Another of creationism’s central dogmas was unintentionally laid to rest by science yesterday, when three scientists from Surrey University's Leverhulme Quantum Biology Doctoral Training Centre, which includes the famous science broadcaster, Professor Jim Al-Khalili, published a paper which showed that DNA can spontaneously mutate due to nothing more than a random quantum fluctuation. Creationist dogma insists, with no evidence to support it and in spite of evidence to the contrary, that no new information can arise in the genome without violating the Second Law of Thermodynamics [sic]. Don't ask! It's based on some half-baked notion that information is like energy and can't be created, or rather, in creation world, can only be created by magic.
But, as the Surrey University team say in their open access Communications Physics paper:
The Surrey University news release explains what that means:Due to the significance of the quantum tunnelling even at biological temperatures, we find that the canonical and tautomeric forms of G-C inter-convert over timescales far shorter than biological ones and hence thermal equilibrium is rapidly reached. Furthermore, we find a large tautomeric occupation probability of 1.73 × 10−4, suggesting that such proton transfer may well play a far more important role in DNA mutation than has hitherto been suggested.
The two strands of the famous DNA double helix are linked together by subatomic particles called protons – the nuclei of atoms of hydrogen – which provide the glue that bonds molecules called bases together. These so-called hydrogen bonds are like the rungs of a twisted ladder that makes up the double helix structure discovered in 1952 by James Watson and Francis Crick based on the work of Rosalind Franklin and Maurice Wilkins.In other words, random mutations can arise spontaneously in DNA during replication without any external influence or violation of any fundamental laws of physics or chemistry and, being a quantum event, without cause. Once again, science shows how a natural process has no need for magic or gods in the explanation.
Normally, these DNA bases (called A, C, T and G) follow strict rules on how they bond together: A always bonds to T and C always to G. This strict pairing is determined by the molecules' shape, fitting them together like pieces in a jigsaw, but if the nature of the hydrogen bonds changes slightly, this can cause the pairing rule to break down, leading to the wrong bases being linked and hence a mutation. Although predicted by Crick and Watson, it is only now that sophisticated computational modelling has been able to quantify the process accurately.The protons in the DNA can tunnel along the hydrogen bonds in DNA and modify the bases which encode the genetic information. The modified bases are called "tautomers" and can survive the DNA cleavage and replication processes, causing "transcription errors" or mutations.
Dr Louie Slocombe, first author
Leverhulme Quantum Biology Doctoral Training Centre
University of Surrey, Guildford, Surrey, UK
The team, part of Surrey's research programme in the exciting new field of quantum biology, have shown that this modification in the bonds between the DNA strands is far more prevalent than has hitherto been thought. The protons can easily jump from their usual site on one side of an energy barrier to land on the other side. If this happens just before the two strands are unzipped in the first step of the copying process, then the error can pass through the replication machinery in the cell, leading to what is called a DNA mismatch and, potentially, a mutation.Watson and Crick speculated about the existence and importance of quantum mechanical effects in DNA well over 50 years ago, however, the mechanism has been largely overlooked.
Professor Jim Al-Khalili, co-author
Department of Physics
University of Surrey, Guildford, Surrey, UK
…[T]he Surrey team … used an approach called open quantum systems to determine the physical mechanisms that might cause the protons to jump across between the DNA strands. But, most intriguingly, it is thanks to a well-known, yet almost magical quantum mechanism called tunnelling – akin to a phantom passing through a solid wall – that they manage to get across.Biologists would typically expect tunnelling to play a significant role only at low temperatures and in relatively simple systems. Therefore, they tended to discount quantum effects in DNA. With our study, we believe we have proved that these assumptions do not hold.
Dr Marco Sacchi, co-author
Department of Chemistry
University of Surrey, Guildford, Surrey, UK
It had previously been thought that such quantum behaviour could not occur inside a living cell's warm, wet and complex environment. However, the Austrian physicist Erwin Schrödinger had suggested in his 1944 book What is Life? that quantum mechanics can play a role in living systems since they behave rather differently from inanimate matter. This latest work seems to confirm Schrödinger's theory.
In their study, the authors determine that the local cellular environment causes the protons, which behave like spread out waves, to be thermally activated and encouraged through the energy barrier. In fact, the protons are found to be continuously and very rapidly tunnelling back and forth between the two strands. Then, when the DNA is cleaved into its separate strands, some of the protons are caught on the wrong side, leading to an error.Schematic depiction of the Guanine–Cytosine proton transfer reaction.
More details are given in the team's published paper in Communication Physics:
AbstractIf they weren't so proud of their ignorance and intellectual dishonesty, I could almost feel sorry for creationists who must ignore so much information to retain their belief in their absurd and childlike belief in magic. Who I do feel sorry for are their children whom they refuse to allow to be any less ignorant than they are or to have any better understanding of the world in which they live.
One of the most important topics in molecular biology is the genetic stability of DNA. One threat to this stability is proton transfer along the hydrogen bonds of DNA that could lead to tautomerisation, hence creating point mutations. We present a theoretical analysis of the hydrogen bonds between the Guanine-Cytosine (G-C) nucleotide, which includes an accurate model of the structure of the base pairs, the quantum dynamics of the hydrogen bond proton, and the influence of the decoherent and dissipative cellular environment. We determine that the quantum tunnelling contribution to the proton transfer rate is several orders of magnitude larger than the classical over-the-barrier hopping. Due to the significance of the quantum tunnelling even at biological temperatures, we find that the canonical and tautomeric forms of G-C inter-convert over timescales far shorter than biological ones and hence thermal equilibrium is rapidly reached. Furthermore, we find a large tautomeric occupation probability of 1.73 × 10−4, suggesting that such proton transfer may well play a far more important role in DNA mutation than has hitherto been suggested. Our results could have far-reaching consequences for current models of genetic mutations.
Slocombe, L., Sacchi, M. & Al-Khalili, J.
An open quantum systems approach to proton tunnelling in DNA.
Commun Phys 5, 109 (2022). https://doi.org/10.1038/s42005-022-00881-8
Copyright: © 2022 The authors. Published by Springer Nature Ltd.
Open access
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
It's perhaps worth quoting the evolutionary biologist and devout Christian, Francis Collins here:
No wonder then that, faced with that choice, so many people, especially the young, are rejecting creationism and with it, religion entirely, hence the accelerating decline in religious belief in the USA as they catch up with the rest of the developed world in accepting that science is responsible for the fact that they don't live as subsistence farmers or hunter-gatherers any more but have all the trappings, conveniences and comforts of a modern, industrial society.By sending a message to young people that science is dangerous, and that pursuing science may well mean rejecting religious faith, Young Earth Creationism may be depriving science of some of its most promising future talents.
But it is not science that suffers most here. Young Earth Creationism does even more damage to faith, by demanding that belief in God requires assent to fundamentally flawed claims about the natural world. Young people brought up in homes and churches that insist on Creationism sooner or later encounter the overwhelming scientific evidence in favor of an ancient universe and the relatedness of all living things through the process of evolution and natural selection. What a terrible and unnecessary choice they then face! To adhere to the faith of their childhood, they are required to reject a broad and rigorous body of scientific data, effectively committing intellectual suicide. Presented with no other alternative than Creationism, is it any wonder that many of these young people turn away from faith, concluding that they simply cannot believe in a God who would ask them to reject what science has so compellingly taught us about the natural world?
Collins, Francis, The Language of God.
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.