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Author | Topic: Can random mutations cause an increase in information in the genome? | |||||||||||||||||||||||
Garrett Member (Idle past 6193 days) Posts: 111 From: Dallas, TX Joined: |
That's where we disagree.
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EZscience Member (Idle past 5181 days) Posts: 961 From: A wheatfield in Kansas Joined: |
It always works like a ratchet in the sense that there is no 'going back', no reversing the arrow of time.
It is only that increasing complexity is not necessarily an outcome of this process. A species can be 'ratcheted' toward greater simplicity of body form if this improves survival in a particular niche. Whales evolved a simplified body plan relative to their bear-like ancestors because this was body plan was more conducive to remaining in a marine environment.
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crashfrog Member (Idle past 1494 days) Posts: 19762 From: Silver Spring, MD Joined: |
No new functions have ever been created in this process...just new side effects to old functions. What makes you think you can't go from the bottom to the top this way? Like I said, there's almost no biological novelty. Every biological function is the side effect of an old function. Every single one. I don't see the need for all this novelty you claim is required.
And I don't really think we need to define complexity to understand that it isn't increasing. Oh, well, I'm glad we need nothing more than your subjective opinions about "complexity" to dismiss the single most successful model in the history of biology. Oh, wait.
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SuperNintendo Chalmers Member (Idle past 5862 days) Posts: 772 From: Bartlett, IL, USA Joined: |
Garrett, Garrett, Garrett.....
Don't you know that evolution has no direction? In fact there IS no such thing as devolution. Take this for example.... Can you prove that Dinosaurs are more or less "advanced" than their descendants?
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Garrett Member (Idle past 6193 days) Posts: 111 From: Dallas, TX Joined: |
The point is you degrade the existing function to arrive at the new side effects. Explain how you can continue to degrade a system without it eventually becoming inoperable. This is why the mutation that helps prevent malaria also causes deadly sickle-cell anemia. Adding more holes to your pants in summertime may benefit you in terms of heat retention, but continue this process long enough and the overall function of the pants is destroyed. Demonstrate how this isn't a valid anology.
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EZscience Member (Idle past 5181 days) Posts: 961 From: A wheatfield in Kansas Joined: |
Garrett writes: Are you suggesting that the higher organisms which dominate their ecosystems didn't evolve at one point from simple-celled organisms? Not at all. Simple organisms necessarily preceded more complex ones. I am only pointing out that not all lineages are destined for increased complexity. Increasing complexity is not an *inevitable* outcome of organismal evolution, although where it has occurred, evolution is responsible.
Garrett writes: ...what do you mean when you say that it isn't necessary for there to be a trend of increased complexity over evolutionary timescales? I am refering to complexity in specific lineages - some will increase in complexity - others not.However, as the number of species in a community increases, the complexity of the ecosystem must necessarily increase. This is not to say that some organisms in that community will remain in very simple forms while others increase in complexity. But I really dislike this word 'complexity' because it has no real biological meaning. It is a subjective quality we tend to assign living things based on our own perceptions of them. It is not quanitifiable in any way, as I explained below. This message has been edited by EZscience, 02-15-2006 02:51 PM
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Garrett Member (Idle past 6193 days) Posts: 111 From: Dallas, TX Joined: |
That really makes no logical sense. What you are trying to say is that not all lineages in a given time span are destined for increased complexity.
It is only logical though, that if all life arose from the first, less-complex life, that a ascension in terms of complexity was necessary be each and every life form (except for the still existing simple celled organism..why is it still around again?)
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NosyNed Member Posts: 9004 From: Canada Joined: |
Excuse me? You made the positive statment that mutations can not cause an increase in something originally called "information" in the genome.
We have shown that there isn't ANYTHING defined which can't be "increased". Your originaly position isn't supported at all. You may not "really think" that it is necessary to define complexity to understand that it isn't increasing but you can't defend such a position. To say that something can't be increased by some process you have to say what is wrong when someone shows a process increasing anything that we can think of that might represent your unknown something. The original idea was a "scientific sounding" but unfounded attempt to suggest that evolution can't do something. Now you've dug a bit deeper and found that those putting forward the idea never really had much idea of what the heck they were talking about in the first place. In addition, it is apparent any precise definition of "complexity" that also meets intuitive ideas will be shown to have a wide range of variation in extant living things. Those living things are still (even after having huge swaths cut through life on the planet) very closely connected so steps can be shown to get from one to another to another. A few small, tiny changes a year to get from one to another.
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EZscience Member (Idle past 5181 days) Posts: 961 From: A wheatfield in Kansas Joined: |
The problem is you are equating 'change' with 'degradation'.
You also begin with the mistaken assumption that all gene products are perfectly functional or somehow 'optimal' to begin with. Not so. Functionality is very often determined by the genetic and external environment in which the gene is expressed. Plus some mutations produce sort of 'effective alternatives' to the original product. They are effectively 'neutral' under most conditions, but may provide advantages under others. So many genetic mutations may accumulate, and many alternative alleles may spread in a population, without necessarily having big effects on fitness. That's why every population is genetically heterogenous - even asexual ones.
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EZscience Member (Idle past 5181 days) Posts: 961 From: A wheatfield in Kansas Joined: |
Garrett writes: What you are trying to say is that not all lineages in a given time span are destined for increased complexity. Exactly. And why is this not logical?Could it be you mistakenly assumed that evolutionary theory posited that all lineages necessarily increased in complexity over time? Garrett writes: ...still existing simple celled organism..why is it still around again? Because it happens to exploit a niche in which simplicity is favored.Do you think that bird flu would be able to spread around the world and cross-infect birds and humans if it was as complex as an elephant?
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crashfrog Member (Idle past 1494 days) Posts: 19762 From: Silver Spring, MD Joined: |
This is why the mutation that helps prevent malaria also causes deadly sickle-cell anemia. It doesn't, though. You're confusing hemoglobin C with hemoglobin S. C has all the benefits of S in regards to malaria but it doesn't cause sickle-cell. That was explained to you about 10 times but you seemed to miss it each time.
Demonstrate how this isn't a valid anology. Put some holes in a cloak and you have a vest, or a cossak, which is a warmer and more effective garment than a cloak because it's more snug. Duplicate the vest - put two on - and you have an even warmer garment. A mutative modification to the arm holes might cause them to extend over the shoulders, keeping rain from flowing into the arm holes. Duplication on those features results in increasingly longer sleeves over time. Eventually you have a coat, and nobody wears cloaks anymore. And, also, you have a huge pile of modified cloaks that didn't work, couldn't be worn, or had so many holes they were useless. Nobody's saying that evolution ensures that every organism gets better over time. In fact, the fossil record proves that the ultimate result for 99% of species is extinction. Most of the products of mutation will be invisible; they won't have an effect. Most of the remaining mutations are fatal, which is why they're not around anymore. A scant few are beneficial, as has been proven to you. The result of that seems obvious to me, and to anybody not motiviated by a dogmatic need to oppose science.
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crashfrog Member (Idle past 1494 days) Posts: 19762 From: Silver Spring, MD Joined: |
It is only logical though, that if all life arose from the first, less-complex life, that a ascension in terms of complexity was necessary be each and every life form It's not logical, no. It is merely required that some organisms have offspring of slightly greater complexity, and we observe that this is the case.
(except for the still existing simple celled organism..why is it still around again?) It's not still around. Hasn't been around for billions of years.
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Garrett Member (Idle past 6193 days) Posts: 111 From: Dallas, TX Joined: |
A few small tiny changes a year would undoubtedly leave more of a transitional fossil record than we currently see...and that is accepting the few questionable examples as valid. Given the lack of fossile evidence how do you quantify these small changes?
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Garrett Member (Idle past 6193 days) Posts: 111 From: Dallas, TX Joined: |
I guess you think I meant the same one?
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NosyNed Member Posts: 9004 From: Canada Joined: |
The genomic differences between life forms and the time from earlist appearances of two separate lineages to today.
There is a thread on fossil record. You state "undoubtedly". How much taphonomy do you know? This is, of course, NOT the thread to discuss it so you can find or start one on the fossil record anytime.
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