Chirality of life: Another false positive?

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Creationists have considered the âmysteryâ of the chirality of life a problem inaccessible to scientific explanation. Of course, science as usual takes little notice of claims to ignorance and has provided yet another explanation for the chirality of life.

Point in case, a recent paper in Nature shows that:


Editorâs Summary âChemistry mirrors lifeâ

The paper in question is:


Based on the work by Dembski, this âresearcherâ concludes that


So letâs look at the âdesign inferenceâ in more detail

Letâs first establish that the chirality of life matches the definition of complex specified information.


However, this does not solve the mystery of where the optical activity in living organisms came from in the first place. A recent world conference on âThe Origin of Homochirality and Lifeâ made it clear that the origin of this handedness is a complete mystery to evolutionists.4 The probability of forming one homochiral polymer of N monomers by chance = 2âN. For a small protein of 100 amino acids, this probability = 2â100 = 10â30. Note, this is the probability of any homochiral polypeptide. The probability of forming a functional homochiral polymer is much lower, since a precise amino acid sequence is required in many places. Of course, many homochiral polymers are required for life, so the probabilities must be compounded. Chance is thus not an option.

All that is needed is a polymer of length 500 (500 bits) to meet Dembskiâs stringent limit but Dembski also seemed satisfied with 40 out of 41 in the Caputo case. In other words, the complexity criterion in met. But what about specification?

Specification The specification is simple. In biology a function is all that is needed for specification to exist and thus any functional polymer will do. But in addition, another specification is a âSorted set of amino-acids where all amino acids posess a left chiralityâ.



Or will it argue that

1. The original claim by the explanatory filter was flawed 2. ID is still a logical possibility (for instance via front loading) 3. Ignore the whole issue in the hope that it will go away 4. The scenarios proposed are not specific enough and are âjust so storiesâ as opposed to the story about the unembodied designer.


The authors conclude:


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So in other words when creationists claim that chirality is a problem for science they are unfamiliar with the science? Perhaps itâs time for ID to teach the reality.




He hasnât made one single argument over a period of months that doesnât fit the pattern noted above.

thatâs literally over hundreds of pages of posts, btw.

PvM Wrote:




That did seem to be the case when we explored the issue in the last Berlinski comments thread. Thereâs an embarrassment of possible mechanisms for chiral amplification, with new ones being proposed all the time. Of course, the more that are found, the wider the possibilities for which one or combination actually contributed, and creationists make the usual âWell, if scientists canât stop arguing over which one happened, then they donât actually know anything, do they?â argument.

Itâs precisely analogous to the transitional fossils situation. We find a bajillion birdish-dinosaurish-species, therefore it becomes unlikely that any one of them can be established as the ancestor to modern birds, therefore, saith the creationist, there are no transitional fossils. That much irony could kill a man, but theyâve built up resistance.


Wtf? Talk about your false dichotomy!

From one of the quotes in the main post:

the origin of this handedness is a complete mystery to evolutionists.

Itâs a âmysteryâ to the IDists too. The difference is that scientists are productively trying to solve it, rather than thinking a lack of knowledge is somehow informative in itself.

Arthur Asuncion Wrote:








Only under unwarranted assumptions such as independence of events.





One must question Dembskiâs ability to count, also. Letâs take another instance of chirality: sugars. The D and L stereoisomers of the basic sugars and the chirality of amino acids are intimately interrelated, especially thermodynamically, when those amino acids interact with the sugars. Dembskiâs âcountâ would include every atom as an independent element in determining the âcomplexityâ of the molecule.

However, the complexity of a thermodynamically stable sugar stereoisomer has only two possibilities: D or L (depending upon whether the C-O ring bond points âupâ or âdownâ). A one in two chance certainly doesnât point toward âcomplexityâ, let alone âdesignâ!

Further, the {t=0} = {t=n} identity implied by these calculations omits a critical factor that anyone who has even cursorily studied biochemical systems (as opposed to test-tube reactions) is all too aware of: positive feedback selectivity. Consider a species that is attempting to obtain energy by breaking down sugars in its environment. If its immediate environment has even a slightly greater than equal distribution of D sugars, individual organisms whose enzymes more efficiently metabolize D sugars will be selected. Further, the breakdown products will, at some stages, themselves be optimized to form more D sugars by simple reversal of equilibriumâ¦ and since those sugars are used by the same organism for energy storage, the organism has a âmotiveâ to expend the least possible energy in reconstituting the sugars. And thatâs the positive feedback loop.

Dembskian counting is rather like claiming that an aircraftâs structure and complexity are determined by the number of rivets used to attach the wings to the body, without regard to the number or shape of the wings (or, for that matter, the possibility of weldingâ¦). It conflates structural considerations of inherently different orders; if weâve learned nothing else from quantum chemistry, itâs that we donât get accurate results or predictions when we do that.





300 posts by that guy, without a single intelligent statement. Thatâs why he won the vote :-)


Such as . â¦ . â¦ ?

On UncommonDescent Dembski claims that he personally has not personally argued that homochirality triggers a design inference. In addition, Dembskiâs response shows how the EF will never be allowed to fail by moving the goalposts to another area of our ignorance. Since I did not argue that it was Dembski himself who had argued in favor of chirality showing design I fail to see the relevance of him distancing himself from the work of other ID activists. If Dembski were interested in the scientific validity of the claims of other ID activists, he could for instance point out the scientific problems with the young earth IDists claims. Teach the controversy Iâd say. But I digress.

What lessons have we learned here? That the EF is scientifically vacuous either because it leads to false positives (which would make the method useless since it does not provide any way of estimating the likelihood of a false positive and can thus not even compete with âwe donât knowâ) or it cannot be falsified because the goalposts can always be moved to another gap in our knowledge.

Dembski Wrote:

But the chirality problem pales in comparison to the problem of sequencing amino acids to form functional proteins. Thatâs where Steve Meyer and I have always focused our attention. Let the Thumbsmen at PT come up with a plausible mechanism for protein generation along with a detailed account for how this proposed mechanism could generate a modest sized 250-amino acid protein, and Iâll take notice. Until then, indulge your homochiral fantasies.


Letâs explore Dembskiâs arguments a bit further based on his public statements. Ironically, Dembski comments on the imprecise nature of probabilistic reasoning in the creationist literature and thus must have included his imprecise and incomplete âcalculationsâ for the formation of a flagellum protein in âNo Free Lunchâ.

Dembski argues also that specification is needed to deal with the problem of rejecting small probabilities but in biology function IS a specification and thus natural selection cannot be excluded as the âdesignerâ since it is exactly function which arises under the processes of variation and selection.

Dembski Wrote:


Even ID is claimed to have at most âsome successâ in this area. So where is the beef?

Re âSo where is the beef?â



I donât normally have access to Nature, but I ran across two other articles (apparently) dealing with the same phenomena some time ago.

See for example:

âHegstrom et al. [3], as well as Mason and Tranter [4], have calculated PVED [parity violation energy difference] for chiral carbon molecules, like amino acids, and found that for such molecules, at around room temperature, PVED is in the order of 10^Ã¢Ëâ17 kT or 10^Ã¢Ëâ17 RT per mole. More recent elaborate calculations [5, 6, 7] suggested that PVED in such molecules is actually greater by about one order of magnitude, i.e, PVED=10^Ã¢Ëâ16 kT . In other words, one enantiomer will be of a lower energy state of 10^Ã¢Ëâ17 Ã¢Ëâ 10^Ã¢Ëâ16 kT .â


See also:

P-Violation Manifested at the Molecular Level - A Simple Means for an Absolute Definition of âLeftâ vs. âRightâ Avshalom C. Elitzur and Meir Shinitzky arXiv:physics/0601010 v1, 3 Jan 2006[…]/0601010.pdf

In essence, it seems that the structure of water itself is amplifying the weak force parity violation to a level that affects the relative rates racemization of left-handed and right-handed amino acids. This potential for amplification may be related to the higher-than-expected sensitivity of water to electric fields â which has been demonstrated by water being frozen at room temperature in electric fields which are 1/1000 of the strength that was expected.

Please see:


In any case, once the break in symmetry is amplified such that the balance for serine is tipped, it should be tipped for all other amino acids â given the strong bonds which serine forms for amino acids of the same chirality.

Please see:


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