Evolution and complexity

It's nice to think about 'complexity niches', but I agree, it's hard to think nature has such things. However, you can think of 'size niches', often you can move over a bigger distance, reach higher leaves, and so on when you're bigger. And a bigger size often requires a more complex organism.Ordinarily, I relate complexity with robustness (reversed proportional). If I think of size in stead of complexity it makes the issue a little bit easier for me.Problem: If you define some kind of niches, the top ones are only able to evolve further. They are most often able to fill a niche of another kind when they find it, isn't it? And will (d)evolve in this before unknown area. So, if the reptile-ancestors conquer the world, the mammals-ancestors wouldn't get a chance. Maybe a catastophe will explain some things, but wouldn't the old species not evolve faster then some new mutants? Or do kinds lose some elasticity by evolving?

Thanks! It was what I was thinking intuitively, for the reasons I explained. Bigger organisms can cover greater distances, reach higher leaves, have predator advantage, overcome natural barriers more easily (why do you think birds are so succesful?), and so on. I do not want to define complexity or information, I never found a good definition. Nobody did give me one, neither. Do you want to give me one?It's only based on the idea that size not can be extended without adaption. A little example: the large neck of the giraffe has consequences for the blood circulation. I think it requires more often a more complex organism in stead of a less complex organism. You can overwhelm me with counterexamples if you want. Problem, summarized: What's the chance that new mutants will overcome old species (even if there occurs some catastrophe)?[This message has been edited by Saviourmachine, 01-31-2004]

Okay, maybe there aren't things as 'size niches' neither. It was an attempt to search for an alternative for 'complexity niches'. It's almost answered by MarkAustin, maybe it's out of context, but it has some parallels. What kind of environment changes do you think of?

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I was playing devil's advocate, because I'm not convinced about the working of the evolution mechanism in biological sense. I would rather say that there is some decrease in complexity from a range of ancestors until current life. But I don't want to say much about that before an evolutionist will define 'information' and 'complexity' for me.I want to give it a try first:Definition of information
I'm thinking of information in terms of
1. the amount of genetic variety in a population
2. the amount of genetic material in an individual / a population
3. the amount of genetically-regulated abilities
4. the amount of variety in the natural environmentI see natural selection as that thing that transfers information type nr. 4 to information type 1, 2 and 3. There are three ways to do this:
A. add new information of type 1, 2 or 3
B. change old information of type 1, 2 or 3
C. delete old information of type 1, 2 or 3
(everything with the result of synchronizing information of type 4 with the other types)If you accept the evolution theory (from unicellular life to current life) you're stating that A and B will occur more often then C.That's not likely for me, I will give you an example: I would expect type 1C on the grounds that the mutations have a more or less randomly nature. Why do you expect type 1A or 1B?
(I know that this happens sometimes by the way, but I don't see why this should happen, and neither why this generally should happen)[This message has been edited by Saviourmachine, 01-31-2004]

I think information is related to complexity. It seems at least the Kolmogorov-Chaitin information theory tells that, where complexity is related to the length of the shortest program it would take to output a specific string.
Maybe you don't see biological systems as complex too, why is that?[This message has been edited by Saviourmachine, 01-31-2004]

So, the point is this? That's why I defined 4 types of information (take a look at number 4).I defined natural selection as the process that transfers 'information' about the environment to the organism/specie. How would you define natural selection?Let's try to find an analogy. Speed? Moving organisms have some speed. A quantity has a lowerlimit and an upperlimit. Somewhere on earth you will find the fastest animal, somewhere the slowest. They've to be there, although nature doesn't explicit select for a particular side. Actually, nature does select a little bit for a higher speed, I think. Maybe blood temperature is a better quantity. Correct me, if you find some flaws.Complexity is only a side-effect, just as blood temperature. If nature doesn't have a mechanism what favours complexity, why is there such a range in current life? You do not have to accept that there is a creator, but you've to admit that 'natures nature' is very creative. To keep it simple: I do not understand, why you think that declaring complexity as a side-effect will explain (high) complexity in current life.

Definition of complexity
It’s even more difficult to find a definition for complexity then for information. So, I prefer a definition in relation to information: complexity on a certain level is proportional to the amount of information on that certain level. I defined 4 types/levels of information. An increase of information on level 2 will lead to an increase of complexity on level 2. It says nothing about information/complexity on other levels.
I want to illustrate this with an example: Adding a regulator gene (level 2) will lead to increase of information of type 2. If it is switching off some ability, it’s decreasing information of type 3 and the complexity on level 3 is decreasing.Maybe there are situations were adding information on a certain level will lead to a decrease of complexity on that very same level. In that case, I’ve to include a possibility for fluctuations in the definition, but I think that the definition generally holds.

Yes, complexity is that important! First question; yes. It's necessary for declaring the observed difference in complexity over time. Second question; no. Increase or decrease, it doesn't matter, if it changes it's okay, that's evolutionary change. But it counts for an increased level of complexity over time. You can call that evolution on the big scale. It's the observed hierarchy in the layers. Yes, that's where I'm afraid of. Adaptation doesn't have to lead to an increase, but maybe it's worse, why should it generally lead to an increase at all? (it does maybe only in some extraordinary cases as in the case of the 'nylon' bacteria) Of course, we do. But in generally over time everything became more complex (from unicellular life to mammals/birds).It seems natural selection is indirectly prefering adding of code/abilities above deleting them. Why isn't adaption by deletion just as probable as adaption by addition/insertion? An explanation of the example of the human tail would help, I think (see above).[This message has been edited by Saviourmachine, 02-05-2004]

I don't know, doesn't matter. I'm not looking at different branches, but at ancestors. If I may give it a try, I would think the organism that endured more time on the planet, became more complex (that's the dino, isn't it?). But I don't understand the process behind. Sorry, you're right. It's not everything (although I'm thinking that even microbes are more complex now). It's about that percent or less.Can you explain me this exception of an exception of an exception?

If it is a Bell-curve then it will be okay. But I don't think that that's a right representation. It looks for me as some steepy cliffs in the biological landscape.I understand your point like this: no matter how the evolution mechanisms function, even if it's generally destructive, there have to be some exceptions due to statistics.

Okay if ToE doesn't predict this, please give me the chance on a complexity-adding adaption. That has to be far less then the chance on a beneficial mutation by the way, (because you're all speaking about exceptions).

What is the chance that such a thing occurs? Almost zero?What is the complexity-adding mutation rate? Almost zero?What is the time organisms needed to reach known complexity-levels? Almost infinity? Is 65 millon year from the K-T event enough?

I defined complexity in post 27. We haven't agreed about an increasing complexity level, no. Indeed, we didn't. Maybe everything is just devolving from a range of complex ancestors, sort of Noah's story with super-devolving species. I thought the layers were teaching us something different. I'm not comparing the triceraptops from before the KT boundary with current life!!! I only want to compare a mammal (palaeomastodon?) from before the KT event with the now existing elephant.Or do you all think that, if I'm coupling complexity with information, every creature on our planet nowaydays, is of the same complexity level? So: trillions = amount of individuals over whole earth in short period * amount of mutations. Yes, why not? But you did only use pro-numbers.pros:
amount of individuals per generation
amount of generations over time
amount of mutationscons:
amount of beneficial mutations (versus other mutations)
amount of complexity-adding mutations (versus beneficial mutations)
probability that nature selects sufficient for the mutation
probability no bad luck happens to the bearer
probability of inheritance (Mendel)

You're right! That's true. But if there is no way to decode it, and information of the higher level (type 3) doesn't exist, this complexity of type 2 will not lead to complexity of type 3 (see post 21/27 for the different types).What does the fossil record tell you?Does proportional mean linear? I didn't know. It can be quadratic and so on, but I clearly suggest a positive defined relation between information and complexity on the same level. Try a definition yourself. I started with Kolmogorov-Chaitin (post 23), and that was not good enough (post 26). Do you have something better?If I'm speaking about increase, decrease, then it's qualitative. Maybe sometimes in orders of magnitudes, but not quantitative. Until now I used reasoning, no numbers. That's a difference that's obvious for every person. What's the biological term for this difference????

The dual coding system [2CS] (italicization is mine) It seems you've the same idea as me about the relationship between complexity and information. Thanks to the dual coding system there is more information on the protein-level, so you can call it more complex. If the second coding system shouldn't result in a protein, it's not adding that much complexity isn't it? Or does it? We've to discuss about that.There are 3 things to think over:
- the coding system, is it a kind of information? or does it only transfer information from one level to the other?
- is it possible for a 2CS to work in 'more advanced organisms' (because apperently nature selected against it)? does it hinder the appearance of beneficial mutations (nature can not optimize properties one by one in the 2CS)?
- are there realy no similar systems developed in 'more advanced organisms'?At least, you're right, that eukaryotic cells can be more sophisticated on a particular level, but that's why I defined more levels. So, it's not only the amount of base pairs, it's not only the amount of proteins, it's not only the amount of DNA-regulated abilities of a cel or an organism. But if all those are generally more complex / contain more information, then I want to call that organism more complex.

The complexity of the food chain. I think you're right about suggesting that there are more kinds of complexities envolved (I'm also thinking that time does effect this kind too, by the way).It seems that you're relating this 'food chain complexity' with 'organism complexity' in the second part of your post. How? I think being predator is just as dependent of 'size' or 'speed' then of 'complexity' of the organism. In post 16 I suggested 'size niches' in stead of 'complexity niches'. NosyNed said that it was a rather rambling post... And indeed, it's difficult to sustain this with stochastical information or things like that.