Posted: Jul 06, 2010 6:13 am
CharlieM wrote:Quite right, tinkering with one protein on the path affects the whole system. Its a bit like a Rubic cube only vastly more complicated. I'd say beyond the capabilities of unguided forces.
You'd say that, with nothing to back it up. In other words an ex recto assertion.
Did you completely ignore the hemoglobin example provided to you? Turns out "unguided forces" work pretty well.
CharlieM wrote:Protein homologues give us a clue that the proteins are related and were possibly derived from the same source. I have been told constantly that the path is too complex to work out. So how do we know that naturalistic evolution is the means by which the path is crossed or is even capable of negotiating that path?
Because we constantly observe naturalistic evolution work in the laboratory without the aid of your god. Because no single line of evidence for evolution stands on it's own. Because it all fits together and your theological wishthinking is making you deny the obvious.
CharlieM wrote:Must I just take it on faith? Just because we observe mutations/duplications/shufflings does not mean that they are unguided.
Are you fucking kidding me? Am I supposed to believe that it makes MORE sense that an invisible, immaterial mind, "wills" the nucleotides into position?
CharlieM wrote:If DNA replication is the result of an accident where did the error correcting mechanism come from?
Is this question supposed to cast doubt on the entirety of evolutionary science? Are you honestly making a god-of-the-gaps argument?(yes, you are) Can you possibly shovel any more fallacies into one single question?
By the way, you do realize that we have successfully evolved the DNA replication mechanism in the lab, right? What I mean is that the DNA copying-fidelity mechanism is itself an evolvable entity. That means we took an enzyme that copies DNA, and then let it make a lot of copies. We then selected the enzymes that had mutated in such a way that they made less copying mistakes, had higher thermostability and a number of other positive side effects.
Directed evolution of polymerase function by compartmentalized self-replication
http://www.pnas.org/content/98/8/4552.full Full paper.
Abstract
We describe compartmentalized self-replication (CSR), a strategy for the directed evolution of enzymes, especially olymerases. CSR is based on a simple feedback loop consisting of a polymerase that replicates only its own encoding gene. Compartmentalization serves to isolate individual self-replication reactions from each other. In such a system, adaptive gains directly (and proportionally) translate into genetic amplification of the encoding gene. CSR has applications in the evolution of polymerases with novel and useful properties. By using three cycles of CSR, we obtained variants of Taq DNA polymerase with 11-fold higher thermostability than the wild-type enzyme or with a >130-fold increased resistance to the potent inhibitor heparin. Insertion of an extra stage into the CSR cycle before the polymerase reaction allows its application to enzymes other than polymerases. We show that nucleoside diphosphate kinase and Taq polymerase can form such a cooperative CSR cycle based on reciprocal catalysis, whereby nucleoside diphosphate kinase produces the substrates required for the replication of its own gene. We also find that in CSR the polymerase genes themselves evolve toward more efficient replication. Thus, polymerase genes and their encoded polypeptides cooperate to maximize postselection copy number. CSR should prove useful for the directed evolution of enzymes, particularly DNA or RNA polymerases, as well as for the design and study of in vitro self-replicating systems mimicking prebiotic evolution and viral replication.
So, was god hiding the the lab and tingling with the mutations?
CharlieM wrote:Pierre Paul-Grassé:
In sum the mutations of bacteria and viruses are merely hereditary fluctuations around a median position; a swing to the right, a swing to the left, but no final evolutionary effect.
How nice of you to quote a dead zoologist and believer in Lamarckian evolution. "The enemy of my enemy is my friend"... or what? So you quote him because he agreed with you or because you believe in Lamarckian evolution too?
In any case, his assertion is factually incorrect. As the several peer reviewed papers linked in this very thread already demonstrate beyond doubt for any rational sane person.
CharlieM wrote:The amino acid sequence of FlgE is far longer than its homologs and so gene duplication and joining is the proposed path in its development. This involves more than a single step so I'd be surprised if anyone believed that a sequence of functional proteins in single steps occurred.
You have anything to back up this claim other than a mere assertion? Got any research? It's funny how you first use the fact that noone knows the intermediates as an argument against evolution. But you aren't afraid to go speculate on it yourself when you think it can support your position. A double standard there or what?
CharlieM wrote:Well Matzke proposed the path so ask him. Although the search space that naturalistic evolution needs to sample is so large that it would indeed take a supercomputer to find a way through.
You keep talking about this "search space" that needs to be "sampled". What does that even mean? Please elaborate on it.
CharlieM wrote:Why? With the flagellum we have a novel structure with a new function, with the others we don't, unless you want to stretch the definition of, "function".
Yes but the flagellum was build by fitting existing stuff together and letting them evolve further for superior function in their new unit
CharlieM wrote:And besides that is not what I'm arguing against.
Uhh, yes it is. You have done nothing else than assert that the evolution of the flagellum was too impropable to have happened by chance. You have even asserted that it must have been planned by god.
CharlieM wrote:Not exactly. This is the evidence I have been presented with. This to me only demonstrates the plasticity of types to adapt to their environment.
Your claim was that beneficial evolutionary change was too impropable to happen by chance and therefore had to be guided. The evidence provided refutes this claim. You now move the goalposts and again just asserts out of thin air, based entirely on an emotional position brought forth by theological wish-thinking, that the demonstrated evidence doesn't result in speciation. These are the same patently false creationist arguments we have seen a million times before.
CharlieM wrote:I have no problem with humanity emerging through all the forms from a single cell to what we are today, so if you presented me with solid evidence that we were once aquatic, fish-like beings, I'd say, well done, but it doesn't affect the way I envision evolution happening.
You are of course free to interpret the evidence any way you like. But when you start trying to cast doubt on an entire field of science that works pretty fucking well without the involvement of your favorite pet magic man(who himself has not been demonstrated to exist either, which makes the claim that he is involved in tweaking evolutionary change with some grand scheme, doubly ludicrous), well people get pissed off.