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02-22-2002, 12:30 AM | #11 | |||
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Why have eyes on backs? Is being sneaked up on a significant selection pressure, given what we’ve already got in the sensory department? (Maybe it is, in the paranoid world of theism.) I thought that’s why we can turn our heads, and have ears. Surely if seeing behind us were so useful, the creator would have given us such eyes. Where seeing round you is really useful, herbivorous mammals for example have eyes at the sides of their heads. Funnily enough, many mammals can turn their ears to point towards sounds, the better to identify them and their direction. We can’t do that. But we do have the same ear muscles that those mammals have, even though the best we can do with them is wiggle our ears. Bit of a cock-up on the design front there, if telling what’s behind you is that important... Quote:
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02-22-2002, 03:02 AM | #12 |
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Hi Oze.
As an engineer, I come across irreducibly complex structures all the time. Believe me, there is no obstacle at all for incremental evolutionary steps to create an irreducible structure. You see, although it has been a big thing in the creationist camp recently, due to the Behe, it is neither a new concept or an unresolved one. I had a link to a great site that explained all the different ways biological structures create irreducible complexity, but have since lost it. I am sure talkorigins covers all the same ground. As a brief summary however, I'd like to give you two important ways IC is produced. These are also the most visually-easy examples. 1) Scaffold. A good analogy is an arch. It cannot be built stone by stone by itself - it will fall in almost immediately. However, when constructed in a scaffold you can put bits of stone in here and there, until it is complete. Remove the scaffold, and you have an IC structure produced by incremental steps analogous to evolutionary development. 2)Change of function A good example of this is wing-evolution theory. Often, creationists make the charge that stump wings wouldn't work, and so are useless and an example of an IC strcture. However, this completely ignores the possibility that these proto-wings could be used for something entirely different. Body heat control in ostriches, insect trapping in bats, gliding. The wings developed with these uses, and only then changed into flight structures. An IC structure has been produced. It really is startlingly easy, when you think about it. Finally, I'd like to mention the subjects Behe used in his book. The biochemical processes he examines have since had valid evolutionary pathways postulated - I am sure someone here knows the cite. He also uses the example of a mousetrap - I recall someone mentioning an online debate where his opponent demonstrated 2 and 3 part mousetraps with stage props like his clipboard. What you have to remember is that 67% of an eye is better than 0%. |
02-22-2002, 04:17 AM | #13 | ||||
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02-22-2002, 05:40 AM | #14 |
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Correct me if I am wrong, but you a couple of you seem to be writing long responses to mac_philo, whereas to me it looks like a parody.
If it isn't, then I feel sorry for that person! |
02-22-2002, 06:04 AM | #15 | |
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evolution liquid. He'll just claim these are examples of intelligent design. You needed an intelligent being to form those IC structures, rather than them falling into place. I think this is the same as the "747 in a junkyard" argument. |
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02-22-2002, 06:06 AM | #16 |
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Kosh: The principles of scaffolding are found in many a geological structure in nature.
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02-22-2002, 06:21 AM | #17 | |
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02-22-2002, 06:43 AM | #18 | |
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Cheers, Oolon |
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02-22-2002, 11:10 AM | #19 |
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Kosh, yeah you are right - I should have listed a biological example as well as the analogy (which I like because it is so clear and easy to understand). But I was running low on time so didn't pay too much attention (hence why I only gave two methods. I am aware of at least 2 others).
ummmmm..... automaton mentioned geological examples - well, how about the stones that sit on the rock pillars in the badlands? They are a harder rock that prevents the column below from being eroded, and over millions of years, they form the weird shape we see today. Remove the column, and the stone falls, remove the stone and the column erodes. and biological... probably a biochemist is better suited for this, as it often happens in metabolic pathways, which I have only scratched. But I'm sure I can find one if no-one else can. |
02-22-2002, 01:34 PM | #20 | |
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Where I disagree is the concept that liquid is trying to advance is valid. Liquid, it seems to me, is just speaking from an engineer's point of view. His argument lacks strength with regard to evolution because he doesn't combine the example of the arch (which Gould talks about in one of his essays in "Natural History") with a biological example of the same principle. Evolution can take pieces and parts of other systems, build a scaffold of something that works, and end up with something that stands on it's own. In other words, co-opting enzymes, structural proteins and regulatory mechanisms from other pathways to form an entirely new pathway over time. The pre-existing pathways serve as the "scaffold" for the new one. <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=870309 6&dopt=Abstract" target="_blank">This paper</a> by Melendez-Hevia E, et al. J Mol Evol 1996 Sep;43(3):293-303, discusses just such a "scaffolding" situation with regard to the evolution of the Citric acid cycle. (Just as a note from the standpoint of intellectual honesty, I caught this bit about the arches and the relevence of TCA cycle evolution from reading "Finding Darwin's God" by Ken Miller.) Where you are correct is that most design proponents, especially the ones outside of science, are too lazy to do anything BUT "see" only intelligent design due to their ignorance. They can be excused to some extent, however, because it does take some effort to actually learn something rather than simply believe what they want to believe--ie "Goddidit". What is more disturbing are the scientists like Behe who ought to know better but insist on upholding the ID charade. +++++++++++++++++++++++++++++++++++ Sorry liquid, I didn't see your follow-up to kosh's post. I guess that will teach me to not wonder off to the lab in the middle of a post and forget to check check for replies. [ February 22, 2002: Message edited by: pseudobug ]</p> |
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