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#1 |
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Critical Thinker
Join Date: Sep 2002
Posts: 381
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Evolution in action: new plant species
This seems timely given the other active threads ongoing:
http://www.timesonline.co.uk/article...584528,00.html
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#2 |
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Guest
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Sadly, I'm not sure this is really an example of evolution and it's likely to be shredded by creationists.
This plant appears to be the result of cross-fertilisation between two related species. The fact the resulting hybrid was fertile is certainly interesting and the inability of the new plant to breed with either parent plant does show it to be a new species, but is it evolution? Is it too simple to see evolution in terms not involving cross-breeding to engender new characteristics? We would normally look to a genetic mutant of organism A finding a selective advantage and outcompeting non-mutated forms of organism A without the introduction of genetic material from organism B. The York groundsel would appear to be the result of one genetic event (the 'accident' that allowed the offspring of two different species to be fertile). I'm also assuming the team addressed the question of whether the common groundsel and the Oxford ragwort are indeed separate species and not simply racial varieties of the same plant. |
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#3 |
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Penultimate Amazing
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
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Speciation is speciation. Provided it can be verified that this is indeed a new species, it doesn't matter whether it came by from mutation or cross-breeding. Evolution theory is not based on some certain method of speciation, surely speciation has happened through the ages by cross-breeding, gene swapping, mutation, and possibly other methods as well.
If verified, this IS a slap in the face of any Creationist who says "we have never watched a species evolve". Hans
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Don't. Just don't. |
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#4 |
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Illuminator
Join Date: Aug 2002
Posts: 4,994
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I dont agree with you spoon-
The principle driving force of evolution is not mutation- as is commonly understood but is recombination. As is the case here. I think this is an excellent example of speciation of a higher organism. Creationist: How do you know God didnt put it there? ![]() Other Creationist: The speed at which this species evolved shows that the earth is only 6,000 years old
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Radicals and Racists Don't point your finger at me I'm a small town white boy Just tryin' to make ends meet Don't need your religion Don't watch that much T.V. Just makin' my livin', baby Well that's enough for me |
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#5 |
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Critical Thinker
Join Date: Dec 2002
Posts: 497
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#6 |
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If the genetic of the plant is unique and there has been no evidence of cross breeding then it is evolution, but as with many plants they all arise from cross breeding there lies the fatal flaw in deciding what is a genuine new unknown plant and what is just another cross bred hybrid species etc.
Technically the exact same flaw can be readily applied to humans. We are all a result of cross breeding, and not as a result of evolution, but then again on the other hand we are all new species that have adapted and evolved via our genetic makeup to be a new species. |
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#7 |
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New Blood
Join Date: Jul 2001
Posts: 7
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[sarcasm]
It's just variation within a kind. after all it's still a plant. show me a plant that gives rise to a cat and maybe i'll reconsider. [/sarcasm] good news for our team, but they will ignore it. |
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Only Sheep Need a Shepherd |
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#8 |
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Guest
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Recombination is the principal driving force for diploid organisms. "Cross-breeding" that results in speciation is what is claimed here. It is speciation because the hybrid cannot be mated back to either parent. This constitutes reproductive isolation, therefore a new species, and, therefore, evolution.
Yes, the fundies will pick it apart, but we need to keep our evolutionary understanding sharp to defend against the wretched onslaught. Cheers, |
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#9 |
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Cheers, |
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#10 |
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Critical Thinker
Join Date: Nov 2001
Posts: 305
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Blind natural selection, is the evolution's only driving force!
Suppose its is a survival advantage for a rabbit to have long legs, and loci x in the chromosome 12, is the loci for the "gene for longer legs" and its competitor for this loci, is a gene for shorter legs. It is reasonable to assume that this allele competition will end up with the gene for short legs as extinct. For instance; a fox is only running for his dinner, but the rabbit is running for his life, the fox can afford with to lose this hunting race, time to time, but rabbits will end up as dinner every time they lose, so on average; a rabbit is naturally selected to run little faster than foxes! But genes for shorter legs are favored in the mole gene pool, and thus genes for longer legs tend to go extinct there. Of course the working ground for natural selection is mutation either for longer, or shorter legs, or some other traits. There is a kind of Arms Race between gene-replicators, and bodies are their survival-machines!
When you consider the Darwinian description, don't forget its panorama! Random mutation, and nonrandom natural selection; I mean its variation and selection is a mechanism in evolutionary biology. A parallel can be drawn to the basics in economy, namely, its supply and demand! A market place supply a variation of products, and its costumers selecting the products they need, the mechanism can be found close to everywhere, for instance in arts, and music, etc, this market consists of different styles, and predilections and so forth! |
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A simple explanation with few explanation grounds is to prefer, except when you need to hide your flaws! |
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#11 |
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NLH
Join Date: Oct 2002
Posts: 25,885
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"Species" is a human concept, as is "speciation". Nature neither knows nor cares. Speciation has occurred when our definition of a species says it has. Our definition is satisfied when a non- interbreeding stable sub population exists.
Now define "stable". Now define "Non-interbreeding". Darwin struggled mightily with the variant / subspecies/species question. We still do. Given the way genes now appear to leap specific, generic and probably higher taxonomic boundaries, maybe it's time we dropped the term "species" as a useful division and accepted the fact that all life is a continuous spectrum. (Except of course, the uniquely created Homo Fundamentostrichensis- head firmly buried in the sands of time). Some things remain true to type. |
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#12 |
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Creationists will just say that it's "variation within a kind." Of course, they won't specify what a "kind" really is...
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#13 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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Any wasps yet? Some new thing along those lines would be a start, I'd think. |
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#14 |
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Seriously, you want to debate the veracity of evolution? I'd truly cherish the experience of doing so. Should I create a new thread, or shall we commence our debate here?
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#15 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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I am curious, have we seen any wasps yet? |
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#16 |
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A post by Alan Smithee
Join Date: Aug 2001
Location: USAian is not a word
Posts: 26,349
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![]() Also, and I know you know this, but a fruit fly would not evolve into a wasp. It would evolve into a different type of fly and descent with modification might produce an entirely different insect form, let's say it's called a "stanzio," but a fly would not give birth to a wasp. You only find that sorta stuff happening in the KJV Bible. |
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I am an American citizen who is part of American society and briefly served in the American armed forces. I use American dollars and pay taxes that support the American government. And yes, despite the editorial decison to change American politics to the nonsensical "USA politics" subforum, I follow and comment on American politics. |
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#17 |
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A post by Alan Smithee
Join Date: Aug 2001
Location: USAian is not a word
Posts: 26,349
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http://www.talkorigins.org/faqs/comdesc/ |
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I am an American citizen who is part of American society and briefly served in the American armed forces. I use American dollars and pay taxes that support the American government. And yes, despite the editorial decison to change American politics to the nonsensical "USA politics" subforum, I follow and comment on American politics. |
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#18 |
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Illuminator
Join Date: Aug 2002
Posts: 4,994
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Radicals and Racists Don't point your finger at me I'm a small town white boy Just tryin' to make ends meet Don't need your religion Don't watch that much T.V. Just makin' my livin', baby Well that's enough for me |
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#19 |
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If you want to go toe to toe on this issue, my shoes and socks are off. Are you prepared to discuss either the evidence or the theory? Are you prepared to defend yet another drive-by? Cheers, |
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#20 |
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Critical Thinker
Join Date: Nov 2001
Posts: 305
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Regarding the continuous spectrum and descent with modification
TO SOAPY SAM AND UNREPENTANT SINNER
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WHAT IS LIFE? ERWIN SCHRODINGER CHAPTER 3 'JUMP-LIKE' MUTATIONS -THE WORKING- GROUND OF NATURAL SELECTION De Vries called that a mutation. The significant fact is the discontinuity. It reminds a physicist of quantum theory -no intermediate energies occurring between two neighboring energy levels. He would be inclined to call de Vries 's mutation theory, figuratively, the quantum theory of biology. We shall see later that this is much more than figurative. The mutations are actually due to quantum jumps in the gene molecule. But quantum theory was but two years old when de Vries first published his discovery, in 1902. Small wonder that it took another generation to discover the intimate connection! On the other hand, by virtue of their breeding true, mutations are a suitable material on which natural selection may work and produce the species as described by Darwin, by eliminating the unfit and letting the fittest survive. In Darwin's theory, you just have to substitute 'mutations' for his 'slight accidental variations' (just as quantum theory substitutes 'quantum jump' for 'continuous transfer of energy'). In all other respects little change was necessary in Darwin's theory that is, if I am correctly interpreting the view held by the majority of biologists. Soderqvist1: A gene consists of nucleotides A. T .C and G molecules which are strung together, a mutation is new configuration of these nucleotides, it is a random wrong spelling, some is bad, some is nonsense, some is good, and these good ones are the working ground for natural selection to work on, and produce the species as described by Darwin! |
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A simple explanation with few explanation grounds is to prefer, except when you need to hide your flaws! |
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#21 |
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Graduate Poster
Join Date: May 2002
Location: USA
Posts: 1,422
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Re: Blind natural selection, is the evolution's only driving force!
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Longer legs may make mating more difficult. The long-legged rabbits may flourish where foxes tend to give chase and eliminate the short-legged rabbits; in neighboring regions where the foxes are loathe to go (e.g. because of briar patches), short legs may prevail because of their greater proliferation. This split may be the first in several which eventually lead to two populations of rabbit which are somehow different enough that they are no longer able to mate--or to produce fertile offspring. Or, this may not happen. |
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#22 |
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Guest
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There are three basic types of selection: stabilizing, directional and disruptive. I'll avoid the differential equations that define them rigorously and define them as follows: o stabilizing - tending to maintain the status quo of the genome's allele frequencies o directional - favoring one allele over others and shifting the genome's allele frequencies over time o disruptive - forcing a divide in the population such that two different alleles become favored over all others. Peter is describing directional selection, and Dr. Matt is describing disruptive selection. As a somewhat technical aside, in the directional selection case, selection doesn't eliminate alleles. Selection can only reduce alleles as far as the mutation-selection equilibrium value, which is always non-zero. A random force, genetic drift, is responsible for eliminating alleles. Even then, mutation can always reintroduce it from time to time. Cheers, |
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#23 |
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NLH
Join Date: Oct 2002
Posts: 25,885
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Peter- Long time since I read Schrodinger's little book. Extremely perceptive considering it predates Crick & Watson. My own evolutionary position is firmly Dawkinsian if there is such a word. I'm quite content with the idea that evolution is a matter of relative gene selection. There are numerous processes by which gene selection can take place, ranging from genetic drift, mutation, sexual selection etc. all the way to dropping an asteroid on a planet and awaiting events.
But there is evolution and there is Human description of evolution. One is a process that happens by itself, the other is a question of education, perception and classification. At times, it will be simple and useful for us to describe evolution in terms of allelle competition; at other times, the species will be a useful concept; sometimes even ideas of group selection may be useful. These are questions of explanatory model and metaphor- a description of reality, not to be confused with reality itself. Where "species" is a fruitful concept, it should be used. Where it limits our thinking, we should find a tool which works better. The fact that many people of intelligence have struggled with the speciation argument for two centuries suggests to me that it is often not a helpful concept. - Hammegk's (probably deliberately) naive question about turning fruit flies into wasps is a classic example. To any intelligent alien from Andromeda, it would be instantly apparent that fruit flies and wasps are closely related lifeforms. Any such alien would immediately be able to identify both as Earth Arthropods. It would point to the similarity of hox genes, the near identical structural form and material: Indeed it would perhaps be pushed to tell them apart. Species difference would be just too trivial to mention. To Hammegk, they are different species, as if that somehow makes them fundamentally distinct. The effect of the terminology is to enforce a distinction where no distinction of relevance (to evolutionary theory) exists. (Of course it matters to the wasp!). This is a historical effect. Biology began with classification. Linnaeus stressed the importance of species and his system was grabbed with glee by the many studious collectors of his day. When he tried to establish a similar mineral classification, it was universally rejected as impractical. My point about overuse of the specific distinction is very simple. If your classification system is causing people to miss the point, then it should be altered. |
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#24 |
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Muse
Join Date: Dec 2002
Location: Pennsylvania
Posts: 627
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This (the original thread) is not the first example of claimed witness to speciation.
Just in the past month or so (Science 299(5607):654-655) had an article describing sympatric (in the same area) speciation among fish in Lake Baikal and Lake Victoria--seems it might have been related to color vision & the human influence of making the waters murky. It seems that Creationists commonly think that "evolution" means near-instantaneous, bizarre changes--"a bat with one wing," a dog "evolve" into an elephant," or "fruit fly to wasp." When we think of species as being reproductively isolated, it may not be obvious (dog & cat)--some fruit flies & other bugs can only be identified by careful examination of their genitalia. Some critters may be isolated in ecological terms, even if some biologist can collect & mix gametes & produce viable offspring. Genetic analysis can give some idea of the extent of isolation, as well as the timing thereof. |
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Professor Pupdog |
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#25 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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However, from time to time you appear to conclude that one of my drive-bys contains sufficient "content -- or lack thereof" you need comment on it. My mission here is admittedly different from yours; I have no interest in converts to my way of thinking. My interest stops once I've clarified to my satisfaction some particular point. When I began using the JREF board, I would have considered my self a dualist. Posters here have convinced me that dualism is not logical, and in fact is a less tenable position than materialism -- even under the materialism definition of some that is so inclusive that nothing else could be left. Hmm, so "energy" is something we "measure" but actually no we don't know what it is, and as materialists realize it is not scientific to even speculate. I mentioned I'm onboard evolution from an Idealist perspective, which can and does provide some logic for what the record is interpreted to depict. I.E. LIFE strives towards organisms that support higher & higher consciousness (human the best we know of at the moment). No problem with the first male/female pair for each new critter which has apparently happened here a very large number of times -- other than time, randomness, and luck. And yes dropsila may well evolve -- but, a fly is a fly is a fly. I suggest that the mismatch between gravity, the other 3 forces, and a fifth? (currently nominated for Higgs) is a much larger cloud on the horizon than was radioactivity 100 years ago. Are we beginning to look at energies that destroy solar systems (or more) rather than life on a single planet? For us my main thought for the next "oops" will come from genetic engineering; damn, who thought we could come up with a virus that kills a human in minutes, lives forever in all conditions, and infects yet is benign in every other lifeform on the planet. Cheers back at 'ya..... |
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#26 |
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Graduate Poster
Join Date: May 2002
Location: USA
Posts: 1,422
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We've observed zillions of objects the size of the sun or bigger, all in space, but the earth hasn't collided with any of them. Does that arbitarily made-up failure disprove everything we know about gravitation? We've observed zillions of acorns over time, and not one has ever become a blowfish, so does that arbitarily made-up failure disprove the theory that acorns sometimes change into bigger life forms? Hey, I'm just a musician, but even I can see that this "any wasps" bit is really stupid. |
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#27 |
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NLH
Join Date: Oct 2002
Posts: 25,885
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I've seen grass turn into cows.
I once saw a man turn into a street.
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#28 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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Any materialist/atheist evolutionist would be quite pleased to have an unspeculative example of fly-to-wasp to trot out. Even arthropod to arthropod just doesn't provide a real open & shut case. Soapy's aliens should have trouble seeing what the fuss was all about, yet this would be trumpeted as absolute proof of "evolutionary theory". Evolutionists make do with 6" horses to 6' horses, a speculative land critter to whale (oops went the wrong way), a "feathered dynosaur", and a great number of other speculative "links" to make the case for time & randomness without intent. "Evolving species" of bacteria also get mentioned often. Again, looked at with life/consciousness/will/what-have-you as the basis of what-is, it becomes easier to see some potentially rational basis for terran evolution, and expect "evolving life" to be widespread (in some universal Bergsonian sense ).
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#29 |
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Guest
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Wait! Wait! I get it! You're saying that species of the fly "kind" can evolve into other species of the fly "kind," but not into other "kinds," such as the wasp "kind"! OK, now we're getting somewhere.
Oh, by the way, could you be so kind as to describe a cohesive, biologically-sound definition of "kind"? Thanks. |
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#30 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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That seems even more problematical than "species -- oh, can't breed you say". Let's stay simple. What do DNA based classification schemes imply to you at "species" level? What is the DNA code difference between dropsila & the common house fly? What DNA level mechanism stops the potential for cross-breeding? After we explain flies, we can move on to wasps vs. flies. Or would you rather move directly to the prion/virus level? Or maybe bacteria? |
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#31 |
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Critical Thinker
Join Date: Nov 2002
Posts: 274
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In fact, a fly producing a wasp would be evidence against evolution as we understand it. Evolutionary theory predicts that changes of that magnitude happen over huge periods of time, far longer than anyone's been capable of observing these things in laboratories.
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Many an ancient lord's last words had been, "You can't kill me because I've got magic aaargh." --Terry Pratchett, Interesting Times |
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#32 |
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Guest
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For the record, the gloves are coming off...now.
Here it is, the official definition of species, the "Biological Species Concept," as proposed by Ernst Mayr: Species are defined as "groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups." That's it. There's no magic to the definition of a species. Any species could theoretically evolve into any other species, given enough time. Of course, you need to remember that all presently existant species are equally old. We can theorize that "primitive organisms looked very much like modern-day bacteria," but all species that we see to day are equally evolved. Asking whether one modern-day species can evolve into another modern-day species is like asking whether you can ever "evolve" into your sister. No, you can't, but your sister and you have a common ancestor. Likewise, the fly and the wasp have a common ancestor, a long-extinct species which eventually evolved into both the fly and the wasp. Evolution works on large timescales. Even punctuated equilibrium, which suggests that changes happen much faster than Darwin suspected, works on timescales of "only" tens of thousands of years. Yes, any species which evolves today will look like species closely related to it. If a fly suddenly gave birth to a wasp, it would disprove all extant versions of evolutionary theory. Besides, evolution works to find the organisms best adapted to their environment. It doesn't specifically try to produce any one organism; it just tries to make organisms which are most "fit" in their environment (and "fit" is not a tautological term; it relates to what elements in the environment most limit the expansion of a species; those individuals which best circumvent this limiting factor are the "fittest"). If evolution were to start again, it would be unlikely that the same variety of animals would evolve. The experiment which would most reflect the true nature of evolution would be to put a group of flies in an environment which stresses them in a particular manner, and see if they respond to that stress by evolving into a new species. You could then take that new species, and put it into another environment which would stress it further, and watch it evolve into yet another new species. After many repetitions of this, you would create something which was not a fly. Of course, this would take thousands of years...but if that's what creationist "scientists" demand as proof, they should get started right away. I guess it's better than Kent Hovind, who requires that scientists create the Big Bang in a laboratory to prove evolution. |
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#33 |
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Critical Thinker
Join Date: Dec 2002
Posts: 497
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Isn't evolution simply the process by which the creature most fit survives, produces viable offspring, thusly reproducing the new features that permitted the original off-shoot to survive where its ancestors perished? It's not a process that seeks a solution to a problem, it is a process that simply occurs. Only our interpretation can lend it any meaning, that is to realize that evolution benefits the superior (to the circumstance or environment) life form... |
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#34 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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The time aspect is noted, but it's like looking for a decaying proton; expect one every 10^32 years, OR watch a lot of protons. Either way, no more luck with fly to "something else", decaying proton, and no derned monopole magnets either! |
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#35 |
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Guest
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Isn't that what I said? I realize I was anthropomorphizing to some extent, but that's basically what I meant. If evolution seeks to solve a "problem," per se, it's some environmental stress which is limiting the reproduction of the individuals. The individual whose genetic advantages allow it to partially circumvent this stress will produce more offspring, and its genes will be over-representated in the filial generation. Maybe I could have made that clearer, but I think we both understand one another.
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#36 |
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Guest
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It's not a matter that biologists can "speed up the process" with a lot of fruit flies. I'm reminded of the old adage, "You can't get a baby in one month by screwing nine women." Unless scientists somehow managed to drastically decrease the generation time of flies, they're working no faster than natural evolution. They might be able to apply pressures in a more specific fashion, and thereby cut the timeframe down by a factor of 2 or 3, but even if they did that you would complain that it was "artificial selection," not natural selection. You simply can't speed up evolution.
And a fly giving birth to a wasp would still throw a monkey wrench into evolutionary theories, even with mutations. Evolution is about how natural selection selects the best mutations and uses them to make new species. Random mutations alone can occationally make new species, but it wouldn't make any large jump (such as from fly to wasp). |
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#37 |
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Critical Thinker
Join Date: Dec 2002
Posts: 497
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I just wanted to be sure. Tone is not something that can be easily inferred on a message board.
Besides, until I started actually reading Interesting Ian's posts, I thought he was an intelligent person. I just sought clarification. Thank you for providing such. ![]()
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#38 |
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Guest
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On the population level, rwald is right, the population is "solving a problem." The problem is producing more of itself. You are also right to point out that it isn't teleological, and, in that sense, "directed." You may want to see my earlier description of the three basic forms of selection to see where "directed" clearly comes into play. Cheers, |
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#39 |
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#40 |
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Banned
Join Date: Jan 2002
Posts: 8,422
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