Posted on 03/05/2009 6:22:06 AM PST by SeekAndFind
ScienceDaily (Mar. 3, 2009) — As the world marks the 200th anniversary of Charles Darwin's birth, there is much focus on evolution in animals and plants. But new research shows that for the countless billions of tiniest creatures – microbes – large-scale evolution was completed 2.5 billion years ago.
"For microbes, it appears that almost all of their major evolution took place before we have any record of them, way back in the dark mists of prehistory," said Roger Buick, a University of Washington paleontologist and astrobiologist.
All living organisms need nitrogen, a basic component of amino acids and proteins. But for atmospheric nitrogen to be usable, it must be "fixed," or converted to a biologically useful form. Some microbes turn atmospheric nitrogen into ammonia, a form in which the nitrogen can be easily absorbed by other organisms.
But the new research shows that about 2.5 billion years ago some microbes evolved that could carry the process a step further, adding oxygen to the ammonia to produce nitrate, which also can be used by organisms. That was the beginning of what today is known as the aerobic nitrogen cycle.
The microbes that accomplished that feat are on the last, or terminal, branches of the bacteria and archaea domains of the so-called tree of life, and they are the only microbes capable of carrying out the step of adding oxygen to ammonia.
The fact that they are on those terminal branches indicates that large-scale evolution of bacteria and archaea was complete about 2.5 billion years ago, Buick said.
"Countless bacteria and archaea species have evolved since then, but the major branches have held," said Buick, a UW professor of Earth and space sciences.
(Excerpt) Read more at sciencedaily.com ...
Translation: “We have no evidence of the evolution of these microbes.”
Read the article, not just the excerpt.
I kind of think it’s a no-brainer that where ther is life, there is interaction and change within the enviroment it lives in. It may cycle within a band of variation, but life impacts it’s enviroment.
Can’t be true. Stone Age literature says so.
If it didn’t involve one man, one rib-origin woman and a talking snake, I ain’t buyin’ it.
why screw around with “billions of years”? Go directly to trillions or zillions. With enough time leftist darwinians can construct a liberal president out of the “primordial slime!”
Well, if *anyone* came from the primordial slime ...
Or to put it another way, if life had spontaneously evolved on some ancient beach, and conveniently had reproductive capabilities, it would simply have drowned in its own waste after covering the planet.
I found the statement fascinating for a different reason.
“. . . way back in the dark mists of prehistory.” Since “prehistory” in part ended perhaps 7,000 years ago (being very generous), stating it was from the “dark mists of prehistory” when referring to some alleged event *billions* of years ago is just silly.
It seems to imply that historical periods began sooner (exponentially sooner) than they did. Stating something billions of years ago is prehistoric is like saying, “The Pope, a person who tends to believe in some Roman Catholic ideas . . .”
INTREP
Once you find something that works really well you stick with it.
We can tell that bacteria have evolved by evidence of common descent. And we can tell that bacteria DO evolve by studying them in the lab.
Evolution can only occur in single mutational steps (for macroscopic life) or two mutations at once (for bacteria life, with its larger populations and rapid generation times). This eliminates it as a cause for more complex systems that require simultaneous formation of many elements (such as an eye/eyespot that to be functional requires not just the eye itself but also nerves and a brain wired to make use of the information coming from the eye.)
The similarities found across life are indeed evidence of unity - just as the similarities in objects designed by a single designer are evidence of unity. Instead of common physical descent they are better understood as evidence of common conceptual descent, from a single creator.
Evolution can take place by single, double, triple and quadruple mutations. An eye can easily develop from a photosensitive patch to an eye spot to a concave eye spot to an enclosed eye. These links are not even “missing” but living among us.
Nylon digestion is a novel feature that bacteria evolved by several mutations of an esterase enzyme.
Citrate digestion in e.coli evolved in an experimental population by means of multiple mutations.
If you look to Dr. Behe as a source I must first warn you that he accepts the ancient age of the earth, the common descent of all species, and all the evidence that supports both. I must also warn you that Behe’s “irreducible complexity” was laughably demolished as a principle on Behe’s flagship example.
You made an interesting statement that evolution can take place with up to quadruple mutations. I assume you mean 4 mutations taking place simultaneously to produce a beneficial result. I'm not familiar with such a claim and would appreciate documentation (not to mention a theoretical explanation of how such an astronomically unlikely occurence could even happen and yield a phylogenetically meaningful result).
If you would read Behe (and others like Dr. Lee Spetner), instead of only his critics, you would know that nylon digestion and citrate digestion fit within his 'edge' of evolution and are basically degenerative mutations that enable metabolism of these substances only by breaking down a previously more specific and complex metabolic process. Kind of like kicking down a door allows anyone entry, instead of just people with a key. It doesn't explain how the door and lock appeared in the first place.
This has been a common weakness of Darwinian apologetics in the last generation - beneficial mutations that are beneficial only because of fluke side effects to biologically damaging mutations only emphasize that life is on a degenerative trend, consistent with creation but inconsistent with evolutionary models. Take a look at claims of beneficial mutations by Darwinists, and anti-evolutionary discussions of those mutations (which are invariably more detailed than the superficial treatments of Darwinists) and you will soon see what I mean.
Rather than refusing to believe in a self-evident concept like IR (which Darwin himself believed, as is evident from his famous comment that his theory _requires_ gradual evolutionary pathways or it "breaks down"), evolutionists should accept it, confident that they can show that all biological phenomena fit within the limitations imposed by IR. This would be strong evidence that life is purely naturalistic in origin. The failure to do so, indeed the hostility to even looking at the evidence from this perspective and the emotional response to it, underscores the failure of Darwinism to come to grips with modern science.
I see that you have a “beneficial mutations are degenerative” stance. Sort of a “heads I win, tails you lose” proposition. A lot more logical than the claim that there are no beneficial mutations, but still steaming load of bovine excrement. There was nothing degenerative about the newfound ability of a bacteria to digest nylon. The ability to digest esters, which the enzyme originally did, was not lost, as it was and remains present on a plasmid in as many copies as the bacteria has need of.
There is nothing “self evident” about “irreducible complexity”, just a simplistic mindset that “it looks hard, God must have done it by means of magic rather than reliance upon natural and predictable phenomena”.
A problem with your philosophical prejudice is that you have no consistent means of distinguishing between intelligent causes and natural causes, if you are consistent. For example, consider a future plague released by unknown terrorists who have secretly bioengineered a microbe. In your religious worldview you have to automatically discount the possibility that an unknown intelligent agent is at work, so matter how obvious that conclusion might be to those of us who are not wearing blinders.
Saying "God did it" about everything and ignoring natural law is scientifically ignorant and stupid. But it is equally scientifically ignorant and stupid to say "nature did it" with equal dogmatism. Science tells us what nature cannot do just as it tells us what natural processes can do. What ID advocates and other non-Darwinian fundamentalists are doing is working out rigorous tools to identify what is the product of chance, natural law, and intelligent design. There will be mistakes in this effort as in any other endeavor, but that is better than an ignorant and fanatical dogmatism.
A few seconds with google will give you responses to the challenges you present, such as Dr. Behe's response to the secretory system claim. But if you aren't prepared to consider them evenhandedly there is little point in my taking the effort to present them.
Sorry but that is just laughable and another case of your “heads I win, tails you lose” mindset. You say that there are no beneficial mutations just degenerative ones, and that they cannot take place by subsequent accumulation of mutations. I point out an example of a beneficial mutation that is not at all degenerative and took place by accumulation of several mutations; and your lame excuse was that the bacteria was “pre adapted” to be able to digest nylon.
All living organisms are “pre adapted” to being able to change its DNA and the resulting proteins they code for, and organisms are “pre adapted” to being able to allow for natural selection to act upon these genetic variations.
Behe’s claim was that a flagella was irreducibly complex. He defined irreducibly complex as that none of the working parts had function without all the others. That is clearly not the case with a flagellum as several of the parts work just fine without the other parts, they work as a type II secretory system. I really don't care how he excuses himself his error or hand waves away the error. His claim was laughably inept.
If I take an engine out of a car, the car still functions as a very large paperweight. You will always be able to define a subset of a functional system as having some other function if you try hard enough. Behe has always acknowledged that IR did not address substitionary pathways, though he does caution against flippantly assuming that any given substitionary model is plausible.
There are several problems with such a model. For one, evolution of a secretory system should drive it to be a better secretory system, not something else.
Even if a single mutation could cause it to immediately become a flagellum, the new structure would have to be integrated into the cell in a beneficial manner. That means command and control systems to direct the action of the flagellum, and sensors to determine when and how to activate the flagellum, at a minimum. It goes back to the realization that single point mutations are not going to bridge the gap required to integrate any new functionality, even should it come into existence.
Besides, you are fighting the last war. In the Edge of Evolution Behe introduces the tools to identify the limits to evolutionary modeling at a much more refined level than IR. The silly thing is that his assertions about single and double mutation limits correspond to what evolutionary scientists themselves have been saying for decades, as is his discussion of rugged morphospace and the tendency for evolutionary pathways to wind up in dead ends. But somehow accepting those conclusions at face value is not OK when a non-evolutionist says them.
Behe also acknowledges the ancient age of the earth and the strength of the data for common descent. Amazing that you take him as such an authority on what you agree with him on (the supposed implausibility of evolution to actually accomplish novel biological features), but completely ignore him about common descent and the age of the Earth.
I see you no longer wish to discuss how nylon digestion was degenerative, or how one would distinguish what was “pre adapted” from what is an actual novel use of a mutated protein, other than that if it is a novel use then, by your definition it by necessity was “pre adapted”.
DNA is impossible to keep exactly the same generation to generation.
DNA change introduces novel genetic variations.
Novel genetic variations are subject to natural selection due to the disparate reproductive success of differing genetic variations.
Novel genetic variations are not “degenerative”.
All living systems are “pre adapted” to changing DNA and natural selection of the resulting genetic variation.
Novel adaptations like citrate digestion in e.coli and nylon digestion bacteria are not degenerative or “irreducibly complex”. They are fully explainable by the mechanism of mutation creating genetic variations and natural selection acting upon those variations.
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