Stupid guided evolution hypothisis

[Anarchaus]

I am currently looking thru massive amounts of material concerning the mutaion of creatures big, bigger, and small. Mutations in the DNA seem to remove genetic information not slap on more, so in order for evolution to work, it must be adding relevant information to new enviromental factors that allow for the mutaions to rise. But since the DNA does not accomidate for random mutations what about protein? Could protein molecules change with the enviroment? could it be the protein that mutates first, then with its new Shape and information, add information relavant to the survival of the cell into the DNA thus altering the information encoded in the DNA?

Also, mutatiuons would not "edit" the DNA, the old DNA adapted to a previously suited enviroment is still there, so retreating back to the previous is possilbe, (so called de-evolving) but it does not remove DNA info once again, and if a certain gene is highly important, the protein will copy it into theDNA for further emphisis on that gene.

 

so its the Prions or some other protein molecules that react to the enviroment, change shape, then add relevant information to the DNA?

 

could you guys add any suggestions please

 

 

P.S don't shoot this hypothisis down before you remind yourself that no one person can adequetly explain the very nature of the mutaions of DNA any better than this far out hypothisis.

[Mokele]

Mutations in the DNA seem to remove genetic information not slap on more, so in order for evolution to work, it must be adding relevant information to new enviromental factors that allow for the mutaions to rise. But since the DNA does not accomidate for random mutations what about protein?

 

A few things:

1) Mutation and other DNA foul-ups (most notably unequal crossing over during meiosis) can actually add DNA, often huge chunks containing many genes. Aside from the fact that we've seen it happen, it's past occurence is evidenced by "gene families", clusters of closely related genes that have duplicated in the past, then divereged. The hemoglobin/myoglobin family is an excellent example.

 

2) DNA *does* accomodate random mutation, both due to chemical insults and errors in replication.

 

Could protein molecules change with the enviroment?

 

Can and do. pH, temperature, phosphorylation of the protien and other factors can all alter the shape and functionality of a protien.

 

could it be the protein that mutates first, then with its new Shape and information, add information relavant to the survival of the cell into the DNA thus altering the information encoded in the DNA?

 

The trick is that, while we know that protiens are made from DNA, we haven't observed any process to run in the reverse. Such a process would, in a way, make Lamarckian evolution a possibility.

 

Is it possible? Probably. Is it the case for life on earth? Very unlikely. We'd've noticed something by now, I think, if this as happening.

 

Also, mutatiuons would not "edit" the DNA, the old DNA adapted to a previously suited enviroment is still there, so retreating back to the previous is possilbe, (so called de-evolving) but it does not remove DNA info once again, and if a certain gene is highly important, the protein will copy it into theDNA for further emphisis on that gene.

 

Well, aside from the problem I mentioned above about there being no know mechanism to turn altered protiens back into DNA, what about kids? They inherit DNA, not protien from all over the body (especially from sperm). So wouldn't the kid have to "re-modify" itself, rather than having the modifactions passed down to it?

 

An interesting sidenote: In a recent issue of Nature, someone found that a particular plant can do something vaguely similar to what you suggest, but using mRNA. The plant seems to store old mRNA transcripts, and can alter the DNA based on them even after several generations. Of course, this is bleeding-edge stuff, so there's not much more info floating around about it, but there's definitely more than we thought happening.

 

P.S don't shoot this hypothisis down before you remind yourself that no one person can adequetly explain the very nature of the mutaions of DNA any better than this far out hypothisis.

 

Actually, we've got a pretty good handle on what chemical insults cause what chemical effects in DNA. Like UV light, which causes two adjacent thymines to form a bond, "kinking" the DNA and causing transcription and duplication errors.

 

Mokele

[Anarchaus]

hmmm.... interesting indeed. Thanks.