Viruses do not have any function that is related to living organisms. Therefore, it is not a living organism.
I apologize. I thought I was talking to chinglu. But don't crystals form essentially identical copies? Don't viruses?
No crystals change size, not make new essentially identical copies. Yes, I consider a virus a complex life form which is alive, much like a fetus in the womb is, even thought both do depend upon other lifeforms for part of their lives to make more of their kind.
They do make identical crystalline structures of other material; it just happens to be attached. Note, many plants and animals also grow and reproduce in this way on a macroscopic level (having to be broken off to create a completely distinct individual). There are also things that are smaller and simpler than viruses- like prions- which happily replicate by using (/bumping into) the raw material around them- that raw material just happens to be another protein (very specific requirements).
If you mean replicate more of the same latice structure, yes but not new crystal of the same form. E.g. as a NaCl crystal grows more of that structure is added to the outside, not a new cubic crystal. True, but the new part, individual is not of the same form; however it is alive, and may acquire that same form later. Prions do convert the same ALREADY EXISTING chemical compound into their form by refolding the pre-existing identical compound. They do not create new life, but only change the shape of existing molecules. They certainly do not draw any material in to make new life from it and take insignificant energy from the environment to do the refolding - possibly all is supplied by molecule they refold if any is required. I suspect they serve just as a template for it to refold with. It is close call, but I would say they are not alive. My definition of living had the living creature make compounds found in themselves from environmental materials and energy, not just change the shape of existing compounds. An oil companies "cracking unit" producing higher percent of gasoline does that, and it is not alive either. Some prions can kill you as the shape of molecule is very important to many cells - many entirely different molecules but with the same shape can trick their shape specific sites - how artificial sweetners and many drugs work.
Billy T There are many chemical reactions that draw energy and materials from the environment, the only difference between those and life is that life replicates itself, to a more or less degree(mutations, gene swaps, gene expression, etc). But both are just different forms of chemistry, there really isn't a hard line you can draw between complex chemistry and simple life. By some definitions of life we have already succeeded in creating it in the lab(through chemistry, I might add). There is an unbroken continuum between simple chemistry and complex life, it's easy to see that an elephant is a complex lifeform and it is easy to see that water is a simple chemical compound, but where you draw the line between chemistry and life is an entirely arbitrary decision based on what your definition of life is. Prions are probably as close to the first life as we have found extant today, simple snippets of protein material that assembles copies of itself out of the chemical around it, but would you call the amino acids we have found in meteorites and interstellar gas clouds life? After all, just assemble a few amino acids and you have a protein, and some proteins are definitely organic in behavior. We have also found organic sugars in gas clouds, as well as formaldehyde, ammonia, methane, water and other building blocks of life. It may be that life is inevitable wherever it can exist in the Universe, simply because the laws of physics creates it. chinglu You are not here to learn, nor to discuss, but only to regurgitate the pap you have been indoctrinated into. Stop trolling and leave. Grumpy
I agree that there is no clear line between living and non living chemical processes with many definitions of life various people have offered. That is why I used some care to make my definition (which you quoted). With it there is a clear line between between living and non-living. I you think not, try to find an example that is not clearly on one side or the other of my deciding line? I have discussed prions and viruses already and with my definition a virus is alive and a prion is not. Fact that a virus may do nothing for long period does not mean it is not alive. Brine shrimp can be dry and dormant for more than a decade, I believe, and certainly are alive when restored to brine.
The life form as a whole may have unique qualities, but if we consider just a small part of it, isn't it just chemical? Are all the parts of a living thing reducible to chemical interactions?
I think so*, but all may not yet be known. I.e. I do not believe, as once many if not most did, that there is some special "life force" - I forget its Latin name. * Physicists may claim some processes are in their domain. For example mitoses and some earlier stages of DNA division, perhaps. AFAIK only forces are acting with no chemical changes in mitoses and piron conversion of another chemically identical molecule to its shape. Also, now that I think about it, probably most neurotransmiters have no chemical change when used - most pre-synaptic nerve cells have a re-uptake mechanism to avoid cost of re-fabrication of them for one time only use. I.e. any given neurotransmitter may be reused many dozens, if not hundreds of times.
Hi Billy, I disagree with what you said in your reply; I feel that you are drawing an arbitrary line and rationalizing it without realizing. Of course, that is your right; I would rather not argue about it Please Register or Log in to view the hidden image! We can all have our personal definitions of life, and perhaps all categorical definitions are ultimately arbitrary and indistinct personal evaluations when it comes down to it. Best regards,
CERTAINLY I am being arbitrary*, but I realized that. - I was trying to show defend my statement in post 94, that ToE was (or could be) a clearly defined separate domain of study, "cut at a natural joint" from the origin of life. If you cannot do that clean cut of living from non-living mater, then Chinglu has quite a strong argument in his post 93 that ToE, as normally limited to not include abiogenesis, is just religion, not science. I.e. he said in 93´s main summary argument line that: "Either TOE is based on the natural operations of chemistry and physics or it is not. If it is, then abiogenesis is part of TOE." * All definitions are (and not just definitions of life). I took a second approach in post 94 too, i.e. accept Chinglu´s logic and then note it implied the origin of planet Earth from a gas cloud must be part of ToE too.
No domain of science can be clearly or perfectly separated from another- they merely are in practice of those fields of study due to specialization. That's absurd. I don't think you needed to go through that much trouble justifying evolution for that fellow (I guess, good of you to try...). There's no hard and fast distinction between a pizza and a muffin either- that doesn't mean making muffins is a religion if the muffin man doesn't want to bake pizza, or doesn't care about pizza at all. They're certainly related, and have quite a bit in common, but fields are labeled as they are based on what those within the fields specifically study and work with- and they do have arbitrary boundaries, but that's not a problem (and it doesn't make them religions). This Chinglu fellow doesn't seem to understand domains of study. Be careful about saying 'all'. That's not strictly true. The farthest we can stretch evolution, if we want to apply it consistently as a domain of a general process, is with regards to the process of evolution of any information system in the most general sense. In that sense, it would apply to computer software, memes, prions, crystals (which can evolve too), and what we generally accept as life forms. This would not pose a problem for evolution. It's still a proven process- we just find more and more things it can apply to all of the time. If we want to be specific and say 'biological evolution', then we're dealing with a subdomain of all of that limited to biological systems- probably understood as relating to information stored as Nucleic acids in organic systems.
Certainly the different domains of science share some common characteristic, for example testing predictions of their theories etc. but also there can be little in common of between some of their subject maters - say between nuclear physics and thermodynamics, etc. To have a well defined subject area for ToE, it is IMHO necessary that definable boundaries of that field exist. As ToE is the study of how life forms change it is thus necessary to know what is a life form and what is not if ToE is to be a well defined field of study. That does not mean that other fields of study have no importance to ToE, they can and do impact it. For example, the study of climate and its history, but the study of climate is a well separated field of study from the field of ToE -at least that is my and a very common POV. Unlike history, science does have natural, non-arbitrary, boundaries for its fields of study.
Of interest also is the role primitive viruses may have played in the prebiotic era (another arbitrary but useful boundary). Given that lipid vesicles can form naturally, any virus capable of passing into a membrane would have an evolutionary advantage due to shielding. Call it a niche, and by application of ToE, the first cell may simply be some virus that sustained this "trait", in the simplest sense of the term, merely on account of lasting longer behind the shield. Some primordial puddle or ooze seep where lipids were rich would be a prime site for sustaining such a virus longer (prolonging its "life") than without the shield. Once you have a colony of nuclear material setting up shop behind membranes, you come awfully close to that Occam's Razor/entropy-violating mechanism that gives the fundies a place to look for their order out of chaos. I have no idea if this is even close to what any biologist might say is feasible. I'm just addressing the ludicrous way fundies are so certain something wouldn't/couldn't/shouldn't have happened and will engage these prolonged and sometimes even elaborate arguments in the manner of flogging a dead horse.
There are reasonable boundaries like that, yes. But they aren't necessary- without them the study does not become 'religion'. I disagree. Evolution goes beyond the study of living things, and is applicable to any replicating information system. Only if we specify biological evolution is that boundary necessary- but in that specification the boundary is inherently defined anyway (as to what "biological" is). I don't see that it is necessary to go through any extra effort to present apologia for the boundaries lest science be equivalent to faith- it's just not the case. Does this make history equivalent to religion? In that case, history shouldn't be allowed in public schools! We must fight this affront to our democracy! Please Register or Log in to view the hidden image! I think you're giving this person's argument more credence than it deserves.
Billy T Then you have a problem with your definition, as prions are clearly on the living side of the divide(barely, but we are talking about first life). Prions create copies of themselves from elements in their environment, they reproduce. Reproduction is the basis for any definition of life(at it's simplest). In fact prions are probably the kind of thing that developed from chemical "evolution" to start the whole process of evolution. Of course, by this definition, crystals(at least some of them)are barely on the other(non-living)side of the demarcation between life and non-life. It's all a bit fuzzy where that line should be drawn but when looking for the simplest our definitions must be the simplest. No, Chinglu does not. Despite the problem the two are entirely separate studies. Abiogenesis is the study of the chemical basis for that first life, evolution is the study of the behavior of life after it exists. The TOE stands on facts and testing, it would be a better world(and an entirely atheist one)if religion was approached the same way. Accepting the fact that evolution has occurred and still occurs today is not belief, it is knowledge, it is fact. The fact that we do not yet know how the process started means nothing to the fact that it does occur just as the first cause of a house fire not being known means nothing to the fact the house is on fire. Life began and abiogenesis is our effort to understand that process, life evolves and the TOE is our effort to understand that process, they are two entirely separate processes that do not intersect. GrumpyPlease Register or Log in to view the hidden image!
Definitions are arbitrary. Mine for life, requires that the life form takes energy and material from the environment to reproduce, which prions do not. Some existing protein molecules can be refolded during collisions to make the "hit molecule" into the prion version that molecule even if the molecule or atom that hit the "existing protein molecule" is not a prion, or not even the shape of the prion. There is a whole field of study of many so called "chaperons molecules" that control the refolding of proteins.* Thus when it happens to be a prion that hits the existing protein molecule to trigger the refolding making another prion, I don´t consider that refolded molecule to be life. It could have been created by non-piron collisions too - no "reproduction." But again definitions are arbitrary - You may prefer one for life that does not require the living creature to take any energy or material from the environment, but my definition does. I don´t want a cosmic ray or some other radiation or some chaperons molecule that happens occasionally to refold an existing protein´s shape to be called alive, regardless of the new shape of the pre-existing mole happens to end up in. - I.e. even if that new shape is a prion. SUMMARY: We probably will not agree. I don´t call prions a life form, but just a protein molecule in one of its many possible folded shapes. * One anti-viral drug uses / is a "chaperon molecule." As I understand it, it prevents the viral DNA from becoming the shape it needs to become in order to enter the cell it would "like" to reproduce in. It does not kill the virus or turn the immune system on to kill it - just just blocks its ability to take the shape needed to enter a host cell. Probably an "evil scientist" (or team of them) could make some chaperons molecule that convert existing proteins into lethal prions.
Billy T And thus the demarcation between life and non-life is also arbitrary. GrumpyPlease Register or Log in to view the hidden image!
Yes, but with care, as I took, in making mine, it is possible to draw the line between living and non-living clearly.
You could make a clear and exhaustive list. For example: Alive: Humans, dogs, cats, trees, snails, electric can openers, Buz lightyear toys. The nature thereof of those things vs. those which are not as defined by a random usage panel of ten people selected from adult Canadian citizens whose first language is English. Not alive: Everything else! This is pretty clear. It's also highly arbitrary. It doesn't matter how clear your line is- if it's truly arbitrary, it's not very useful, philosophically speaking. FYI, a sufficiently advanced molecular printer could also print out any life form without itself being alive. Life being able to have a source which is not alive does not disqualify it from being alive- and it does not make that source itself alive. Prions created by other means, rather than fellow prions, are still alive in their context- the things that created them being, usually, non-living. That's perfectly fine.
