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Author | Topic: Mikey's concerns about mutations and ancestors | |||||||||||||||||||||
mike the wiz Member Posts: 4755 From: u.k Joined: |
It seems to me, that every part we have now, could be traced back through one pathway atleast. A kind of reversal process, to show how systems like the blood - could live without aortas and such. Or how the eye could work without a lense. UNLESS, there is a mass production of mutations at the same time.
Yes, I suppose I can imagine a rudimentary system building on what it has - but can ever living organism - throughout all of history - be relied on as having all the systems coming together - by chance, - hearts, lungs - ears, eyes, etc. What were all the previous systems? Can they be shown from some parts of a system?
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RAZD Member (Idle past 1425 days) Posts: 20714 From: the other end of the sidewalk Joined: |
to see how the eye works without a lens look at the Nautilus, whose vison is better than ours underwater.
and it has the retina facing the light instead of away from like ours. see Pin-hole eye of Nautilus James B. Woodhttp://www.dal.ca/~ceph/TCP/nautiluseye.jpg from Oops! Page not found! - Dalhousie University as far as IC systems go consider the electric light bulb: you need both the bulb and the electical system to make it work, take away either and light is not produced -- they must have been developed together all at once. I think you can see the logical fallacy of this argument even in a case where we know design was involved .... This message has been edited by RAZD, 01-10-2005 21:10 AM we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}
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NosyNed Member Posts: 9003 From: Canada Joined: |
Yes, I suppose I can imagine a rudimentary system building on what it has - but can ever living organism - throughout all of history - be relied on as having all the systems coming together - by chance, - hearts, lungs - ears, eyes, etc. What were all the previous systems? Can they be shown from some parts of a system? As the Nautilus post shows you don't have to imagine all these cases. There are extant organisms that have the "partial" solutions. Not all creatures that have blood have a circulatory system like ours either. (Just to head one possible confusion off:The "partial" above does NOT mean that these solutions are "as good as" other solutions. Not all creatures NEED an eye like ours. (some need better -- much better). Many can do very well with simple light detection. All of us are equally "evolved"; we have all had the same background of 3+ billion years.
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Sylas Member (Idle past 5280 days) Posts: 766 From: Newcastle, Australia Joined: |
mike the wiz writes: Let's assume current function, how can a system produce function if there is always a rudimentary system required? At some stage - isn't there some kind of synchronisation inherently needed? Can there be a mass production of mutations, in sync - via chance? No, mass synchronisation is not needed, in any case of which I am aware. I think you should not assume current function. Change of function is ubiquitous; an essential part of any long term evolutionary hypothesis for some structure. We should be skeptical about just-so stories. We usually just don't know all the predecessors for some structure, and making up a plausible sequence is of limited value, except perhaps in helping someone to appreciate the amazing potential of living forms to adapt over successive generations. The classic example of so-called irreducible complexity is the bacterial flagellum. A biology student has constructed a fairly detailed just-so story, which has been very useful in helping people see how IC can arise in the flagellum. It can be found at Evolution in (Brownian) space: a model for the origin of the bacterial flagellum. The author, Nick Matzke, also contributes here at EvCforum. Note that the starting point is structures in place for a different function.
These problems bother me Sylas. It just seems so logical that an intelligence answers these questions. Shrug. It also seems obvious that the natural world has an astounding capacity for complexity... and some Christians have percevied a grand transcendent design to the whole universe in this potential. I personally find it a bit amusing to see some theists impressed at a purported inabilty of the natural world to perform in some way; and at the same time other theists are impressed at a perceived ability of the natural world to perform the same thing. Both are arguments from design, yet they are polar opposites. One group charges the other with being closest deists; the other charges in return the application of god-of-the-gaps.
Can the functions of say - the heart system, be shown to be working with less parts, as a useful previous system? Sure. Just look at the many examples of simpler systems in living things right now to appreciate that the heart system has heaps of scope to have evolved. Here is a interesting sequence for development of the heart in vertebrates. There is also an interesting set of diagrams in http://www.chelationtherapyonline.com/articles/p198.htm. Cheers -- Sylas
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Loudmouth Inactive Member |
quote: Blood and circulatory systems are very ancient. They are even seen in earthworms, for example, where the mucous covered epidermis of the earthworm acts as a lung. The very first circulatory systems may have been used for waste management, a way to move metabolic waste into a central location where it is either recycled or excreted. Also, there are several solutions for getting oxygen to cells. In insects there are tubes that lead from central locations (spiracles) to the tissues, eliminating the need for a circulatory system. The bigger question should be why we ended up with the type of circulatory system we have instead of a different system. The other thing that Behe seems to overlook is that even a very rudimentary circulation system is more beneficial than no circ. system whatsoever. Again, in a kingdom of the blind the one eyed man is king. Therefore, small increments will always be selected for, no matter how ineffecient they are. For example, if a very crude circulatory system increased tissue oxygenation by 5% it would be selected for (given the right environment). It is very possible that the first circulatory systems were a secondary system. Once the circulatory system became much more effecient then the primary oxygenation system was removed through mutation. **If you only read a section of my post, the last two sentences are the most important**
quote: Let's look at how the mudskipper "breathes" air. The mudskipper is a fish that can move freely on the shore of lakes, streams, etc. It needs access to mud in order to keep it's gills wet, however. What the mudskipper does is store air in pouches, much like lungs. However, these pseudo-lungs do not absorbe oxygen. Instead, these pseudo-lungs push air over the wet gills allowing for gas exchange. As you can well imagine, if these pseudo-lungs developed the ability to absorb small amounts of oxygen then this trait may be selected for. Each subsequent mutation that increased the effectiveness and effeciency of these pseudo-lungs would also be selected for. After a while, gills would no longer be needed for moving about on land. Therefore, if this species also became specialized for surviving on land (eg improvement of limbs) then mutations that removed the gills would not be selected against. You might ask "why doesn't the mudskipper evolve lungs". Well, the land is already full of terrestrial animals, so competition is quite high on land. This wasn't true for the first tetrapods moving on to land. The mudskipper gives us a hint at how the transfer from water to land occured. Firstly, do you agree that my mudskipper scenario is a legitimate explanation on how lungs could have evolved? Do you have any problems with it? Also, this type of scenario causes problems for Behe's ideas. For Behe to suggest that these types of IC systems came about in "one fell swoop" he must have a documented history of all the other sub-systems that existed. Also, he must document all the systems that may have acted in the same role as the one he is studying. Take flagella, for example. It may be very possible that bacteria used to have very simple and ineffecient methods of locomotion. The flagella may have started as a simple system unrelated to locomotion, such as in ion transport. At some point, the pre-flagella structures acquired the ability to add to that locomotion in some sense through the mutation of one of it's proteins. As the new flagella became more effecient the old system was no longer needed and so it disappeared. Subsequent mutations increased the effeciency of the flagella over time which resulted in the system we see today. What Behe needs is an actual history of how the flagella developed. Without this history he is not able to claim that the flagella had to come about in "one fell swoop", nor can he argue that there were other methods of locomotion before the current flagellar system evolved.
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tsig Member (Idle past 2929 days) Posts: 738 From: USA Joined: |
But the critical point is that that is exactly the level at which Darwinian evolution would have to work in the cell. Every relevant detail has to fit or the system fails. If an arm is too long or an angle not right or a staple placed incorrectly, the mouse dances free. If you want to get to a certain system, but the road there isn't a series of continual improvements, Darwinism won't take you there. - Michael J.Behe. Behle is confusing the mouse with the mousetrap.This is the common error for IDists. Why would looking at how the mousetrap was made tell you anything about how the mouse was made?
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