That is to say, according to some studies that a recent paper in Nature cites, an enzyme used in mitochondrial DNA transcription is “distantly related” to that of Bacteriophage T7 (a virus which infects E. coli), a similar enzyme that does the same thing in chloroplasts, and Pol I polymerases generally (whatever they are). This paper itself adds to the table the 3D structure of the human version of the enzyme.
This study – and the associated press release, which is slightly less dense and unreadable-to-anyone-who-knows-nothing-about-the-subject than (the abstract of) the paper itself – has apparently travelled through the black-box that is the mind of the ICR’s “Science Writer,” Brian Thomas, who writes: Could a Virus Jump-Start the First Cell? For clarification, he appears to mean the first cell that contained mitochondria.
Evolutionists have had a hard time imagining how mitochondria evolved. One theory is that these cellular powerhouses originated when bacteria invaded a primitive cell. A recent study deciphered the structure of a key mitochondrial enzyme, some features of which were described as providing “new insights” into this theory. The insights it actually provided, though, make an evolutionary origin even less likely.
Hey, I can imagine how mitochondria evolved just fine – the only problem is that my own uninformed idea of how it could have done it is probably rather wrong…
I should point out that whenever Mr Thomas claims that a given study makes the evolution of x (or whatever) less likely, he’s not only wrong about that but doesn’t even try to make that case later on in his article. He’s just reassuring the masses.
A press release highlighting the enzyme discovery stated, “It is now generally accepted that mitochondria evolved from free-living bacteria that were engulfed by the progenitor of today’s animal cells at an early stage in evolution.”
Indeed it is. For any non-elephant matriarchs out there, I last posted on the subject of Mitochondria in Quasars, Mitochondria and Archaeopteryx – What I Missed Because I Had Homework a month or two ago. It was accepted then too.
However, evolving mitochondria are not possible. These tiny cellular machines produce energy for the cell through clockwork-like machinery and interdependent networking. The cells would have died while waiting for just the right changes to retrofit a bacterium into an effective mitochondrion. Plus, retrofitting would have required an engineer, which naturalists are dogmatically unwilling to consider.
Now, my probably false idea about how mitochondria could have evolved is:
- You have a cell that does not have mitochondria in it but has nevertheless managed to grow very large (for a single-celled organism).
- A small bacterium invades it, and sets up shop as a parasite.
- After a while, the bacterium’s descendants don’t ever leave the cytoplasm – thus, it is to the advantage of the genes in the mitochondrion to do things that are also to the advantage of the cell.
- Everything naturally flows from there.
For all its flaws, this does not fall into the problem that Mr Thomas gave, namely that the cell would die before things got working. I might even say that it is him that is having “a hard time imagining how mitochondria evolved.”
The newly described mitochondrial enzyme, an RNA polymerase, forms RNA molecules by reading and matching corresponding DNA sequences. This enzyme shared some features with the RNA polymerase found in certain viruses.
Because of these shared features, some scientists now suggest that right at the time when the cell supposedly engulfed its would-be mitochondrion bacterium, a virus attacked the cells. However, instead of causing any damage, the virus supposedly donated the DNA code for its RNA polymerase enzyme!
I don’t know where he got this from – it’s in neither the abstract nor the press release. In any case his incredulity is unfounded. I note with interest that he himself has “suggested” that viruses were designed as “tiny robots to carry life-enhancing genetic information from one cell to another.” Strangely, he doesn’t bring that up here…
It was difficult enough to believe, without any observational precedent, that one bacterium could engulf another without killing it, that the engulfed bacterium would then immediately become an integral part of the host cell, and that nature somehow retrofitted the bacterium into a mitochondrion. But now readers are asked to believe—again with no observational support—that a virus donated the gene for an enzyme that was also immediately adopted by the imaginary cell-within-a-cell.
Note, please, that there are, indeed, types of bacteria that live inside eukaryotic cells – is there a reason why they could not inhabit prokaryotes, which are on their way to becoming eukaryotes? An example of such a bacteria is Rickettsia, if you’re interested.
But that’s not all. The gene was precisely and rapidly modified, all at the same time. What are the odds of that?
I can’t comment on that as I have absolutely no idea what he is talking about. However, when creationists calculate odds they usually do it wrong, assuming that something happened via a different mechanism to how it really did.
The researchers, publishing in Nature, explored the structural differences between the viral RNA polymerase and the human mitochondrial RNA polymerase enzymes. They found that the mitochondrial RNA polymerase required at least two additional proteins to “melt” DNA so that it could read the sequence. Apparently, the presence or absence of these partner proteins enables “mitochondrial gene regulation and the adaptation of mitochondrial function to changes in the environment.”
What they found was that two things in the T7’s enzyme – the “fingers domain and the intercalating hairpin” (again, whatever they are) – that does the ‘melting’ are “repositioned,” which, in their eyes, “explain[s] the need for [one of the other proteins] during promoter melting.” Curiously, the T7 enzyme does not need either of the two additional proteins.
Though the study authors mentioned these concepts in their paper’s abstract, they didn’t explore them in the rest of their report. However, it is apparent that the mitochondrial RNA polymerase’s methods of interacting with DNA are fine-tuned to the microscopic world of the cell’s mitochondria, not to that of viruses. Insisting that such a fine-tuned machine arose by a chance viral infection and that the viral machine just happened to modify and integrate so perfectly as to activate mitochondrial machinery is too much to ask of nature.
To much to ask of random chance maybe, but natural selection works wonders.
But of course, fine-tuning molecules that enable life is not too much to ask a super-intelligent Being to accomplish. Indications are clearer than ever that God purposefully engineered the machinery of life.
As I said at the start, whatever he says this study certainly provides no positive evidence for God, or anything other “super-intelligent Being.” He’s just preaching to the choir, as always…