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06-22-2002, 04:24 PM | #11 | ||||||
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Along these lines, why would evolution be so "selective" as to be able to "select" the hooks in bird feathers, yet not "select out" something which is apparently sometimes fatal (the fetal circulation system I earlier mentioned)? Surely you aren't going to claim that evolution couldn't "detect" a higher proportion of deaths in certain fetuses, and that this should not have resulted in the elimination of such features? With all the "random mutating" and "convergent evolution" supposedly going on, and all the "competition for scarce resources", why didn't mammals evolve a more efficient and less deadly fetal circulatory system? Quote:
In Christ, Douglas [ June 22, 2002: Message edited by: Douglas J. Bender ]</p> |
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06-22-2002, 04:50 PM | #12 | |
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KCdgw,
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In Christ, Douglas |
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06-22-2002, 04:59 PM | #13 | |
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Unfortunately,there is no link, and as I said, I hadn't read the article either, but that it might be an interesting place to start. So I gave a proposed scenario of my own here Cheers, KC |
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06-22-2002, 05:12 PM | #14 | |||||||
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[quote]Me: However, if it was clear that there was no known natural process which could reasonably account for your existence, then either you don't exist, or you were "supernaturally" created. scigirl: Oh, but I think you said it yourself quite precisely in another thread: Douglas (from the "New Debate with Douglas Thread): [...]we KNOW that human beings are created through two "parents", and have never observed human beings being "miraculously created" out of "thin air". I should have added, to the above, that, "...however, if we have solid testimony as to the origins of humans, and that the orinal humans were 'miraculously created' out of 'thick dust', but humans are now 'reproduced' naturally, then we can be confident in that testimony, especially if it comes from God". Quote:
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06-22-2002, 05:31 PM | #15 | |||
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The article was in a journal, actually: Quote:
And in fact, it was just the first article in a series of them during the 1990's that have greatly clarified the relationships between the various carnivorous plants (so actually, a comment by a previous poster that the molecular studies hadn't been done yet isn't quite accurate). You'll get some if you click on "<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=pubmed_pubme d&from_uid=1523408" target="_blank">Related articles</a>" in pubmed, although you have to dig through a lot of less relevant stuff. But you probably don't want to mess with the library. Online, the only two good resources on the evolution of carnivorous plants, and the Venus Flytrap specifically, are: 1) This article: <a href="http://www.steve.gb.com/vegetable_empire/index.html" target="_blank">http://www.steve.gb.com/vegetable_empire/index.html</a> ...or rather, this subarticle specifically on carnivorous plants, "<a href="http://www.steve.gb.com/vegetable_empire/murder.html" target="_blank">When plants kill</a>". 2) Various threads on the talk.origins usenet newsgroup, which you can find by searching the google archives. E.g. <a href="http://groups.google.com/groups?q=%22carnivorous+plant%22+evolution+group:t alk.origins&hl=en&lr=&ie=UTF-8&scoring=d" target="_blank">look at these threads</a>. I need to write up a long and horrendously detailed article on how the evolution of traps like the Venus Flytrap, which puts Behe's mousetrap to shame, constitute yet another refutation of the IC argument. But it will take some time. For now I'll <a href="http://groups.google.com/groups?q=%22carnivorous+plant%22+evolution+group:t alk.origins&hl=en&lr=&ie=UTF-8&scoring=d&selm=74227462.0206072200.70c30029%40po sting.google.com&rnum=1" target="_blank">quote my own t.o. post</a>: (with some added formatting and pics) Quote:
[edit to add figures, which came from here: <a href="http://www.sarracenia.com/" target="_blank">http://www.sarracenia.com/</a> , a great website for pics and general CP info] [ June 22, 2002: Message edited by: Nic Tamzek ] [ June 22, 2002: Message edited by: Nic Tamzek ]</p> |
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06-22-2002, 06:24 PM | #16 |
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so actually, a comment by a previous poster that the molecular studies hadn't been done yet isn't quite accurate).
I figured, if I made a dumb comment like that, somebody would come along to show me up.... That was a wonderful post! I hope you stick around to spread enlightenment. The T.O crowd is definitely a cut above -- does Ted Holden still show up there? Vorkosigan |
06-22-2002, 06:49 PM | #17 |
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"Ad hoc systems that work". I like that. Cells, DNA, the human brain, etcetera. "Ad hoc systems that work". Would that NASA engineers could take this to heart. I don't know what you've studied about NASA, but NASA systems are extremely ad hoc; like evolution, NASA must work within constraints, in its case, political, budgetary and engineering. The result is often not optimal -- for example, have you looked at the design of the current Int'l Space Station? I'd decribe it, but my knowledge is now out of date -- like bacteria, the ISS mutates every generation. The human brain is entirely ad hoc. If you were building an intelligent animal from scratch, would you use a chimpanzee as a basis? Would you make it susceptible to strokes and other diseases? Would you design the visual processing system so that it has to flip images from the retina in order to see them properly? Would you limit the language learning period to the first few years of its life? Would you design it so that the left side of the brain controls the right side of the body? I am sure a brain expert could give you many examples of ad hoc approaches in brain design. But these should suffice. Well, that's not what one of the primary information sites on the "Venus Flytrap" said (I can't remember which one said it, but it was some kind of Internet science "encyclopedia" or what-not...probably on the level of an introductory college biology textbook). Of course, perhaps they forgot to add, "...can subsist on photosynthesis alone, as long as there is plenty of nitrogen in the soil", or something. That is the case -- as long as there is sufficient nitrogen in the soil, then the plants can use it. But the soils they are usually found in are nitrogen-impaired: <a href="http://waynesword.palomar.edu/carnivor.htm" target="_blank">http://waynesword.palomar.edu/carnivor.htm</a> "But why would some insectivorous plants need an additional supply of nitrogen, particularly when they are living in organically-rich bogs? The answer to this question may involve the pH of the water and soil which is too acidic for nitrifying bacteria that convert ammonia from protein decay into nitrite and nitrate ions. This important bacterial process is called nitrification. The nitrite and nitrate ions made available by the bacteria are readily absorbed by the roots of plants. If the nitrification process is impaired, there could actually be a shortage of these nitrite and nitrate ions; hence, the carnivorous plants have evolved a mechanism to obtain a supplemental supply of nitrogen." <a href="http://www.uvm.edu/news/?Page=News&storyID=2656" target="_blank">Here is a story on how nitrogen is related to plant size</a> I think the point is clear -- carnivorous plants live in nitrogen--poor environments and have evolved their strategy to enhance their nitrogen intake. They retain the ability to obtain nitrogen from the soil, and to photosynthesize. Just like other plants. That strong hints at common ancestry. Well, shoot, why would that not be an indication of "Design", especially if the Designer made a way for the plant to obtain nitrogen when it was located in nitrogen-poor soil? This is why nobody uses ID in science, Doug. No matter what the situation, an auxiliary hypothesis like this can explain it. Why make a plant for nitrogen--poor soils, and then make it require nitrogen to live?. Obviously, the whole problem can be eliminated with the right design that eliminates the need for nitrogen. Of course, other solutions exist -- some plants take nitrogen from the air, while others fix their own. Why not use those designs? And why reuse the same genes as in all angiosperms? Why build the trap from a modified leaf that only works a couple of times, rather than design a dedicated one that can be re-used? The questions are endless. ID is a bad idea, Doug. It provides no framework for explanation -- it simply says "Things are the way they are because that's the way they are." But please, there's no need to describe the "Design hypothesis" as "laughable" - we are trying to have a civil, reasoned discussion, aren't we? I apologize for using the term "laughable" to describe an idea that was decisively refuted over two centuries ago, and went out of science over 150 years ago, and owes its current vogue to a the resurgent political clout of the Christian Right. ...when those "early, very simple stages" would have added very, very little "survival advantage". This is a profound misunderstanding of how evolution works. Evolution is a compound interest problem, Doug, where small advantages pay huge dividends over time. Let's suppose you invest a million at 5% and I invest a million at 5.01% annually. In fifty thousand years, I will have many times more money than you. I know you're good at math; run the numbers for this: There are two groups in a population. Group A reproduces at a 1% higher rate than Group B. How many generations before A constitutes 99% of the population? See how those tiny advantages add up? Those tiny advantages add up, iterated again and again after each generation. What good is 5% of a wing? Precisely 5% better than no wing at all. That's why there are fully winged animals, like plovers and dragonflies, and animals that can glide, like squirrels and snakes, and animals that obtain a slight lift and stabilization from having a small bit of wing. ..why didn't mammals evolve a more efficient and less deadly fetal circulatory system? Because the one they have now works fine enough. Evolution doesn't produce the most efficient systems for performing something, it produces ones that work. "Efficiency" is a value that has no meaning, except with respect to some arbitrary engineering standard that humans create. Evolution, like NASA, is a constraint-driven process. If more resources go into one system, fewer resources are available for another. Further, the system may not be able to become more efficient; the necessary material and genetic basis might not be there. Finally, how do you know the fetal circulatory system is not becoming more efficient? Of course, it is your claim that this system that kills a certain portion of its users was in fact Intelligently Designed. Vorkosigan |
06-23-2002, 03:23 AM | #18 |
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Scigirl sez:
"I still say - if there was a divine creator of life on this earth, it sure as hell isn't the Christian God. Nope, the god (goddess?) who made life on this earth does not believe in good and evil, likes homosexuality, and has a very strange sense of humor (as evidenced by venus fly traps, hippos, etc). Doesn't sound like good ol' Yahway to me." 'Twas Quetzacoatl, obviously. Now that that's cleared up, I'd like to thank Nick Tamzek for a mavelous post! Great pics, also! I live not too far from flytrap country. Here in NC, this plant is protected by law, with a ridged quota for licensed collectors. Plant fosslis other than trees, particulary small, soft plants that live in or near swamps, are not easy to come by. But, it is not hard to see where a 'sensitive' leaf might evolve into a carnivorus one, as has been mentioned above. I say "might" because this is another species that has an incomplete record. Nobody knows. Yet. For some reason, I find the sundews, which have turned the sticky, movable leaf-trap into an art form, more interesting than the flytraps. And pitchers are just downright pretty. doov [ June 23, 2002: Message edited by: Duvenoy ]</p> |
06-23-2002, 05:51 AM | #19 | |
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Cheers, KC |
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06-25-2002, 06:36 AM | #20 |
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I've been out of town, otherwise I would have addressed this. As it is, it seems to be pretty well addressed by others. Perhaps when I have some more time I'll be able to add something that hasn't already been discussed, but for now here's a question:
Since the only substantial difference between the venus flytrap and its closest relatives--e.g., sundews--is the speed with which the trap closes (we already have the sensory hairs, the digestive juices, and the closing mechanism, albeit a slow one) do creationists deny that this speed is something that could have evolved? In other words, would the evolution from something like a sundew to something like a venus flytrap be "macroevolution", would it involve "more information", and most importantly, would it imply the evolution of a new "kind" of plant? |
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