DNA entropy?

[Fred56]

Does anyone know the Shannon entropy of DNA (any representative organism will do)? Or does anyone know how to calculate this with any accuracy or even within the ballpark?

[lucaspa]

Does anyone know the Shannon entropy of DNA (any representative organism will do)? Or does anyone know how to calculate this with any accuracy or even within the ballpark?

 

Doesn't anyone know how to do a simple Google search?

http://www.pandasthumb.org/archives/2004/05/shannon_entropy.html

http://www.citeulike.org/user/zono/article/769969

In this paper the Shannon entropy of several species was ~1

 

http://itb.biologie.hu-berlin.de/Research/publications/schmidt1997 Get the paper and it will give you the Shannon entropy of the Epstein-Barr virus.

[pioneer]

There are two competing factors in the DNA, entropy and enthalpy. If we took at a gas and allowed it to expand, the entropy or disorder will increase. This will absorb energy, i.e., system cools due to the absorption of energy. The enthalpy is the opposite. It will cause order to increase. The analogy is the compression of the gas. This will give off energy. As the system reaches steady state, a more stable system forms if there is chemical attraction.

 

Relative to the DNA, evolution has resulted in the stable genes on the DNA. This is maximum enthalpy. The entropy of the DNA are the defects. These are higher energy states, such as improper hydrogen bonding. In light of these defects or higher energy, the DNA needs to figure out how to use this energy potential to reach a state of better enthalpy, using the free energy within the defect.

 

A good analogy is a group of people with a common set of beliefs. As long as there are no defects in their logic, there is no need to change. But if someone finds a little problem, this will increase information entropy. This adds energy to the discussion. Everyone debates until there is a logical way to iintegrate the entropy, in a way that does not cause further group chaos. The final state has now evolved.

 

Relative to the DNA, one of the final judges on whether the DNA has been duplicated properly, are proof reading enzymes. Like any proof reader, simple mistakes can cause the meaning to become alterred. The DNA is like the book of a lifeform's life. There are genetic words, sentences, paragraphs, chapters, etc. If we change a word in the first sentence of a paragraph, that can change the entire meaning of the paragraph. If the same word is changed in the middle of the paragraph, the impact is less, since the implied intention of the paragraph is already self evident.

 

In terms of DNA and entropy, all entropy mistakes may be similar in simple chemical terms. But some will create a much higher information entropy within the DNA. A higher information entropy may cause a major change in the protein composite that expresses a paragraph. The first sentence, now changes the precursor for an entire protein train. The output result will cause a pertubation of the DNA. The DNA is now sort of confused and needs to attempt to reach a new lowest enthalpy state. But being so stable, it needs to wait for DNA duplication. New defects may be needed to further increase the information enthapy, until it can lower energy and reach a new state of improved enthalpy. If is sort of analogous to the group with their information entropy. Sometimes, one problem opens up a can of worms causing even more information entropy. This can cascade until finally, a new steady state.