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Member (Idle past 5185 days) Posts: 961 From: A wheatfield in Kansas Joined: |
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Author | Topic: Macroevolution: Its all around us... | |||||||||||||||||||||||||||
AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
We never delete posts so the continuity of the thread is apparent.
What you did with the duplicate post is the usual way to handle it.
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EZscience Member (Idle past 5185 days) Posts: 961 From: A wheatfield in Kansas Joined: |
Boy, I'm not a virologist, but this is good stuff. I suppose the chance aquisition of viral symbionts could well have resulted in speciation events. I never really thought of symbiotic relationships as potential catalysts for phylogenetic divergence.
I remember once writing a paper as an undergraduate on the evolution of internal fertilization. The information you present opens up new perspectives on the evolution of viviparity in higher animals... and the extension of that to prolonged gestational periods. Fascinating. I will have to read some of your links before I can comment further.There are also a couple of molecular biologists haunting this board who might have some educated commentary on the subject.
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TimChase Inactive Member |
Actually, there has been a great deal of controversy regarding the role of symbiosis in evolution. It goes back as far as about nine years after the publication of "The Origin of the Species." But I believe that in many ways, symbiosis has been a major driving force in evolution.
For example, it had been assumed that fungus was essentially non-productive, and if it entered a relationship with some other organism, the relationship was one between parasite and host. But while investigating the roots of an apparently healthy tree at one time, it was discovered that those roots were infested with a fungus. More investigation lead to the discovery that different species of tree typically play host to several different species of fungus at the same time. And in fact, such trees are incapable of living without their fungal symbionts: the roots of the trees, once stripped of their fungal symbionts, are stubby and relatively small, whereas the fungal symbionts are much larger, with a far more extensive web of fine branches extending out, increasing the tree's uptake of neutrients and water typically by somewhere between a factor of 100 and a 1000. We now know that mitochondria were originally bacteria which entered into an endosymbiotic relationship with eukaryotes approximately two billion years ago, and chloroplasts have a similar bacterial origin -- as indicated by their circular genes. At the time that mitochondria entered the endosymbiotic relationship, they had about 3000 genes. Today I believe they have about 35, with most of their genetic material having gradually migrated to the nucleus of the eukaryotic cell. The closest known non-endosymbiotic relative of the mitochondria is the rickettsia bacteria, which is responsible for typhoid. The closest known non-endosymbiotic relative of the chloroplast would be a species of cyanobacteria, which is more commonly known as blue-green algae. Of course, viruses have historically been viewed simply as parasites, both reproductively and, genetically. It had been common to assume that if the host of a virus and the virus itself contained some of the same genetic material found nowhere else, then surely this genetic material originally belonged to the host, and the virus had simply acquired it from the host. (In fact, a common view at one time was that viruses were originally part of the genomes of hosts, then somehow became separated, but "return" to the nucleus for the purpose of reproduction.) What this does not take into account is the fact that viruses typically mutate approximately 1000 times more quickly than their more conservative, less error-prone hosts, and when under stress are able to increase the speed at which they mutate by approximately another factor of a 1000. It is a safe bet that if a genetic innovation is present in both, the innovation was the product of the virus, not the host. Thus, for example, we are fairly confident nowadays that retrotransposons originated with retroviruses. And currently, the only hypothetical origin being discussed for transposons (as far as I have been able to gather) are DNA viruses. Likewise, in the human genome, we appear to have roughly 30,000 endogenous retroviruses -- three of which are at a "low" level of activity in normal placental and embryonic tissue development. Some of course are implicated in various kinds of disease, such as leukemia, cancers, and schizophrenia, but the fact that most people are able to live quite well with 30,000 endogenous retroviruses suggests that the vast majority are well-behaved, after having existed in a symbiotic relationship with their host over perhaps millions or tens of millions of years. And it has recently been suggested that some play a regulatory role in the expression of other genes -- although this is fairly tentative at present. However, the fact that they are well-behaved now does not mean that their ancestors were similarly well-behaved. One of the endogenous retroviruses involved in human placental and embryonic development is HERV-K, which entered the genome for the first time approximately 30 MYA (shortly after the old world monkeys separated from the new world monkeys), and most recently about 5 MYA. Currently, we have approximately 50 HERV-K proviruses. From what they have been able to gather, HERV-K is closely related to HIV-1. While endogenous retroviruses account for only about one to three percent of the human genome, roughly half of the human genome consists of retroelements -- most likely the wreckage of earlier ERV proviruses or artifacts of earlier retroviral infections. In essence, if we are talking about a given endogenous retrovirus, a retrotransposon or transposon, what we are talking about is lateral gene transfer. Thus viruses can have a far greater impact upon host evolution than the simple predator/prey-relationship in which they were first identified would first suggest. (Similar lateral gene transfer between host and bacteria had been suggested as a driving force in eukaryotic host evolution. However, currently the literature seems to be turning against this.) Here are a few more articles which may be of interest... Periodic Explosive Expansion of Human retroelements Associated with the Evolution of the Hominoid PrimateTae-Min Kim, Seung-Jin Hong, Mun-Gan Rhyu J Korean Med Sci 2004; 19: 177-85 http://jkms.kams.or.kr/2004/pdf/04177.pdf 'Punctuated' evolution in the human genome (popularized)Medical and health information An ancient family of human endogenous retroviruses encodes a functional homolog of the HIV-1 Rev proteinJin Yang, Hal P. Bogerd, Sheila Peng, Heather Wiegand, Ray Truant, and Bryan R. Cullen Howard Hughes Medial Institute and Department of Genetics Approved September 28, 1999 Just a moment... Constructing primate phylogenies from ancient retrovirus sequencesWelkin E. Johnson and John M. Coffin Proc. Natl. Acad. Sci. Vol. 96, pp. 10254-10260, August 1999 Just a moment... Helpful junkHelpful junk | The Economist (NOTE: this is a popularized article dealing with a topic covered at a technical level in a recent article in Nature -- where retrotransposons have been implicated in the chaotic over-generation of neurons within the mammalian brain, and a process akin to natural selection eliminates roughly fifty percent of the neurons -- those which apparently do not make the right connections. It is also suggested that the retrotransposons may be responsible for there being a greater variety of cells in the brain than in any other organ.) Transposable elements as the key to a 21st century view of evolutionhttp://shapiro.bsd.uchicago.edu/Shapiro_1999_Genetica.pdf Finally, for readers who are interested in the role of symbiosis in evolution and the history of its treatment in evolutionary thought, a good book for laymen would be "Darwin's Blindspot" by Frank Ryan. This message has been edited by TimChase, 06-19-2005 01:01 AM
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randman  Suspended Member (Idle past 4930 days) Posts: 6367 Joined: |
They are not errors in context, but nice ban when plenty of totally unsubtantiated and wrong statements are said on the other side, but you don't seem to censure them at all.
For example, my basic point is quite clear. You cannot tout the fact things evolve as exclusive evidence of ToE when all the other theories include the same data. The guy I was debating went as far as to make the absurd statement that any theory that admits the basics of plant breeding is a theory of evolution. Personally, I consider what you and others are doing is tantamount to a lie because you equate evolution in the general sense with the specific theory of common descent from a single common ancestor. His posts and your ban and statement are proof of that. He claims that if creationism includes natural selection, that it too is the ToE, but that's a lie. Be honest and specific. The fact things evolve is not exclusive evidence that everything evolved from a single common ancestor. That's a bald-faced lie, if you ask me, and does not do justice to the fact that no one discounts the fact things evolve, but that does not prove that everything evolved from a single common ancestor, and that my friend, is why a YEC, an OEC, an IDer, or just about anyone else besides an evolutionist can be just as good a plant breeder as an evolutionist, and why all of those theories work just as well for plant breeding as ToE, regardless of the rants and bans of evolutionists. Moreover, to talk about the TOE in this context, it is indeed perfectly reasonable to bring up the beliefs of the "story" of evolutuionists which does indeed include abiogenesis, separate theory (equally-held in the camp) nonetheless, and to bring up randomness and chance is valid. Of course, the method is mutations and natural selection, but the idea of randomness is part of that. But once again, you seem to have no problem ignoring the false statements of evolutionists, despite them being corrected numerous times, but have no problem banning me. Selective treatment?
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Kapyong Member (Idle past 3473 days) Posts: 344 Joined: |
Greetings,
quote: Yes,randomness is PART of it. quote: No.It does not ALL "occur by chance". You don't grasp the difference.No matter how many times you are told. That's the problem -you don't understand the subject, you don't listen to people who DO. Iasion
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Andya Primanda Inactive Member |
Randman at least you got the distinction correct--common descent and natural selection are separate Darwinian theories. (Read Mayr for details)
Now, of course both were supported by evidence. We see examples of natural selection in action. As for common descent, plagiarized genetic errors make good evidence for it, don't you think?
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AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
You were suspended because you made a statement that indicates that you are not in the slightest interested in actually learning anything. This is a waste of everyone's time and eventually produces frustration on the part of those attempting to debate with you.
This was the statement:
But that's not the same thing as accepting all life spontaneously generated all on it's own, and then evolved from one single common ancestor all via randomness and chance. Do you need to have the errors pointed out to you?
The guy I was debating went as far as to make the absurd statement that any theory that admits the basics of plant breeding is a theory of evolution. Why not ask him to back this up then? (It's possible I agree with you but I'd have to see the arguments first.) You level of understanding is not so great that you should be too quick to dismiss any ideas presented to you.
Personally, I consider what you and others are doing is tantamount to a lie because you equate evolution in the general sense with the specific theory of common descent from a single common ancestor. I agree with the earlier post by AP that the single common ancestor is separtate. That isn't the major issue. It is you confusion about abiogensis and randomness that is.
But once again, you seem to have no problem ignoring the false statements of evolutionists, despite them being corrected numerous times, but have no problem banning me. You will have to spell this out more specifically. Which statements?
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crashfrog Member (Idle past 1498 days) Posts: 19762 From: Silver Spring, MD Joined: |
The fact things evolve is not exclusive evidence that everything evolved from a single common ancestor. Nobody's claiming it is, which you would know, if you were reading my posts. As I said: if you accept NS and RM, then you accept the possibility that common descent is true; if you accept the evidence of genetics then you accept the likelyhood that it is true. Or else you're being intellectually dishonest, like the creationists.
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randman  Suspended Member (Idle past 4930 days) Posts: 6367 Joined: |
Why don't you look at the statement in context?
And, in fact, any model that encorporates selection and mutation is the exact same thing as evolution. It's an evolutionary model. So Young Earth Creationism is now by definition ToE. Yippee! You guys ever get tired of overstating things. Every model out there incorporates natural selection and mutations. Every creationist I have ever read or heard of does that. But that's not the same thing as accepting all life spontaneously generated all on it's own, and then evolved from one single common ancestor all via randomness and chance. That's a myth, could be a true myth, but a myth nonetheless. The fact that things evolve has never been contested and still is not contested by anyone today. I was responding to a quote by an evolutionist here that claimed "anything that incorporates selection and mutation is the exact same thing as evolution. It's an evolutionary model." Of course, that was my point to a degree, that Young Earth Creationism, Old Earth Creationism, and ID all incorporate natural selection, but still disagree with the overall Theory of Evolution. I was the one here speaking truth and trying to clarify something, namely that is absurd to continually, as most evolutionists, do and overstate the evidence and claim that just because things evolve that common descent must be true. Crash seems to be backing off now and claiming that with genetic evidence, that it is conclusive, but that's not what EZ was arguing when Crash jumped into the conversation, and regardless, to lightly dismiss critics by saying on the one hand they are an evolutionary model, and the other that they are wacko, is quite telling. Why not just concede the truth? Evolution in the larger sense is not equal to the Theory of Evolution or Darwinism? You guys use the terms interchangeably, even after being told repeatedly the obvious error on your part. A reasonable conclusion is that you guys are deliberately obfuscating here. Getting to the quoted section, considering the context here, I think it is entirely appropiate. Every creationist accepts the fact things evolve. No one debates that, but they don't accept things like all life evolved from a single life source which sponteneously generated and continued to evolve via random mutations and natural selection. Sorry, but imo, creationists are right to not buy into those things, which evolutionists do buy into, even if they separate abiogenesis out. It looks to me, personally, like just selective editing and banning on your part. You claim someone like me "hasn't learned anything" as if my role is to learn from evolutionists when in fact, it is usually the other way around. People like myself have heard your arguments ad nauseum, and can generally argue them as well as you can. But you guys refuse to concede even basic points, such as the observation that evolution occurs is not the same thing as the ToE which creationists and IDers question.
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crashfrog Member (Idle past 1498 days) Posts: 19762 From: Silver Spring, MD Joined: |
Of course, that was my point to a degree, that Young Earth Creationism, Old Earth Creationism, and ID all incorporate natural selection, but still disagree with the overall Theory of Evolution. But they don't. They simply reject the logical, necessary conclusions of their own models. Why is this the third time I've had to tell you that?
Evolution in the larger sense is not equal to the Theory of Evolution or Darwinism? That's stupid. How can the Theory Of Evolution not be the theory of Evolution? How long before you get serious about this, Randman? These ridiculous word games get you nowhere. It's obvious that you're not at all interested in a real debate on these issues.
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randman  Suspended Member (Idle past 4930 days) Posts: 6367 Joined: |
But they don't. They simply reject the logical, necessary conclusions of their own models. No, the question crash is when you will grow up and realize that the fact species evolve does not logically, scientifically equate common descent as you claim. It's time for you to be honest. Your quote above indicates you think incorporating natural selection and the fact things evolve leads only to the "logical, necessary conclusion" of universal common descent. Will you finally and unequivocally admit that? The next thing for you to realize is that it is not logically necessary that just because species can evolve, that they did all evolve from a single common ancestor. That's why creationists and IDers can logically include evolutionary processes without accepting what I call the evolution myth (the story) that all life evolved from a single common ancestor which spontenously generated all on it's own without any help from an Intelligent Cause. That's the myth you cling to, which many disagree with. The myth could possibly be true, but claiming it is well-nigh proven as evolutonionists do is false. It is not "proven beyond a reasonable doubt", and the fact speciation and micro-evolution occurs is not exclusive evidence for universal common descent.
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randman  Suspended Member (Idle past 4930 days) Posts: 6367 Joined: |
As for common descent, plagiarized genetic errors make good evidence for it, don't you think? I am not sure if I know 100% what you refer to, but genetic similarities in non-coding DNA, if that's what you refer to, could also be explained by convergent DNA possibly. I think we'll know more in a few years when we understand the mechanisms responsible for convergent DNA.
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crashfrog Member (Idle past 1498 days) Posts: 19762 From: Silver Spring, MD Joined: |
No, the question crash is when you will grow up and realize that the fact species evolve does not logically, scientifically equate common descent as you claim. Since I've specifically repudiated that claim more than three times now, including in my first post to you on this thread, the question is, when are you going to learn to read?
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crashfrog Member (Idle past 1498 days) Posts: 19762 From: Silver Spring, MD Joined: |
I am not sure if I know 100% what you refer to, but genetic similarities in non-coding DNA, if that's what you refer to, could also be explained by convergent DNA possibly. Why would they converge? Are you proposing a force that converges DNA simply to fool us into concluding common descent? Is that a model you expect us to take seriously?
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randman  Suspended Member (Idle past 4930 days) Posts: 6367 Joined: |
Crash, repudiated what claim?
1. the claim that you claim the fact things evolve leads only to "the logically necessary conclusion" of common descent, as you reiterate here:
They simply reject the logical, necessary conclusions of their own models. 2. Or are you asserting you do hold to that position and think you have repudiated how evolutionary processes can be included in alternative theories?
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