Posted on 11/16/2005 3:40:35 AM PST by snarks_when_bored
* 14:02 15 November 2005
* NewScientist.com news service
* Gaia Vince
A new microscope sensitive enough to track the real-time motion of a single protein, right down to the scale of its individual atoms, has revealed how genes are copied from DNA – a process essential to life.
The novel device allows users to achieve the highest-resolution measurements ever, equivalent to the diameter of a single hydrogen atom, says Steven Block, who designed it with colleagues at Stanford University in California.
Block was able to use the microscope to track a molecule of DNA from an E.coli bacterium, settling a long-standing scientific debate about the precise method in which genetic material is copied for use.
The molecular double-helix of DNA resembles a twisted ladder consisting of two strands connected by “rungs” called bases. The bases, which are known by the abbreviations A, T, G and C, encode genetic information, and the sequence in which they appear “spell out” different genes.
Every time a new protein is made, the genetic information for that protein must first be transcribed from its DNA blueprint. The transcriber, an enzyme called RNA polymerase (RNAP), latches on to the DNA ladder and pulls a small section apart lengthwise. As it works its way down the section of DNA, RNAP copies the sequence of bases and builds a complementary strand of RNA – the first step in a new protein.
“For years, people have known that RNA is made up one base at a time,” Block says. “But that has left open the question of whether the RNAP enzyme actually climbs up the DNA ladder one rung at a time, or does it move instead in chunks – for example, does it add three bases, then jump along and add another three bases.
Light and helium
In order to settle the question, the researchers designed equipment that was able to very accurately monitor the movements of a single DNA molecule.
Block chemically bonded one end of the DNA length to a glass bead. The bead was just 1 micrometre across, a thousand times the length of the DNA molecule and, crucially, a billion times its volume. He then bonded the RNAP enzyme to another bead. Both beads were placed in a watery substrate on a microscope slide.
Using mirrors, he then focused two infrared laser beams down onto each bead. Because the glass bead was in water, there was a refractive (optical density) difference between the glass and water, which caused the laser to bend and focus the light so that Block knew exactly where each bead was.
But in dealing with such small objects, he could not afford any of the normal wobbles in the light that occur when the photons have to pass through different densities of air at differing temperatures. So, he encased the whole microscope in a box containing helium. Helium has a very low refractive index so, even if temperature fluctuations occurred, the effect would be too small to matter.
One by one
The group then manipulated one of the glass beads until the RNAP latched on to a rung on the DNA molecule. As the enzyme moved along the bases, it tugged the glass bead it was bonded too, moving the two beads toward each together. The RNAP jerked along the DNA, pausing between jerks to churn out RNA transcribed bases. It was by precisely measuring the lengths of the jerks that Block determined how many bases it transcribed each time.
“The RNAP climbs the DNA ladder one base pair at a time – that is probably the right answer,” he says.
“It’s a very neat system – amazing to be able see molecular details and work out how DNA is transcribed for the first time,” said Justin Molloy, who has pioneered similar work at the National Institute for Medical Research, London. “It’s pretty incredible. You would never have believed it could be possible 10 years ago.”
Journal reference: Nature (DOI: 10.1038/nature04268)
Perhaps you misunderstood the original comment. To say that you don't want to be included, would be to state that the intelligent design work that you are involved in, is a non-scientific pursuit. Somehow I doubt that you would relegate yourself into the ranks of the unwasher non-scientific.
Empty lack of response noted.
One may approach this by the simple expedient of pointing out that we humans have the ability to understand (at some level) many of the processes of nature. As applied to ID, one could point out that we understand the practical purposes satisfied by various traits and phenomena. Furthermore, they are similar to the optimization approaches that we, ourselves, apply. The fact that we can understand these things directly, in terms of their practical applications, would argue strongly against the idea of inscrutability on the part of the hypothesized designer.
As I say, if you want to start limiting the designer as to motivation and/or powers, you'd better start saying what those limits are. Behe et al carefully avoid making any such statement, on the contrary.
Recall that the comment was made in response to your claim that a designer must be completely inscrutable. But because inscrutability is not a necessary condition for a designer (for example, humans designers don't meet this standard), pointing to the "scrutablility" of what we see around us has quite a bit to do with ID, particularly in dismissing your attempt to impose inscrutability.
The inscrutability of the designer isn't my claim, it is IDs claim. ID places no limits on the designer. Are you proposing a new ID in opposition to Behe et al, or are you going to get them to agree to limit the designer.
Nobody was contending DNA replication involved "...and then a miracle occurs."
The basic standards of science should not rule out something merely because it implies a force that cannot presently be directly observed. Just because that force may be personal or intelligent does not make the object any less scientific. What a bass-ackwards way to do science: rule out a possibity and proceed from there.
Yes, science has standards. Apparently you would prefer it have substandards.
Good point.
Androgyny will be 'in'.
Isn't that the point?
The school boards would be more reasonable.
The only necessary hypothesis would be that the effects of his design are observable. It's otherwise an interesting question, but it's not particularly relevant to the (hypothesized) fact that something occurred as a result of design.
If one hypothesizes that "this is designed," one would expect to test (in some way) the observable traits by which we could distinguish between design and non-design. The identity and nature of the designer are not germane to that question -- though they would obviously become very important questions if a "design" result ever came up positive.
Er, ID is what they do for a living.
No one denies that living things are designed. Evolution says natural selection is the designer. This is a testable hypothesis.
What hypothesis does ID propose, and what are its characteristics. You are the one who said the characteristics of the designer could be known.
Organized matter is physical evidence of intelligent design. Science is well within its bounds to infer a designer where there is design. It may make statements accordingly and with qualification. It by no means must avoid the possibility alogether but is free to explore it. Besides, science is known for making assumptions and exploring things for which there is currently no "physical evidence."
Baloney. Unless you think the "biotech guys" created everything. Don't be so coy.
Here is the correct response:
Bah! Humbug!
Not empty at all. You're trying to force inscrutability on the putative designer, and there is no reason for you to do so.
At least let's try to be clear about the logical requirements of the discussion, OK?
As I say, if you want to start limiting the designer as to motivation and/or powers, you'd better start saying what those limits are. Behe et al carefully avoid making any such statement, on the contrary.
Please cite where Behe, et al., state that the designer "must be inscrutable."
The inscrutability of the designer isn't my claim, it is IDs claim.
No, it is your claim. You're imposing a requirement ("the designer must be inscrutable in methods and motivation") for which there is no logical basis.
Why? How do you know?
Behe's claim is that flagella are an example of irreducible complexity, and that an intelligent agent is necessary to explain their development.
...and that line of reasoning is fallacious, as I've already pointed out.
Also for reasons I've already pointed out, showing a possible evolutionary origin for any particular system would in no way falsify the "ID postulate".
As I noted above, the idea that flagella can occur as a product of design is quite plausible based on current technology and an extrapolation of technological trends.
No argument here, but that doesn't help Behe's point.
The question has to do with the issue of necessity. If one can demonstrate the evolution of flagella without intelligent agents, Behe's claim of "necessity" in that case would obviously be falsified, and his claim of "irreducible complexity" fails in that case.
The problem here is that his argument of "necessity" is flawed from the *start*, and thus any "disproof" of that argument doesn't falsify "ID" either.
One more time: Evidence *against* evolution is not evidence *for* ID. Conversely, failure of that alleged evidence against evolution does not constitute falsification of ID. Period.
If one were unable to demonstrate the evolution of flagella, then it still would not say that Behe was correct, though it would tend to support his claim of "necessity".
No it wouldn't, and therein lies the whole problem. There is no "necessity" of ID even if one could prove beyond all doubt that the flagella could not have evolved. The reason is that Behe -- like most IDers -- is engaging in a false dichotomy. They falsely presume that there are only two possible explanations: a) evolution, or b) design. And that if one is wrong, the other must perforce be true. This is completely incorrect -- they could *both* be wrong, and some *other* (non-evolutionary *and* non-design) process might have been responsible for the flagella (even if we don't yet know what it might be).
Consequently, any evidence regarding evolution -- for, against, or indifferent -- does *not* constitute evidence for, against, or otherwise about ID. Period. If "ID" wants to approach something like an actual science, they'll have to eventually find actual evidence *for* ID, and determine some way in which ID *itself* could potentially be falsified. They're wasting their time trying to "disprove" evolution or claiming that demonstrating the evolution of anything (includign the flagella) falsifies ID, because it doesn't.
However, a result of "didn't evolve" would be of immediate concern to those who claim that flagella evolved. After all, for it to be a scientific theory it's supposed to be testable, right?
Indeed, this could (depending upon the exact nature of that discovery) be a falsification of at least part of evolutionary theory. But no such test has yet been proposed for ID (or at least no such test that actually holds up under examination).
It's OK. last night my boys were playing the muppet version and it came to me.
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