Degeneration > evolution

[Saviourmachine]

Corruptions of old information is more likely

Yes, without any proof out of practice, I based that on stochastics. Information out of the environment can be pushed in an organism by natural selection in adding new or deleting/corrupting old information. When speaking about a random process that handles these additions of new information and corruptions of old information, I think the last option is easier for her. For you, field men, it’s maybe utter nonsence, but for me it sounds very reasonable.

Read very carefully! Both processes push information about the environment in the organism through natural selection.

It's like this:
A. ACT TTG "CODE FOR A TAIL" ATTC enz.
Now nature selects against a tail, what would you expect?
B1. ACT TTG "DO NOT" "CODE FOR A TAIL" ATTC (with added genetic code) or
B2. ACT TTG "CDE FOR A TAIL" (with some code destroyed)

as I said, we already know that it is extra instructions that do these things.

And that's what everybody says here, but I think I should never comprehend this, if you don't explain me, why B2 isn't probable.

 

[Arikay]

a thought, if he is talking about the addition or deletion of features and not individual mutations, then could IC be a reason for the apparent "upward" change in evolution?
Since we know in a supposed IC system, any deletion of a section of that system will cause the entire system to fall (except for a deletion thats exactly the same as the addition that created the IC system). So an addition of a feature, or the addition of a full off switch for a certain feature, is more likely than a deletion.

If that makes any sense.

 

[Saviourmachine]

Ah, Arikay, that sounds very reasonable for me. Can you give me some links about IC systems?

I don't think there is any definition of information that can be applied to the subject. All our intuitive notions of "information" fail here. The problem is that the DNA codes for an individual organism and that organism goes thru a developmental process that amplifies what is in the DNA in ways that don't allow a linear correlation from DNA to individual. And it is the "complexity" of the organism on which we base our ideas of "information", with the more "complex" individual representing more information.

Once, you should give it a try. It's not a linear correlation, but there is correlation. Besides, the system is converting information from the environment into an organism. There is information, although you can't define it in a proper way, yet!

 

[Saviourmachine]

http://www.genetics.org/cgi/content/full/156/1/297
"The high deleterious mutation rate in humans presents a paradox. If mutations interact multiplicatively, the genetic load associated with such a high U would be intolerable in species with a low rate of reproduction (MULLER 1950 ; WALLACE 1981 ; CROW 1993 ; KONDRASHOV 1995 ; EYRE-WALKER and KEIGHTLEY 1999 ). The reduction in fitness (i.e., the genetic load) due to deleterious mutations with multiplicative effects is given by 1 - e-U (KIMURA and MORUYAMA 1966 ). For U = 3, the average fitness is reduced to 0.05, or put differently, each female would need to produce 40 offspring for 2 to survive and maintain the population at constant size. This assumes that all mortality is due to selection and so the actual number of offspring required to maintain a constant population size is probably higher. The problem can be mitigated somewhat by soft selection (WALLACE 1991 ) or by selection early in development (e.g., in utero). However, many mutations are unconditionally deleterious and it is improbable that the reproductive potential on average for human females can approach 40 zygotes. This problem can be overcome if most deleterious mutations exhibit synergistic epistasis; that is, if each additional mutation leads to a larger decrease in relative fitness (KONDRASHOV 1995 ; CROW 1997 ; EYRE-WALKER and KEIGHTLEY 1999 ). In the extreme, this gives rise to truncation selection in which all individuals carrying more than a threshold number of mutations are eliminated from the population. While extreme truncation selection seems unrealistic, the results presented here indicate that some form of positive epistasis among deleterious mutations is likely."

Degeneration after all?

Would anybody explain me what positive epistasis is?