Posted on 06/10/2007 10:30:58 PM PDT by Sleeping Beauty
Before life emerged on earth, either a primitive kind of metabolism or an RNA-like duplicating machinery must have set the stage – so experts believe. But what preceded these pre-life steps?
A pair of UCSF scientists has developed a model explaining how simple chemical and physical processes may have laid the foundation for life. Like all useful models, theirs can be tested, and they describe how this can be done. Their model is based on simple, well-known chemical and physical laws.
The basic idea is that simple principles of chemical interactions allow for a kind of natural selection on a micro scale: enzymes can cooperate and compete with each other in simple ways, leading to arrangements that can become stable, or “locked in,” says Ken Dill, PhD, senior author of the paper and professor of pharmaceutical chemistry at UCSF.
The scientists compare this chemical process of “search, selection, and memory” to another well-studied process: different rates of neuron firing in the brain lead to new connections between neurons and ultimately to the mature wiring pattern of the brain. Similarly, social ants first search randomly, then discover food, and finally build a short-term memory for the entire colony using chemical trails.
They also compare the chemical steps to Darwin’s principles of evolution: random selection of traits in different organisms, selection of the most adaptive traits, and then the inheritance of the traits best suited to the environment (and presumably the disappearance of those with less adaptive traits).
Like these more obvious processes, the chemical interactions in the model involve competition, cooperation, innovation and a preference for consistency, they say.
The model focuses on enzymes that function as catalysts – compounds that greatly speed up a reaction without themselves being changed in the process. Catalysts are very common in living systems as well as industrial processes. Many researchers believe the first primitive catalysts on earth were nothing more complicated than the surfaces of clays or other minerals.
In its simplest form, the model shows how two catalysts in a solution, A and B, each acting to catalyze a different reaction, could end up forming what the scientists call a complex, AB. The deciding factor is the relative concentration of their desired partners. The process could go like this: Catalyst A produces a chemical that catalyst B uses. Now, since B normally seeks out this chemical, sometimes B will be attracted to A -- if its desired chemical is not otherwise available nearby. As a result, A and B will come into proximity, forming a complex.
The word “complex” is key because it shows how simple chemical interactions, with few players, and following basic chemical laws, can lead to a novel combination of molecules of greater complexity. The emergence of complexity – whether in neuronal systems, social systems, or the evolution of life, or of the entire universe -- has long been a major puzzle, particularly in efforts to determine how life emerged.
Dill calls the chemical interactions “stochastic innovation” – suggesting that it involves both random (stochastic) interactions and the emergence of novel arrangements.
“A major question about life’s origins is how chemicals, which have no self-interest, became ‘biological’ -- driven to evolve by natural selection,” he says. “This simple model shows a plausible route to this type of complexity.” Dill is also a professor of biophysics and associate dean of research in the UCSF School of Pharmacy. He is a faculty affiliate at QB3, the California Institute for Quantitative Biomedical Research, headquartered at UCSF.
The research was supported by the National Science Foundation and the National Institutes of Health.
What do you think?
My guess would be a great big round rock.
I was hoping this was some sort of actual physical evidence of life on Earth Mark I.
Evidently not.
I have not read or heard of any evidence of life prior to the collision that created our moon.
Any suggestions here?
We know that the Earth and Moon are estimated to be 4.5 billion years old.
How long did the Earth exist prior to that collision?
Anyone know?
I think God said it and then it happened... His way. Life has since continued to unfold according to His plan.
...and God breathed...
Hmmm that science sound a hell of lot like act of faith ie... they dont know but "believe" & "it must have"
It may be proven true some day but science should never be so smug to say they don't engage in acts of "faith" geting there
ML/NJ
It’s life, Jim, but not as we know it.
The 2nd Law of Thermodynamics (not theory but Law) alone refutes idle speculation about self assembling and replicating and ever increasing complexity whether living or not.
Without WORK (energy) to offset increasing disorder you have eventual disorder (increasing entropy), disassembly, decay, in short, breakdown.
All of the Dawkins fans and Dawkins fellow travelers have to abrogate a proven Law of the Universe as step one.
Once you ignore a Law any speculation becomes possible however impossible said speculation is rendered by violating the second Law of Thermodynamics.
2nd Law of Thermodynamics : The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.
1) You have to have an ISOLATED SYSTEM... For all practical purposes a planet is not an "isolated system".
2) You have to have a system NOT in EQUILIBRIUM: A bowel of water & some chemicals (C, N, O, S, etc..) is stable to an outside observer.i.e. Throw some gun power into a bowel of water... What happens... So I'd read the research before being so dismissive & claiming that the 2nd Law is violated....
And yet those who argue self assmbly and increasing order argue both closed and open systems to avoid the 2nd Law—semantics in the end. You may exceed the speed limits posted but you may not argue the law.
The bowl you describe will disintegrate. The contents placed within will dissipate, putrefy, evaporate, and the residue will break down and oxidize.
Sounds like the missus after a night of mexican food...
Regardless of the misconceptions regarding the 2nd law of thermodynamics, the paper clearly states that the organization is dependent on a non-equilibrium state.
I know very little of this view. It is hard to imagine many sciences all jostling for the truth. It is hard to imagine science or truth without an everyday language to support it. It is hard to imagine anything without a language. And language too, apparently, comes from the id.
Linguists believe that the structure of language is embedded in the DNA. For example, all languages form sentences with subjects, verbs, and objects.
A headier subset of linguists believe that not only are languages embedded, but ideas, as well. As the language evolves, it gives rise to new “ideas.” They are released like bubbles — and form the basis of innovation. They trigger conscious evolution in groups of humans.
This is probably the same as your “id” idea, merely expressed using a different paradigm.
Your image of ideas as bubbles is like dreams released from the subconscious that bubble up through the floor boards of consciousness. I can see your comparison.
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Note: this topic is dated 6/10/2007. |
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