Logical Mutations

[HydrogenBond]

The DNA within cells exists as heterochomatin and euchromatin. The heterochomatin stay packed away, while the euchomatin are much less packed or unpacked and are usually undergoing transcription. The distribution of genes existing within the euchromatin of the DNA will define a cellular differentiation. If the environment is alterred for a single cellular creature the chemical feedback to the DNA will change and thereby alter the cellular differentation. New genes may become active while genes that are no longer being used will repack. When the new cell divides, it will have accumulated proteins due to the demands of its new environment, such that its two daughter cells will come out more differentiated to the new environment. It did not mutate even though it is different. With many cells containing way more DNA than is needed, a lifeform can differeniate to the environment without mutating.

 

Something similar is observed within multicellular animals, for example a human. Every cell within a human body will have the very same DNA, yet there are hundreds of viable variations all using the same DNA. Each cell is a product of its biochemical environment such that its packing and unpacking distribution will be maintained by its local environment to get a particular differnatiation.

 

One rapid way cells can mutate is connected to viruses. In some cases a virus can add some external or environmental DNA to the cell's DNA. Again, external chemical potential is setting the potential for cellular differentiation and mutation. Normally one looks at viruses as a negative thing, however, viruses by alterring the DNA may have played a role in evolution. Indirectly is easier to see. If a virus weakens an animal it may be easier to hunt thereby alterring the external biochemical potential seem by a preditor. The virus AIDS causes sickness and death, but it has also alterred human behavior, thereby alterring the biochemical environment and differenatiation of the brain for those not effected, i.e., more fear tone and less desire tone.

 

Progressive mutations can happen in a direct sense by adding DNA, human can add splices of genes to existing lifeforms, like corn, to create mutated corn that is better than the original. It does not seem that far fetched that viruses, containing DNA, may have played a direct role, along with the evolving earth, to alter cellular differeniation leading to progressive mutations. Viruses do not just appear from nothing, they are a waste or output product of another lifeform that was differentiated by the environment.The waste of animals become the food for trees. The output of trees become the food for animals. But not every fruit is good for every animal nor everyone animal 's waste product beneficial to every plant. When the match is found there is symbiosis and health.

[Fishteacher73]

The virus AIDS causes sickness and death, but it has also alterred human behavior, thereby alterring the biochemical environment and differenatiation of the brain for those not effected, i.e., more fear tone and less desire tone.

I think this really only works well in sentient species. Most predators must be teach every generation what animals are prey and which ones are not. This is the whole support for Batesian mimicry. Only individuals that have had contatct with the "dangerous" twin will avoid the mimic.

 

While the idea as viruses being mutative agents is quite plausable and in all likelyhood a factor in natural selection, only gametes altered would pass on any change, thus the reproductive organs would be the area in which viral mutations could be passed.

 

A eight-eyed baby STD.... :)

[Boerseun]

I think viruses have a great future in medical science and research.

 

Can't remember where I read it - it think it was on http://www.livescience.com - where researchers are currently having great success with a 'terminator virus' for cancer cells.

Basically, what they do is to manipulate a virus' DNA so that when it invades a cell it looks for a specific chromosome to attack in the host cell's DNA. They've been 'programmed' to look for a chromosome that exists only in cancer cells, and all forms of cancer shares that specific chromosome. So what it does is to invade the cell, plug into the DNA at that specific point, and breed - thereby killing the cell and their offspring goes off through the body looking for more cancer cells. All normal cells are left alone, because without that faulty chromosome the cell is useless to the virus.

 

Apparently they've had great success in mice with this 'terminator virus', and just goes to show that we can use the properties of something like a virus very much to our advantage - almost like my Uncle Stan; nobody likes him, but he's not all bad...

[Biochemist]

..It did not mutate even though it is different. With many cells containing way more DNA than is needed, a lifeform can differeniate to the environment without mutating. ...

One rapid way cells can mutate is connected to viruses. In some cases a virus can add some external or environmental DNA to the cell's DNA. ...Progressive mutations can happen in a direct sense by adding DNA, human can add splices of genes to existing lifeforms, like corn, to create mutated corn that is better than the original.

I do not think it is reasonable to use the term "mutation" to describe a genomic change that has a designed outcome. Viruses do not casues "mutations", they change genes by design (that is, they reproduce the same outcome in separate vectors).

 

We have this tendency to assume "mutation" as a key component in genomic change over time, even though evidence for real mutation (other than destructive damage) is remarkably thin. We produce thousands of examples of genomic change that are certainly not mutative, and then reflexively refer to them as mutations.

 

HB- This is a pretty interesting thesis, but I sure wich we could fix our language to reflect this characteristic of the ecosystem without mislabeling it as "mutation"

[HydrogenBond]

I think you are correct about the word mutation being used inappropriately by myself and others. When I was formulating this idea, I was thinking about evolution and how mutations often assumed to happen in quantum leaps, giving selective advantage. Continuous evolution has seems to make more sense because it leads to the same result with the twist the environment helps condition selective advantage. The quantum mutation theory probably stems from data collection. We only have limited fossil evidence, and thereby discontinuous data point, making things appear to happen in quantum jumps.

[Biochemist]

I think you are correct about the word mutation being used inappropriately by myself and others.

Thanks for the affirmation. It is a slippery problem.

The quantum mutation theory probably stems from data collection. We only have limited fossil evidence, and thereby discontinuous data point, making things appear to happen in quantum jumps.

I am not sure this is true. There is a reasonable argument that the fossil data is spotty, but I really do think that the Eldredge/Gould Puncuated Equilibrium argument (from 1972) has merit as well. Their point was that the record is not complete, but we have enough of a fossil record to conclude that the generalized assumption of gradualism-by-mutation does not really hold water. That is, the evidence that we do have (circa the Cambrian explosion) does not support a gradual introduction of ever-increasinlgy-complex body plans.

 

We can demonstrate a resonable case for gradualism in speciation through genetic drift (i.e. selection of recessive allelles in small populaitons) , but not through serialized mutation. It does not look (to me) like serial mutation is the norm for speciation. But we still assume it in nearly all academic literature.

[sciborg]

I have read that that at least two things cause differentiation of cells: first, the "signal" environment changes in reference to protein signals that then cause gene expression to change. Second, genes are progressively "tagged" by methylization which inactivates some genes causing differences in expression depending on where we are in a cell division scenario. Presumably fewer genes are tagged in "stem" cells (near the beginning of a division tree) and therefore more genes can potentially be activated (or deactivated) by the signal environment.

 

If you chop tissue out of an organism and put it in a petri dish the signal environment changes as signals are washed away. This presumably partly explains why cells in vitro don't behave as they do in vivo.

 

If this is right, is mutation, that is permanent alteration of the cell genetic data required to explain differences in gene expression?

 

Apparently, animals can be cloned from skin cells. Skin cells would appear to be (but not necessarily) pretty far down a cell division tree. So apparently, somehow, the tagging does not cause a problem for the cloned animal. Why not?

[HydrogenBond]

The unpacking of DNA is required for genetic expression, while the distrubtion of unpacked genes will define genetic differentiation. As such, the trick is to unpack what you need and repack what you don't to get a new genetic distribution. The environment and cytoplasm is interwired for feedback to the DNA. When new daughter cells form, their cutoplasm differentiation feedback will help determine the unpacked distribution. The environment will fine tune this to the real time genetic needs of the cell. Human DNA has many ways to fold the paper. When one refolds the paper you can get a different design sometimes with odd creases from the previous folds. Stem cells are easier to refold because its design is very basic and therefore one can make us of the previous creases.

[sciborg]

The unpacking of DNA is required for genetic expression .... Stem cells are easier to refold because its design is very basic and therefore one can make us of the previous creases.

 

Thanks. I assume all the folds are ironed out in skin cell cloning?

 

Is it thought the folding involves long stretches of DNA? Therefore the physical position of a gene on a chromosome is critical to whether it gets expressed? Genes in the same locus area would tend to be expressed or suppressed together?