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Author | Topic: The End of Evolution By Means of Natural Selection | |||||||||||||||||||||||||||||||||
Dr Adequate Member (Idle past 314 days) Posts: 16113 Joined: |
You're arguing with the Wikipedia article as much as me although you claim not to be. You mean the Wikipedia article which reads:
During allopatric speciation, a population splits into two geographically isolated allopatric populations (for example, by habitat fragmentation due to geographical change such as mountain building or social change such as emigration). The isolated populations then undergo genotypic and/or phenotypic divergence as: (a) they become subjected to dissimilar selective pressures; (b) they independently undergo genetic drift; (c) different mutations arise in the two populations. When the populations come back into contact, they have evolved such that they are reproductively isolated and are no longer capable of exchanging genes. I sure hope you won't have the temerity to argue with Wikipedia. It's practically the voice of God, after all. Edited by Dr Adequate, : No reason given.
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Faith  Suspended Member (Idle past 1474 days) Posts: 35298 From: Nevada, USA Joined: |
What I quoted I copied directly from the article and it didn't have the mention of mutations in it. I didn't leave anything out.
Of course they are going to include mutations at some point. But they, and the professor on You Tube, do nevertheless discuss the processes of selection and drift as enough in themselves to bring about new varieties from the given allele frequencies. They probably assume mutations among them anyway.
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Faith  Suspended Member (Idle past 1474 days) Posts: 35298 From: Nevada, USA Joined: |
You all keep insisting on mutations as if without them you can't get the changes that become new varieties. Seems to me quite enough, especially when you figure in the likelihood of many more genes for a particular trait than we have been discussing here, and most likely for such features as elaborate plumage and bird song, that a mere recombination of existing alleles could do it all.
In any case, I have a question about this insistence on mutations. It's been emphasized by a few here that mutations always accord with the character of the species anyway, so the best you can get is an allele for a new color at the gene for color, or a larger or smaller or differently-shaped appendage such as a beak or a tail or ears or whatever, at the gene that governs that particular trait. In other words even mutations work within the basic structure of the species. There's nothing in how mutations operate to suggest that a change outside the species could ever occur. Also, speciation as defined by the population geneticists is nothing more than the fixation of a particular form of a species. It could include all the mutations you like and it will still be a variation on that species. You need some special kind of change that is not included in any of the processes we have been discussing if evolution is to get from one species to another. A mere accumulation of new traits within the structure of a given species isn't going to do it. A sort of meta-change has to happen at some point. Usually it is just assumed that this happens. You need specifics. Do you have any? ABE: feathers to scales or scales to feathers would be a meta-change. Edited by Faith, : No reason given.
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Percy Member Posts: 22505 From: New Hampshire Joined: Member Rating: 4.9 |
Faith writes: Of course they are going to include mutations at some point. But they, and the professor on You Tube, do nevertheless discuss the processes of selection and drift as enough in themselves to bring about new varieties from the given allele frequencies. They probably assume mutations among them anyway. This has been said at least several times before, but once again, selection and drift all by themselves without any mutations at all and just drawing upon the pool of existing variation (existing alleles) are sufficient for evolution and the creation of new varieties. They are insufficient for speciation under any reasonable circumstances. --Percy
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Percy Member Posts: 22505 From: New Hampshire Joined: Member Rating: 4.9 |
Faith writes: You need some special kind of change that is not included in any of the processes we have been discussing if evolution is to get from one species to another. A mere accumulation of new traits within the structure of a given species isn't going to do it. A sort of meta-change has to happen at some point. Usually it is just assumed that this happens. You need specifics. Do you have any? Mutations can not only create new alleles, they can also create and destroy genes and even entire chromosomes. --Percy
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Percy Member Posts: 22505 From: New Hampshire Joined: Member Rating: 4.9 |
Hi Faith,
I should have commented on this in my previous post:
Faith writes: It's been emphasized by a few here that mutations always accord with the character of the species anyway... No one on this thread has even remotely suggested this. You're probably thinking of explanations about beneficial mutations tending to be in very tiny undetectable steps. Instances of easily apparent beneficial mutations should be rare. Reproduction is almost invariably imperfect. There's not really any such thing as "the character of the species." All you can talk about is the current moment in a process of continuous accumulating change over time. Species classifications are just human beings imposing their own classification systems at a static moment in time. --Percy
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bluescat48 Member (Idle past 4219 days) Posts: 2347 From: United States Joined: |
What I quoted I copied directly from the article and it didn't have the mention of mutations in it. I didn't leave anything out. You better check again. What Dr A quoted is what the wiki site has. There is no better love between 2 people than mutual respect for each other WT Young, 2002 Who gave anyone the authority to call me an authority on anything. WT Young, 1969 Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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You all keep insisting on mutations as if without them you can't get the changes that become new varieties. You have it the wrong way around. The differences between varieties is due to differences in DNA sequence which occur through mutations. Using three closely related species (e.g. humans, chimps, and gorillas) you can determine the common ancestral sequences and the mutations that have occurred in each lineage.
It's been emphasized by a few here that mutations always accord with the character of the species anyway What does that mean?
In other words even mutations work within the basic structure of the species. To put it in neo-Darwinian terms, mutations modify the structures. Our limbs are modified fins, as one example. Two of our middle ear bones are modified reptilian jaw bones, as another example.
There's nothing in how mutations operate to suggest that a change outside the species could ever occur. Pick any two species. The differences between those two species is due to a difference in DNA sequence. How can mutations not be responsible for this?
Also, speciation as defined by the population geneticists is nothing more than the fixation of a particular form of a species. Not at all. Speciation is the fixation of DIFFERENT MUTATIONS in each lineage (which is even stated in the Wiki page). Divergence is the key here.
It could include all the mutations you like and it will still be a variation on that species. So humans are a variation of chimp?
You need some special kind of change that is not included in any of the processes we have been discussing if evolution is to get from one species to another. Of the DNA differences between humans and chimps which required something other than the observed mechanisms of mutations? Care to enlighten us?
A mere accumulation of new traits within the structure of a given species isn't going to do it. Why not? Because you say so?
ABE: feathers to scales or scales to feathers would be a meta-change. Is this or is this not due to a difference in DNA sequence? If it is, then please explain why a mechanism that changes DNA sequence is incapable of producing this change?
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slevesque Member (Idle past 4670 days) Posts: 1456 Joined: |
There is usually a way to know when the wiki article was last edited. Anybody know how to check that ?
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Pluto Junior Member (Idle past 5063 days) Posts: 4 Joined: |
quote: Just to clear up any confusion, this is the last edit on that page.
06:59, 20 April 2010 70.173.130.156 (talk) (29,003 bytes) (→Allopatric: Edited because an idiot creationist was using the absence of explicit mention of mutation to pretend that this was implicitly excluded.) So both are right. It was like she quoted it, and then it was changed(probably because of this very discussion), And now it's how Dr A is quoting it.
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CosmicAtheist Member (Idle past 4921 days) Posts: 31 From: Washington, USA Joined: |
Speciation: Revision history - Wikipedia
On the top of every article there lists several tabs. "Article, Discussion, Edit this page, and History". Edited by CosmicAtheist, : No reason given.
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Faith  Suspended Member (Idle past 1474 days) Posts: 35298 From: Nevada, USA Joined: |
Thank you for checking on that. I suspected it had been changed, possibly by Dr. A himself for that matter, but didn't want to make such an accusation. I do know, however, that I copied and pasted the quote exactly as I found it. Perhaps I should also take a screen shot of every page I quote from for evidence now that I see how such things can happen.
Edited by Faith, : added comma Edited by Faith, : possibly for probably
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Faith,
Thank you for checking on that. I suspected it had been changed, ... Wikipedia is a volatile source, as any paragraph is subject to change. Several pages have experience change wars between people of different opinions. If the page has changed since your quote you can look at the history and pull up the version you quoted from, rather than accuse people of changing it just to embarrass you. The other thing you can do -- good practice for any reference from any internet site -- is not only cite the webpage, but when it was last accessed. Enjoy. we are limited in our ability to understand
by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hi Faith, you accuse us of not understanding you, here you have a misunderstanding:
You all keep insisting on mutations as if without them you can't get the changes that become new varieties. New varieties are not new species, but subspecies, populations that are isolated, usually geographically, and that undergo different selection pressures can evolve to show visible differences. This may occur by your pet hypothesis of allele loss in both parent and offspring population, so that we can see different alleles in the majority of the populations. What you do not get is reproductive incompatibility. As long as you maintain all the alleles within either population that the ancestral population had, then there cannot be reproductive incomptibility, because they are the still the same species. ps -- I'm still waiting for you to work out the math on how your system works. Enjoy. we are limited in our ability to understand
by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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Percy Member Posts: 22505 From: New Hampshire Joined: Member Rating: 4.9 |
RAZD writes: As long as you maintain all the alleles within either population that the ancestral population had, then there cannot be reproductive incomptibility, because they are the still the same species. If this is intended as a rebuttal to Faith's scenario, then I think you meant to say "maintain all the genes" instead of "maintain all the alleles," because Faith believes that reducing allele diversity is what causes speciation. --Percy
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