Early RNA Life

This is to carry on a discussion of prions that Lam noted was off topic in:
Message 110This is the series of posts:

Thread moved here from the Proposed New Topics forum.

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By studying the genetics of afflicted families, researchers were able to clone the responsible gene. It turned out to be the gene coding for that same brain protein. In each disease, the gene carried a slightly different mutation. But all these mutations occurred in regions believed to be critical to the structure of the protein.

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There is another source of these prions. I read in Outdoor Life about a disease that is effecting North American Deer. It is believed to be caused by viri using the bodys own protiens to cloak themselves. These are the only cases I know of, and both require a genetic beginning. I don't think a prion could be considered life anyway.

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While we would not consider a protein a living thing, it nevertheless through this process of templating, acts like a living virus, infecting, copying itself and ultimately killing its host. In fact this process is very reminiscent of theories of self-replicating systems and the evolution of life.

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Bob, I don't think there's any known involvement of a virus in Chronic Wasting Disease of deer and elk, any more than in scrapie in sheep, "mad cow", or Creutzfeld-Jacob disease in humans. Do you have a source a little more on the technical side than "Outdoor Life?"

There are many theories for the cause of CWD. Of course no one knows for sure.

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Dr. Frank Bastian, a research professor of neuropathology at Tulane University in New Orleans questions the prion protein theory. He is quoted as saying, "A protein has never been known to be the causative agent for a disease." Bastian feels that CWD may be caused by a bacterium known as a Spiroplasma. His research has shown that Spiroplasma is associated with CJD and scrapies. To make itself unnoticed by the immune system as it enters a host, Spiroplasma bacteria may cloak itself with host proteins such as prions.

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That is one theory. There are several.

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According to a paper on the USDA's website dated November 2002, "The agent responsible for CWD (and other animal TSE's, such as scrapie and bovine sponigorm encephalopathy) has not been completely characterized. There are three main theories on the nature of the agent that causes CWD: (1) the agent is a prion, an abnormal form of a normal protein, known as a cellular prion protein, most commonly found in the central nervous system. The abnormal protein "infects" the host animal by promoting conversion of normal cellular prion proteins to the abnormal form. (2) the agent is an unconventional virus; (3) the agent is a virino, or "incomplete" virus composed of nucleic acid protected by host proteins. The CWD agent is smaller than most viral particles and does not evoke any detectable immune response or inflammatory reaction in the host animal. Based on experience with other TSE agents, the CWD agent is assumed to be resistant to enzymes and chemicals that normally break down proteins, as well as resistant to heat and normal disinfection procedures." If a virus causes CWD scientists may be able to produce a vaccine that would make both animals and humans immune to CWD.

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I got this info here.

As you can see from the links i've provided prions are a product of life, but are not in and of themselves considered life. It does not matter however, because they are a product of life DNA being necessary for their beginning. I maintain my original position that DNA is necessary in the formation of all life.

I have looked everywhere, and I can't find anything more than speculation. that supports your position that life could start on it's own without some form of life being present in it's beginning.

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The genetic work indicates that the complexity of genetic codes doesn’t track that well with the apparent complexity of the organism and that even very simple organisms have quite complex genomes. The simplest known living thing is the microbe mycoplasma genitalium which causes human non-gonococcal urethritus. This microbe has a genetic code of about 570,000 base pairs. Viruses are simpler but aren’t really alive in the sense that they cannot reproduce or grow without using the mechanisms in a living cell to do so. The bacteria e coli has a genetic code of about 5.7 million base pairs.

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link
Evolution can never be proven until we can find some form of life that is not dependant on preexisting genetics.

The only thing that isn't clear to me is how you're defining "life". There is sort of an endless debate as to whether virii are alive in the conventional sense. Certainly prions are NOT alive. But virii? I agree that virii can't self-replicate, although as to that there are auto-catalytic RNA, pRNA and PNA strands that do so under the right circumstances which would not be considered "alive". So is that the only criteria that separates life from non-life? Virii are in many respects just like any other parasitic organism requiring a host, so I don't believe that the lack of self-replication is all that hard and fast a division. For me, although we're talking a very grey area down at the very shallowest end of the gene pool, IF we allow that self-replication isn't necessarily a defining criteria, we THEN have a much smaller genome to worry about evolving: the phage (theta)X174 for example contains only around ~5300 bp. It doesn't strike me as any huge leap of faith to get that. And these are derived, modern organisms, so conceivably there was something simpler "in the beginning".

Have you ever looked at what evolution is talking about?
It is a theory of how the forms of life on earth have diversified from an original single (or few) forms. It is a discussion of changes in allele frequencies in genes. It is, by that very definition, talking about living, imprefectly reproducing things.Therefore, evolutionary theory doesn't have anything to do with how life arose other than that it must have. The way life arose can be anything that you'd like: aliens, God, good luck, chemical inevitablitly, take your pick.Separately, evolutionary theory is an explanation of how life forms on earth were able to change over time. That evolution has happened, by whatever means, is the obvious and only resonable conclusion from the facts at hand. Again, nothing to do with how life started just that it did (somehow) and that it has changed and changed again over a long period of time.Why do you bring up evolution and the origination of life in the same sentence then?This message has been edited by NosyNed, 11-03-2004 01:36 PM

That it happened in and of itself. My position ls that if it didn't there must be a creator. The very backbone of evolution is that life began by itself without the aid of a creator be it God or virus. I was told that prions were life. Then I was questioned on every post I made. now I am handed (theta)X174 and asked to accept it as the end all explanation of the formation life. If I would only have a little faith. Faith is the thing that you have been telling creationists has no place in science for years. Now you say the formation of life has nothing to do with evolution. Well I think you are just yanking my chain. I was asked to provide something better than outdoor life. yet you have offered no proof at all not even mad mag.

(Orignially postedhere). Sometimes the source of defective prion is in the DNA template. For example, there do exist human families with inherited, familial prion diseases that have been well linked to DNA mutations. There also seem to be "sporadic" cases where mutations arise later in life (akin to cancer) to produces infectious prion as well.However, an organism doesn't need to have those DNA-level changes to develop a prion-based disease, they just need infectious prion protein from another organism introduced into their body (under certain conditions). Infectious prion disease is of immediate health concern to humans, so it is usually thought of as a purely infectious disease. However, DNA-level changes in food animals may contribute to the problem, and so are worthy of study/discussion.What I find fascinating is that the biological role of normal prion remains unknown...A recent review, emphasis mine:

Incorrect. You are referring to the Theory of Abiogenesis, NOT the Theory of Evolution. They are two distinct theories and fields of study. Evolution deals with genetic changes in populations over time, NOT how life first came to be (have you ever considered that God may have created life via evolution?)Reread Nosy's last post - he is not "yanking your chain". Who told you, out of curiosity?Even if one were to define prions as life (which I highly question), they do not have the characteristics that would suggest they are equivalent to "first life". In fact, it would seem that cellular life, and potentially multicellular life, would be required for prions to take on their scant life-like qualities. They really act more like crystals than life.

Bob did ask for support for the claim that the boundaries of evolutionary study is limited to living things (or at least to things which approximate much of what we are willing to call living). It is fair to ask that.Here is the last few lines of the very original work on modern evolutionary theory. Darwin's "Origin of Species". It doesn't seem that it discusses the original orgin of life anywhere else.In other words it leaves abiogenisis to another area of study.

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There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

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Additionally, I've stated what biological evolution is defined as. Do you have a different definition? What support do you have that those who are involved in the study of biological evolution use your definition?That definition excludes non-living things. Therefore it has to exclude the process of getting from non-life to life.What you seem to be claiming is that biological evolution has to include the all of chemistry too since the genes are chemicals. That isn't an issue; chemistry is simply a given too.As I noted earlier life can arise by any number of speculated paths. Evolution is a process based on certain characteristics of life NOT of the path by which it arose.You disagree but you have yet to state why.However, even if biology somehow included the origin of life (it is really more chemistry than biology) the so what? All you end up with is a something which is not currently known.We both agree that there was an event where life first appeared on earth. Before that event there was no life.I might say that we don't know how that happened. At best we have clues but we aren't in a position to be certain about any pathways to life from non-living chemistry.You claim that God did it because there is no other available explanation. This is called "god-of-the-gaps". Other explanations of this type included the source of diseases, lightening and volcanoes. The gaps were closed. This one may be too. Sophisticated theologians are not about to hang their hat on such simplist ideas.This message has been edited by NosyNed, 11-03-2004 04:54 PM

No, the backbone of evolution, like any scientific theory, is the evidence that it explains. Obviously, this must be the case. Evolution is a theory of biology. The formation of life would be a problem of chemistry. Two entirely different diciplines.

We were talking about about the evolution of DNA, or at least I thought that was the subject. We can call it chemistry, or whatever you want. This thread started, because (I posted in a dead thread) as far as I knew life required DNA. At least at some point in its creation. So far I have been given no evidence that this is not true. I was told that prions were life. I was attacked for my use of the word evolution. I was told to have faith. I will admitt my use of language was lacking, but the fact remains, that I have been given no real evidence That mud could ever become life. My position was, and is that life can be traced back to some very simple forms, but all forms rely on that darn double helix. If I have been proven wrong in this belief, I have somehow missed it.