Edited by Pressie, : No reason given.


This message is a reply to:
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NoNukes
Inactive Member


Message 36 of 374 (772587)
11-16-2015 12:10 PM
Reply to: Message 35 by Pressie
11-16-2015 6:02 AM


What about these parasites?

http://arstechnica.com/...es-harvest-atp-directly-from-hosts

Mitochondria-free parasites harvest ATP directly from hosts

quote:
One of the defining features of the eukaryotes is the presence of mitochondria, which burn energy-rich molecules like sugars and fats to generate the ATP that runs most cellular processes. A few rare eukaryotes, however, appear to lack mitochondria, as well as the small genome the organelles posses. The best-studied example of these organisms are the microsporidia, parasites that live in animal cells, where they cause diarrhea and bronchitis. These organisms have a mitochondrial remnant, called a mitosome, but few of the genes normally involved with its activity.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King

If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams


This message is a reply to:
 Message 35 by Pressie, posted 11-16-2015 6:02 AM Pressie has not yet responded

Replies to this message:
 Message 66 by AlphaOmegakid, posted 11-19-2015 12:58 PM NoNukes has responded

  
AlphaOmegakid
Member (Idle past 1071 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 37 of 374 (772691)
11-17-2015 5:42 PM
Reply to: Message 17 by Tanypteryx
11-12-2015 7:36 PM


Tany writes:

If you have an argument to make, make it. We do not debate bare links here.

It just appears to me that you misunderstood part of what RAZD said. I don't think he was saying that individuals are the only unit of evolution.

Individuals are the unit of reproduction. They pass on the mutations that are selected for or against by the environment.

Yes, It wasn't I, but you who misunderstood RAZD or you misunderstand evolution. That was my argument. If you would have taken a quick look at my link you should have easily seen your mistake and RAZD's.

The simple fact is that individual organisms do not evolve period. Populations evolve. This is a fact even though you have stated otherwise. I have already supported this fact in the link I gave you .

Now using RAZD's definition, that means bees are alive, but a bee is not. A colony of bacteria is alive, but any individual bacteria in that colony is not. So, the definition doesn't work for most living things unless , of course, unless you equivocate on the definition of evolution, and then we are back to an illogical definition that isn't very scientific. Equivocation is what we are striving to eliminate even though many scientists like the logical inconsistencies.


This message is a reply to:
 Message 17 by Tanypteryx, posted 11-12-2015 7:36 PM Tanypteryx has responded

Replies to this message:
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AlphaOmegakid
Member (Idle past 1071 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 38 of 374 (772694)
11-17-2015 6:05 PM
Reply to: Message 18 by Blue Jay
11-12-2015 9:21 PM


Hello BJ,

You have some strong opinions about ecology, genomics, and climate change which I disagree. However this is probably not the right time/forum to drag those out, so I will decline to continue.

BJ writes:

Yes, needlessly specific. You're trying to define life in terms of a specific chemistry, when we don't really know that life couldn't exist on alternative chemistries. I suggested a hypothetical life-form that uses GTP instead of ATP. The two molecules are chemically very similar, and store the same amount of energy --- there's no reason why a metabolism couldn't exist that uses GTP.

If such an organism were discovered, would you entertain the notion that it wasn't alive, just because it doesn't fit your definition?

Well specific, yes. That's the point. What we have now is definitions that are not specific and equivocate regarding life. Needlessly specific? I disagree. GTP is involved in a small portion of some cells metabolic processes, but ATP is involved in all of them. So since a cell is the smallest unit of life, "needlessly" I don't see any reason to be less specific.

Of course, as you asked, if an organism was discovered that used GTP for all cell metabolism, then my definition would be falsified. Correct? So it would be modified or totally defeated. That's the process of the scientific method.


This message is a reply to:
 Message 18 by Blue Jay, posted 11-12-2015 9:21 PM Blue Jay has responded

Replies to this message:
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 Message 41 by New Cat's Eye, posted 11-17-2015 7:16 PM AlphaOmegakid has not yet responded
 Message 60 by RAZD, posted 11-18-2015 5:44 PM AlphaOmegakid has responded
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Dr Adequate
Member
Posts: 16097
Joined: 07-20-2006


Message 39 of 374 (772695)
11-17-2015 6:12 PM
Reply to: Message 38 by AlphaOmegakid
11-17-2015 6:05 PM


Well specific, yes. That's the point. What we have now is definitions that are not specific and equivocate regarding life.

Again I would point out that not one single one of those definitions equivocates. Each is perfectly unequivocal and specific.


This message is a reply to:
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AlphaOmegakid
Member (Idle past 1071 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 40 of 374 (772696)
11-17-2015 6:23 PM
Reply to: Message 19 by Dr Adequate
11-12-2015 10:15 PM


Equivocation
Maybe you are not understanding the term "equivocate" correctly. What the term means is

dictionary.com writes:

to use ambiguous or unclear expressions, usually to avoid commitment or in order to mislead; prevaricate or hedge:

That's what caused some scientists to say yes, and some to say no. For instance "reproduction" which many books say is a hallmark of "life". And indeed it is. But when it is used to define life (part of the definition) then the definition of "reproduction" must be ironed out, because for many reasons some organisms do not reproduce , but this doesn't make them not alive. The term is equivocal as used in the definition of life. So are many other defining terms currently in our textbooks.

IMO "evolution" would be the most equivocal term as we have already witnessed.


This message is a reply to:
 Message 19 by Dr Adequate, posted 11-12-2015 10:15 PM Dr Adequate has responded

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New Cat's Eye
Inactive Member


(1)
Message 41 of 374 (772700)
11-17-2015 7:16 PM
Reply to: Message 38 by AlphaOmegakid
11-17-2015 6:05 PM


Why though?
Well specific, yes. That's the point. What we have now is definitions that are not specific and equivocate regarding life. Needlessly specific? I disagree.

Where is the need for your level of specificity?

What does it do for Biology?

How is it utilized? How does it help? How does it work?

quote:
Life, or a living organism is a self contained entity which uses ATP (adenosine triphosphate) for metabolism and synthesizes ATP with enzymes which are synthesized from a genetic process requiring the transfer of information from DNA to RNA.

I don't really have a problem with your definition. It's good enough.

What I don't understand is your insistence on it?

Why are you amazed that Biologists are comfortable with definitions of life that are what you're calling equivocated?

First of all, life is blurry. So that's just something we're gonna hafta deal with.

And it seems like you are trying desperately to draw a line between biology and chemistry.

Biology is like a derivative of chemistry. There may not be a fine line between them.

quote:
This definition covers all known life.

Sort of, but not really.

You've already responded to the question of viruses:

quote:
It is not alive by my definition, and this is consistent with the consensus understanding of whether a virus is alive.

Whoa, slow down. Why just lop it off like that? How does that help the situation?

What good is it to bound our definitions by what we already know? Won't that hinder expansion?

Too, your definition would be better for biologists if it leaned more towards inclusion rather than exclusion... at least from a financial perspective >.>

What do you want them to do? Kick all the virologists out of the microbiology department because they're really not studying life, by definition?

If so, can they get a new Unbiology department? Or do they have to go to the mix with the Chemists?

then my definition would be falsified. Correct? So it would be modified or totally defeated. That's the process of the scientific method.

Biologists need definitions they can use. Ones that work.

I concur that your definition seeks to be too specific.

It's not that big of a deal. Biologists don't care about doing what you are referring to as equivocating.

In fact, it behooves them not to.


This message is a reply to:
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Dr Adequate
Member
Posts: 16097
Joined: 07-20-2006


(3)
Message 42 of 374 (772701)
11-17-2015 7:21 PM
Reply to: Message 40 by AlphaOmegakid
11-17-2015 6:23 PM


Re: Equivocation
Maybe you are not understanding the term "equivocate" correctly. What the term means is

I understand it perfectly.

That's what caused some scientists to say yes, and some to say no.

But they are different scientists.

Sheesh. "Some women oppose the fur trade. Other women wear fur. Therefore, women are hypocrites."

They're different women.

Edited by Dr Adequate, : No reason given.


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New Cat's Eye
Inactive Member


Message 43 of 374 (772702)
11-17-2015 7:24 PM
Reply to: Message 25 by RAZD
11-13-2015 9:15 AM


you are (like a colony of ants) a (colony) population of cells, and so yes, you are living by my definition.

But, a breeding population?


This message is a reply to:
 Message 25 by RAZD, posted 11-13-2015 9:15 AM RAZD has responded

Replies to this message:
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Tanypteryx
Member
Posts: 2250
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 5.3


Message 44 of 374 (772706)
11-17-2015 8:43 PM
Reply to: Message 37 by AlphaOmegakid
11-17-2015 5:42 PM


OK, thanks for making your argument.

Back to your definition of life. As a biologist, I don't think it is good enough.

What difference does it make to you if biologists use multiple definitions for life?

As I said in Message 9

quote:
It turns out that scientists use the definition that fits the context best. I have several friends who are virologists and they often treat viruses as living and refer to them as surviving or dying. At other times, they talk about viruses as complex molecules. Life is complex molecules and complex chemistry.

When biologists talk about life, if there is any confusion of their meaning, they define exactly what they mean. It depends on who we are talking to and what we are talking about.

As one alien entity on Startrek referred to humans as "Ugly bag of mostly water". It's all in the context.

This may not be very satisfying for non-scientists, but science is tentative and we are not sorry about that.



What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


This message is a reply to:
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Pressie
Member
Posts: 2074
From: Pretoria, SA
Joined: 06-18-2010
Member Rating: 2.7


(1)
Message 45 of 374 (772712)
11-18-2015 7:29 AM
Reply to: Message 44 by Tanypteryx
11-17-2015 8:43 PM


Exactly.

Tanypterix writes:

Back to your definition of life. As a biologist, I don't think it is good enough. What difference does it make to you if biologists use multiple definitions for life?

As a coal geologist, what difference does it make whether those blackish rocks obtained from the Waterberg Coalfield are defined as coal or not?

According to international classification, the Waterberg Coalfield is comprised of carbonaceous shale. Not coal. Yet, it burns. And is used in coal-fired power plants. And can also produce high quality coking coal. And metallurgical coal.

One definition for everything relating to coal doesn't describe everything...what applies to some rocks don't apply to others. Some are not even classified as coal...yet, they can and do perform the same functions when used in real life by people. One size does not fit all.

It's also not an equivocation either; it is trying to describe reality. Reality can't always be described in one definition.

Edited by Pressie, : No reason given.

Edited by Pressie, : No reason given.

Edited by Pressie, : No reason given.


This message is a reply to:
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