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Author | Topic: The Origin of Novelty | |||||||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Here's a picture showing various possible stages of the evolution of the eye: Darwin actually did a good job of discussing the evidence as it concerns the eye (at least in molluscs):
quote: This hits on two parts. First, a transitional fossil is not necessarily ancestral. This was made plain by Darwin from the very start. A transitional is a fossil or living species that show "gradations having been transmitted from the earlier stages of descent, in an unaltered or little altered condition". And of course we can point to much simpler eyes, such as those found in basal urochordates and planaria.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
But let's look at this more seriously than the sort of canned explanation that is popular amongst evolutionists. I think subbie gave you evidence in post #7 that might help in this conversation: "The website for Encyclopedia Britannica has a very nice graphic showing various stages in the process, including an example of a currently living organism for each stage." (emphasis mine) We see the transitional stages.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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The problem I think being posed is how close evolutionists can come to providing direct evidence of evolution producing novelty by using examples. That was already done in a previous post [edit: a previous thread actually]. We used melanism in pocket mice because we could trace the adaptation to specific mutations in a specific gene: "We conducted association studies by using markers in candidate pigmentation genes and discovered four mutations in the melanocortin-1-receptor gene, Mc1r, that seem to be responsible for adaptive melanism in one population of lava-dwelling pocket mice."Just a moment... So we can point to specific mutations that give rise to novel phenotypes. Edited by Taq, : No reason given.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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So, what kind of semi-aquatic creatures do you have in mind, that were descended from a species of animal with no skin between their toes? Dog breeds adapted to water are a good example. For example, Newfies have much more webbing between their toes than wolves do. This is because this trait was selected for by breeders who were looking for a dog that is a strong swimmer (Newfies helped with gathering nets and saving those who fell overboard). We also understand the developmental pathways that are involved. We all start with webbed phalanges. During development a process called apoptosis removes the skin between them. For webbed feet, all you need is a mutation that turns off apoptosis during this period of development.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Read the first sentence, I said elucidate a plausible chain of events. What makes it plausible is that each stage offers an advantage over the previous stage. A depressed pit offers crude directionality. Pinching the opening to a pin point can produce a focused image just like a pinhole camera. Covering the opening protects the sensitive retina. Manipulating that covering offers much better focusing, more light, and a better image.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
I think Bolder-dash is looking more for structural novelties (though it's ultimately up to him). He understands that many structures have predecessors, such as legs evolved from fins, but if at one time you had a creature whose body had nothing where his distant descendants have fins, how did fins originate? It would appear to me that Bolderdash wants to see these changes on such a fine scale that they will cease to be novel structures as they will be slight modifications of what is already there (just as your fins to legs example demonstrates).
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Perhaps a better example would be the evolution of the mammalian middle ear where bones change function in a stepwise manner.
Reptiles have one middle ear bone and three lower jaw bones. Mammals have three middle ear bones and one lower jaw bone. So what happened? When mammals evolved from reptiles two of those jaw bones became middle ear bones (in an irreducibly complex system, nonetheless). There was even an intermediate step where there was a double hinged jaw joint. 29+ Evidences for Macroevolution: Part 1
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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I believe one of the biggest failures of the evolution camp is their inability to elucidate any plausible chain of events that leads to a new novel feature, which can be seen in modern animals. I think this is a good example of the disconnect between scientists and the general public. How a scientist views a problem is quite different from how you may view that same problem. I can understand why people think scientists are jumping the gun when there are still so many basic structures that do not have a well understood evolutionary history. Hopefully I can explain where scientists are coming from. Scientists have to be pragmatists and use the evidence they have in front of them. This set of evidence is always going to be imperfect, and there may be evolutionary pathways that may never be known, ever. However, theories are meant to be an explanatory framework for the facts we DO have, and in that sense the theory works amazingly well. Time and again we see a nested hierarchy. We see lineage specific adapations. We see the fingerprints of evolution wherever we look in biology. Time and again the evidence fits what the theory of evolution predicts it should be. The theory explains what we know in biology. That is why it is accepted by over 99.9% of degreed biologists worldwide.
The theory about how new novel features have arisen, such as eyes, or noses, or internal organs, always are explained as taking thousands, millions of years, and thus are not easy to see. But in order for this to make sense, you need to propose a realistic scenario of how this can occur. I think your side severely lacks the ability to do so. Perhaps you can tell us why you think that mutations and selection are incapable of producing these changes, or why you think the case has not been made. If we were to compare chimps and humans, would you agree that the reason we look different from chimps is that the DNA sequence of our genome is different? If so, can you point to any those differences that the observed and known processes of mutation could not produce?
But at some point you can't always use the excuse that it was something else, at some point you must be able to say what an original use was, before it was adapted from some other use. Or we can say, "I don't know". Some things will always be a mystery unless we invent time travel.
If you say that it was a useless mutation, that eventually gained usefulness and then caused an increase in survivability, I think it is incumbent on your side to give a example, a reasonable pathway. That is exactly what Lenski observed in his E. coli experiment: E. coli long-term evolution experiment - Wikipedia They found that neutral mutations in earlier generations made possible beneficial mutations in the future. This very process has been observed in the lab.
Everyone of these mutations that started out as harmless defects can't have only happened in the past. If this is the pathway to all animal features, the mutations must be continuing today. What are some plausible examples of how this could happen in modern animals, starting from scratch? Mutations are still occuring. You were born with 50 to 100 mutations not found in either of your parents, and your children will have about the same number of mutations specific to them along with half of the mutations specific to you. This process never stops. Also, evolution doesn't start from scratch. It starts with already existing species and modifies already existing genomes.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
So that's the first mutation that leads to an eye ? Ok fine,gets go with that. so then I just need a mutation which leads to a dimple or depression somewhere on my body and I will be able to feel that sunlight even more. Amazing. No, you will be able to tell which direction the sunlight is coming, and also which direction shadows are coming from.
Next we need the dimple to be passed to the next generation. I have not yet heard of these skin dimples which get passed along like this, would it be like a dimpled chin? It's still kind of hard imaging a dimpled chin focusing light. Are you saying that you have never heard of a mutation being passed on? Perhaps you want to think about that one for a second?
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Hi, have been a member a while, only posted a couple of things, this does interest me though. So in the picture in message six, I presume that picture one and picture six are the ones based in reality and the rest is just the imagination of an evolutionist? It is a proposed pathway by which there is a selectable advantage at each step showing that eye development is attainable by selection. Also, there are living species with each type of eye. For example, the planaria has a simple depressed eye spot.
So what mechanism is it that leads to new genetic information? Until you show us how to measure genetic information that is impossible to say.
I know that mutation leads to loss of information but can be beneficial, Then evolution does not need to produce new information in order to evolve novel functions.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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wow, who would have thought the term 'information' would be so troublesome. It doesn't need to be troublesome at all. You could simply define new information as a new DNA sequence produced by a mutation. It could be a very simple thing to measure and understand. The problem in these discussions is that creationists define new information as "what evolution can not produce". Each creationist has different ideas of what evolution can not produce, so we get an almost endless string of vague definitions. Even worse, they usually have nothing at all to do with actual biology or genetics. In fact, creationists strain the definition of "new information" so severely that by the end of a discussion you come to the conclusion that evolution does not need to produce the creationist vision of "new information" in order for evolution to produce the biodiversity we see today. "New information" is really just a placeholder for "I don't believe you" in creationist talk. Edited by Taq, : No reason given.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Arguments that evolution is not good at explaining the development of life features is not very compelling? Of course its compelling. Evolution is extremely useful in explaining the development of life's features. What you are asking for is specific historical events which we may never have enough evidence to reconstruct even if we understand the mechanisms that were involved. Let's use gravity as an analogy. I say that gravity is a very good explanation for why planets orbit their star. You tell me that gravity is not a good explanation. Why? Because I can not show that planets in the Andromeda galaxy are moving about their star in a way consistent with gravity. I point out that we simply can not see those planets because they are too distant, but this does not stop you from using this absence of evidence to try and refute gravity. We will never know the history of every feature found in life. Never. What we can do is test the theory of evolution using the evidence we have found, just as we test the theory of gravity against the planets we can see. Time and again, the evidence we find fits the predicts made by the theory of evolution. That is why the theory is accepted by biologists, because IT WORKS, just as the theory of gravity works.
If nothing around you is pointing towards a random, chaotic, meandering type of evolution, We have mountains of evidence supporting evolution. 29+ Evidences for Macroevolution: The Scientific Case for Common Descent
quote: We do see the result of those mutations. The differences between us and chimps is a perfect example.
Instead what we see are very purposeful, very specific series of steps, that don't have any of the meandering your theory calls for. "Oh well, we can't know everything..." That's absurd. Evidence please.
I made a statement about the blindness of your side to see and admit the obvious-yet you still want to stick by them and say, well, it comes close enough to explaining things for me. That's not that scientific if you ask me. We are not the ones ignoring the evidence we do have. That would be you. Edited by Taq, : No reason given. Edited by Admin, : Fix quote.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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What in the world is that even supposed to mean? A case of irreducible complexity evidenced? No one has yet shown that IC systems can not evolve. That is what is being referenced.
Just because Kenneth Miller can blithely say, well, you see, a mousetrap makes a great tie clip, you seem to think that this is actually making a point about evolution. Just because Michael Behe can blithely say, well, you see, a mousetrap missing a part stops functioning as a mousetrap, you seem to think that this is actually making a point about evolution.
So you have a million different systems of life features, (more like a billion really) and everyone of them (without the slightest thread of evidence) you are going to claim were once as useful as a mousetrap as a substitute for a tieclip. That would make for a pretty ******* -->******* messy looking world of fossils. And so is that what we have, a really messy bunch of fossils? I can point to bones that once functioned as jaw bones but now function as ear bones. This is seen in the transitional fossils between reptiles and mammals. We can actually observe the evolution of an IC system in the mammalian middle ear. 29+ Evidences for Macroevolution: Part 1
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Saying a skin patch gets a dimple is not just problematic because of the lack of any real examples to point to, but because this is even a grain of sand in the giant desert of mutations that are weird at fortuitous that we would need to account for. A cornea, a liquid filled sack, tear ducts, irises, photo receptors,.... You not only have to account for all of these odd mutations which in itself seems preposterous, but you have a thousand other systems going on at the same time, ALL of which need these crazy things to happen, and NONE of which we ever seeing happening randomly. This is an argument from incredulity which is a logical fallacy. Claiming something is preposterous is a long ways away from actually demonstrating that something is impossible. Even more, the pattern of shared and derived sequences between species exactly matches the pattern we would expect from random mutations and selection (along with other mechanisms such as genetic drift). We have the evidence that these mechanisms were active in the past. Do you agree that the differences between humans and chimps is due to a difference in DNA sequence? Yes or no?
How can you get a mutation to something as specific as eye features, when it involves multiple genes, and not just one? Mutations in just one gene can change the development pattern that involves all of those genes.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Is the fact that you have not done so up to this point in this thread, a tacit admission, that yes indeed, it is true, you can not describe a series of events, both within the organism, and within the behavior of the species population, which could describe the emergence of a new novel complex function, which makes sense in the whole scope of the animals development? I have cited the evolution of the complex mammalian middle ear where jaw bones evolve new function. I have cited pocket mice where specific mutations gave rise to a novel fur color. Not only that, but DIFFERENT mutations gave rise to the same phenotype in separate populations of pocket mice demonstrating the random nature of mutations. I have also cited the DNA differences between humans and chimps. Perhaps you can explain why none of these are valid topics for this conversation?
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