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Author | Topic: Can mutation and selection increase information? | |||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: No mutations needed, no extra alleles needed, just the combining of the two-form genes through sexual recombination. (I'm only thinking of sexually reproducing creatures). That just doesn't work. You can't get all of the species living today and all the species that have existed from a universal common ancestor using just two alleles per gene.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes:
Would you please explain to me how genes duplicate? Since they occupy a position along the DNA strand, and they are thousands of codons long, and the replication process follows the strand codon by codon how does a copy of a gene get separately inserted into the strand?
One of the mechanisms of gene duplication (if memory serves) is homologous recombination. This whole process is caused by the chemical characteristics of DNA. DNA bases on separate strands of DNA can stick to one another through a process called hydrogen bonding. However, not all bases will stick to all other bases. Instead, the hydrogen atoms have to be lined up for the bonding to occur. Therefore, only A will stick to T, and only G will stick to C (and vice versa). These are called complementary bases:
Any time you have enough complementary bases you can get two strands of DNA to stick to one another, like the meshing of a zipper. Most of the time this results in perfectly aligned strands of DNA where the same pieces of DNA are always across from one another. However, during meiosis there is a stage where pieces of each pair of chromosomes is switched back and forth between each other, and during this process you can get more distant pieces of DNA to stick together. This can cause a gene to be duplicated elsewhere in the chromosome. You can read more here: Gene duplication - Wikipedia
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: My first answer is what I think was the plan at the Creation, but the question usually comes up in discussions of what evolution actually does -- that is, the process of evolving loses information, that's how you get new phenotypes. I prefer to describe it as losing alleles which I think is clearer than "information." And the example I use because it's so clear is domestic selection or breeding: to get a purebred animal requires losing all the genetic material, alleles, for other breeds. You select them out of the breeding pool, so you get the purebred on the basis of homozygosity at the loci that are the main traits of your breed, and that means eliminating all the other alleles. Let's start with a common ancestor for humans and chimps. Those branches separate and then each branch accumulates mutations that change both species into what we see today. Are you saying that you would classify all of those mutations that led from an ape-like human ancestor to modern humans as losses in genetic information?
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bluegenes Member (Idle past 2506 days) Posts: 3119 From: U.K. Joined: |
Faith writes: Would you please explain to me how genes duplicate? Since they occupy a position along the DNA strand, and they are thousands of codons long, and the replication process follows the strand codon by codon how does a copy of a gene get separately inserted into the strand? You won't like it. Errors while reproducing. There are several different types. Chunks of DNA duplicate quite often, and when there's a gene in the segment, that's a duplicate. It's common. You've got loads of duplicates in your genome. This will tell you the different ways.
Gene duplication Didn't you know it happened? ABE: a bit redundant, because Taq got there first and linked to the same article. Edited by bluegenes, : pipped to the post
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
I've certainly heard of gene duplications but not how they work, and I'm still not getting it. Please don't refer me to links, they are hard for me to read.
How do they duplicate? Does the strand break apart to admit a whole new segment or what?
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: How do they duplicate? Does the strand break apart to admit a whole new segment or what? That can be another way that gene duplication occurs. The sugar-phosphate backbone of DNA can break and then be reattached to another piece of DNA floating around. Homologous recombination can also occur, as detailed above. The proteins that copy DNA can also fall off of the DNA and strand and start again elsewhere, causing a duplication of DNA (replication slippage). Needless to say, gene duplication does happen and biologists understand the mechanisms by which it happens.
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bluegenes Member (Idle past 2506 days) Posts: 3119 From: U.K. Joined:
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Faith writes: Well, I'd been assuming that new information WAS needed for all the diversity of life to exist, because that's often claimed, but now I don't think anything new is needed, it was all built in to the original genome of each Kind at Creation, most or all of it provided through genes for traits made up of two and only two forms or alleles. As I showed on the thread about YEC supposedly needing mutations and positive selection, a mere two genes with two alleles each provide sixteen different versions of a trait simply by combining the effects of the four different proteins produced by the four different alleles. Since many traits have quite a few more genes than two the possible variation in only one trait is enormous. No mutations needed, no extra alleles needed, just the combining of the two-form genes through sexual recombination. (I'm only thinking of sexually reproducing creatures). So, if a mutation did produce a new functional allele with a new effect on the phenotype, wouldn't you agree that that constitutes new information, whether it's "needed" or not?
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
So, if a mutation did produce a new functional allele with a new effect on the phenotype, wouldn't you agree that that constitutes new information, whether it's "needed" or not? I would figure it had managed to replicate an existing allele, not anything actually new, but so far I'm not convinced that anything new at all, even in that sense, is ever created by a mutation. Evidence you gave on the other thread was all based on a supposed high frequency which I think is just an illusion based on assuming a new allele instead of a neutral mutation which doesn't change the protein or the function of the original allele. Edited by Faith, : No reason given.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: I would figure it had managed to replicate an existing allele probably at another gene, not anything actually new, but so far I'm not convinced that anything new at all, even in that sense, is ever created by a mutation. If we started with the chimp genome and changed that genome at 40 million places to end up with the human genome, would you consider that a new genome with new information?
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bluegenes Member (Idle past 2506 days) Posts: 3119 From: U.K. Joined: |
Faith writes: bluegenes writes: So, if a mutation did produce a new functional allele with a new effect on the phenotype, wouldn't you agree that that constitutes new information, whether it's "needed" or not? I would figure it had managed to replicate an existing allele probably at another gene,..... Why and how would you figure that?
Faith writes: .....not anything actually new, but so far I'm not convinced that anything new at all, even in that sense, is ever created by a mutation. Evidence you gave on the other thread was all based on a supposed high frequency which I think is just an illusion based on assuming a new allele instead of a neutral mutation which doesn't change the protein or the function of the original allele. No, different alleles are known to give immunity to different parasites, and you'd know that if you'd read the extracts from the paper on MHC that I posted there. My question was conditional. If a new mutation created something new in the phenotype (even if you don't believe this actually happens) would it constitute new information?
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
If that paper is above Percy's pay grade as he put it, it's certainly above mine. I read what I was able to read, and nothing you said gave evidence that new alleles actually exist. As I keep saying the "evidence" of supposed positive selection shown by increased frequency is an illusion if the allele in question is really a neutral mutation, which would be passed on and easily look like increased frequency based on your assumption.
You seem to think that paper actually shows that new alleles give immunity to different parasites, but it doesn't. It assumes it. Edited by Faith, : No reason given.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: If that paper is above Percy's pay grade as he put it, it's certainly above mine. I read what I was able to read, and nothing you said gave evidence that new alleles actually exist. By your own admission, you wouldn't be able to spot the evidence if it does exist, so you can't claim that the evidence doesn't exist.
You seem to think that paper actually shows that new alleles give immunity to different parasites, but it doesn't. You can't claim ignorance of what a paper says, then turn around and make claims about what the paper says.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
I understood what I understood, and interestingly you don't say one thing that shows I'm wrong about that.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1 |
Faith writes: I understood what I understood, and interestingly you don't say one thing that shows I'm wrong about that. The paper already demonstrates you are wrong.
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Faith  Suspended Member (Idle past 1473 days) Posts: 35298 From: Nevada, USA Joined: |
Quote it if it demonstrates I'm wrong. It doesn't. It assumes what you think it proves, it does not prove it. That's why Percy asked for evidence.
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