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Member (Idle past 2904 days) Posts: 564 From: The city of God Joined: |
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Author | Topic: Life - an Unequivicol Definition | |||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
It appears that my response was not clear. I agree that speciation between horses and donkeys is complete. ... Curiously I would say 99% complete -- they can still mate and produce offspring, and almost all are sterile. Some can occasionally mate back with one of their parent stocks.
... But what the infertility of mules does not show is that the mule offspring is on an evolutionary path. ... When you look at mules in terms of evolution you have to consider what the breeding population is that produces the mule, ie - the horse and donkeys (and zebra and quagga) parent population. This population produces several types of offspring: horses, donkeys, zebras, horse/donkey hybrids (mules, hinneys), horse/zebra hybrids and donkey/zebra hybrids; the quagga is now extinct (fairly recently as there are pictures of them) and thus does not produce any offspring. Is the recent extinction of the quagga an evolutionary path? I don't see how you can say otherwise -- extinction of species is necessary to evolution just as individual death is necessary to evolution. Without death and extinction selection does not occur.
... The question is whether mules are evolving and thus alive and not whether donkeys and horses are alive. I don't believe it is necessary that mules be able to evolve. They are the reproductive offspring of living creatures. That's enough. And it would be enough even if every single mule offspring were sterile. The death of sterile animals, or actually of all animals that do not reproduce, is part of the evolutionary process that selects more fit individuals for reproduction. To say that only those that pass on their genes are evolving, while ignoring those that are removing less viable genes, is rather myopic in my opinion. It's like saying people only have right hands. And the actual question is whether mules are capable of evolution ...
quote: This isn't saying that every organism has to undergo every known process of evolution, as that would be absurd. Removal of less viable traits - the death of any individual organism that doesn't reproduce - changes the frequency of distribution of traits withing the breeding population, whether by selection or drift, and thus they take part in evolution. The removal of hybrid phenotypes that bridge between diverging daughter populations are necessary to the process of speciation, and are a definite part of evolution. Death is one of the processes for removal of less fit traits.
Message 93: ... There is no such thing as a reproductive pool of mules. ... The reproductive pool is their parent population, which includes horses and donkeys (and zebras and quaggas and other hybrids).
Mules are sterile. As best as I can tell, males are 100 percent sterile and females are essentially so. ... And some donkeys and some horses are sterile, some purebred racehorses in particular are sterile. Sterility is a fact of biology and evolution, and is not restricted to hybrids or any one species -- it is an evolutionary process. Any new traits that occur in any sterile individual are not passed on to following generations, and the loss of such a new trait, whether beneficial or not, is genetic drift.
... For that reason, a population of mules does not undergo genetic drift, because there is no random sampling of the characteristics of the mule population to produce a new generation of mules. Amusing. What you are saying is that there is no fitness\mating selection in the removal of their genes from the breeding (parent) population. They are remove in the same way a tree falling on a colt would remove its genes from the breeding population. That is what drift does. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
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Yes, it is. My definition is consistent with cell theory as well as evolution theory. Yet it doesn't explain the existence or evolution of viruses, nor does it allow for RNA life forms, and this is a failure. You like to cite (appeal to) authority and pick and choose who you quote, ignoring those that say viruses are alive and are one of 4 branches of life.
Nope, not even close. In your dream world yes, but not according to my definition. You can't just pick and choose which parts of it you like. Incorrect on two counts: (1) your definition isn't the acid test for life, so your use of it to validate it is tautological, and (2) invalidating any one part of it invalidates the whole as being the definition of life. Your definition is like saying only right hands are hands, and left hands don't qualify as hands because they aren't right hands.
My definition does show the boundary quite well. It requires a self contined entity in which ATP is used for metabolism and proteins are being synthesized from a DNA to RNA synthesis. ... Your definition shows A boundary event in the evolution of life, just as the evolution of eukaryotes shows a boundary event in the evolution of life, but we don't consider prokaryotes to be non-life because they don't fit the definition of eukaryotic life. This is an arbitrary choice, rather than one based on facts.
... Life does not require evolution. We have plenty of asexual populations which don't vary from generation to generation. That doesn't make them not alive according to your definition. You make the claim, you provide the evidence. Show me one species that does not show any evolutionary processes from generation to generation. Or are you picking and choosing what you consider relevant.
Message 92: Amazing. Just Amazing. Not only can you equivocate on what a population is within your own definition, you can distort the meaning of mine. Just amazing! Curiously, what I was showing you was two different ways your definition fails. That is not distortion, it is pointing out the inadequacy of your definition.
Here is the definition of self-contained which you evidently are unaware...
quote: A living organism, by my definition , has everything within itself to use and synthesize ATP, It has DNA, and RNA, and it has proteins. NO, A MOLECULE DOES NOT CONTAIN WITHIN ITSELF THESE ABILITIES. This is just one big strawman joke. And thank you for demonstrating another failing of your definition: cells consume, as part of their living processes, consumption of raw materials is one of the well known elements of life, the raw materials to use in the synthesis of proteins, enzymes, etc ... and thus cells are not self-contained according to your definition. And if you allow consumption of raw materials from outside the cell, you just allowed the use of raw materials by molecules to reproduce. Either way, fail.
My definition describes, in part, the Central Dogma of Biology. The principles of which are taught in "every" high school Biology book around the world. ... Big whap. Typical creationist appeal to assumed authority. Definitions, like theories, change all the time, especially when a better one comes along that does a better job of explaining all the evidence. Your definition does not explain the existence and behavior of viruses, mine does; mine explains more evidence than yours does. That alone makes it a better definition. The fact that the same definition was developed by NASA is more validation of its usefulness. Has anyone else developed a very similar definition to yours in all those Biology text books you appeal to?
... If you read this wiki article you will find the word "information" is used 29 times. It seems the evidence that this is well understood in Biology is overwhelming. My objection to using "information" is not that it has never been used, but that it needs to be well defined so that everyone understands the meaning. If the use in wiki means one thing and the way you use it means another, then that is the logical fallacy of equivocation. This is a common source of misunderstanding in IDological circles.
Contrary to yours, the definition of genetic information is quite well defined within a biological context. Here is a definition:
quote: And as long as you consistently use that definition for "genetic information" you should not have a problem. Amusingly, you also need to consider that the "genetic information" is there because of evolution, in both DNA and RNA (whether virus RNA or not).
Message 94: The sign of a good definition is how it relates to it's opposite. You have defined life in relationship to its ability to evolve. So my question is then, using your definition, describe death to us. When does an organism die, ... When it ceases to function and begins to break down. Yours?
... and when do populations die? or become extinct? When every individual of the population dies. Yours? oh, that's right, your definition doesn't say anything about species ...
So with your molecules that you desire to define as "alive", please describe what makes these molecules die? ... When they cease to function and begin to break down. And the fact that they can go through this process means they had to be alive to function and hold together, doesn't it?
... With viruses which you desire to define as "alive", please describe the death of a virus. ... When they cease to function and begin to break down. And the fact that they can go through this process means they had to be alive to function and hold together, doesn't it?
... And finally, describe the death of cellular life in relationship to your definition. When it ceases to function and begins to break down.
You have said that "death is a part of evolution". Just what exactly does that mean? Do dead things evolve too? That it is one of the processes of evolution.
Message 97: ... Clearly what you are doing is equivocating on what the "population" is. ... Saying it does not make it so. Your claims of equivocation are like a broken record to all who disagree with you, and yet you have not shown one actual instance of equivocation. In the 6 levels of evolution post I clearly described what the population was composed of at each level. Nor am I alone in viewing life at those different levels, check E.O.Wilson for one looking at the evolution patterns of survival and selection of whole species as but one example. Species reproduce by speciation, giving rise to new species in much the same way that asexual bacteria reproduce and evolve.
So what you are doing is equivocating between a population being properly a population of mules or a population being some group of cells within the mule. ... Nope. Failure to understand is not refutation. Looking at life at different levels is not equivocation, but looking at how each of those different levels fit the same pattern. It is looking and the difference between microevolution and macroevolution ... and sub-micro and super-macro ... at the whole spectrum of evolutionary processes. I mentioned E.O.Wilson above. He is not alone either. Many scientists talk about the Biosphere:
quote: Pierre Teillard de Chardin talked about an "Omega Point" of evolution and of the "noosphere" (a sphere of thought/consciousness). And I can equally go in the other direction, with geneticists, microbiologists and scientists involved in the study of abiogenesis, ... and where they draw the line between life and non-life.
My thought experiment ... Failed for reasons already discussed. Not accepting that fact does not change that refutation of your argument, its just plain unadulterated denial.
... And clearly many organisms have populations for generation after generation that show no change in alleles either. Again, please list one. With the evidence to support it.
So evolution has many defeaters which makes it a very poor definition, but I can see why you want it. The faith in naturalism is strong. And the unsuccessful field of OOL needs such equivocation to survive. It's naturalism of the GAPS. Yet no matter what the evidence shows, the imaginations of men want to show something other than what is. It's called magic. Your opinion, ignoring the facts. Enjoy Edited by RAZD, : clrtyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Concerning death and individuals of a population, what you said feels a little too confined if you're using the definition of selection where it means selecting who gets to reproduce and who doesn't. Death is only one form of selection. Agreed, but rather than selection death is also necessary for the succession of life, genetic drift and to remove less viable forms from the population to make room for new individuals; without death habitats would become overcrowded. Likewise the extinction of species is necessary to make room for the new species - an ecological view of evolution.
Concerning extinction and species, what you said also feels a little too confined, since a species can cease to exist by evolving to a different species. The fossil record might cease to contain any record of a species, and paleontologists might conclude that it went extinct, but extinction means "the death of the last individual of the species" (Wikipedia), and the population might simply have evolved over time into something else. In which case you would be talking about anagenic or cladogenic speciation, both leaving the old species behind due to their being less fit species than the new ones. The old species goes extinct and makes room for the new ones. Again this is a necessary part of large view (macro) evolution and ecology (carrying capacity of habitats). You can think of species as asexual bacteria, reproducing via budding. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Sure, but that's orthogonal to my point, that death isn't necessary for selection. The way you expressed it was a statement that death *is* necessary for selection. Well curiously, as regards mules in particular, I was not talking selection, I was talking death and drift as an evolutionary mechanism that stochastically removes genes. In the case of mules whole phenotypes are culled, whether their genes are beneficial or not. The same occurs for any sterile phenotype of any species. The same for any individual that dies before reproducing.
Both those terms are new to me, so I had to look them up. I'm definitely not talking about cladogenic speciation. Anagenic speciation would be closer but because it posits "rapid evolution in the ancestral form without speciation taking place" I don't think it's what I was talking about. I had in mind evolution of a population (slow, fast, doesn't matter) that over time becomes significantly different than the original. Species are a continuum. There was no point in time where the ancestral species became a new species, but at some point it became so different that it must be labeled a new species. ... Yeah, I was looking at that too, it appears that this article has been edited and changed since last I looked. Looking at the history it was changed 15 April 2015 to make it "rapid" (one of the problems with wiki ... ) and before that it read:
quote: Another definition is:
quote: Now I don't think the speed of the evolution really affects the result, so I'll stick with the simpler definition, which is what you were talking about, yes?
... There was no extinction. There was no death of the last individual of a species. AbE: Granted that once a species no longer exists we do call it extinct, but in the case I'm talking about there is no extinction event, no death of the last individual. Yet this still requires the death of the "old-timers" (from old age if nothing else) as they are gradually replaced by the newer forms. Again, more of a genetic drift pattern than a selection pattern. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Mules are a dead end. ... As are ALL organisms that don't reproduce. So? Is not failure to reproduce one of the processes of evolution? It seems you keep thinking of mules as a separate population\species -- they aren't. The come from horses and donkeys. Both parent species also have sterile offspring that you would call horse or donkey, and which would also be dead ends as regards passing their genes to the next generation. So too would be any young offspring killed before reproducing. Is not failure to reproduce one of the processes of evolution?
... But it appears that you are willing to accept a small subset of the evolutionary process as indicating life. ... Do you seriously think that my definition means that every single organism undergoes every single evolutionary process? Curiously I see the development of hybrid sterility between subpopulations as part of the process of speciation, and a rather important one at that, as that is the point at which gene flow between the populations ceases. The horses and donkeys don't share that element of evolution -- would you then say that my definition says that they are not alive? Really?
... . On the other hand, you rely this time on death, and then drift, the latter of which I dispute occuring in mules except by death. Well duh! Is that not how all drift occurs? -- by the death of the individuals bearing genes that are then not reproduced. That is how genes are lost. That is one of the ways gene frequencies shift. Genetic drift is an evolutionary process. Mules can also have mutations*, but the point is not how many evolutionary processes need be involved, but that they are "capable of evolution."
Which leaves for me that you are willing to say that mules are alive because they experience death. Surely that is somewhat of a tautology. It would be if that were what I was saying. Enjoy *I also would entertain the thought, for instance, that -- as people keep force mating horses and donkey long beyond any natural inclination for them to mate (google it) -- there is a remote possibility that they could develop a mule that is not sterile: every time a mule is created there is that possibility ... or with Hinneys. Can you say that this would [i]not/i be possible?by our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
At this point, I'm just trying to understand your argument. Originally it seemed to be summed up in one sentence, but I don't think our discussion since has confirmed that. It seems now that you are arguing that undergoing one or more evolutionary processes is sufficient. Demonstrating "capable of evolution" does not mean demonstrating every single process of evolution.
I respectfully disagree. Mules are a separate population and they are neither the same species as horses nor donkeys. Mule - Wikipedia
quote: That means hybrid and not a separate species. Mules only exist within a population of horses and donkeys that are made to interbreed, usually by raising the male donkey and the female horse together so that they are their only opportunities to breed. Mules are not a separate species nor a separate breeding population. The breeding population is male donkey and female horse, ie the genus Equus.
Yes, mules do participate in some processes that are evolution. They are born and they die leaving their peers behind. But mules don't reproduce. Even in those cases where some female mules are fertile, they are not fertile with male mules which are invariably sterile. So there really are essentially no second generations of mules and there is no feedback from mule survival that would allow nature to produce more mules based on which mules survive. Humans have to intervene. So mules, in my opinion, fail to participate in natural selection (which I take to describe the process of surviving to reproduce and thereby pass on personal traits) and which I also take to mean that mules do not truly evolve. Your opinion. You are saying that one specific process is absolutely necessary to show "capable of evolution" and you are beating a dead horse over it. Is the genetic makeup the same for each mule? Do the alleles of all the mules change with the introduction of new mules from the breeding population (donkey x horse) and the death of old mules?
... Humans have to intervene. ... Actually humans "intervene" because it is to their advantage to have mules, let's go back to wiki
quote: Thus they have different traits than their parents -- evolution has occurred. The reason they keep being made is because those traits are beneficial to humans. In this sense they have adapted humans to provide their reproduction for them. There are lots of forced hybrids (humans "intervene") and they have different levels of sterility; mules appear to be the extreme in that regard, but even they are not totally prescribed from reproducing withing their breeding population. There are also lots of individuals from many many many species that are sterile. What that means is that they have a selection of traits that prevents that phenotype from reproducing, and thus alters the frequency of alleles\traits in the breeding population. In any breeding population that is evolving some individuals reproduce more than others and some fail to reproduce before dying, and the frequency of alleles\traits changes as a result. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
This opens a rather large can of worms, and I'm not sure where to begin with it. Every definition opens a can of worms, some more than others. Defining life based on what is observed aspects of life (the 'standard' definition and AOK's definition) all are post hoc definitions. They all leave out one thing or another that then isn't considered life, but which is certainly more than just chemical. Such as evolving viruses. I'm going to take this opportunity to summarize where I am on this issue, and include some history of how I got here, so this will be loooong.
As AOkid and NoNukes have pointed out, evolution is a population phenomenon: individuals are all incapable of evolution. So, maybe you could get away with this if you said, "anything whose population is capable of evolution." And I have no problem with that, but I looked back to where I originally developed my definition on the Definition of Life (circa July 2006) and in particular my post A Simple Definition of Life ...:
quote: Now I note that adding "potentially" to my current definition would solve some of the problems raised thus far (it can be argued that mules are potentially capable of evolution, as new mules with new genetic variations are constantly being added to the mix). Note that this previous definition is rather more restrictive than I have argued here, with the nested hierarchies addendum. Not all species form nested hierarchies whey they are on the track to extinction, yet the individuals are still considered alive, so I am willing to drop that element; successful life-forms will likely speciate and form nested hierarchies but it isn't critical that they do so. Instead what I have argued here is that all multicellular life is essentially a colony population of cells -- or more specifically an ecosystem of colonies that interact and compete for resources -- that all have generations and evolve during the lifetime of the multicellular life-form, and thus it is alive by my definition. This also works for sterile drones in ant and bee colonies and any sterile offspring within a species. This also gets into the distinction between multicellular life and single cell life, with colonies of single cells as an obvious, observed, intermediate stage of development\evolution. There is another aspect that I have also been considering, and that is the transplanting of living tissue upon the death of a donor; part of the organism dies (see What Is the Medical Definition of Death?), but useful parts are still living: they are parts of the colony that are still able to function, and thus they can be transplanted into another support structure (colony/ecosystem), in much the same way endangered species can be transplanted into new ecosystems where they might survive. Curiously I also listed the 'standard' definition of life on that post, for reference:
quote: Now AOK's definition is essentially #1 (Organization) plus #2 (Metabolism) in a reductionist extreme, and doesn't include all the other 'standard' observed aspects of currently existing\known terrestrial life. His insistence on including DNA (which the 'standard' definition doesn't) means that he has to consider that there are then three areas of consideration instead of 2, and that the middle one (viruses) behaves just like living things by reproducing and evolving, something that rocks and water don't do. What do you call that -- quasi-life? proto-life? -- and I would think that such a category would be a large problem for your typical creationist type. In addition, his insistence on a cell raises other problems.
quote: And that a cell wall was not necessary for life to function. Another post on that thread goes into this in more detail:
quote: So the replicators and catalysts would have existed before the cell evolved, and the cell then enabled DNA to evolve along with the mechanisms to form proteins. And the issue is still - where do you draw the line: after the house is complete and occupied or when the foundation is laid and the building materials are on hand or some magic point in between? Are viruses "alive" or not? Again this was discussed on the previous thread:
quote: So it looks like DNA evolved before cell walls in this instance. There are also several other viruses that self replicate (without using existing cells), and these can be dredged up and posted if necessary; suffice it to say that the biological world is seeing more and more scientists accepting viruses as life/living. Enough for now (if not too much) Enjoy.by our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
This may be what you meant to say or wished you said, but it isn't what you actually wrote: ... Fine. Still rather a minor point to how life is defined. Consider it clarified. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
In my opinion, 'capable of evolving' ought to mean "undergoing a change in allele frequency in a population from generation to generation". ... Again, are you claiming that every new generation of mules have exactly the same distribution of alleles as the previously existing population?
... We don't even agree that mules are a population, which is something I find strange. ... They are not a breeding population, just as any grouping of all males, or of all females, or of a 'superpopulation' gathering during non-mating times, are not breeding populations.
Beyond that, I think agreeing that something less than demonstrating the process of evolution is sufficient might mean that a simpler definition of life is possible. Feel free to develop one.
You've skipped over something obvious. Horses and donkeys are not the same species. Therefore a mule cannot possibly be the same species as horses and donkeys. It is a hybrid. We can easily discuss a separate population of mules without requiring a separate species. But not a separate breeding population ... Curiously I am not making a claim that they are anything but a hybrid, that individually each mule is the product of (human) breeding a (female) horse with a (male) donkey, and that as such their breeding population includes (female) horses and (male) donkeys. Do you think mules are a breeding population? If no, then that should clear up your problem.
Separate population is not the same thing as separate species. It simply means a group of animals distinct enough to talk about. Like a population with a different number of chromosomes than either horses or donkeys. And there are many non-breeding population groups -- often involving several different species -- but when talking about evolution you need to be talking about the breeding populations. Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
... Ten to twenty years ago, it was pretty much the consensus that viruses were not alive. Now, it depends on who you ask. I heard a virologist on NPR this morning who referred to viruses as "organisms" that are alive. So the thinking about whether viruses are alive or not is shifting towards the "yes" side; not because definitions are changing or because scientists are being equivocal, but because we are changing how we view these grey areas. ... Indeed, especially as we see more and more ... In the same way, by his definition, viruses are not in this blurry area between living and non-living; they are simply defined as non-living. Which then creates a problem with some parts of 'non-living' structures behaving like 'living' structures and unlike what is normally viewed as 'non-living' structures (like rocks). That just moves the blurry area but doesn't get rid of it. Note that by AOK's definition only cells are alive because only they process\manufacture ATP -- multicellular life-forms consume raw materials and metabolize them by breaking them down and sending the raw materials into the cells which then process them. That puts multicellular life into a gray area when it is usually de facto accepted as life.
4. I think your attempt to define life as "anything capable of evolution" is also problematic, IMO. I am not sure I can explain exactly why I don't like that definition, ... Perhaps it appears to much like a tautology at first glance.
... but it seems to require too many caveats and additional explanations, otherwise it simply means "anything that can change over time." As noted before it is modified to "anything capable of (biological) evolution" as I had felt "biological" was understood when discussing life.
I think we should stick to the time-tested, simple description of life we all learn in school. Life has (1) self-contained and organized structures (2) the ability to convert chemicals into metabolic and structural components (3) the ability to regulate it's metabolism (4) the ability to grow (5a) the ability to reproduce (5b) heritable traits (6) the ability to adapt to its environment (7) the ability to respond to stimuli I would argue that viruses ARE capable of all the above within a suitable environment (regulate metabolism is questionable but all the rest seem solid). I think the above "definition" is simple enough and is thoroughly descriptive of life as we know it. It is not too specific about any of the processes so some as of yet unknown life could still fit this definition. There are some life forms that do not exhibit all those elements (see looong post above for link to The Definition of Life By Joseph Morales). I would also delete "self-contained" as that is not entirely correct, and I would consider "metabolism" and "regulate metabolism" to be a subset of replication of molecules from raw materials (some viruses can make proteins for instance, which I would consider regulated metabolism).
But who knows, we may someday need to update the definition somewhat to accommodate new discoveries. We can also treat definition as theories; they explain evidence, they can be falsified, and they can be altered to accommodate new evidence ... and you can have competing or alternate theories ... and we can investigate to see which one best explains all the evidence. Enjoy Edited by RAZD, : . Edited by RAZD, : .. Edited by RAZD, : ... Edited by RAZD, : .... Edited by RAZD, : link to The Definition of Life By Joseph Morales Edited by RAZD, : {corrected}by our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
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A definition is to create the description that differentiates living organisms from other chemical arrangements. I chose the simplest arrangement that includes the production of metabolic molecules and the production of the enzymes required for their synthesis. A mitochondria's DNA level is much smaller than the entire cell's. There are two main problems with your definition. (1) It doesn't address the issue of viral life, which is increasingly being accepted as life forms as more is found out ( (2) Because it is based on microbiological functions inside the cell, it only defines cells as being alive:
Message 1: 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. ... the ATP is only synthesized inside the cell, DNA and RNA are also operating inside the cell (or are viruses); as a result your "mule" is not alive but it's cells are -- a condition you implied was fatal for my definition (Message 97): "So what you are doing is equivocating between a population being properly a population of mules or a population being some group of cells within the mule." Not being directly applicable to multicellular life is a fatal flaw. So you've created two gray areas with your definition that aren't life and that aren't really non-life ... as "non-life" is generally understood: one between cellular life and first life, and one built up of multiple cells working together.
And finally, any good definition of life must also identify it's opposite (or death). Life is not the continuum. Death is. ... Make that 3 problems ... Consider tardigrades ... Tardigrades:
quote: Seeds and bacteria can also have a phase where there is no metabolism (ie - no production of ATP, no function of DNA\RNA) until conditions become favorable for it's life. Are they dead in between periods of being alive? Your definition would say so. Are they resurrected? Seeds were recently recovered from an archaeological dig inside a pottery container ~800 years old ...
quote: And the oldest known viable seed recovered and grown to date is
quote: And then there is the bacteria:
quote: And yeasts, moss, and many other life-forms also use spores to propagate ... By your definition these spores are dead, so is life created from non-life when they revive\grow? Not being able to distinguish between life and death in such instances is a fatal flaw. Curiously, these organism are capable of evolving ... Enjoy Edited by RAZD, : (3) Edited by RAZD, : ] Edited by RAZD, : correctionby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
RAZD writes: (1) It doesn't address the issue of viral life, which is increasingly being accepted as life forms as more is found out (self replication without host, metabolism and making of proteins used to encase it, etc) You have claimed this several times now. Admittedly, I am totally unaware of this. Evidence Please! Hopefully papers I can access on the web. Not journalistic articles I hope.+ Rather than go back to old posts to find this material I did a search on this topic to also see what the current status is. My original information involved the first paper\article, and I am pleased to see that further progress has been made on this. Start with these two articles (bold added for emphasis):
Astrobiology: Test-Tube RNA, 2001 quote: I haven't found the Science article yet, perhaps you would like to try. Follow up research leads to (bold added for emphasis):
The Daily Galaxy: "Evolution in a Test Tube" -Scientists Create Immortal Genetic Molecule, 2010 quote: So as long as there was substrate (food to metabolize) the RNA enzyme\catalysts replicated, competed, evolved. In other words QED -- independent self-replicating RNA molecules. For an overview of the RNA world current status see Wikipedia: RNA world (accessed Dec 2015) (bold in original):
quote: [22] and [23] would be the Science articles related to the first article above; it doesn't appear that the wiki article has been updated with the information from the second article above. I'll have to look into that. See also Science: Mirror image RNA enzymes may hold clues to origin of life:
quote: A possible path to chirality. In between self-replicating RNA and modern cell life would be self-replicating DNA molecules, with DNA viruses as 'living fossils' of their pre-cell existence. From News | BioEd Online
quote: This isn't self-replication and it is inside a cell, but it is the RNA virus acting alone to make its proteins, another step on the road to RNA world. And now I will add a copy of this post to Self-Replicating Molecules - Life's Building Blocks (Part II) Enjoyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
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You have claimed several times now that viruses can self replicate, metabolize and make proteins outside a host cell. I claim your bluffing or sadly misinformed on this. I have asked for supporting evidence to support this claim. You provided a bunch of non-relevant material. Ah, so comprehension of parenthetical statements modifying the main statement of what is posted is also one of your problems in understanding what is said. Do I need to parse it for you? Do you not see the difference between: (me): viral life, which is increasingly being accepted as life forms as more is found out ( (you): you claim viruses can self replicate, metabolize and make proteins outside a host cell. Perhaps I used a poor choice of wording and structure. Scientists are increasingly accepting viruses as living, forming a fourth domain of life. This is because of what they are learning. There are seven types of viruses:Class 1: Double Stranded DNA Viruses Class 2: Single-stranded DNA viruses Class 3: Double-stranded RNA viruses Class 4: Single-stranded RNA viruses - Positive-sense Class 5: Single-stranded RNA viruses - Negative-sense Class 6: Positive-sense single-stranded RNA viruses that replicate through a DNA intermediate Class 7: Double-stranded DNA viruses that replicate through a single-stranded RNA intermediate From an RNA world perspective, if (RNA) viruses are "fossils" of the RNA world, and RNA life, then we need to look at RNA self-replication, and we find (learn) that there are (now) several known self-replicating RNA molecules. Molecule metabolism occurs when available raw materials are converted\combined\catalyzed into larger, more complex structures, which can then be joined in the making of a replicate. We have found (learned) that there are many additional RNA molecules known that are capable of this type of action. From an early life perspective (before cells evolved) we need to look at how DNA evolved, and (DNA) viruses can be "fossils" of the early evolution of DNA from RNA, able to manufacture proteins to form a protective sheath against UV and other hazards to early life. We see (learn about) this occurring with the (class 1) Mimivirus when it is in a suitable ecology (which in this case is an amoebic cell, but it uses raw materials and not the cell mechanisms or structures). We can also consider cells to be mini remnants, "fossils", of a pre-cellular world. And I note that the scientists that researched the genome of this (DNA) virus seemed quite excited to call it a life form. Does that mean that DNA viruses can be considered life, but not RNA viruses? Or is it just another matter of degree, of the gray area between living things and never living things? Curiously, I also see that you have failed to reply to my points that show your definition fails ... (Message 142) ... just as your "reply" (Message 144) failed to address a single one of the problems .... attacking my post without addressing (eg ignoring) those problems doesn't make them go away: do I need to repost them in yellow? Perhaps you think that discrediting my posts\definition makes your definition stronger. It doesn't. Enjoy Edited by RAZD, : added details, clarity Edited by RAZD, : correctionby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
I am claiming that there are no new generations of mules. ... And yet mules have been around for thousands of years, so either they pop up out of nothing, they are immortal or there are new mules being bred. New mules being bred would be a new generation would it not?
... I am saying that a population of mules does not produce a new generation of mules. You are saying that it is a population that does not breed, and I am saying that it is not a breeding population. The difference is that you need a breeding population to have evolution and not some other arbitrary population. A population of all males is not considered a breeding population and cannot produce a new generations with hereditary traits. A population of all females is not considered a breeding population and cannot produce a new generations with hereditary traits. A population of individual animals from different species, one per species is not considered a breeding population and cannot produce a new generations with hereditary traits. A population of mules is not considered a breeding population and cannot produce a new generations with hereditary traits. ALL of these organisms in each one of these populations are products of reproduction carried out in their respective breeding populations.
I thought at this point we at least understood each others arguments. Let's just end this. Do you agree that a population of mules is not a breeding population? Enjoy. Edited by RAZD, : clrtyby our ability to understand Rebel☮American☆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)
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RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
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A single cell of a dog could not live by itself outside the dog. A cell wouldn't be able to live by itself (meaning without outside help), but cells can be kept alive and dividing in a lab, invitro. The HeLa for example, which is generally considered to be living. Organ transplants and skin grafts fall into the same category. You could say they are transferred from one life support system to another. Enjoy Edited by RAZD, : .by our ability to understand Rebel☮American☆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)
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