Evolution of complexity/information

I just had to say, it's a strawmen.

What is a strawman? The comparison to Rube?

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Aslan is not a Tame Lion

I think this is why I drifted onto specific things. It is practically impossible to say this animal is more complex than that animal. It IS possible to say, this structure is more complex than that structure. The planaria is simple because it's eyes consist of some photosensitive cells that I presume are linked to neural pathways of some sort. It has about 2 features that I'm aware of that work together: the photo cells, and the neural pathways. I'm not quite sure what the next step up would be, but lets take an insect eye. It has lenses made of a crystalin material, these lenses have definate shape, together they form a dome, the sit atop photo cells at the right distance from the lenses, the cells are linked to neural pathways, that run to the brain, and there may be some more features that I'm not aware of. So let's say the fly's eyes have about 20 features or structures, that work together to serve a purpose that is beneficial, infact crucial to the flies survivability. I would consider this an increase in complexity.So, perhaps one measure of an increase in complexity can be an increase in the number of featres/structures along with an increase in interoperability of these structures.On the cellular level this would work by a prokaryote adopting other bacteria to serve as chloroplasts and mitochondria and becoming a Eukaryote. More interwoking features = more complex. Also, going from uni- to multi- cellular organisms would be an increase because more cells or features work together in one body.I'm not intending to bring this back off topic again and discuss the intricacies of the designs of these things, but I think in order to analyze complexity it is better to compare the interworking features of two similar elements of an organism, rather than the whole organism.

I agree with all your comments on complexity but they aren't useful. The topic of the thread is the evolution of complexity/information. Even if we can agree that the extreme cases (planaria eye to octopus eye) show an increase in our mysterious quantity of complexity it doesn't help.We need to know when complexity has changed more subtly than that.There are those who say that evolutionary processes can not increase complexity. I want to know if my cat is more complex than my neighbors dog. When that can be quantified then maybe we can talk about what various processes can and can not do.What we do know is that there are genetic mechanisms that with evolutionary processes applied can dramatically change (increase) the base pairs and the number of different patterns. I don't know how else you would describe this but as an increase in "complexity".The mechanisms can copy segments of the genetic code, modify existing parts and the copies. The evolutionary processes can drive these in ways which separate them based on their phenotypical effects. Just those mechanisms and processes are enough to make any genome we see from relatively simple ones.Until someone defines this thing called complexity more precisely and shows how it can not increase under these conditions the issue is settled.

But evolution deals with changes to one element of an organism at a time, so we cannot easily lump animals into classifications of complexity. We can analyze features by complexity. We can look at one feature and what it evolved from and determine if complexity increased or decreased. Using my definition of complexity and assuming my knowledge of cats and dogs is complete (which it probably isn't), I would say your cat is more complex than your neighbor's dog, because it has two added features: retractable claws and vertically slitted eyes which add to it's abilities. Well, reading the article Jar pointed me to on the eye, I learned that a simple mutation in a fly can cause eye lenses to form all over it's body. This would be an increase in genetic info and an increase in the number of different patterns, but the new eye lenses are not (TTBOMK) hooked to any nerves, and do not offer the fly any advantage and may decrease it's abilities (eyes on the wings and legs aren't aerodynamic or mechanically advantageous). Since the new patterns do not work together with the existing functions, they do not add complexity in my opinion, and would likely be weeded out under selective pressure. I agree. THIS has failed to be established. As Crashfrog pointed out, I could join the "legions of Biological scientists" engrossed in trying to understand and establish this. As I have pointed out, there are certain leaps in complexity (by my definition), which cannot yet be explained unless one imagines how they MIGHT have evolved. Because of this, I cannot confirm your statement as true.I think there are two forces at work in evolution. Natural selection is the positive force, which struggles to overcome the tendency towards randomness, which is the negative force. The question is: are the two forces in equilibrium or is one overpowering the other? I think the only way we can answer this is by looking at nature. Do we see mutations occuring in nature that add interoperating features/structures to an organism that improve its survivability? So far, I have not heard of any. On the other side of the coin, do we see mutations occuring in nature that inhibit features in a way that jeopardizes the survival of the ENTIRE species or retards the reproduction of the ENTIRE species? (as loudmouth pointed out all that matters is that the species survive) I MAY have heard of some. And since it APPEARS that extinctions outnumber speciations during this period of very light selective action (compared to earth's rough and roudy past) I am inclined to assume the latter occurs more often than the former, in which case overall complexity is decreasing. I don't think the issue is settled by a long shot. BTW do you accept my definition of complexity? If not, on what grounds?

Let's work backwards: I don't think it is a useful definition because it isn't precise enough or well defined enough for someone to take the definition and determine, for themselves, what the complexity of a given thing is. It isn't a quantifiable thing. I am not talking about the specific genome on phenotype of any particular oganism. What is true is that the mechanisms can create new genetic information (and have been shown to do so). There is nothing to stop them from continuing this process up to the extinction of a line. But that's why we need a good clear definition. useing your opinion doesn't help anything. Is part of the definition of increased complexity that it adds to survival? That wasn't there before. Why introduce it now.The idea of "Rube Goldberg" machines has been brought up. I don't think (but surprise me) that we would disagree that they are more complex than others. However, they may not work or not work well compared to a much simpler machine. If you want to introduce better or working into the definition of complexity you have an even harder time. This is getting silly! The dog has an exquisitly powerful sense of smell. Is that equal to retractable claws? Is it 5 CU's (complexity units) more complex than the claws? Is it less? There is no way of telling?The dogs hearing is better. We can play back and forth like this and maybe get to a definition for these two animals. Then when someone introduces an eagle we start all over again.The next two people who try get different answers from you and I. We have NOT got a USEFUL definition. It is fruitless to talk about something that you don't even know what the units it's in are much less how to calculate it. Then show me a complexity calculation when one small evolutionary change has happened. That is what I need to see to tell if it increased or decreased.There is this kid with the myostatin mutation. He appears to be very much stronger than average. He may, however, have cardiac problems later in life (don't know yet). Is he more complex or less complex than the kid down the street?

This is precisely the problem with trying to assign a complexity value to an organism, for I could just as easily say, canines have more complex social structure and interactions, and a more acute sense of smell than cats, and are therefore more complex. Either way it's an apples-and-oranges argument.In a way I agree that it is easier to assign complexity to features. As an example, my dogs have webbed toes and an extra, clear set of eyelids as adaptations to desert hunting, so perhaps an argument could be made that their eyes are more complex than a dog without such structures.Even feature-by-feature analysis has its issues - are slitted eyes really more complex than non-slitted eyes? I don't think it is quite that simple, and I see problems with even a semi-quantitative measure of complexity in this way.When it comes to quantifying complexity, is a webbed foot equivalent to a clear eyelid as a complexity "unit"?Perhaps complexity via a genetic route is a better measure, since we could measure numbers of genes in a gene family, or number of promoters per gene, or number of gene-gene interactions. But this also has its problems - fruit flys and nematodes have one Erbb gene, mammals have four Erbb genes, minnows have sixteen Erbb genes. But all this really describes is Erbb complexity, so it is like your "features" idea, except at a genetic (quantifiable?) level.We would really need a complete understanding of every genetic interaction in the genome of two organisms to create a complexity comparison.Sorry - I've realized I've rambled quite a bit, and contributed little to a working definition. Since we can't go back and witness evolution, perhaps there will always be a bit of imagination involved (just as a theory can never be proven). However, all of the pieces are there:Scientists have witnessed/established:
- mutation
- gene duplication events
- gene rearrangements
- the creation of novel hybrid genes with novel function
- frame-shift resulting in a completely novel gene with novel function
- speciation
- genome-level analysis that follows gene-by-gene evolution within a genusAt this point, it comes down to whether or not you believe DNA-based paternity tests, since essentially the same concept is used to establish ancestry of a species as is used to determine ancestry of a child.

[qs]At this point, it comes down to whether or not you believe DNA-based paternity tests, since essentially the same concept is used to establish ancestry of a species as is used to determine ancestry of a child.[qs] It just doesn't matter about the past. I'm not, yet, arguing for these mechanisms having caused the emergence of any given animal. I'm just pointing out that they CAN cause large changes in the genome. Apparently without any clear limit.Now since they can do this the question becomes; "Did they?"That is where we look to DNA patterns.

Me too - your reply reiterated what I was trying to get across... though I could see how my point might have got lost...The one part that confuses me: Your "did they?" question and DNA pattern answer seems to require using ancestry concepts ("the past") - what am I missing here?(As a clarification - my point in bringing up the ancestry tests was to state: describing relatedness of species (or comparison of genetic complexity; or description of evolution at genetic level) by DNA sequence analysis is usually considered a "leap of faith" by many anti-evos; even those that accept both the genetic changes in my bulleted list, and DNA-based paternity tests.)

You elided too much. What I was trying to say is that first we establish that the processes can produce changes of a type that we are interested in. Then we can move on from there and ask if they did.We can (and have)prove that they can and then, from evidence like the DNA comparisons, can strongly infer that they, in fact, did.

Right - Hangdawg already agreed to the processes more than once, that's why I wasn't sure why you were still arguing them. Since we've established the processes, aren't we at this point?
That's why I was taken aback with the "it just doesn't matter about the past" comment.I think we're arguing but saying the same thing - no need to respond unless I'm way off...

Perhaps I should be embarassed for not paying more attention.

We have established that these processes CAN produce changes. As to whether or not they are capable of accumlating these changes so that a new structure with interoperable features (such as the eye) has NOT been established. And you are right, we must move on from there and ask if they did/are to settle the question. Since we only see eyes A and B but not A.1 A.4 A.6 A.7 A.8 and B this does not settle the question. We would have to try to find a mutation that causes a new feature that would improve the survivability of the organism. I think there may be a few examples dealing with simple one step structures like webbed feet.Also, we would have to look at nature and determine whether or not natural selection is capable of removing the far more abundant detrimental or non-essential changes, which I have not seen clear evidence of either. But the romantic notion that "life finds a way" seems to me based more in the imagination than the real world. By this do you mean the fact that several organisms share the same gene to control the same features?

Thank you for acknowledging this. Perhaps you will understand a little better why I don't like it when people tell me evolution (as in single cell to us)is a FACT and that no true scientist would deny evolution.

It has also been shown that the accumulation can happen when natural selection is operating. The processes and mechanisms can be simulated and they behave as the theory needs them to. That is correct. We would like to see every single step but for almost all cases we won't. However, if we see A.1 and A.6 and A.8 and they are moving in the direction of B we might be willing to infer with some confidence that the other steps happened. The more we see the more confidence we have without haveing 100 % certainty. What evidence do you need to be satisfied? That is a small part of the story. You spoke of seeing A.1, A.2 etc. The fossil evidence for those isn't the only evidecne. The patterns of changes in the genes (especially non coding DNA) is another form of it. Sometimes the steps are still showing and haven't been confused by too many changed which has overlaid others.It is all of the sharing, the build up of changes (that matches pretty closly the historic record and the classification based on morphology) and the nature of the changes that overlay with each other.