Hey guys,
I'm new to the board, but I've been reading up on the latest posts here, and instead of trying to jump into conversations already in progress (many of them drifting way off original topic), I decided to start a new topic.
First off, I'm a Christian, but am not a "creationist". I've come to accept (at least tentatively) some of the work of ID theorists such as Dembski, Behe, etc. However, as one who is dedicated to science, I'm not married to theories, as they are (by their very nature) falsifiable, therefore I have no reason, emotional or otherwise, to accept any scientific conclusion based on anything but the facts.
I generally accept the age of the universe/earth as best theorized by cosmologists and geologists, and accept the theory of natural selection as a mechanism for change in biological organisms.
I do, however, also take seriously the logical inadequacies of the best theories for the evolution of Irreducibly Complex features in biology, which I may discuss further in later threads.
Also, and this is my main concern presently, I have serious questions about the process by which natural selection works on in which to provide novel functionality to biological organisms. I think I read here that you guys don't consider Darwinian evolution to be a progressive process NECESSARILY, but that many times it is progressive.
My question is, what proof do you have that Darwinian evolution is an informationally positive process? Can you provide examples of net information gain simply by a series of random mutations, preserved by natural selection? Please let me know if I need to provide more details.
Pregressive evolution?
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Post #41
Hi diggnate,
Here’s another puzzler. (Yes it is my day off) I’m quoting from the NewScientist 12 August 2006.p12
I’m going to assume for argument sake that there is no loss of information. But then what about some unique disease that does not yet exist that finds it easier to break down the Hox1 gene because it is that bit bigger than either the Hoxa1 or Hoxb1. The difference made is such that instead of the mice becoming ill but surviving, the disease is now fatal.
However maybe the larger Hox1 gene provides greater mathematically probability of a disease surviving mutation. The disease then wipes out all the mice save those with the mutation. These mice being less affected by the disease that the ill Hoxa1/Hoxb1 mice. So there could be an over all net gain.
So there has been some possible information loss or has there?. How on earth do we come to objective decision making criteria?
Here’s another puzzler. (Yes it is my day off) I’m quoting from the NewScientist 12 August 2006.p12
The two genes make the same protein, but in different places in the brain, and at different times…..a billion years ago, the size of our ancestors’ genome quadrupled. With four copies of every gene knocking about, genes either had to make themselves useful, or be swiftly dumped. The quadrupling meant that 13 Hox genes, which control the development of body shape, became 52. The ones that didn’t mutate to do something useful were lost, so today mammals have 39 Hox genes.
Tvrdik and Capeccchi focused on two that were originally duplicates but have evolved to perform different functions. Hoxa1 controls brain stem development in the early embryo, while Hoxb1 directs nerve growth in an area of the brain that controls facial expression.
Ok the genotype of the newly engineered Hox1 mice has been reduced. Their genetic code is simpler. If the genetic code of the mice has been reduced there are now slightly less places for mutation occur. This seems a clear case of loss of future possibilities. Does this count as loss of information? However the mice develop just as well. Does that count as no loss of information?…Tvrdik and Capecchi attached the regulatory sequence from Hoxb1 - which turns the gene on later in fetal development - to the Hoxa1 gene. That way, one gene did the job of two. Mice with the new Hox1 gene, but with their Hoxa1 and Hoxb1 genes knocked out, developed normally.
I’m going to assume for argument sake that there is no loss of information. But then what about some unique disease that does not yet exist that finds it easier to break down the Hox1 gene because it is that bit bigger than either the Hoxa1 or Hoxb1. The difference made is such that instead of the mice becoming ill but surviving, the disease is now fatal.
However maybe the larger Hox1 gene provides greater mathematically probability of a disease surviving mutation. The disease then wipes out all the mice save those with the mutation. These mice being less affected by the disease that the ill Hoxa1/Hoxb1 mice. So there could be an over all net gain.
So there has been some possible information loss or has there?. How on earth do we come to objective decision making criteria?
Post #42
well, you guys have given me some interesting things to think about. I'm by no means "closing the discussion" so please keep it up. I'll be around too.
I don't know about you guys (since I'm new here), but I really enjoy the intelligent conversation. Thanks for it.
By the way, I want to clarify, again, the purpose of my argument.
So far, we agree that most, if not all, mutations are deleterious (as quoted by prof. Dawkins). The rest could possibly add new information and function, but at the expense of a previously useful functional piece of genetic information.
I guess my question is, if this is the nature of the generation of complexity, then how can evolution be a truly progressive process, going from 500,000 base pairs or less, to over 2 billion? Could polypoid mutations be the answer for new potential mutations? If not that, then how do we gain genes without actually, at first, reducing our reproductive efficiency, something that natural selection would inevitable select against? Where do to genuine novelties come from? Where does the new gene capacity come from? How do we go from a very limited number of gene specified functions in bacteria, to the limitless number of gene specified functions in humans, if the generative mechanism does nothing more than "plus 1 minus one", and does so on a limited number of genes?
Anyway, thanks for all the help!
I don't know about you guys (since I'm new here), but I really enjoy the intelligent conversation. Thanks for it.
By the way, I want to clarify, again, the purpose of my argument.
So far, we agree that most, if not all, mutations are deleterious (as quoted by prof. Dawkins). The rest could possibly add new information and function, but at the expense of a previously useful functional piece of genetic information.
I guess my question is, if this is the nature of the generation of complexity, then how can evolution be a truly progressive process, going from 500,000 base pairs or less, to over 2 billion? Could polypoid mutations be the answer for new potential mutations? If not that, then how do we gain genes without actually, at first, reducing our reproductive efficiency, something that natural selection would inevitable select against? Where do to genuine novelties come from? Where does the new gene capacity come from? How do we go from a very limited number of gene specified functions in bacteria, to the limitless number of gene specified functions in humans, if the generative mechanism does nothing more than "plus 1 minus one", and does so on a limited number of genes?
Anyway, thanks for all the help!
Nathan
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Post #43
New Sceintist, 31 MArch 2007 p18, How Selfish DNA saved the fruit fly.
This appears to be a case of “information gain”. In fact one mutation in its DNA left the fruit fly gaining masses of information without even knowing it. The rise in its detoxification agent lead to resistance to multiple number of insecticides. So I guess each insecticide the fruit fly is resistance to counts as ad additional piece of information gain. Well no the whole information gain notion is completely bogus. All it would take is for some predator to find the fruit lies detoxification agent to be particularly tasty, and then you get negative information. Or if humans stop using insecticides then the change is informational neutral.Selfish DNA has caused an entire species to become resistant to a range of insecticides in just 40 years…..The bit of selfish DNA involved, called Accord, is a transposable element that jumps around the fruit fly genome copying itself. When Accord landed un Cyp6g1, a gene that makes a detoxification agent called cytochrome P450, things got interesting. Accord copied itself and jumped out again, leaving behind a 149 base pair footprint- a section of DNA called a long terminal repeat (LTR)….This LTR just happens to express itself in exactly the same way as Cyp6g1. With double the amount of detoxification agent was made-and the insect became resistant to the insecticide, as well as a whole slew of new insecticides.
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Post #44
Duck With Four legs
Genetic mutation can throw up strange anomalies A duck with four legs for instance. However is this informationally positive or negative? Well the extra legs could be a hindrance or a bonus depending on environment. In most environments there is probably no advantage, but can we say that about all environments? If that is right then that just shows that the notion of informationally positive is empty of merit, because the nay Sayers against evolution can point to the negative aspect of attaining four legs to the life of a duck, whilst the evolutionist try to point to the advantages. But of course the negatives and positives are purely relative to environment, and whether they change in the phenotype works towards purveying that form across generations.
Genetic mutation can throw up strange anomalies A duck with four legs for instance. However is this informationally positive or negative? Well the extra legs could be a hindrance or a bonus depending on environment. In most environments there is probably no advantage, but can we say that about all environments? If that is right then that just shows that the notion of informationally positive is empty of merit, because the nay Sayers against evolution can point to the negative aspect of attaining four legs to the life of a duck, whilst the evolutionist try to point to the advantages. But of course the negatives and positives are purely relative to environment, and whether they change in the phenotype works towards purveying that form across generations.
Post #45
I apologize if I bring up things that have been discussed already; I haven't gone back and read the whole thread (I probably should). I'd like to comment on some of the recent posts.
Looking at the duck with four legs, I'd say this is most likely not a mutation, but a developmental hiccup, rather like the epidemic of frogs in the US with similar anomalies. In the case of the frogs, it's been traced to an infection that screws up molting. (It was first thought to be chemical pollution.) One can create the same kinds of anomalies in, say, cockroaches by taking a young nymph, cutting off part of a left and right leg, and then gluing them back on, with the left leg on the right side, the right leg on the left side. When the nymph molts to a larger size, there are mirror-image legs growing out of the junctions where the legs were glued on.
There are models to explain why this works, but that's a bit off-topic. The point is: chemical or physical interference with development can produce these kinds of duplications. Sometimes they are legs, sometimes heads. The duplications occur as a result of the cells following the normal rules of development, producing the duplications as a way of resolving the "conflict" produced by the interference. It does not require genetic change (ie mutation).
As for information gain, there are many, many instances of gene duplication. Most are inferred from comparison among species, rather than watching it happen. Even so, there are few, if any, alternative explanations to account for the DNA sequence data.
A gene duplication, initially, just doubles the number of genes that are duplicated. This may not count as additional information. But, over time, as mutations occur in the DNA, one copy is usually selected to maintain the original function, while the other copy diverges. The divergent copy is new information. Often, mutations in the divergent copy make it non-functional, but other times, divergent copies remain functional, and acquire functions that did not exist previously.
This is a bigger addition of information than is an LTR of a transposable element, though that, too, represents addition of information. Gene duplication is particularly significant when it encompasses whole chunks of chromosomes, and duplicates hundreds of genes.
As far as I know, evolutionary geneticists consider gene duplication to be the most common mechanism for increasing information in the genome.
Looking at the duck with four legs, I'd say this is most likely not a mutation, but a developmental hiccup, rather like the epidemic of frogs in the US with similar anomalies. In the case of the frogs, it's been traced to an infection that screws up molting. (It was first thought to be chemical pollution.) One can create the same kinds of anomalies in, say, cockroaches by taking a young nymph, cutting off part of a left and right leg, and then gluing them back on, with the left leg on the right side, the right leg on the left side. When the nymph molts to a larger size, there are mirror-image legs growing out of the junctions where the legs were glued on.
There are models to explain why this works, but that's a bit off-topic. The point is: chemical or physical interference with development can produce these kinds of duplications. Sometimes they are legs, sometimes heads. The duplications occur as a result of the cells following the normal rules of development, producing the duplications as a way of resolving the "conflict" produced by the interference. It does not require genetic change (ie mutation).
As for information gain, there are many, many instances of gene duplication. Most are inferred from comparison among species, rather than watching it happen. Even so, there are few, if any, alternative explanations to account for the DNA sequence data.
A gene duplication, initially, just doubles the number of genes that are duplicated. This may not count as additional information. But, over time, as mutations occur in the DNA, one copy is usually selected to maintain the original function, while the other copy diverges. The divergent copy is new information. Often, mutations in the divergent copy make it non-functional, but other times, divergent copies remain functional, and acquire functions that did not exist previously.
This is a bigger addition of information than is an LTR of a transposable element, though that, too, represents addition of information. Gene duplication is particularly significant when it encompasses whole chunks of chromosomes, and duplicates hundreds of genes.
As far as I know, evolutionary geneticists consider gene duplication to be the most common mechanism for increasing information in the genome.
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Post #46
Hi Jose,Jose wrote:I apologize if I bring up things that have been discussed already; I haven't gone back and read the whole thread (I probably should). I'd like to comment on some of the recent posts.
Looking at the duck with four legs, I'd say this is most likely not a mutation, but a developmental hiccup, rather like the epidemic of frogs in the US with similar anomalies. In the case of the frogs, it's been traced to an infection that screws up molting. (It was first thought to be chemical pollution.) One can create the same kinds of anomalies in, say, cockroaches by taking a young nymph, cutting off part of a left and right leg, and then gluing them back on, with the left leg on the right side, the right leg on the left side. When the nymph molts to a larger size, there are mirror-image legs growing out of the junctions where the legs were glued on.
There are models to explain why this works, but that's a bit off-topic. The point is: chemical or physical interference with development can produce these kinds of duplications. Sometimes they are legs, sometimes heads. The duplications occur as a result of the cells following the normal rules of development, producing the duplications as a way of resolving the "conflict" produced by the interference. It does not require genetic change (ie mutation).
As for information gain, there are many, many instances of gene duplication. Most are inferred from comparison among species, rather than watching it happen. Even so, there are few, if any, alternative explanations to account for the DNA sequence data.
A gene duplication, initially, just doubles the number of genes that are duplicated. This may not count as additional information. But, over time, as mutations occur in the DNA, one copy is usually selected to maintain the original function, while the other copy diverges. The divergent copy is new information. Often, mutations in the divergent copy make it non-functional, but other times, divergent copies remain functional, and acquire functions that did not exist previously.
This is a bigger addition of information than is an LTR of a transposable element, though that, too, represents addition of information. Gene duplication is particularly significant when it encompasses whole chunks of chromosomes, and duplicates hundreds of genes.
As far as I know, evolutionary geneticists consider gene duplication to be the most common mechanism for increasing information in the genome.
I believe Duck's with four legs has been observed before. So it is not unprecedented, and I suspect there is some common mechanism at play.
The problem I have with the concept of "informationally positive" is its semantic slipperiness. The way diggnate has introduced this idea is that the information that counts is at the level of the phenotype. So a duplication and increase in the number of genes that lead to say permanent stomach ache would be information ally negative. But then if that means there is then some potential alternative food group that the organism can take advantage of that would be informationally positive I guess. So the increase in the genetic code is then informationally neutral. The Iders like diggnate are saying that for evolution to be a successful theory it must account for informationally positive developments. Of course every example given then gets rejected as negative or neutral. Thus evolution is not a successful theory because it cannot account for informationally positive changes. But this is amounts to no more that a card trick. Like playing Black Jack, except to beat the house one must draw 23 with only two card to win. What is really the problem is not the theory of evolution but the notion of informationally positive.
Post #47
Slippery definitions are a problem, all right. If we are going to talk about "information" with respect to biology, we're pretty much stuck with DNA sequence. That is the information. Is a change in DNA sequence positive, neutral, or negative? That often depends on the environment in which the organism finds itself. A phenotype that is negative in one context may be positive in another, and neutral in others. A change in phenotype, determined by a change in information, is a change in phenotype, regardless of its positive or negative impact.
Where evolutionary theory makes sense is in evaluating what happens when a phenotypically-relevant change in information occurs. If it has a positive impact, it improves the individual's survival and reproductive success. If it has a negative impact, it tends to disappear as individuals die or fail to reproduce efficiently. This sort of thing has been documented so many times, it's no longer in dispute.
Where evolutionary theory makes more sense than ID is in explaining stupid designs. If our photoreceptor axons came out the back of the retina, instead of the front, we wouldn't have a blind spot. A blind spot is a dumd design. But from an evolutionary perspective, it makes sense if backwards photoreceptors were there first, and worked OK as light-sensing organs. By the time we've got an image-focusing lens, the rest of the system is there--and to turn the photoreceptors around would require an intermediate step of lousy vision. Lousy vision would be selected against. So, we end up with a goofy eyeball with backwards photoreceptors and a blind spot where the neurons dive through the retina toward the brain.
The trouble with evolutionary theory is that it's so straightforward, the IDers have to create difficult-sounding scenarios to make it sound like evolution can't work. In general, though, they're laboring under misconceptions of how evolution works. If you really believe that evolution requires building new structures from the sudden appearance of all of the genes needed, then you're going to laugh at how dumb evolutionists must be to think such things can happen. What they don't do is address the actual theory of evolution using actual observations.
Where evolutionary theory makes sense is in evaluating what happens when a phenotypically-relevant change in information occurs. If it has a positive impact, it improves the individual's survival and reproductive success. If it has a negative impact, it tends to disappear as individuals die or fail to reproduce efficiently. This sort of thing has been documented so many times, it's no longer in dispute.
Where evolutionary theory makes more sense than ID is in explaining stupid designs. If our photoreceptor axons came out the back of the retina, instead of the front, we wouldn't have a blind spot. A blind spot is a dumd design. But from an evolutionary perspective, it makes sense if backwards photoreceptors were there first, and worked OK as light-sensing organs. By the time we've got an image-focusing lens, the rest of the system is there--and to turn the photoreceptors around would require an intermediate step of lousy vision. Lousy vision would be selected against. So, we end up with a goofy eyeball with backwards photoreceptors and a blind spot where the neurons dive through the retina toward the brain.
The trouble with evolutionary theory is that it's so straightforward, the IDers have to create difficult-sounding scenarios to make it sound like evolution can't work. In general, though, they're laboring under misconceptions of how evolution works. If you really believe that evolution requires building new structures from the sudden appearance of all of the genes needed, then you're going to laugh at how dumb evolutionists must be to think such things can happen. What they don't do is address the actual theory of evolution using actual observations.
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