DNA can only shrink?

[BGoodForGoodSake]

That mutations only subtract and do not add to the DNA sequence is certainly not the case. This however is a scientific debate and probably not appropriate for this board.

We must go into detail on what exactly a mutation is. DNA is copied through a flawed and complex mechanism involving RNA transcriptase. Segments of code can be coppied erroneously deleted and duplicated.

Environmental factors can also alter the nucleic acid chain.

http://gslc.genetics.utah.edu/units/dis ... tionbg.cfm

[August]

Hi Bgood,

Yes, it's an interesting scientific question. I want to point out though, that if you are referring to my previous post, I did not make an absolute statement. Insertions into DNA does happen. I believe I used the words "biased towards" and "almost never", when I described the tendency towards deletion. There are many studies confirming that bias, if you are interested.

The other point is that these insertions must also contribute to the increase in information, or complexity, for the organism that distinguishes it from it's primitive ancestors. The mutations must enable the characteristics necessary to serve as elements of that organisms evolution. For a mutation to qualify as a candidate for the long series of mutations required for evolution to happen, it must bring new information not only to the genome of the organism, but to the whole biocosm.

There is a high likelyhood that a mutation will be fixed in the current or next generation, thereby reducing the chances of any mutation being reproduced. A step in the evolutionary process consists of a rare beneficial mutation conferring a survival or reproductive advantage on the individuals that carry it, thereby leading over several generations to the spread of that characteristic throughout a population. Millions of these steps need to happen to cause the rise of new species.

I am not aware of any empirical evidence that this happens. Even the e-coli experiments show that beneficial mutations taper off after about 5000 generations, well short of the quantity of steps needed to create new species.

[BGoodForGoodSake]

Hi Bgood,

Yes, it's an interesting scientific question. I want to point out though, that if you are referring to my previous post, I did not make an absolute statement. Insertions into DNA does happen. I believe I used the words "biased towards" and "almost never", when I described the tendency towards deletion. There are many studies confirming that bias, if you are interested.

The other point is that these insertions must also contribute to the increase in information, or complexity, for the organism that distinguishes it from it's primitive ancestors. The mutations must enable the characteristics necessary to serve as elements of that organisms evolution. For a mutation to qualify as a candidate for the long series of mutations required for evolution to happen, it must bring new information not only to the genome of the organism, but to the whole biocosm.

There is a high likelyhood that a mutation will be fixed in the current or next generation, thereby reducing the chances of any mutation being reproduced. A step in the evolutionary process consists of a rare beneficial mutation conferring a survival or reproductive advantage on the individuals that carry it, thereby leading over several generations to the spread of that characteristic throughout a population. Millions of these steps need to happen to cause the rise of new species.

I am not aware of any empirical evidence that this happens. Even the e-coli experiments show that beneficial mutations taper off after about 5000 generations, well short of the quantity of steps needed to create new species.

Speciation is not quite that simple. Phenotypical distribution and isolation have alot to do with it as well, also mutations in which a single nucleic acid is swapped may not necessarily alter the shape of the resulting protein in a harmful manor. After multiple changes to genes it causes an organism to have a slightly different chemical consistency then its ansestors. This can allow for instance, an organism to take advantage of new opportunities if that chance arrises. Or as you said it could dissapear as there is nothing favoring it. I have written some computer programs which calls for random variations within an environment with a few basic laws. The results are astonishing. You can have order from chaos if there are first a few underlying principals or laws. Take crystal formation for example.

It is in the nature of the mechanism to create imperfect copies.

[AttentionKMartShoppers]

Crystal formation? Non sequitor...crystals are simple repeating patterns, while information is an entirely different matter, which instead of complying to atomic orientation, complies with a non-material gammer structure. If you say that DNA has self-ordering properties (Kenson, who wrote a book saying they do, later refuted his own work), all you'd get is a repeating letter or word sequence, like "the the the the the the"

[BGoodForGoodSake]

Crystal formation? Non sequitor...crystals are simple repeating patterns, while information is an entirely different matter, which instead of complying to atomic orientation, complies with a non-material gammer structure. If you say that DNA has self-ordering properties (Kenson, who wrote a book saying they do, later refuted his own work), all you'd get is a repeating letter or word sequence, like "the the the the the the"

Well replace a few letters in the sequence and you have a non viable organism. There must be some rules which DNA sequences have to follow. It only takes a few rules to create order. As in the crystal.

For example take a few hydrogen atoms and carbon atoms and they will organize themselves into methane. Continue and you'll see how order is created in the natural tendancy to increase entropy(chaos). There is no law which states information(order) cannot come from disorder.