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Author | Topic: How do you define the word Evolution? | |||||||||||||||||||||||||||||||||||||||||
CRR Member (Idle past 2262 days) Posts: 579 From: Australia Joined: |
Clearly you're avoiding the point that different scientific sources give different definitions of evolution. You can't just pick one you like and say "This is THE definition of evolution"; especially since it is such a poor one that even Creationists are willing to adopt it.
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Coyote Member (Idle past 2126 days) Posts: 6117 Joined: |
You can't just pick one you like and say "This is THE definition of evolution"; especially since it is such a poor one that even Creationists are willing to adopt it. And creationists have no say in the matter at all, being inherently anti-science. You wouldn't hire a plumber who busted up your pipes instead of fixing them, would you?Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge. Belief gets in the way of learning--Robert A. Heinlein In the name of diversity, college student demands to be kept in ignorance of the culture that made diversity a value--StultisTheFool It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers If I am entitled to something, someone else is obliged to pay--Jerry Pournelle If a religion's teachings are true, then it should have nothing to fear from science...--dwise1 "Multiculturalism" demands that the US be tolerant of everything except its own past, culture, traditions, and identity. Liberals claim to want to give a hearing to other views, but then are shocked and offended to discover that there are other points of view--William F. Buckley Jr.
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Faith  Suspended Member (Idle past 1464 days) Posts: 35298 From: Nevada, USA Joined: |
You say the ToE "works." I wonder if it's really the ToE that you are using.
The ToE assumes that variation is open-ended, that any species can vary and just go on varying until eventually you have to regard it as a different species. Is this assumption essential to your work? Speciation is supposed to be that point, defined by the new variety or race's inability to breed with the parent population. The new species is assumed to have the ability to go on varying just as the previous population did. Is this assumption essential to your work? Mutations, or random changes in the DNA, are considered to be the source of genetic variants, essential to the organism's ability to vary. Are mutations as the explanation for this variation essential to your work? Or, could you please try to be more specific about exactly how the ToE is necessary to your work? Walk us through your thought process on a particular problem.
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jar Member (Idle past 414 days) Posts: 34026 From: Texas!! Joined: |
Oh "Change over time" works just fine as long as it is understood by those who are not willfully ignorant, deluded or dishonest.
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Dr Adequate Member (Idle past 304 days) Posts: 16113 Joined: |
Clearly you're avoiding the point that different scientific sources give different definitions of evolution. I just looked at the first of your "different scientific sources":
CRR, post #265 writes: Or we could go to Evolution 101 at Berkley.
Biological evolution, simply put, is descent with modification. ... The central idea of biological evolution is that all life on Earth shares a common ancestor Hmm, what used to go where you put the ellipses? Let's have a look.
Biological evolution, simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations). You found a definition of evolution, saw that it proved you wrong, cut out the bit that proved you wrong, and posted what remained as proof you were right. This is not arguing in good faith.
You can't just pick one you like and say "This is THE definition of evolution"; especially since it is such a poor one that even Creationists are willing to adopt it. If creationists agreed with the standard definition of "giraffe" (as I believe they do) would that make it a poor definition too? Do they taint everything they touch? Edited by Dr Adequate, : No reason given.
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Dr Adequate Member (Idle past 304 days) Posts: 16113 Joined: |
Clearly you're avoiding the point that different scientific sources give different definitions of evolution. And now let's look at the second of your "different scientific sources" with an allegedly different definition. It says:
The "allele-frequency" definition of evolution has survived to become the "standard" definition in textbooks and discussions about the nature of evolution. You had the whole internet to look at to find a reference proving me wrong. And again you found one that proves me right --- and pretended that it proves me wrong. Edited by Dr Adequate, : No reason given. Edited by Dr Adequate, : No reason given.
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Dr Adequate Member (Idle past 304 days) Posts: 16113 Joined:
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And would CRR and Dredge like to tell us what the right word is for evolution, if not "evolution"?
Let us consider a not uncommon evolutionary event. A population of bacteria is exposed to an antibiotic. A mutation arises conferring immunity; it spreads through the gene pool as a result of natural selection. Compensatory mutations occur and are likewise selected for. We end up with a robust healthy population immune to the antibiotic. Any biologist would say that the bacteria have evolved resistance to the antibiotic. 'Cos they have. Then along comes Dredge and says that we can't call that evolution because it does not conflict with his primitive religious dogma --- and the term "evolution" must be reserved only for things that he personally disbelieves in. (Presumably the definition would have to be revised any time he changes his beliefs, and the makers of dictionaries will have to call him up again every time they bring out a fresh edition.) But what, then, should scientists be calling it? Our language has thousands of words from aardvark to zymurgy, and not one of them except "evolved" will sensibly and exactly fill in the blank in the sentence "the bacteria have _______ resistance to the antibiotic". There is no better word. So I would suggest that we let scientists use scientific terms in the established and customary manner, and if creationists want to talk about something other than evolution, they should find another word for it. Edited by Dr Adequate, : No reason given.
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CRR Member (Idle past 2262 days) Posts: 579 From: Australia Joined: |
And further on it says;
The allele-frequency definition, if adequate, would leave us unsatisfied that evolution really had been explained. and finishes with;
Eli Minkoff (1983: 575) consolidated the contemporary understanding this way: Evolution Originally, a synonym for ontogeny....According to Lamarck and his contemporaries, the unfolding of (evolutionary) potentials as each species ascends the scala naturae. From 1809 on, the transformation of one species into another; phyletic evolution. According to many geneticists..., changes in the gene frequencies of populations. Anagenesis plus cladogenesis. Phylogeny and the changes in gene frequencies that produce phylogenetic change. In the nearly two decades since the publication of Minkoff's book, there have been many exciting developments in evolutionary research. Models of evolutionary change based on our emerging understanding of developmental and regulatory genes, transposons, somatic hypermutation, endosymbiosis, and other previously unrecognized mechanisms for producing and maintaining biological variation present exciting new opportunities for evolutionary biology. Although the precise role and contribution of each of these mechanisms to the pattern of evolutionary change is still unfolding, it is certain that they will add to a fuller understanding of evolution as well as a new definition of evolution that incorporates these mechanisms. The article as a whole doe not endorse the "allele frequency" definition; which btw was not your definition.
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Pressie Member Posts: 2103 From: Pretoria, SA Joined: |
This one is funny. I can't see anything about measuring genetic information at all.
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Dr Adequate Member (Idle past 304 days) Posts: 16113 Joined: |
The article as a whole doe not endorse the "allele frequency" definition; which btw was not your definition. It says it's the standard definition, literally the textbook definition; and it is in fact synonymous with the one I offered.
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caffeine Member (Idle past 1044 days) Posts: 1800 From: Prague, Czech Republic Joined:
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Sorry if I'm not being clear, not sure exactly what this is about. The hundred I mentioned aren't "viable" then, occurring in individuals where they can't be passed on, but supposedly might do something undesirable in the person's body? The idea is that most of the mutations are in the individual's body but don't get passed on, those mutations we are all said to accumulate, most of which don't get passed on. Yes, most mutations do not get passed on; since only those that happen in a germ-line cell (ie. a sperm or an egg) can be passed to a child. A mutation that happens in a skin cell of your arm is not important for evolution (this is true of something like a human, anyway - some other organisms (like many plants) can reproduce vegetatively as well and pass on pretty much any mutation). The 'hundred or more' you mention, however, are I think supposed to be germ-line mutations - those which are passed on to children. The figure in humans is now believed to be lower; however - about 60 (this is based on direct comparisons between parents and children now that they're able to sequence whole genomes).
The question is what each of those alleles actually does. I accept that there are all these variations in the sequence, defining them as different alleles, but what exactly do they DO? How many of them just do what lots of others also do? We're talking about different versions of a particular gene, right? Presumably different versions, diffrerent alleles, exist to vary what the gene produces. If it's a gene for hair color one allele may be for brown, another for black, another for red and so on. If you have hundreds of such alleles, what does each of them do? In other words, why would more than four in a population be useful anyway? Especially when there may be a number of genes for the same trait that also have different alleles/versions, that combine with the other genes toward a particular effect in the organism. Well, they won't all be useful variants. A lot of variation is selectively neutral, as you pointed out before. And of course unhelpful mutations can also be passed on. The only mutations which will be instantly removed by selection in every case are the dramatically deleterious ones. The mutations which cause the foetus to miscarry in the womb, or which make you certain to die in childhood, or which make you sterile; a mutation which is more subtly disadvantageous should be expected to lose out in the long term; but the term can sometimes be very long.
This raises all kinds of questions in my mind. How can such "mutations" really be mutations if they specifically and pointedly do things that are SO beneficial to the people in this situation? How do they get selected? But as just pointed out, there are hundreds of known mutations (in this one gene). There are undoubtedly more that we haven't found - plus all those that were selected away or happened to die out. Most of them probably don't do anything beneficial to anyone. We're just looking at the few specific ones that are known to do something useful because that's what we were talking about. As for how they get selected; surely this is something you understand already. People have been living on the Tibetan plateau for tens of thousands of years (though I know you don't accept the dating). People prone to altitude sickness are going to be at a disadvantage over people who aren't; especially in the hard times - when there is plague, famines, invasions, etc; and so over the long haul the variants which protect from altitude sickness will become more common. This is not an instant process. This study identified a specific protective ELGN1 variant which is much more common in Tibet than anywhere else; but it's frequency in Tibet is at about 70%.
Even if what selection does is merely favor the reproduction of the best equipped/fittest individuals wouldn't getting such capacities established throughout the population cost an awful lot of (way too many) losses on the way to getting them established? There's no threshold of acceptable loss - what would 'too many' be? But I think you're thinking about it wrong. Imagine a situation where there are two organisms, but only enough food for one. The one who gets the food will live and reproduce, the other will starve. Now, if one has some advantage over the other (being faster, stronger, more persistent, whatever), and the advantage is genetically based, this one is more likely to get the food and survive, and its genetic advantage is likely to be passed on. If the two are genetically identical, then one of them will still die anyway. In the first case there's selection, in the latter case not, but there's no difference in the loss to the population.
ABE: BUT, there is still the question how you know they are mutations anyway, as opposed to built in variations that simply accumulate, just as the mutations would supposedly do. How do you know the SOURCE of the alleles? I'm not sure I understand this question. How can something accumulate if it's already built in? We know that a diploid population which starts with only two individuals can only have a maximum of 4 versions of each gene. If we find more than four versions in a later generation; then something changed.
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Faith  Suspended Member (Idle past 1464 days) Posts: 35298 From: Nevada, USA Joined: |
I'm not sure I understand this question. How can something accumulate if it's already built in? We know that a diploid population which starts with only two individuals can only have a maximum of 4 versions of each gene. If we find more than four versions in a later generation; then something changed. It's the traits that accumulate, based on the built-in alleles. I'm supposing that all the other "alleles" are mutations, that none of them adds anything new to the function of the basic four for the trait governed by the gene, that some at least don't destroy the function so you still get the variation it governs despite the differences in the sequence. Those are the "neutral" ones? But in reality over time the neutral ones would most likely become deleterious. Four for a gene should be all it takes to provide all the variety we see for any given trait, and this is greatly increased where there is more than one gene that governs that trait, which is fairly common, right? I'm going to have to come backi to this.l Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Dredge Member (Idle past 93 days) Posts: 2850 From: Australia Joined: |
Dr. Adequate: "You are not an evolutionist."
The only way to stop creationists like me claiming to be evolutionists is to include the theory that all life evolved from a single-cell-like organism in the defintion of evolution.
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Dredge Member (Idle past 93 days) Posts: 2850 From: Australia Joined: |
Can you explain please the chronology of your cited "not uncommon evolutionary event"? I'm confused. When did the mutation that confers immunity (to the antibiotic) arise - before the introduction of the antibiotic or after?
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Dr Adequate Member (Idle past 304 days) Posts: 16113 Joined: |
Can you explain please the chronology of your cited "not uncommon evolutionary event"? I'm confused. When did the mutation that confers immunity (to the antibiotic) arise - before the introduction of the antibiotic or after? Obviously either can happen, but in the example I gave the antibiotic came first.
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