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Author Topic:   Life - an Unequivicol Definition
RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(2)
Message 10 of 374 (772338)
11-12-2015 3:54 PM
Reply to: Message 1 by AlphaOmegakid
11-12-2015 10:32 AM


Welcome back/

... But not me! I believe it is possible to create an unequivocal, simple definition of biological life or for simplicity sake an organism. I have created this definition over a period of years, and it has been tested by a number of personally know scientists.

So here it is:

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.

Mine is simpler: anything capable of evolution. (cue definition of evolution ^(1)... ).

This not only includes viruses but self-replicating molecules. The essential difference in my opinion between life and non-life is that one evolves (life) and one doesn't (non-life).

Enjoy

(1) The process of evolution involves changes in the composition of hereditary traits, and changes to the frequency of their distributions within breeding populations from generation to generation, in response to ecological challenges and opportunities for growth, development, survival and reproductive success in changing or different habitats.

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Replies to this message:
 Message 13 by AlphaOmegakid, posted 11-12-2015 5:40 PM RAZD has replied
 Message 21 by dwise1, posted 11-13-2015 1:06 AM RAZD has replied
 Message 26 by Blue Jay, posted 11-13-2015 12:03 PM RAZD has replied

  
RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 23 of 374 (772387)
11-13-2015 8:32 AM
Reply to: Message 21 by dwise1
11-13-2015 1:06 AM


Mine is simpler: anything capable of evolution. (cue definition of evolution ^(1)... ).

Since evolutionary processes require some mechanism for replication (whether self- or otherwise), that would make the ability to replicate a defining characteristic of life.

Replication (with inheritable errors) is a part of evolution, but crystals replicate (without inheritable errors).

Enjoy


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 Message 24 by Dr Adequate, posted 11-13-2015 9:01 AM RAZD has replied

  
RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(1)
Message 25 of 374 (772389)
11-13-2015 9:15 AM
Reply to: Message 13 by AlphaOmegakid
11-12-2015 5:40 PM


Look at your definition. You of all people should know better than this! Populations evolve, not individual organisms. So by you definition, only populations are alive, because only populations are capable of evolving. Individual entities cannot be alive, because individuals do not evolve. I guess you just died. I don't think you will get too far with that one in the science community. But then again maybe you will!

Agreed.

Populations are indeed alive and constantly changing and indeed evolving; you can also view species as individual organisms that compete for fitness with other species in being able to survive and reproduce (with unfit species becoming extinct). Ant colonies as a single entity, for example, but applicable to all species. This is a macroevolutionary view, and if we take your argument to it's logical terminus, then we have to consider that this definition of life only applies to all of life as one complete unit. Life is what lives.

But curiously, not only (as has already been pointed out) are asexual organisms capable of being a population of one that evolves, that isn't the only point regarding individuals within a population. Multicellular organisms -- like us -- are composed of many many many individual cells, some dying (skin cells in particular) some being formed by cell division, but not pure clones of other cells, they have their differences. The cells in your body are completely exchanged\replaced over a period of years (~10 years on average iirc), so you are like those 'macroevolutionary level species organisms' that are composed of individuals -- you are composed of individual cells that go through the process of evolution, you are (like a colony of ants) a (colony) population of cells, and so yes, you are living by my definition.

You can even go further and consider a multicellular organism to be an ecology composed of several different species of cells that sometimes live in peaceful coexistence and sometimes compete with other groups for fitness within the ecology.

Enjoy

Edited by RAZD, : .

Edited by RAZD, : ..


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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 30 of 374 (772460)
11-14-2015 12:49 PM
Reply to: Message 24 by Dr Adequate
11-13-2015 9:01 AM


Except that individual mules are colonies of individual cells and microorganisms that go through the process of evolution. Skin cells reproduce skin cells with modifications, same with other organs, same with gut bacteria. This doesn't mean that the body transforms into a new species (and evolution in a breeding population is not about necessarily becoming a new species), 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.

Enjoy


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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


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


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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


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


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This message is a reply to:
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 Message 34 by NoNukes, posted 11-15-2015 12:22 PM RAZD has replied

  
RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 56 of 374 (772789)
11-18-2015 5:06 PM
Reply to: Message 34 by NoNukes
11-15-2015 12:22 PM


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

Crystals can reproduce without change, but are not generally considered life, so I don't see how anything that reproduces without change should be.

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 ...

Mules are not capable of evolution by the accepted definition of biological evolution. ...

Curiously I disagree. That their ability to reproduce is severely hampered by infertility (although not 100%) just shows they are participating in the part of evolution dealing with speciation and the formation of daughter populations that can't interbreed. They are not a distinct species, but a hybrid between species ... daughter populations ... with limited ability to interbreed or interbred with their hybrids. Being capable of evolution also means capable of death and extinction.

... 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. ...

Again I disagree -- the following generation would have virtually zero distribution of alleles from the existing mule population, and this would be a very distinctive change in the frequency of all the alleles. But existing mules have never been the source of new mules. New mules created by hybridizing horses and donkeys would also have different distribution of alleles compared to the current population, so the next generation by this method would still have a different distribution of alleles. Thus mules do evolve from generation to generation.

... 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. ...

That trait would be lost in the same way that many traits are lost through genetic drift, aka part of evolution.

... You would have to redefine evolution somehow to make this stuff work. ...

Nope, I just look at the whole picture, including the part where death and extinction play their roles and the part where reproductive incompatibility between daughter populations forms new species.

... But you said that you were using evolution to mean biological evolution as currently understood.

Indeed, including death and extinction and the development of reproductive isolation between daughter populations.

... So yeah, the mule has living organs. But is a mule alive? Not according to your original definition.

Organs, skin, bones, every part of the mule is a product of cell division, with mutations and cell death, there is no part that you can point to and say "that is not due to evolution."

Nor can you point to the mule and say it is not a product of evolutionary processes that are acting on the mule.

Is it capable of evolving? Yes, because it is capable of dying due to not being fit to survive and reproduce. If it is capable of dying then isn't it alive? Is not dying a part of evolution?

Enjoy


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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 57 of 374 (772790)
11-18-2015 5:15 PM
Reply to: Message 43 by New Cat's Eye
11-17-2015 7:24 PM


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?

Like bacteria, cells breed by asexual reproduction -- cell division. All the cells in your body are replaced by new cells several times in the course of your life, so you better hope they keep breeding.

Enjoy


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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 60 of 374 (772795)
11-18-2015 5:44 PM
Reply to: Message 38 by AlphaOmegakid
11-17-2015 6:05 PM


... So since a cell is the smallest unit of life ...

Is it? By your definition (Message 1):

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.

You could have a prebiotic molecule in the RNA world that synthesizes ATP from ATP and uses that to reproduce the molecule, and according to your definition that would be life even though no cell is involved.

It seems that your impetus (from reading other posts on this thread) for your definition is to find the boundary between life and non-life, to define the point of origin, the transition from chemistry to life. The point at which it is capable of undergoing evolutionary processes, the point at with it is capable of evolving.

Enjoy

Edited by RAZD, : ..


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This message is a reply to:
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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 77 of 374 (772897)
11-20-2015 9:04 AM
Reply to: Message 64 by AlphaOmegakid
11-19-2015 10:08 AM


Yes, Please don't forget Cell Theory which is much more important than evolution theory regarding OOL. Also, Evos have argued for years that evo theory does not apply to OOL. So what ist it? You seem to think evolution does apply to OOL. Hmmmm?

Evolution doesn't apply to how life arises from non-life, it applies once life has risen. That is why being able to evolve defines life, because OOL is then completed.

And regarding my impetus to find the boundary between chemicals and life, I think is quite well defined. A living organism must be able to synthesize ATP for metabolism and it must produce it's own catalysts for that synthesis. Your faithful blindness to evolution requires it's involvement everywhere, but why cannot living things come into being chemically, and not evolve? The first fossilized life shows no evolution in any measurable sense after 3.5 B years! And we know that bacterial live generation after generation with no evolution in a stable environment. Does that make them not alive? Of course not.

And in this you are wrong, you confuse visible change (or the assumed lack of it from ignorance) with evolution. The processes involved over that 3.5 billion years involved the diversification of bacteria into many different types while also maintaining the fitness of cyanobacteria for their ecology, and then evolving eukaryotes and multi-cellular life forms, built on the changes that occurred over those billion years.

Stasis does not mean no evolution, it means strong evolution to select and maintain fitness to an ecology, selecting against mutations that make it less fit.

You have an interesting false interpretation of the definition. First at a minimum, my definition requires a self contained entity which means that the metabolic processes and the synthesizing processes occur inside whatever contains the entity. So my definition is not molecular in any sense as no living thing is. It is an assembly of molecules as every cell is. So self replicating molecules, even though quite interesting, are just novelties that are recognizably light years away from the complexities in living things.

Equivocating now? Curiously I quoted your definition from Message 1 -- here it is again:

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.

Any molecule is a "self-contained entity." Self-replicating molecules are self-contained entities that don't require enclosing membranes to synthesize more molecules, just raw materials (ie -- food for metabolism, as is used by all life forms). Self-replicating molecules can also be said to "transfer ... information" from one molecule to the next.

Note that I say "can also be said to 'transfer ... information' " because what you mean by "information" is not defined, poorly understood, and in my opinion is a poor choice of words when what is happening is simply the replication of molecules.

Your definition also requires DNA to exist, while current research into OOL says that it occurred after life began in an RNA world.

Your definition does not require a cell wall or an enclosing membrane, hence why I challenge your statement that "a cell is the smallest unit of life" -- you haven't established that from your definition.

So it appears that both DNA and the use of enclosing membranes evolved after first life forms arise. Note that your definition does not explain the existence viruses and prions. If you are interested I can show you how mine does.

Enjoy


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RebelAmerican☆Zen☯Deist
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This message is a reply to:
 Message 64 by AlphaOmegakid, posted 11-19-2015 10:08 AM AlphaOmegakid has replied

Replies to this message:
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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 79 of 374 (772970)
11-21-2015 11:48 AM
Reply to: Message 37 by AlphaOmegakid
11-17-2015 5:42 PM


the 6 levels of evolution
Quite amusing watching you fellows arguing opposite sides of the same issue in trying to show that my definition is incomplete ...

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. ...

Curiously the bee is composed of cells that reproduce, vary are selected and die -- ie processes of evolution are observed within the "colony of cells" that is the bee. You say a colony of bacteria is alive, so you just admitted that a bee is alive, even a drone bee that lives only to serve the colony\queen, just as the mule is alive as a "colony of cells" ...

... So, the definition doesn't work for most living things unless , of course, unless you equivocate on the definition of evolution, ...

This is not equivocating, it is simply observing what is really happening at the cells level. Or do you deny that cells within multicell organisms evolve, even ones not involved in the reproduction of the organism? I have a blood cancer, I was not infected, but a mutation occurred that caused the cancerous cells. Chemo kills most of these cancerous cells but the same treatment cannot be used twice, because the surviving cancer cells are immune to it; variation and selection, and this goes on throughout your body every day, whether you are aware of it or not.

We can look at life from six basic levels:

  1. the macro level, where we observe whole species as individual entities, entities that mutate, vary, and undergo selection, where successful species reproduce and survive and unsuccessful species die (ie species extinction),

  2. the group\ecological level, where we observe sub-populations of many species interacting as individual groups (bee colonies, monkey troops, etc), where neighboring ecologies may have some groups of the same species or where migration between ecologies occurs, where we observe all the groups as individual entities, entities that mutate, vary, and undergo selection, where successful groups reproduce and survive and unsuccessful groups die (ie group extinction within the habitat),

  3. the species\micro level, where we observe all the individuals within a species as individual entities, entities that mutate, vary, and undergo selection, where successful individuals reproduce and survive and unsuccessful individuals die (ie individual extinction),

  4. the whole\macro cell level, where we observe each individual cell as individual entities, entities that mutate, vary, and undergo selection, where successful individuals reproduce and survive and unsuccessful individuals die (ie apoptosis or cell death),

  5. the internal cell level, where we observe different groups of molecules interacting as a biochemical ecology, where we observe all the groups as individual entities, entities that mutate, vary, and undergo selection, where successful groups reproduce and survive and unsuccessful groups die (ie group extinction within the cell),

  6. the sub\micro\molecular level, where we observe all the individuals within a molecular type as individual entities, entities that mutate, vary, and undergo selection, where successful individuals reproduce and survive and unsuccessful individuals die (ie molecular death and those molecules disappear from inside the cell).

To deny that this happens, that these are in fact evolutionary processes, seems to me to be extraordinarily narrow minded; each level depends on the level below it occurring to provide the material for their processes to occur, until you get down to the most basic level of molecules evolving over time. DNA, proteins, etc all evolve over time.

Message 69 ... RAZD is having a ball equivocating on his definition of life. He is squirming all over the place trying to defend it. It is rather amusing to read his posts right now as he is being challenged.

I don't think that when he wrote it, he thought it was equivocal. (Actually this is basically NASA's definition of life) However, as he tries to defend it, he is forced with equivocation to defend it. Let me use your example of "reproduction". Some organisms don't reproduce. It doesn't matter what the reason is, they just don't. So then the defender tries to argue that cells of multicellular organism do reproduce. ...

Amusingly, I am having a ball with your failing attempts while simultaneously having trouble defending your definition. Do you deny that body cells evolve over time? Do you see anywhere in my definition where the entity being evaluated is limited to one specific level? It sees to me that it is you equivocating on what you accept and what you don't accept.

... . (Actually this is basically NASA's definition of life) ...

Which should give you pause, eh? Thanks for putting me with such exalted people.

Message 76: So, according to your statements TOE doesn't apply to OOL. Or better stated, TOE addresses first life to man, but not rocks to first life. But , if you have read this forum, you can see that RAZD wants the theory to apply to rocks to first life. So I am trying to pin him down.

And failing, both on "trying to pin [me] down" and on even, apparently, understanding my argument/s. This:

... RAZD wants the theory to apply to rocks to first life ...

is a falsehood. Feel free to post a quote that you think supports your claim -- or withdraw it.

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
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This message is a reply to:
 Message 37 by AlphaOmegakid, posted 11-17-2015 5:42 PM AlphaOmegakid has replied

Replies to this message:
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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 81 of 374 (772977)
11-21-2015 4:46 PM
Reply to: Message 63 by NoNukes
11-19-2015 2:10 AM


I did not suggest that anything that could reproduce accurately should be considered life. I am suggesting that a single celled, biological organism capable of perfect reproduction via mitosis should not be considered to not be alive simply because it does not mutate.

And again I find this a totally unrealistic proposition, and I would only consider it possible if you show me an example. Extraordinary claims and all that.

It does not show speciation. What it shows is that there parents are not capable of producing fertile offspring.

It does show speciation between horses and donkeys, one of the key elements of evolution is the division of daughter populations into separate populations that are incapable of interbreeding. On the way to that point there are hybrids that are viable (see Interweaving Evolution & Hybrid Vigor for some discussion of this stage in the development of new species), next come hybrids that are sterile, and finally there comes the stage where no living offspring are reproduced. Mules are examples of this second stage (or 99% of it because some are able to breed with horses or donkeys). Failure to recognize this fact does not strengthen your argument.

Seriously, RAZD? There is no following generation of mules. Mules do not descend from other mules. What definition are you using for 'following generation'? Certainly nothing conventional. A following generation is the offspring of a past generation.

"Mule" is not, strictly speaking, a species designation: horse, donkey, zebra are species, and they can all have hybrid offspring that are sterile or mostly sterile. Hybrids are not a distinct species until they become reproductively isolated from their parent populations.

In addition, within any population of breeding individuals there are often sterile individuals, because mutation. There are also many colony species (bees etc) that regularly produce sterile individuals. But having sterile individuals does not mean that evolution is not occurring.

Now I find it quite amusing that you say the mule is not alive because it can't reproduce, even though that ability is not a necessary element of my definition, rather it is just one aspect of evolution. There are many individual organisms that don't get to reproduce before dying -- it's called selection, in particular selection to remove less viable forms of individuals, and curiously one of the more importance aspects of evolution.

Or would you have it that death is not part of evolutionary processes, that removal of unfit genotypes is not a part of evolution, that extinction is not a part of evolution?

Curiously AlphaOmegaKid argues that because evolution occurs in populations not in individuals that the mule could be considered living but the cells would not be ... while you are willing to say that the cells are alive but the mule isn't ... you guys need to get together here: one or both of you are wrong.

Sterile animals do not undergo genetic drift. ...

Really??? I can't think how sterile individuals would not be a part of genetic drift, removing a whole genotype from the reproductive pool, and taking many mutations to the grave with them. It's no different than if a tree fell on them.

Just as any individual organism that dies before producing offspring removes a slew of mutations from the pool. Death without reproduction is an element of evolution.

... New mules do not contain random a sampling of the allelles of a current or past population of mules.

And again, Mules are not a species, they have parents from whom they inherited traits. They don't pop up by magic, do they?

When we look at the population that breeds mules, we have to include both horses and donkeys in that population, and then we can look and see if that population is evolving ... care to speculate what their (natural) interactions show?

Hint: it begins with e.

Enjoy


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RebelAmerican☆Zen☯Deist
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This message is a reply to:
 Message 63 by NoNukes, posted 11-19-2015 2:10 AM NoNukes has replied

Replies to this message:
 Message 90 by NoNukes, posted 11-23-2015 9:47 AM RAZD has seen this message
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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 84 of 374 (772987)
11-22-2015 8:02 AM
Reply to: Message 80 by AlphaOmegakid
11-21-2015 4:12 PM


Re: the 6 levels of evolution
What you are doing is the epitome of equivocation. The definition you used requires populations to evolve. I pointed this out to you and now you equivocate on what the organism is and what the population is. But this is easily fixable logically. ...

No fix necessary because it is not equivocation. The definition stands unaltered. What you see in Message 79 is that definition applied to six different levels of considering life on earth, with a consistent, logically valid application that demonstrates how the definition works.

... . All you have to do is the thought experiment of the last man on earth... healthy or unhealthy with all kinds of human somatic cells mutating and evolving within his body. (I don't disagree with you on this point) We all agree that he is alive. We all agree that his cells are alive. But he is the last human male with no human females. And those mutating and evolving human cells within eventually cause his death.

Yawn. No different from the mule, which you agreed was alive. Death is a part of evolution and the extinction of species is a part of evolution.

That's why over and over again, People who are experts on evolution will tell you that individuals do not evolve, populations evolve.

True, that is what they say, but does that make it unequivocably true? It is the appeal to authority, yes?

The populations of cells that make me do mutate, reproduce, die in generation after generation of cells. But I am still me, I am not radically transformed into an entirely different person, nor am I transformed into a new species -- which, curiously, is what those experts mean by saying the individual is not the unit of evolution, that is the context of those statements. And curiously I am not claiming anything different in that regard.

... So if you want to equivocate about a population of cancer cells within an organism as being a population of the same species then you go right ahead. I cannot stop you. It will require the population of neurons inside you to do that. But maybe they have evolved where they can no longer recognize equivocation???

Saying it is equivocation does not make it so.

Does that population of cancer cells that arose from mutated from normal white blood cells (it's a form of lymphoma) make me a different person than I was before? Certainly my body has changed over time, not just in this regard, as it has aged.

Biologists will refer to this as growth, development and aging processes, to distinguish it from species evolution, but that doesn't mean that they don't recognize how development aspects affect evolution -- you have a whole field of "evo-devo" developing in the last decades that looks at how processes of development affect species, and how environmental factors can affect development. Thalidomide as example. Exposure to radiation can affect your ability to reproduce as well.

Such changes rarely affect the germ cells (Lance Armstrong as an example of a cancer that did affect his reproduction), and thus would not be passed on to following generations (unless sterility occurs), which is another reason why experts say that evolution takes place in the population and not the individual, but that does not mean that they exclude evolutionary processes occurring in your body. Mutations occur, reproduction of cells occurs, transmission of genes\alleles occurs, selection occurs, death occurs ... evolution occurs.

When such processes occur in germ cells, that affects what you pass on to the next generation and most certainly is a part of the evolutionary process of change from generation to generation. When those same processes occur in non-germ cells, that only affects your body, the 'ecosystem' that is your body. That is not equivocation, that is observation of fact.

The other entity you want so desperately to be alive is a virus. But assume a world full of viruses yet the world is sterile of any living cells Not one of those viruses is capable of evolution, because they cannot breed as a population on their own.

What you are likely looking at are the surviving remnants of the RNA world rather than the RNA world life forms that many many many scientists involved in OOL research believe existed before DNA evolved, and then by evolutionary processes (better able to survive and reproduce) displaced the RNA life forms. As I said, this explains the existence of viruses, while your definition doesn't (hence your attempts to ignore it and the fact that RNA life forms would not qualify under your definition because of being alive before DNA evolved). Certainly you cannot just look at modern life and claim that first life forms had the same complex highly evolved cell structure and internal processes with any kind of rational assurance that it is a valid claim. Don't take my word for it though, google your heart out on RNA World.

So your definition fails on multiple levels. And so does NASA's.

Ummm ... not demonstrated here, not yet, not even on one level.

It was you who claimed this definition as your own. I just pointed out the deception. You might be in good company with NASA.

Indeed I was unaware of the NASA definition until you pointed it out, but would be happy to cede priority to any previous published definition that matches it. Curiously I googled and found

quote:
Life's Working Definition: Does It Work?

How to define "life" is a sweeping question that affects whole branches of biology, biochemistry, genetics, and ultimately the search for life elsewhere in the universe.

However, some initial agreement is possible. Living things tend to be complex and highly organized. They have the ability to take in energy from the environment and transform it for growth and reproduction. Organisms tend toward homeostasis: an equilibrium of parameters that define their internal environment. Living creatures respond, and their stimulation fosters a reaction-like motion, recoil, and in advanced forms, learning. Life is reproductive, as some kind of copying is needed for evolution to take hold through a population's mutation and natural selection. To grow and develop, living creatures need foremost to be consumers, since growth includes changing biomass, creating new individuals, and the shedding of waste.


Pretty standard life definition stuff.

quote:
While a "bright line" definition is needed, the borderline cases give life's definition a distinctly gray and fuzzy quality. In hopes of restricting the working definition at least terrestrially, all known organisms seem to share a carbon-based chemistry, depend on water, and leave behind fossils with carbon or sulfur isotopes that point to present or past metabolism.

If these tendencies make for a rich set of characteristics, they have been criticized as ignoring the history of life itself. Terrestrially, life is classified among four biological families: archaea, bacteria, eukaryotes, and viruses. ... The final grouping includes the viruses, which don't have cells at all, but fragments of DNA and RNA that parasitically reproduce when they infect a compatible host cell. These classifications clarify the grand puzzle of existing life, but do little to provide a final definition.


Oh gosh, look at that -- they include viruses as life -- your definition doesn't ... oops?

Second up was this:

quote:
Alternative Definitions of Life: Perspective Matters

The NASA Astrobiology Institute Definition of Life

NASA defined life broadly as "A self-sustaining chemical system capable of Darwinian evolution."


And there it is, albeit with the added condition of being a "self-sustaining chemical system" ...

quote:
While this definition is open enough to include a wide range of potential life forms, it also makes it hard to design a simple test for life. For example, it would be unlikely to observe Darwinian evolution taking place. Steven Benner conducted basic research into DNA and discovered that besides base pairing, another property which gave DNA the ability to self-recognise, act as a template, and hence replicate itself was its charged backbone.

Which could point to an important element in the evolution of DNA ... in the RNA world.

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.


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This message is a reply to:
 Message 80 by AlphaOmegakid, posted 11-21-2015 4:12 PM AlphaOmegakid has replied

Replies to this message:
 Message 97 by AlphaOmegakid, posted 11-24-2015 8:26 AM RAZD has seen this message

  
RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 85 of 374 (772992)
11-22-2015 9:16 AM
Reply to: Message 82 by AlphaOmegakid
11-21-2015 5:53 PM


In biology, cell theory is a scientific theory which describes the properties of cells.

Yes. From your link:

quote:
In biology, cell theory is a scientific theory which describes the properties of cells. ...

The three tenets to the cell theory are as described below:

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and organization in organisms.
3. Cells come from preexisting cells.


Curiously that involves modern highly evolved life forms and not life as it originated.

Now , in case you didn't realize, evolution theory is dependent on Cell Theory. ...

No. The other way around: cell theory applies to modern evolved life forms ... after cells evolved.

... According to Evo theory life began (cellular Life) about 3.5B years ago. Before that.....NO LIFE. ...

As AZPaul3 points out the origin of life is not part of the theory of evolution, so you are talking biological/xenobiological/abiogenesis scientists such as are involved in OOL research and using the typical misguided "CREO" characterization of almost all scientists and science as "EVO" -- as if all science were part of an evolution based world view and that there was some equivalence between reality based science and belief based opinion.

We observe fossils of life 3.5 (to 3.8?) billion years ago in the oldest known rocks that can have fossils, so that pretty well establishes that life existed at that point, life that left behind stromatolite fossils.

... Before that.....NO LIFE. Before that, rocks and water, and any combination of solutions therein. From which you desire to call self replicating RNA molecules as being alive according to your definition. To do this you have to ignore cell theory totally, and there is no good reason to do that.

Except that there is no good reason to include cells as an absolutely necessary element in the definition of life, certainly not for considering what first life forms would be like or what life could be like on other planets -- that would be a post hoc ergo propter hoc fallacy would it not?

Observing cell structures however would be a good indication that evolutionary processes are operating and that we are observing life.

Likewise observing DNA ...

Likewise observing RNA ...

So, according to your words above, if OOL is completed, then it must be cellular unless you ignore Cell Theory which evolution theory depends on. This means you either must reject Cell theory or your definition becomes reasoned though circles, because TOE relies on Cell Theory.

Good try, but fail: my definition does not require that cells are a part of first life forms, it allows that they would evolve early on, as a means to improve survival, protect life maintaining and reproductive processes, and allowing it to displace earlier life forms, most likely by consumption.

Same with the origin of DNA.

Same with the origin of RNA.

Which do you think came first, RNA, DNA or cells? Or did they develop independently and then get combined (by one consuming the other in the way eukaryotes may have derived)? Does it matter to the origin of life?

Enjoy

Edited by RAZD, : ...

Edited by RAZD, : ..


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
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This message is a reply to:
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RAZD
Member (Idle past 639 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 86 of 374 (772996)
11-22-2015 10:48 AM
Reply to: Message 80 by AlphaOmegakid
11-21-2015 4:12 PM


DNA vs RNA and which came first?
It is fairly well accepted in the abiogenesis field that RNA preceded DNA. Lets look at key similarities and differences:

DNA vs. RNA

quote:
DNA, or deoxyribonucleic acid, is like a blueprint of biological guidelines that a living organism must follow to exist and remain functional. RNA, or ribonucleic acid, helps carry out this blueprint's guidelines. Of the two, RNA is more versatile than DNA, capable of performing numerous, diverse tasks in an organism, but DNA is more stable and holds more complex information for longer periods of time.

Comparison chart

DNA RNA
Stands For DeoxyriboNucleicAcid. RiboNucleicAcid
Definition A nucleic acid that contains the genetic instructions used in the development and functioning of all modern living organisms. DNA's genes are expressed, or manifested, through the proteins that its nucleotides produce with the help of RNA. The information found in DNA determines which traits are to be created, activated, or deactivated, while the various forms of RNA do the work.
Structure Double-stranded. It has two nucleotide strands which consist of its phosphate group, five-carbon sugar (the stable 2-deoxyribose), and four nitrogen-containing nucleobases: adenine, thymine, cytosine, and guanine. Single-stranded. Like DNA, RNA is composed of its phosphate group, five-carbon sugar (the less stable ribose), and four nitrogen-containing nucleobases: adenine, uracil (not thymine), guanine, and cytosine.
Base Pairing Adenine links to thymine (A-T) and cytosine links to guanine (C-G). Adenine links to uracil (A-U) and cytosine links to guanine (C-G).
Stability Deoxyribose sugar in DNA is less reactive because of C-H bonds. Stable in alkaline conditions. DNA has smaller grooves, which makes it harder for enzymes to "attack." Ribose sugar is more reactive because of C-OH (hydroxyl) bonds. Not stable in alkaline conditions. RNA has larger grooves, which makes it easier to be "attacked" by enzymes.
Unique Features The helix geometry of DNA is of B-Form. DNA is protected in the nucleus, as it is tightly packed. DNA can be damaged by exposure to ultra-violet rays. The helix geometry of RNA is of A-Form. RNA strands are continually made, broken down and reused. RNA is more resistant to damage by Ultra-violet rays.

Structure

DNA and RNA are nucleic acids. Nucleic acids are long biological macromolecules that consist of smaller molecules called nucleotides. In DNA and RNA, these nucleotides contain four nucleobases — sometimes called nitrogenous bases or simply bases — two purine and pyrimidine bases each.

In both molecules, the nucleobases are attached to their sugar-phosphate backbone. Each nucleobase on a nucleotide strand of DNA attaches to its partner nucleobase on a second strand: adenine links to thymine, and cytosine links to guanine. This linking causes DNA's two strands to twist and wind around each other, forming a variety of shapes, such as the famous double helix (DNA's "relaxed" form), circles, and supercoils.

RNA folding in on itself into a hairpin loop.

In RNA, adenine and uracil (not thymine) link together, while cytosine still links to guanine. As a single stranded molecule, RNA folds in on itself to link up its nucleobases, though not all become partnered. These subsequent three-dimensional shapes, the most common of which is the hairpin loop, help determine what role the RNA molecule is to play — as messenger RNA (mRNA), transfer RNA (tRNA), or ribosomal RNA (rRNA).


Now it seems to me that it is fairly easy to evolve DNA from RNA and that it would be easier to evolve RNA from nucliotides than DNA. RNA being more stable in UV than DNA also speaks to its ability to exist outside cell walls, and thus does not need cell walls to evolve.

This leads readily to a conclusion that the RNA world was composed of RNA based life forms, that cell enclosures then evolved because they formed protective barriers for those life forms enhancing their survival, and that those cell enclosures then allowed DNA to evolve from the RNA of those early life forms.

The question then is where you draw the line between life and protolife and protolife and non-life ...

If you say, as your definition does, that DNA (and enclosing cell membranes) are necessary elements, then you draw the line at the point they are all present and fully operational.

If you say, as my definition does, that the ability to evolve via biological evolutionary processes like mutation, reproduction and selection, is all that is necessary, then you draw the line at an earlier stage.

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 80 by AlphaOmegakid, posted 11-21-2015 4:12 PM AlphaOmegakid has taken no action

  
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