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Author | Topic: Are mutations truly random or are they guided? | |||||||||||||||||||||||||||
Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
The paper, HERE, discusses some possible mechanisms in relation to starvation induced stress. A kind of apparent Lamarckian effect can be the result, because a positive adaption in relation to a new environmental factor can be speeded up. The answer to the question in the O.P. title, "Are mutations truly random or are they guided" is that some mutations are partially guided ... I think that "guided" is too strong a word. The effect discussed in the paper still doesn't allow the mechanism to "know" which mutations would be beneficial, just which genes might benefit from a mutation.
(Of course, since we know from creationist dogma that their are No Beneficial Mutations, Amen, this is in fact a mechanism for royally screwing organisms up in the very locations where they are most vulnerable, as devised by a God who was either retarded or perversely vindictive.) Edited by Dr Adequate, : No reason given.
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Percy Member Posts: 22391 From: New Hampshire Joined: Member Rating: 5.2 |
Dr Adequate writes: (Of course, since we know from creationist dogma that their are No Beneficial Mutations, Amen, this is in fact a mechanism for royally screwing organisms up in the very locations where they are most vulnerable, as devised by a God who was either retarded or perversely vindictive.) It does seem strange that the creationists in this thread seem to be arguing against the possibility of advantageous mutations when the thread's premise is that positive mutations happen and that they are "directed by the cell and by cellular processes." (see Message 1) --Percy
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Peepul Member (Idle past 5018 days) Posts: 206 Joined: |
quote: Evolution is demonstrated by the fossil record, biogeography, morphology, developmental biology and genetics among other things. The only theories that fit the facts are evolution and some form of creation that looks exactly like evolution. Without any scientific evidence for creation, or a creator, and no obvious need for one science prefers evolution. We don't need to understand the mechanism to be sure that evolution has happened. This discussion is NOT about whether evolution has occurred.
quote: who said that?
quote: I don't think it's fundamental whether they are truly random or not. I wouldn't be surprised if we find more mechanisms whereby organisms selectively increase mutation under some circumstances. I also wouldn't be surprised if we find some elements of Lamarkism. There's nothing to rule out changes to genetic material based on life experience. Why does that matter particularly? However it's impossible for a cell to 'choose' specific mutations- there is no way a cell could know that a given change will have a particular effect.
quote: Correct. But not relevant (for the hundredth time) to evolution
quote: [off topic] Scientists don't want to preclude discussion of other scientific ideas. They do want to preclude discussion of religious ideas dressed up as science. People who believe these things for religious reasons cannot properly discuss the evidence for and against evolution, and nor can they be scientists because they MUST believe that evolution is not true, whatever the evidence says. Personally, I'd be perfectly happy to drop evolution if a better theory came along, with powerful evidence to support it, and I'm prepared to bet that most scientists would too. Why wouldn't we? What we 'believe in' is the process of science, not the content. [/off topic]
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Peepul Member (Idle past 5018 days) Posts: 206 Joined: |
quote: It's the fall, Dr A, remember, the fall. It's all our fault....
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bluegenes Member (Idle past 2477 days) Posts: 3119 From: U.K. Joined: |
Bolder-dash writes: bluegenes writes: The initial ancestral tendency would, however, have been a random variation. The end result is an example of evolvability itself ( or adaptability if you like) having been selected for. Once again, like so many of the assertions in the ToE we just have to take evolutionists word for it that this is how it happened, because of course you can't prove this assertion any more than all of the other ones. It must have been random at one time, and then got selected for, and that is how it became non-random.....and so just believe us... Of course you don't have to take my word for it. It's based on the observation that random variations within species are common, and that advantageous ones are selected for. There's plenty of evidence to support that in the literature, as I'm sure you'd agree. So, by all means present an (observation based) alternative explanation for the origin of the stress related reactions I was talking about if you disagree. There's certainly no obligation to agree with me.
Bolder-dash writes: So even when we have examples of evolution being 'guided" by the individual, your theory is so flexible it can simply say, "well, yea, the evolution is guided NOW, but...." There's a reason why the words "environment" and "individual" are spelt differently. It's because they mean different things. The individual cells do not really guide evolution, they react automatically and unconsciously to starvation induced stress in a way that they've inherited. I said:
bluegenes writes: ....some mutations are partially guided by a combination of environmental factors and the history of the species involved (whether or not it has inherited the tendency to react positively to a specific kind of stress). Bolder-dash writes: It should be renamed, The Incredible, Mutating, Adapting, Twisting, and Re-conforming Theory of Evolution of Whatever We Need it to Say That We Don't Have to Prove Theory. If you look at what I'm describing, and you understand it, you will be able to see that it's all due to variation and natural selection, the very key words used to describe biological evolution 150 years ago. The theory does evolve, of course, but it's only micro-evolution so far.
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bluegenes Member (Idle past 2477 days) Posts: 3119 From: U.K. Joined: |
Dr Adequate writes: bluegenes writes: The answer to the question in the O.P. title, "Are mutations truly random or are they guided" is that some mutations are partially guided ... I think that "guided" is too strong a word. The effect discussed in the paper still doesn't allow the mechanism to "know" which mutations would be beneficial, just which genes might benefit from a mutation. What about my phrase "partially guided", especially when we consider that a rock rolling down a hill is guided in its route by the contours of the hill. But I agree that the mechanism doesn't "know" anything specific. We could say that the rate and region of variation can be guided by the environment in certain circumstances.
Dr Adequate writes: (Of course, since we know from creationist dogma that their are No Beneficial Mutations, Amen, this is in fact a mechanism for royally screwing organisms up in the very locations where they are most vulnerable, as devised by a God who was either retarded or perversely vindictive.) Actually, some of the more sophisticated I.D. types get very excited about this kind of thing, and see it as designed/front loaded evolution. I think that they may as well skip all the details, include naturalistic abiogenesis in their view, opt for a "front loaded" universe designed to be as it is, and become Deists. Then they wouldn't have to worry about not having any positive evidence any more.
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Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined: |
It does seem strange that the creationists in this thread seem to be arguing against the possibility of advantageous mutations when the thread's premise is that positive mutations happen and that they are "directed by the cell and by cellular processes." Yes, but if those processes existed they wouldn't be magical, would they?
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slevesque Member (Idle past 4640 days) Posts: 1456 Joined: |
Okok, Yeah I'm from quebec so my original language is french and so your finishing line kind of surprised me since I'm the only one here who speaks french that I know of.
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slevesque Member (Idle past 4640 days) Posts: 1456 Joined: |
I'll add another point that hasn't been highlighted. If the cell had a mechanism to provoke the mutations it needed, that would help it along it's evolution (asI understood the OP) then this very same mechanism would have had to have evolved. and since it wasn't there to direct it's own happening, classical evolution with random mutation are what made this mechanism in the first place.
So even if random mutations appear to you that they can't make biological systems grow in complexity, adding a mechanism to make them none-random doesn't take those random mutations out of the whole picture.
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Species8472 Junior Member (Idle past 4882 days) Posts: 29 Joined: |
I have a question for you guys. I'm an engineering student doubling with computer science. With programing, I have a bad habit of commenting out whole sections of codes, sometimes even whole subroutines, instead of deleting them when I don't use them. I also have the bad habit of reusing programs time after time after adjusting them just a little to do their purpose. The result after a while are programs with hundreds of lines of codes that's been commented out. Sometimes, I even leave things running if they absolutely not affect the result I wanted.
Am I to understand that "neutral" mutations are somewhat like these junk codes?
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Coyote Member (Idle past 2106 days) Posts: 6117 Joined: |
A mutation is neutral only in relation to selection pressure.
With a changing environment, what is neutral one millennium might be beneficial or deleterious the next. As people migrated out of Africa dark skin became deleterious, as it led to a lack of Vitamin D (produced by sunlight in the lower layers of the skin). A mutation for tanning ability in the Mediterranean or light skin in northern Europe was beneficial, though either would have been deleterious in Africa. Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
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slevesque Member (Idle past 4640 days) Posts: 1456 Joined: |
I agree with what you said, but of course this does not apply to all mutations. Many Mutational diseases won't help you whatever the environment.
And also since the vast majority of mutations are only slightly deleterious, therefore 'undetected' by natural selection won't become beneficial in a changing environment (since the environment is a component of natural selection) and so will stay deleterious.
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Coyote Member (Idle past 2106 days) Posts: 6117 Joined: |
And also since the vast majority of mutations are only slightly deleterious, therefore 'undetected' by natural selection won't become beneficial in a changing environment (since the environment is a component of natural selection) and so will stay deleterious.
Some known mutations, such as sickle cell anemia, are both deleterious and beneficial at the same time in some specific environments (i.e., malarial areas). Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
A much better analogue for those 'commented out' bits of code would be pseudogenes. These are what appear to be copies of genes that have mutated in such a way as to become non-functional, or at least to have lost their original function.
An analogue for your habit of reusing code would be the conserved binding domains which turn up in very diverse families of proteins, such as the homeodomain (HOX), the paired box domain (PAX), Zinc Finger domains and many others. There are molecular mechanisms which allow these domains, or modules of more than one of these domains, to be swapped between proteins with distinct functional domains to produce novel combinations of binding and functional domains. A neutral mutation is more like if you changed the way the code was typed but not its functionality, for a bash example it is like changing ' if test $i -ge 10' into 'if [ $i -ge 10 ]'. TTFN, WK
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slevesque Member (Idle past 4640 days) Posts: 1456 Joined: |
Sickle cell anemia isn't a slightly deleterious mutation. (or nearly-neutral mutation. however you want to call them)
Because by definition they aren't perceived by natural selection. In other words, if their deleterious or beneficial nature is dictated by the environment (ie the selection pressures) then they are not slightly deleterious mutations.
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