This post is from here via Uncommon Descent
Proteins consist of a long sequence of amino acids and those amino acids are supplied by the so-called transfer RNA, or tRNA, molecules.
The tRNA molecules, in turn, are loaded with the right amino acid by the so-called aminoacyl-transfer RNA synthetases, or aaRS, proteins. There are several different versions of aaRS proteins, which load the different tRNA molecules with the different kinds of amino acids. These aaRS proteins hang around the ribosome where proteins are constructed. But as I discussed in the previous post, the lysine aaRS, also known as LysRS, has an interesting dual role. Normally it hangs around the ribosome where it binds to another LysRS to form what is known as a dimer. In this dimer configuration, there is a weak binding between (i) the 207th amino acid (a serine) of one of the LysRS proteins and (ii) the 540th and 541st amino acids (a glycine and a leucine, respectively) of the other LysRS protein. The serine side chain consists of a hydroxyl group attached to a methyl group and when the 207th amino acid’s hydroxyl group is phosphorylated (the hydrogen is replaced by a phosphate group), its binding to the opposing 540th and 541st amino acids is broken. Not surprisingly this allows the serine dimer to loosen. But this is only the beginning of a series of events caused by the phosphorylation of that serine. The serine molecules move away from the ribosome, enter the cell’s nucleus, interact with a DNA transcription factor causing (i) the production of a signaling molecule, diadenosine tetraphosphate, (ii) release of one of the transcription factor’s proteins and (iii) expression of the transcription factor’s target genes. Simply put, depending on the phosphorylation state of its 207th amino acid, LysRS has two different structural and functional states. When not phosphorylated LysRS is a crucial part of the translation process, supplying lysine amino acids to tRNA molecules. When phosphorylated it regulates gene expression. This is a major problem for evolutionary theory.
The dual role of LysRS is not viewed as a challenge to evolutionary theory by evolutionists. This is not because evolutionary theory predicts or easily accommodates this finding, but rather because evolutionists assume evolution to be true to begin with, so there can be no real challenges, only unsolved research problems.
In fact, evolutionists have accepted so many contradictions and false predictions that new contradictions have little impact. Evolutionists simply make vague speculations and move on.
But the dual role of LysRS is not easily accommodated by evolutionary theory. In fact, it is a major challenge. This is because evolution calls for a gradual buildup of functionality. New designs do not simply appear out of nowhere. Instead, rudimentary capability is supposed to have slowly been refined by chance events such as DNA mutations.
This makes the evolution of molecular machinery and processes—such as proteins and protein synthesis—not likely without a multiverse to provide a near infinite number of tries.
But ignoring such problems and assuming that proteins and processes could somehow evolve, evolutionists must now believe that random mutations and natural selection simultaneously evolved LysRS for two completely different functions.
LysRS must have had rudimentary capabilities in both translation and transcription, and both capabilities must have been refined by evolution. The phosphorylation of that key serine must have just happened to arise. The transport of LysRS from nearby the ribosome to inside the cell nucleus must have just happened to arise. And the transcription functions of LysRS must have been refined.
All of this while LysRS was refining its translation function. We don’t have scientific evidence for the evolution of these designs, but the point here is that now we must imagine two such refinements, for two different functions, evolving simultaneously.
Or evolutionists could say LysRS evolved only for its translation function, and it just so happened that its design also fulfilled a crucial transcription function as well. It was a lucky strike. And so was the phosphorylation capability of the key amino acid just at times when it was needed.
Now none of this can be proved to be impossible. And perhaps all of this did occur somehow. But the science that we currently have does not indicate this. What we know at this time tells us that the evolution of biological machines, such as LysRS and its surrounding cellular context is, far from a fact. If we are looking for scientific facts to proclaim, the fact is evolution is unlikely.
Simply put, evolution either must have evolved two independent designs simultaneously in the same protein, or it must have been a two-fer, evolving the one design and getting the second for free. Either way the evidence does not bode well for evolution.
We can argue that the metaphysics requires evolution to be true. Or we can argue that all will be well in the future when evolution is vindicated by findings yet to come. But these are not scientific arguments.
From a scientific perspective, evolution is a deeply flawed idea. People believe it is true, and their beliefs should be respected. And who knows, perhaps future discoveries will point to evolution. But for now, gene sharing findings such as with LysRS continue to add yet more scientific problems for the theory.
20 comments:
- For goodness sakes, that a molecule has one function, and a secondary (10^? years later, and in which organisms?) function becomes a problem, as "Evolve(ing) Different Functions Simultaneously" is too improbable?Reply
As I said, “The dual role of LysRS is not viewed as a challenge to evolutionary theory by evolutionists. This is not because evolutionary theory predicts or easily accommodates this finding, but rather because evolutionists assume evolution to be true to begin with, so there can be no real challenges, only unsolved research problems.”
You believe that protein evolution is not a problem, in spite of the facts. So it is not surprising that dual function is not a problem for you. But whether LysRS evolved its two functions simultaneously or in series, the evolutionary search becomes that much more unlikely. If in series, for example, you have a mature protein with an important function. It is likely that more than a few mutations are not well tolerated as function falls off rapidly. So the purefying selection greatly complicates the search for the second function. And if it was the case that only a few mutations would have been required, then evolution got lucky. Another case of evolutionary serendipity. - "But whether LysRS evolved its two functions simultaneously or in series, the evolutionary search..."Reply
"Now Evolution Must Have Evolved Different Functions Simultaneously in the Same Protein"
So you are unsure whether LysRS evolved its two functions simultaneously or in series, but you title the post "Evolution Must Have Evolved Different Functions Simultaneously in the Same Protein?"
Nice.
- Active barnase variants with completely random hydrophobic cores.Reply
Axe DD, Foster NW, Fersht AR.
Proc Natl Acad Sci U S A. 1996 May 28;93(11):5590-4.
Atypical? Or well supported empirical result?
- No response to my first question: can you reference the evidence that "Evolution Must Have Evolved Different Functions Simultaneously" re: LysRS?Reply
http://darwins-god.blogspot.com/2012/12/now-evolution-must-have-evolved.html?showComment=1354421549847#c8191811156858130424
Yeah, I've been here for the whole comment thread. Still missing your proof that the functions evolved simultaneously.
- When reading this blog, UD, or anything from the DI it's good to keep in mind the prophetic words of professional educator William J. Bennetta:Reply
"In all of these efforts [to push Creationism], the creationists make abundant use of a simple tactic: They lie. They lie continually, they lie prodigiously, and they lie because they must."
- I think that Bennetta's words apply to evolution's religious adherents such as yourself, Thorton. Though of course, if I repeat his words that would constitute an ad hom, which implies I have no valid argument to present :-PReply
(Cornelius should remove both our comments since neither is addressing the topic of the post) - Dale, Thorton has a strategy. He knows there is no evidence for UCA, much less for naturalistic UCA. But he doesn't like to see the scam exposed for what it is. So he purposely blogs in a way that will tempt CH to shut off the blogging again.
Good call, Thorton. I would want the blogging shut down too if I were you. ;)
How many years of evolution before the nucleus emerges George?
Please.
For goodness sakes, that a molecule has one function, and a secondary (10^? years later, and in which organisms?) function becomes a problem, as "Evolve(ing) Different Functions Simultaneously" is too improbable?