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Author | Topic: New abiogenesis news article 4/12/02 | |||||||||||||||||||||||||||
thousands_not_billions Inactive Member |
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everyone takes endosymbiosis seriously =================================== This is a sweeping claim. Not everybody excepts the endosymbiosis theory at all. Some biochemists like Behe disagree with it. =============================================The first organisms were extremely simple--microscopic droplets of water containing a few genes and enzymes surrounded by a membrane. ============================================= Wait, this doesn't explain "how" the first organisms evolved! Genes are composed of highly complex DNA, which cannot be "evolved" step by step. Any little error in the DNA, and the cell is damaged or destroyed. Also, where did the DNA come from? =============================================Although such a scenario may seem far-fetched, we know that similar partnerships exist today. For example, the unusual ciliate Paramecium bursaria is host to many unicellular green algae in the genus Chlorella. ============================================= I agree, it does seem far-fetched. The paramecium bursaria is just an example of symbiosis occuring today. the organism is not evolving into another complex organism. The algae is just living inside the paramecium, just as bacteria lives in humans. Also, this doesn't explain how the paramecium could swallow another cell, and become more complex. A Prokaryotic cell is not as simple as most people think however. All cellular life has to contain the following characteristics. All cells have a CELL MEMBRANE that separates the CHAOS outside a cell from the high degree of organization within the cell. A cell without a cell membrane is not a cell. All cellular life contains DNA as its genetic material. All cells contain several varieties of RNA molecules and PROTEINS, most of the latter are enzymes. All cells are composed of the same basic chemicals: carbohydrates, proteins, nucleic acids, minerals, fats and vitamins. All cells regulate the flow of nutrients and wastes that enter and leave the cell. All cells reproduce and are the result of reproduction. All cells require a supply of energy . All cells are highly regulated by elaborate sensing systems (chemical "noses") that allow them to be aware of every reaction that is occurring within them and many of the environmental conditions around them; this information is continually PROCESSED to make metabolic decisions. These are just the minimal requirements for life! Anyway, hope this helps. ;-)
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Percy Member Posts: 22499 From: New Hampshire Joined: Member Rating: 4.9 |
thousands_not_billions writes: everyone takes endosymbiosis seriously This is a sweeping claim. Not everybody excepts the endosymbiosis theory at all. Some biochemists like Behe disagree with it. John was just using a vernacular form to say that endosymbiosis is very widely accepted. While I have no direct knowledge of Behe's views on endosymbiosis, he doesn't usually oppose positions supported by strong evidence - are you sure he disagrees with it?
Genes are composed of highly complex DNA, which cannot be "evolved" step by step. Any little error in the DNA, and the cell is damaged or destroyed. Almost every cell replication includes copying error, and copying errors (mutations) are the foundation of evolutionary change. This "step-by-step" evolution that you say cannot occur has been observed in the lab countless times. Because we've observed cells with mutations surviving and reproducing you would be incorrect to surmise that "any little error" causes cell death. Many cells function quite well with their error-ridden DNA.
Wait, this doesn't explain "how" the first organisms evolved!...Also, where did the DNA come from? There is much supposition and little certainty. It happened long ago and there is little evidence left, and so we may never know. Absence of evidence invites speculation, but current theories of abiogenesis lie within the realm of science because they are consistent with current scientific understanding.
The paramecium bursaria is just an example of symbiosis occuring today. the organism is not evolving into another complex organism. That reproduction is an inherently error-prone process all but guarantees evolution. All organisms are always evolving, though the direction toward greater or lesser complexity would not usually be considered predictable.
The algae is just living inside the paramecium, just as bacteria lives in humans. Also, this doesn't explain how the paramecium could swallow another cell, and become more complex. I don't know the specifics of the paramecium/algae case, but cell predation is a fact. You can observe it in the lab. Your list of requirements for cells is reasonable until the last:
All cells are highly regulated by elaborate sensing systems (chemical "noses") that allow them to be aware of every reaction that is occurring within them and many of the environmental conditions around them; this information is continually PROCESSED to make metabolic decisions. It is only the "highly regulated" and "elaborate" parts that I would object to. The earliest life would have been extremely primitive compared to modern single-celled life forms, and possibly would not even be recognizable by us as life. They could be extremely primitive because they did not have to worry about being food for other life. This is related to the reason why abiogenesis can no longer take place on earth - any complex collection of organic molecules would immediately become food for existing life. --Percy
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John Inactive Member |
quote: You quote this as if it is something I said. I do not remember making this statement, nor can I find this statement in any of my posts. Please do not misquote me.
quote: It is a sweeping claim, but I did not make it. Take up the issue with whomever did make the claim. I would however agree that pretty much all biologists take the theory seriously, if this is not taken to mean that everyone agrees with it. I am sure some do not agree. It is a very well founded theory and it has a some good evidence in its favor.
quote: This isn't my statement, though I tend to agree. Please be clear about these things.
quote: It doesn't appear to be an attempt to explain how the first organisms evolved. Percy has addressed this the bulk of this so there really is no need for me to do the same.
quote: How do you know? You don't. You can't know because the requisite information does not exist.
quote: There are tons of little errors in DNA. It happens all the time. DNA is nothing but atoms held together by chemical bonds. What do you mean where did it come from?
quote: Yet again, not my statement. Please quote what I say, not what someone else says.
quote: Far-fetched or not, the evidence suports it.
quote: Yes it is, and it directly contradicts a statement made in one of the articles you posted. The statement was that endosymbiosis could not happen because the host cell contains enzymes that would break down the symbiont-- ie. digest it. This is clearly false. We have a living example, which I provided.
quote: Irrelevant. As above, the example was a response to a particular objection.
quote: Which is just what the endosymbiont theory proposes. How is this a problem?
quote: The paramecium does swallow another cell and the whole is more complex. How is this an objection?
quote: Funny, given that a few posts ago you were appeared to have no knowledge of prokaryotes at all. But what is the point? With your list of cell requirements you are making the same mistake you first made, which is to assume that early life worked like modern life. The assumption is not justifiable.
quote: Actually, these are the minimal requirements for modern cellular life, excepting the parts Percy commented upon. It does not follow that these are the minimum requirements for LIFE, much less for precursors to life like replicating molecules. What is and isn't alive is largely definitional anyway. The edges are blurred. ------------------
No webpage found at provided URL: www.hells-handmaiden.com [This message has been edited by John, 01-13-2003]
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Percy Member Posts: 22499 From: New Hampshire Joined: Member Rating: 4.9 |
Hi John,
It looks like the quotes provided by thousands_not_billions that weren't from you were actually from one of the articles you provided a link to:
--Percy
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thousands_not_billions Inactive Member |
I'm sorry if I was confusing John. I should have indicated where I got the quotes from. Again, sorry :-).
====================================================== DNA is nothing but atoms held together by chemical bonds. What do you mean where did it come from? ====================================================== Again, I should have been more clear. I was in a hurry when I wrote the post. DNA is comprised of an enormous amount of bases. The bases must pair up with each other in a precise way. If they do not, the cell is defective, and would be eliminated by natural selection, the survival of the fittest. It is unlikely that natural processes, through trial and error matched up the bases. Say that some bases DID form in the "early earth". If they paired up incorrectly, then the cell is defective, and the process must begin again. ===============================the host cell contains enzymes that would break down the symbiont-- ie. digest it. This is clearly false. We have a living example, which I provided. ============================== Did I say this? I forget. ========================Which is just what the endosymbiont theory proposes. How is this a problem? ======================== Well, bacteria in our bodies doesn't mean that we're evolving into another species. It just means that the bacteria is using us for a host. The alge is in the same position. It is living inside the other cell. This is an example of symbiosis, not the endosymbiont theory. There is quite a difference between the example of one cell swallowing another and becoming more complex, and the example of a cell swallowing some algae. ===========================But what is the point? With your list of cell requirements you are making the same mistake you first made, which is to assume that early life worked like modern life. The assumption is not justifiable. ========================== But how can we prove that "early life" was different? Anyway, the big problem is not if a Prokaryotic cell could swallow another prokaryotic cell and become more complex. The big issue is where did the first prokaryotic cells come from? How did they evolve. Until this can be answered scientifically, I cannot accept this theory.
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thousands_not_billions Inactive Member |
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are you sure he disagrees with it? ===================== On page 189 of "Darwin's Black Box", Behe writes, "...Can symbiosis explain the origin of complex biochemical systems? Clearly it cannot... Neither Margulis not anyone else has offered a detailed explanation of how the preexisting cells originated." This is the big problem with the theory. [This message has been edited by thousands_not_billions, 01-13-2003]
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Percy Member Posts: 22499 From: New Hampshire Joined: Member Rating: 4.9 |
thousands_not_billions writes: On page 189 of "Darwin's Black Box", Behe writes, "...Can symbiosis explain the origin of complex biochemical systems? Clearly it cannot... Neither Margulis not anyone else has offered a detailed explanation of how the preexisting cells originated." This Behe quote rejects symbiosis as the origin of complex biochemical systems, not symbiosis itself. As I said before, Behe does not usually reject positions with strong evidential support, and the evidence for endosymbiosis is fairly strong. What text was in the second ellipsis? The portions of the quote separated by that ellipsis seem to be commenting on different aspects of the issue.
This is the big problem with the theory. Falsifications of theory stem from evidence, not lack of evidence. The difficulty of the puzzle of abiogenesis stems from lack of evidence, not from the presence of falsifying evidence. You have no evidence supporting your claim of a "big problem with the theory." --Percy
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peter borger Member (Idle past 7693 days) Posts: 965 From: australia Joined: |
Dear percipient,
P: ...and the evidence for endosymbiosis is fairly strong. PB Is it? If it is, have you considered the loss of information that is required two make one organism out of two? In other words 1+1<2. Best wishes,Peter
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John Inactive Member |
quote: Its ok. Just be careful with the citation.
quote: hmmmm... I don't think the pairing up is much of a problem. They snap together like lego. You want to concern yourself with the order of the bases, for two reasons. 1) The protein codes are in the order of the bases. 2) The earliest replicating molecules were likely something more like RNA which is not a paired base molecule.
quote: It isn't matching the bases. In all sincerity, you aren't going to be able to make much of an argument until you up your basic knowledge of this sort of thing.
quote: You are making the same mistake again that you in the beginning-- assuming a starting point much too far along the line. You wouldn't start with cells, just bare molecules that happen to replicate themselves. It may sound strange but some molecules do replicate themselves.
quote: You didn't say this, no. But...
Yes it is, and it directly contradicts a statement made in one of the articles you posted. The statement was that endosymbiosis could not happen because the host cell contains enzymes that would break down the symbiont-- ie. digest it. This is clearly false. We have a living example, which I provided. I don't remember which article it was which made the statement.
quote: The example adequately addresses several objections to the endosymbiont theory-- primarily that cells cannot live inside other cells and that organisms cannot develop synchronized reproductive cycles.
quote: I don't know that we can right now. We may never be able to prove it. But to insist that things 4 billion years ago are exactly what they are today is still unjustifiable. You are basically claiming that cells are the bottom line when in fact we don't know what the bottom line is.
quote: Don't know. A lot of people are working on it, though, that is the best we can do. Just curious, do you insist that everything be answered scientifically before you believe it? ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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Brad McFall Member (Idle past 5060 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
(my(our) idea) can get to the any NOT paired condition (say RNA) within fluid-contacts that are UNDER constraint per condition due to thermocontacts and electric evolution (in the sense of generation) for any unconditioned so approached. I know not what this means for Mendel's rational numbers which were emprical to others but what is to stop me from using atomics to numerate this idea?
I am begining to wonder if the present QM is due to the historical conservatism for PAIRS which Faraday not argue against since he did not introduce unneeded forces and substances so stuck to bipolar nature of the relation EVEN TO GRAVITY but perhaps mole bio has called for this need ((to know)more).
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peter borger Member (Idle past 7693 days) Posts: 965 From: australia Joined: |
Dear John,
You think that: 1) The protein codes are in the order of the bases. PB: What do you need a code for if you don't have a translator? And you are under the impression that: 2) The earliest replicating molecules were likely something more like RNA which is not a paired base molecule. PB: Except science fiction lovers, nobody holds this view anymore. Where do you think RNA's are made of? The compounds will NOT form spontaneously. It is a well-known fact. Keep it scientific, please. And don't misrepresent the data. As if nobody would notice. Go here for a fair presentation: http://www.arn.org/docs/odesign/od171/rnaworld171.htm It must be said, you have a strong belief. Best wishes,Peter
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John Inactive Member |
quote: Yes, I do think this, PB. Do you think differently?
quote: Which brings us to the following...
quote: Yes indeed.
quote: Thought you'd be at the top 'o that list.
quote: Outside of your mind, this simply isn't true. You shouldn't make assertions so easily refuted. Now, if you meant to say that not everyone accepts the hypothesis, then you'd have a leg to stand on. That NO ONE holds this view is silly.
quote: Sugar and spice and everything nice?
quote: I don't think RNA will form spontaneously. That is why I did not say RNA but said 'something more like RNA.' Any familiarity with the hypothesis which you criticise-- the RNA World Hypothesis-- should have provided you with enough data to avoid these shallow objections.
quote: Why must I follow rules which you do not?
quote: Respectfully, yes you do and every opportunity.
quote: Fair, because you approve? You cannot be serious. Kinda funny though.... The author states:
We find ourselves, however, distinctly in the minority of biologists. .... thereby contradicting your earlier statement that NO ONE believes the RNA World Hypothesis. The author also attacks a straw man. The RNA World Hypothesis postulates that RNA came prior to DNA. It does not postulate that there are no RNA precursors, yet the author behaves as if this were the case.
quote: Must it be said? Seems kinda childish to me. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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thousands_not_billions Inactive Member |
Here is the full quote.
"...Can symbiosis explain the origin of complex biochemical systems? Clearly it cannot. The essence of symbiosis is the joining of two separate cells or two separate systems, both of which are already functioning. In the mitochondrion scenario, one preexisting viable cell entered a symbiotic relationship with another such cell. Neither Margulis not anyone else has offered a detailed explanation of how the preexisting cells originated." ================================Falsifications of theory stem from evidence, not lack of evidence. The difficulty of the puzzle of abiogenesis stems from lack of evidence, not from the presence of falsifying evidence. You have no evidence supporting your claim of a "big problem with the theory." ================================ But is their even evidence that we have not discovered that proves abiogenesis. You can't claim that the evidence does exist somewhere, as it might not. What I am saying is that where did the first cells come from. How did the chemicals automatically join themselves in the precise way, how did the complexity of even a prokariotic cell evolve? Even prokaryotes have DNA in the nucleoid. And DNA is so precise, that it is hard to believe that it evolved naturally.
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peter borger Member (Idle past 7693 days) Posts: 965 From: australia Joined: |
Dear John,
I was under the impression that YOU were a skeptic. Apperently, you are only selectively skeptic. Sorry, but I am not like that. I am a real skeptic (as mentioned before), and I only believe what can be scientifically proven AND my own experiences. Best wishes,Peter
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thousands_not_billions Inactive Member |
==========================
hmmmm... I don't think the pairing up is much of a problem. They snap together like lego. ========================== Not quite as simple :-). True, the bases snap together, but if the wrong bases snap together, this causes all sorts of problems. There are four bases in DNA; cyosine, Adenine, guanine, and thymine. The adenine pairs up with the cyosine, and guanine pairs up with thymine. At least I think that's the way it goes. If the bases get out of wack, then the cell is mutated. ==================================more like RNA which is not a paired base molecule. ================================== True. But RNA is complex as well. It has all the bases of DNA, but has uracil instead of thymine. But, RNA, is transcribed from DNA, which means that DNA had to come first. ==================================It isn't matching the bases. In all sincerity, you aren't going to be able to make much of an argument until you up your basic knowledge of this sort of thing. ================================== I understand that my knowledge of biochemistry is fairly limited. I am 16 and have just finished the first year of biology, so I don't know everything. I signed up on the forums to engage in scientific discussion and to learn some things about science. Please bear with any scientific mistakes I make. I'm still learning. ;-) =======================You wouldn't start with cells, just bare molecules that happen to replicate themselves. It may sound strange but some molecules do replicate themselves. ======================= But where did the chemicals come from to form molecules. And wouldn't any molecules that did start to form in the "early earth" be destroyed by the harsh conditions? =========================I don't know that we can right now. We may never be able to prove it. But to insist that things 4 billion years ago are exactly what they are today is still unjustifiable. You are basically claiming that cells are the bottom line when in fact we don't know what the bottom line is. ========================= Which means that we probably never will know. I don't believe that things were the same 4 billion years ago, as I don't believe in the 4 billion years. I believe that things were the same 6000 years ago at Creation. ===============================Just curious, do you insist that everything be answered scientifically before you believe it? =============================== I want to have scientific evidence for most things. Some things I have to accept by faith, like Creation, which cannot be proven by science. But neither can evolution be proven by science. To clear up any missunderstanding, I have outlined by objections to the endosymbinot theory. I: How did the first prokaryotic cellular life form to swallow other cellular life? II: How did the DNA in the first prokaryote form? III: If a prokaryote ate another prokaryote, how could the internal prokaryote develop into mitochondria etc.? IV: The theory states that genomes from the captured prokaryote traveled to the nucleus which was formed by the captured prokaryote. How could they enter the nucleus, when only RNA can travel out through the nucleus and DNA cannot travel in? V: The host cell would destroy any DNA which would be passed to it from the host cell. Bacteria contain enzymes which destroy DNA.
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