Wednesday, September 25, 2013

The Uncertain Gene

Proton induced evolution
Most everyone has heard of "The Selfish Gene" concept.

If you haven't, then perhaps you have heard about the book of that name written by Dr. Richard Dawkins.

We mentioned it in a recent post (If Cosmology Is "Off," How Can Biology Be "On?").

Today, we are going to introduce The Uncertain Gene and associate it once again with Quantum Mechanics.

This will not be the first time "The Uncertain Gene" has been a subject that has been a factor in various Dredd Blog System posts, but those previous times did not consider the dynamics that will be discussed today.

For example, in past posts we noted some rather unnoticed, some rather odd, but never-the-less certain to become genetic-world-shaking news:
"The analysis of the original proton wave packet involves an interesting phase problem, and, since the energy distribution is temperature dependent, the whole phenomenon is also temperature dependent."
"The tunneling times will depend essentially on the height and the form of the barrier. In DNA, the form of the double-well potentials regulating the hydrogen bonds depend not only on the base pair involved but also on neighboring pairs, their net charges, and the entire electric environment. The tunneling time is hence not only characteristic for a certain biological specimen but is also a function of the position in the DNA molecule involved. The tunneling time is very likely also temperature dependent, even if the protons are well shielded in the double helix. The main problem is whether the tunneling time is very short in comparison to the replication time, or whether there exist organisms where the penetration of the barrier is slow in comparison to the replication." 
"It should always be remembered that, in Born's interpretation of quantum mechanics, the quantity |¥|² represents the probability density for finding the proton in a specific position. The tunneling of the wave packet is hence a time-dependent process which is going to influence the properties of the genetic code."
"In this connection, it should be observed that the tunneling probabilities depend not only on the base pair involved but also on the electrostatic environment, the neighboring base pairs, etc., which may explain the occurrence of "hot spots."
At a DNA replication, the protons have to "choose sides," and the proton code immediately after a DNA replication represents actually a nonstationary state from the quantum-mechanical point of view. The time evolution of the system and particularly the penetration of the potential barrier in the double-well potential represents a loss of the genetic code which should perhaps be considered as the primary cause of aging. The
Proton Tunnelling induced mutation
aging is thus a process which goes on continuously in the DNA molecule but gets "manifested" at the replications.
Proton tunneling may finally be of importance in connection with the occurrence of spontaneous tumors. The growth of an individual is a highly refined balance between factors which enhance the cell duplication and other factors which limit this duplication so that the organism takes a specific shape. The entire process is stimulated and controlled by various enzymes, and there is a feedback from the environment about which we know, at present, very little. If there is a somatic mutation, i.e., a change of the genetic code in a DNA molecule in the body of an organism, the change may influence the protein synthesis and the balance between the enhancing and controlling enzyme actions in the growth cycle. Actually, the new genetic code may lead to the development of a "new individual" within the individual, i.e., a tumor."
"In this paper we have pointed out that, since the protons are not classical particles but "wave packets" obeying the laws of modern quantum theory, the genetic code cannot --in spite of all precautions-- be 100% stable. Due to the quantum-mechanical "tunnel effect," there is always a small but finite probability that the protons will change place, alter the genetic code, and give rise to mutations. This implies also that this transfer of protons over a distance of about 10-8 cm may be one of the driving forces in the evolution of living organisms on the earth."
(Stem Cell Malfunction A Quantum Toxin Source?, quoting Löwdin). That quote is from a 1963 paper in a scientific journal, which evidently did not garner as much interest as it could or should have.

Today, then, we offer you a much more recent paper (6/7/13) which focuses on, and details, that same phenomenon a bit more:
By treating the proton as a quantum ”wave packet” it becomes possible to model the hydrogen bond as a quantum body problem. Due to quantum tunneling, however, there is a small but finite probability that the protons will change place within the hydrogen bond, altering the genetic code, and giving rise to mutations.
(Quantum Tunneling in DNA, by Megan Wolfe). That "small but finite probability" gets much more probable by happening millions of repetitions per short amount of time (like a second or a minute) in the trillions of cells inside us.

In the next episode of this series, then, we will zoom in on the book "Quantum Aspects of Life", a scientific textbook, to further explore the impact of The Uncertain Gene on the evolution of carbon based life ("us").

Stay tuned if you like.

The next post in this series is here.

1 comment:

  1. The quantum tunnelling phenomenon is also considered in the following post: (link)..