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Author | Topic: New abiogenesis news article 4/12/02 | |||||||||||||||||||||||
David unfamous Inactive Member |
It's fairly layman, but it may be of interest to someone here.
BBC NEWS | Science/Nature | Life 'began on the ocean floor'
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thousands_not_billions Inactive Member |
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----------------------------------------------------------- cell came first and was later filled with living molecules. ----------------------------------------------------------- Interesting idea, but where did the living molecules come from? The entire cell is alive. Even the outer membrane, the cellular wall, is a complex system of ion pumps, chlorine gates, and ID tags. How could this have evolved?
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John Inactive Member |
quote: It is really just chemistry. I think too many people get hung up on 'living' vs. 'non-living.' Ultimately, it is all made of the same atoms and molecules, all following the same rules. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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thousands_not_billions Inactive Member |
That's true John, good point :-) . But just think of the intricate machinary of the cell. You have power plants, garbage disposal systems, protein factories, ER, messenger cells, transportation systems, and much more. It seems fairly unlikely that all these would combine together in just the right way to create the cellular life. Anyway, that's my 2 cents. ;-)
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Primordial Egg Inactive Member |
quote: But why can't cells themselve evolve from simpler "stuff" .... eventually all the way back to very simple self-replicating molecules. Here's a nice article on the origins of life (RNA based), but you should note that there are still several competing theories (including autocatalytic systems - which I wish I understood ), most of which conjectural at present. PE
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John Inactive Member |
quote: Very little of which you actually need... at least is the form it currently exists. Open the hood of your car. Half of what is in there isn't necessary. That is, an engine can be built without many of those components or with more simple versions of some components. You have to think about such possibilities when you think about cell origins and complexity. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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thousands_not_billions Inactive Member |
quote: True, but those components are in the car for a purpose. They aren't in there to look good. If you remove them, the car will not be as efficient. The cell is far more complex then the car engine though. Remove the ribosomes, and no more protein is manufactured. Remove the ER, and there is no base for the ribosomes to rest on. Remove the cytoskeleton, and the cell cannot transport proteins. Remove the golgi complex, and no proteins can be packaged for transport. Remove the lysomes, and proteins cannot be recycled. Remove the cell membrane, and the cell ceases to exist. All of these components had to be there at once for the cell to function correctlly. {Fixed quote box - AM} [This message has been edited by Adminnemooseus, 01-16-2003]
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John Inactive Member |
quote: They are in that particular car for a purpose. You do not have to build a car with all of those components. That is the point. The first cars were much more simple but they worked. And before that the components themselves went from very simple to very complicated.
quote: They are there to make fixing ones car painful, but that is beside the point.
quote: So what? Who said it had to be?
quote: Not so. This is not the only possible way to synthesize a protein.
Much of the appeal of this hypothesis arises from the realization that RNA- enzymes (ribozymes) would have been far easier to duplicate than proteinaceous enzymes. Whereas coded protein replication requires numerous macromolecular components (including messenger RNAs, transfer RNAs, the ribosome, etc.), replication of a ribozyme requires only a single macromolecular activity: an RNA- dependent RNA polymerase that synthesizes first a complement, and then a copy of the ribozyme.
No webpage found at provided URL: http://scienceweek.com/sw021122.htm quote: But with no ribosomes, why need a perch for them?
quote: Prokaryotes have no cytoskeleton. They seem to do alright.
404
quote: Prokaryotes also do not have Golgi Complexes.
quote: Ditto. Prokaryotes don't have lysomes.
quote: Now you've found a good one. Cell membranes must have been a major milestone, but molecular replication does not require them. Somewhere around this point the line between living and non-living blurs. Like I said, it is all just chemistry anyway.
quote: Nope, not the case. I believe what I have posted is correct. If not, someone will correct me. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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thousands_not_billions Inactive Member |
Good point about the Prokaryotes John. But if the first cell was so simple, how did it evolve into a more complex cell? Evolution needs a lot of genetic information, which does not seem to arise by natural processes. Also, how did the RNA arise? You mentioned that it would not matter if a car was less efficient and that the first cars were quite simple. True, but intelligent design --in the form of people--designed more complex and more efficient cars. The simple cars didn't evolve into more complex models. Also, a less efficient cell or organism would be eliminated by natural selection, survival of the fittest. Hope I got this all right. ;-)
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John Inactive Member |
quote: quote: There is no clear answer to this right now, but there are answers to how some of the parts may have arose. Chloroplasts, for example, look to have been seperate organisms that developed a symbiotic relationship with another organism and eventually lost its ability to survive and reproduce outside its symbiotic partner. Mitochondria are the same. Look up endosymbiont theory.
quote: Organisms today carry enormous amounts of genetic informations, but todays organisms have had 4 billions years to accumulate such information. The first organism would not have had nearly as much information.
quote: It is just chemistry. I can't tell you how it arose. No one can right now. But all you need is a replicating molecule to get the system started. Given half a billion years in a warm chemical rich environment it isn't hard to imagine. Look up abiogenesis and RNA world.
quote: Right, because cars don't mate and make babies. It is an analogy to make a point.
quote: Leaving the more efficient molecules and cells behind. That is, leaving the cells we are familiar with today, 3.5-4 billion years later. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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thousands_not_billions Inactive Member |
quote: There are many problems with the endosymbiont theory. A good look at them is found at http://aig.gospelcom.net/docs2/4341_endosymbiont.asp Hope this helps. :-)
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Coragyps Member (Idle past 756 days) Posts: 5553 From: Snyder, Texas, USA Joined: |
Wow! That little piece is remarkably free of any real content, even for a Batten article! I don't really even follow the happenings in endosymbiont research, and I've seen four or five papers in Science in the last couple of years showing findings that are pretty hard to explain in some other way. Why, for example, do mitochondria have a double-thick membrane, if not that the inner one was "theirs" and the outer one that from the vacuole that took the first one in? Why do chloroplasts look so much like cyanobacteria at a molecular level?
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John Inactive Member |
quote: coragyps is right. There isn't much on that page that can be called information. Take this for example.
For example, how could the enveloped cells reproduce in close synchronicity? The implication is that enveloped cells can't reproduce in sync with their hosts. The problem is that hundreds of modern parasites and symbionts do just that. The question is vacuous. Or this.
How did lateral gene transfer into the nucleus take place when the nuclear membrane is designed for the passage of mRNA (out), and to contain DNA? Remember the prokaryotes? There is no nuclear membrane with which to contend. Or this.
If DNA were passed between the engulfed cell and the host cell, would not the host respond by degrading the foreign DNA, because it would detect it as a virus? Are not modern symbionts and parasites successful at avoiding the immune systems of the hosts? Again, only a smidgen of common sense shows how vacuous this is. Then there is this dramatic conclusion.
Furthermore, they have the same Designer! I almost missed it as it came from nowhere and there is no attempt to support the claim. This is simply a lie.
The endosymbiont idea was severely dealt with in the 70s and early 80s, and should have died. The idea is quite strong and genetic evidence is making the case stronger as time passes. Try again my friend. ------------------
No webpage found at provided URL: www.hells-handmaiden.com {Fixed 1 shaded quote box - Adminnemooseus} [This message has been edited by Adminnemooseus, 01-12-2003]
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thousands_not_billions Inactive Member |
Here is another website about the issue. The endosymboint theory seems to state that prokaryotes were ingested by other species to form eukaryotic cells. Am I right? ;-)
http://www.freenet.edmonton.ab.ca/...te/articles/eukary.html
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John Inactive Member |
quote: Yeah, something like that. This site also is pretty much devoid of real information. It sounds harsh but don't read creationist sites. They are nothing but propaganda. The arguments contained essentially assume that the original eukaryotes are just like modern ones. This assumption is absurd. Try reading these:
No webpage found at provided URL: http://www.msu.edu/course/lbs/145/luckie/margulis.html No webpage found at provided URL: http://www.geocities.com/jjmohn/endosymbiosis.htm Also, look up Paramecium bursaria. It is a modern organism in just the sort of symbiotic relationship with another organism that endosymbiosis proposes. ------------------
No webpage found at provided URL: www.hells-handmaiden.com
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