Posted on 06/17/2002 4:40:34 PM PDT by Nebullis
CHAMPAIGN, Ill. — Life did not begin with one primordial cell. Instead, there were initially at least three simple types of loosely constructed cellular organizations. They swam in a pool of genes, evolving in a communal way that aided one another in bootstrapping into the three distinct types of cells by sharing their evolutionary inventions.
The driving force in evolving cellular life on Earth, says Carl Woese, a microbiologist at the University of Illinois at Urbana-Champaign, has been horizontal gene transfer, in which the acquisition of alien cellular components, including genes and proteins, work to promote the evolution of recipient cellular entities.
Woese presents his theory of cellular evolution, which challenges long-held traditions and beliefs of biologists, in the June 18 issue of the Proceedings of the National Academy of Sciences.
Cellular evolution, he argues, began in a communal environment in which the loosely organized cells took shape through extensive horizontal gene transfer. Such a transfer previously had been recognized as having a minor role in evolution, but the arrival of microbial genomics, Woese says, is shedding a more accurate light. Horizontal gene transfer, he argues, has the capacity to rework entire genomes. With simple primitive entities this process can "completely erase an organismal genealogical trace."
His theory challenges the longstanding Darwinian assumption known as the Doctrine of Common Descent – that all life on Earth has descended from one original primordial form.
"We cannot expect to explain cellular evolution if we stay locked in the classical Darwinian mode of thinking," Woese said. "The time has come for biology to go beyond the Doctrine of Common Descent."
"Neither it nor any variation of it can capture the tenor, the dynamic, the essence of the evolutionary process that spawned cellular organization," Woese wrote in his paper.
Going against traditional thinking is not new to Woese, a recipient of the National Medal of Science (2000), and holder of the Stanley O. Ikenberry Endowed Chair at Illinois.
In the late 1970s Woese identified the Archaea, a group of microorganisms that thrive primarily in extremely harsh environments, as a separate life form from the planet’s two long-accepted lines – the typical bacteria and the eukaryotes (creatures like animals, plants, fungi and certain unicellular organisms, whose cells have a visible nucleus). His discovery eventually led to a revision of biology books around the world.
The three primary divisions of life now comprise the familiar bacteria and eukaryotes, along with the Archaea. Woese argues that these three life forms evolved separately but exchanged genes, which he refers to as inventions, along the way. He rejects the widely held notion that endosymbiosis (which led to chloroplasts and mitochondria) was the driving force in the evolution of the eukaryotic cell itself or that it was a determining factor in cellular evolution, because that approach assumes a beginning with fully evolved cells.
His theory follows years of analysis of the Archaea and a comparison with bacterial and eukaryote cell lines.
"The individual cell designs that evolved in this way are nevertheless fundamentally distinct, because the initial conditions in each case are somewhat different," Woese wrote in his introduction. "As a cell design becomes more complex and interconnected a critical point is reached where a more integrated cellular organization emerges, and vertically generated novelty can and does assume greater importance."
Woese calls this critical point in a cell’s evolutionary course the Darwinian Threshold, a time when a genealogical trail, or the origin of a species, begins. From this point forward, only relatively minor changes can occur in the evolution of the organization of a given type of cell.
To understand cellular evolution, one must go back beyond the Darwinian Threshold, Woese said.
His argument is built around evidence "from the three main cellular information processing systems" – translation, transcription and replication – and he suggests that cellular evolution progressed in that order, with translation leading the way.
The pivotal development in the evolution of modern protein-based cells, Woese said, was the invention of symbolic representation on the molecular level – that is, the capacity to "translate" nucleic acid sequence into amino acid sequence.
Human language is another example of the evolutionary potential of symbolic representation, he argues. "It has set Homo sapiens entirely apart from its (otherwise very close) primitive relatives, and it is bringing forth a new level of biological organization," Woese wrote.
The advent of translation, he said, caused various archaic nucleic-based entities to begin changing into proteinaceous ones, emerging as forerunners of modern cells as genes and other individual components were exchanged among them. The three modern types of cellular organization represent a mosaic of relationships: In some ways one pair of them will appear highly similar; in others a different pair will.
This, Woese said, is exactly what would be expected had they individually begun as distinct entities, but during their subsequent evolutions they had engaged in genetic cross-talk – they had indulged in a commerce of genes.
Kindly submit your proof that "you have to be alive to replicate." The self-recreating figures of the game of Life will be fascinated to hear about this, as will soap bubbles and various anodic/cathodic crystal formations.
BTW speaking of proof - when you are you going to tell us one of the 'many scientific hypothesis' of evolution?
Sigh. Ever the burnt hand goes wandering back to the fire.
For about the billionth time, abiogensis has not remotely satisfied any of the standard criteria for being a scientific hypothesis--it is just an hypothesis, and evolutionary theory does not rise or fall with it, even if you hold your breath until you turn blue.
And, for about the 2 billionth time, there is no such thing as proof in natural sciences.
I'm going to start ignoring you if can't do anything but recycle old junk we've been over already. I have a life, you know.
You mean, like a retro-virus does, for example.
I have asked you before not to put words in my mouth, now I'm asking you not to put thoughts in my head. You haven't the displayed competency for this task. I cannot imagine how you think plug-ins have squat to do with this discussion.
You cannot turn compressing the storage of the DNA into programming by simply re-iterating the assertion until everyone is too exhausted to care. It is not programming; it is not anything clearly analogous to programming in the biological world; and even if it were programming, I still failed to see your proof, or any response to my counterexamples to suggest why I should assume signs of programming prove the existence of a Mighty Programmer.
You have not responded to my post explaining to you why DNA is not a program; you have not responded to my request for an explanation of the immune system in the face of your thesis, and you just go blithly on with this thesis as if you were arguing in a vacuum.
This thrust in your argument can now, I feel, with justification, be regarded as total vacuous blather, which you refuse to defend, except by constant repetition. I believe you have now strained my patience enough for a day. Have a good evening.
We have been over this territory easily a dozen times on various threads, Including extensively over questions pertaining to viri. There are dozens of extant theories about various stages of life. Oparin's bubbles&mud thesis, published in the 30's, was probably the earliest extensively worked out thesis. I've discussed Kaufmann's thesis with you, I've discussed Hoyle's thesis, I've discussed Dyson's theory, I've discussed Wolfram's thesis, and I've advanced several of my very own theses here, between the 9th and 16th continuations of this long-winded thread which I've pointed out to you at least twice that I remember.
Confident bluster is not the same thing as actually arguing, you know. Actual arguing involves a certain rudimentary principal of charity whereby the arguer might assume that his interlocutor is actually marginally paying some tiny whiff of pretended attention to what he says.
You are trying to say that materialism is true because you deny that any other explanation is possible.
Holy pig drool! Can you not read at all? That is precisely NOT what I just said. I just said science is unequipped to have an opinion about materialism. In plain english which you copied, I might add. My advice? Stop. Get some sleep. Come back when you can behave with some measure of rhetorical competence and decent respect for the efforts others.
Sorry, I cannot waste my time. I thought you were interested in an intelligent discussion, but obviously you are not.
Sorry, I cannot waste my time. I thought you were interested in an intelligent discussion, but obviously you are not.
I am only interested in discussing things with people who respond in some meaningful way to my responses. I'll repeat my response since you accidently failed to notice it, apparently. How are the self-recreating entities in the game of Life not self-replicating? How is it that bubbles are not self-replicating? Have you never observed a bubble popping and leaving behind several smaller bubbles? How is it that anodic/cathodic crystal structures are not self-replicating?
Or, for that matter, and rather relevant to the argument--how is it that adiabatic chemical cycles loosely embedded in a dynamic physical matrix, such as a whirlpool, are not self-replicating?
As usual, you end a discussion by declaring yourself the winner and making for the exits with unseemly haste.
Apparently, you forgot to submit the proof I asked for, as it remains entirely un-obvious to me. It is no more obvious that there could be only be "one way for life to come to be", or an infinite number of ways life might have come to be.
Nothing in modern science or mathematics suggests why I should prefer either of these two conjectures over the other.
At time A there was no life. At time B, which came after time A, there was life. Whether brought here on a meteor or homegrown right here on good ole' planet Earth, there's only one way life could have come about- naturally.
Ah, that's a good trick. You establish the (as yet abstract and unstated) criteria for life, and than declare anything that proceeds it non-life, and hope everyone draws a mental picture of two bricks trying to mate.
A popular song with the creationist choir, but holds no water with those who prefer to look at the theses that are actually on the table. Whatever your criteria for "life" is, there could have been something almost like "life" which was self-replicating, and proceeded it.
Nothing. In a precise, finite, clockwork universe such as we thought we had in the 16th century. In a precise, finite clocklike universe, you can, in theory, write closure on all the entire possibilities in the universe, and thereby establish a field of discourse in which it is statistically meaningful to suggest that failure to discover an event up until now, somehow makes it's supposed obverse more likely.
In our universe, however, it is just a rough and ready perception, which science leans heavily on, and which is intractably subject to error.
And, as I have been trying to point out--this particular thesis is a special case, in that science is not designed to cope with it, whether it is true or not.
And that brings us to the two points I was trying to make previously:
1) There are a number of questions in the material realm that would come up immediately, for example, does God have to operate within the realm of physical law to create life? Can God ignore, for example, the Heisenberg Uncertainty principal in creating life? If not, would it be safer for men to worship such a creature, or hunt Him down before he makes another equally capricious decision to do away with this "life" experiment?
2) No, your contention notwithstanding, science would NOT proceed as usual, should science return to theistic secular dominance. We have plenty of historical evidence to tell us that the most immediate results would be just as chilling as Galileo's trial. The certain knowledge of God's existence will be accompanied by the certain knowledge that theists know best what we should think and feel about God. And we have seen where that leads often enough that you should know better than to advance such a claim.
and the difference between self-assembly and self-replication would be what, exactly?
Thanks for proving my point.
You have no point, just the vague hope that being an inexhaustable word-lawyer will somehow make the unlikely case that there is one and only one possible way for life to arise--by the spontaneous jumping together of a prokariote from raw parts--a totally unlikely creationist strawman--not a case that science is trying to make.
Ah, another self-declared argument winner. How persuasive.
I'm glad to see you've resorted to calling me a "Creationist". How boring.
I did not call you a creationist, I referred to creationist arguments. I don't give a fart in a hurricane what you are, when you advance a creationist argument, I intend to respond to it in the same manner as I would for a self-professed creationist. As with your definitional nit-picking, this is another zero-octane argument over irrelevancies.
Next, quote for me just one single thing I've said that implies that I am a "Creationist".
Get off your throne and get into the game--nobody cares if you are a "creationist" or not.
On second thought, don't bother. I'm done trying to have an intelligent discussion with you.
I have reviewed your contributions to this discussion, which consist of a handful of sentences mostly featuring your compulsive self-absorption about whether or not you are a creationist. The reason you are done trying to have an intelligent discussion with me is that you never bothered to try.
Apparently, you forgot to answer my question in your eagerness to let us all know what it is you aren't. So I'll repeat it so you can remedy this oversight.
...and the difference between self-assembly and self-replication would be what, exactly?
Science barely knows anything about this subject, and here you are claiming all the work is done and we can all go home.
Science knows nothing about viruses? How ridiculous can you be? The US government is spending some 5 billion a year...
Ah! Then it should be trivial to explain something basis, like say, where viruses come from? Go ahead.
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