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Life's Complexity Diminishes Darwinian Potency
Creation-Evolution Headlines ^ | 8/28/03 | Creation-Evolution Headlines

Posted on 09/08/2003 4:58:18 PM PDT by bondserv

How the Eye Lens Stays Clear   08/28/2003
To act as a true lens that can focus light, the lens of the eye must remain transparent for a lifetime.  Yet the eye lens is not a piece of glass, but a growing, living tissue made up of cells.  How can such a tissue stay clear, when the cells must be nourished, and when they contain organelles and chromosomes that would tend to obscure light?
    Actually, that is exactly the problem with cataracts, one of the leading causes of blindness, in which the lens becomes clouded.  Scientists at Bassnet Labs at Washington University (St. Louis, Missouri) have been studying how the eye maintains transparency, and found an enzyme that, when it fails, leads to cataracts in mice.  The job of this enzyme is to chop up and dispose of DNA in lens cells.  In a normal eye, “Light can pass through the lens because the cells break down their internal structures during development,” reports Science Now.  Nagata et al. at the lab found large amounts of an enzyme named DLAD in mouse lens cells that chops up DNA for disposal.  Mice lacking this enzyme developed cataracts.  Failures in this enzyme, or the gene that codes for it, are also probably implicated in cataract development in humans.
    Their work, published in Nature Aug. 28, explains how lens cells develop: “The eye lens is composed of fibre cells, which develop from the epithelial cells on the anterior surface of the lens.  Differentiation into a lens fibre cell is accompanied by changes in cell shape, the expression of crystallins and the degradation of cellular organelles.”  Until now it was not known how the cell dismantled its organelles and DNA.  The fibre cells have their nuclei removed during maturation, but the DNA remains.  It is the job of DLAD to act like a chipper and degrade the long DNA molecules into fragments that can be expelled.  Even if the other aspects of fibre-cell cleanup succeed, this study shows that DNA stragglers are enough to cause cataracts.
    So normal eye operation depends on the successful cleanup and removal of construction equipment and blueprints: organelles and DNA.  Science Now tells a little more about these remarkable lens cells:  “Even so, these cells aren’t simply empty; they house a highly organized network of proteins called crystallins* that transmit and focus the light passing through.  Any disruption in this sophisticated scaffolding can cloud the lens, causing cataracts.” (Emphasis added.)
    Here is an electron micrograph from Birkbeck College, UK showing how the fibre cells in the lens are stacked in neat rows like lumber with hexagonal edges for close packing. 

What an amazing thing a living, transparent lens is.  Did you ever think about this process, that a sophisticated molecular machine had to be produced from the DNA library that could chop up DNA into fragments, so that they could be removed and not obstruct the light path?  Undoubtedly this is not the only enzyme involved in the cleanup job.  Each fibre cell needs organelles and DNA during development, but they must be cleared away at the right time, and in the right order before the lens is deployed into operation, or else the user is denied the wonder of sight.  This is just one tiny aspect of dozens of complex systems that all must work for vision to work.
    Think of an eagle, detecting from high in the air a fish below the water, and using its visual sensors to accurately gauge its approach velocity, pitch, yaw and roll in order for it to capture food for the young in the nest, whose eyes are just opening to the world.  Muscles, nerves, specialized tissues, detectors, software, image processing, cleanup, maintenance, lubrication and systems integration are just a few subsystems that must be accurately designed and coordinated in this, just one of many such complex sensory organs in the body.
    Evolution is a fake fur that gives warm fuzzies to people who think in glittering generalities.  Those who put on lab coats and examine the details and try to fit them into an evolutionary history get cold shudders.
*A National Library of Medicine paper describes one of these crystallin proteins: “alpha-Crystallin is a major lens protein, comprising up to 40% of total lens proteins, where its structural function is to assist in maintaining the proper refractive index in the lens.  In addition to its structural role, it has been shown to function in a chaperone-like manner.  The chaperone-like function of alpha-crystallin will help prevent the formation of large light-scattering aggregates and possibly cataract. ... Reconstructed images of alpha B-crystallin obtained with cryo-electron microscopy support the concept that alpha B-crystallin is an extremely dynamic molecule and demonstrated that it has a hollow interior.  Interestingly, we present evidence that native alpha-crystallin is significantly more thermally stable than either alpha A- or alpha B-crystallin alone.  In fact, our experiments suggest that a 3:1 ratio of alpha A to alpha B subunit composition in an alpha-crystallin molecule is optimal in terms of thermal stability.  This fascinating result explains the stoichiometric ratios of alpha A- and alpha B-crystallin subunits in the mammalian lens.” (Emphasis added.)


TOPICS: News/Current Events
KEYWORDS: darwin
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To: boris
They evolved themselves to "almost" modern size all by their lonesome selves.

Something like the Mongol pony of today, yes. Bigger than a donkey, but not exactly a Clydesdale or even a thoroughbred.

181 posted on 09/09/2003 7:08:41 PM PDT by VadeRetro
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To: coloradan
Evolution requires far more than change, it requires increased complexity and increased number of functions. -me-

Those things have been seen.

Really? Where else than in TalkOrigins? There is absolutely no scientific evidence for any species transforming itself into a more complex one.

182 posted on 09/09/2003 7:24:30 PM PDT by gore3000 (Knowledge is the antidote to evolution.)
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To: ZULU
Not at all the case. What may appear to be a series of merely fortutious "accidents", may indeed be the result of Devine Intervention, regardless of what some evolutionists may theorize.

We are speaking of Darwinian evolution, not evolution in general. A Christian evolution would be one where God created life and set it on a specified path to unfold eventually into man. But this would be a designed life. Design from the beginning, but nevertheless designed. Darwinism denies divine design in all shape and form and posits instead its own 'creator', the non-heavenly 'natural selection' which supposedly creates by killing.

183 posted on 09/09/2003 7:30:48 PM PDT by gore3000 (Knowledge is the antidote to evolution.)
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To: bondserv
Very interesting! Thank you so much for the information!
184 posted on 09/09/2003 8:33:20 PM PDT by Alamo-Girl
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To: AndrewC
Thank you so much for the heads up and the links! It does sound very interesting!
185 posted on 09/09/2003 8:34:31 PM PDT by Alamo-Girl
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To: TXnMA
Thanks for the reminder!
186 posted on 09/09/2003 8:36:26 PM PDT by Alamo-Girl
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To: bondserv; gore3000
"Left-Handed Amino Acids Explained?"

Even the title has a question mark at the end. No big deal. We shouldn't have a problem with subjuctive expressions in scholarly writings as long as assumptions and facts are labled as such. What overtoasts the buns, however, is the insistence that large volumes of scholarly work regardless of their size and longevity - justify an unquestionable predominance in the academic world.

A simple child can see Intelligent Design all over the place and does not even need words to sense it or explain it, but somehow fifteen decades of ever-evolving evolution textbooks are going to satisfactorily explain away what has been obvious to to an exceedingly great number of people throughout history.

By sheer volume of subtle omissions against a Creator God, and by sheer vice of ommatidial omissions WRT whole systems of being, diehard evolutionists further establish that which is more plain than a brilliantly designed sunrise: An Almighty One made this stuff and is behind this stuff, guiding and sustaining it continually.

"Thou dost protest too much." Thousands of corollaries and tens-of-thousands of books. It's easy, given much time, many words, and conviction of heart, to "dismiss" a Creator God from all consideration. But a person - at least one who has a conscience and comon sense - will always have doubts as to whether those thoughts and words accurately fit objective reality.

So . . . all those big, bad books of knowledge are out there. No doubt one can make them sound as sensible as anything. It's not hard to do. Not much harder than filing down a square peg to make it fit a round hole provided one has the discipline. But who is anyone to declare their theory about origins and destinations of the world as the only one worthy of hearing in an academic setting?

Only a sneering pissant about to run into a three-by-four that he swears does not exist.

187 posted on 09/09/2003 9:44:30 PM PDT by Fester Chugabrew
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To: Fester Chugabrew
So . . . all those big, bad books of knowledge are out there. No doubt one can make them sound as sensible as anything. It's not hard to do. Not much harder than filing down a square peg to make it fit a round hole provided one has the discipline.

You have a firm grasp on reality. Thank you for your cogent thoughts on the topic.

188 posted on 09/09/2003 9:54:47 PM PDT by bondserv
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To: Fester Chugabrew
Even the title has a question mark at the end.

The point about right and left handed amino acids is that in nature they both occur with about equal frequency. In life only the left handed are used. That they are all lefthanded is needed to join them together to make proteins. This is a big problem for abiogenesis and origin of life where supposedly randomness 'created' everything.

189 posted on 09/10/2003 4:57:06 AM PDT by gore3000 (Knowledge is the antidote to evolution.)
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To: gore3000
"A Christian evolution would be one where God created life and set it on a specified path to unfold eventually into man."

And why does this refute evolution?

As to linking Darwinism to atheism, I must confess I am totally ignorant of Darwin's religious views. As a biologist and a Christian I have no problem reconciling both.

"Darwinism denies divine design in all shape and form and posits instead its own 'creator', the non-heavenly 'natural selection' which supposedly creates by killing."

I think you in error about Darwinism and evolutionary theory here. The late Victorians and early twentieth century racists envisoned evolution as a tooth and fang competition physical confrontation and its not really that at all. Evolution proceeds on the basis of the species best able to survive in a changing environment, take advantage of existing ecological niches and replicate itself more successfully than other species competing for the same niche ( shelter, food, nutrients, etc.)
190 posted on 09/10/2003 1:49:08 PM PDT by ZULU
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To: ZULU
"A Christian evolution would be one where God created life and set it on a specified path to unfold eventually into man." -me-

And why does this refute evolution?

I did not say it refuted evolution. I said that that is how some sort of evolution would be compatible with Christian principles. Darwinian evolution is completely atheistic and it is proven by its major promoters - Darwin, Huxley, Haeckel, Dawkins, Eldredge and Gould - all of them atheists.

191 posted on 09/10/2003 7:37:39 PM PDT by gore3000 (Knowledge is the antidote to evolution.)
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To: gore3000
This is a big problem for abiogenesis and origin of life where supposedly randomness 'created' everything.

Why would that be?

192 posted on 09/12/2003 10:12:09 AM PDT by OWK
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To: gore3000
A Christian evolution would be one where God created life and set it on a specified path to unfold eventually into man. But this would be a designed life.

And yet indistinguishable from the spontaneous.

193 posted on 09/12/2003 10:14:17 AM PDT by OWK
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To: gore3000
There is absolutely no scientific evidence for any species transforming itself into a more complex one.
194 posted on 09/12/2003 10:17:31 AM PDT by OWK
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To: OWK
There is absolutely no scientific evidence for any species transforming itself into a more complex one.

Let's see it. I mean real scientific evidence, not blogs from TalkOrigins or Don Lindsay. This is a challenge to you show scientific evidence of the transformation of species into more complex ones. Draw all the cartoons you like AFTER YOU BACK UP YOUR CLAIMS WITH FACTS.

195 posted on 09/12/2003 7:18:09 PM PDT by gore3000 (Knowledge is the antidote to evolution.)
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To: bondserv
bump for later reading
196 posted on 09/14/2003 5:30:49 PM PDT by HalfFull (1Thess 5:21)
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To: gore3000
THE DEAD DO NOT REPRODUCE

Only when they are in between lifetimes, at which times they go back into the earth and enter the food chain again. The cycle repeats itself. Then again, maybe not.

197 posted on 09/14/2003 5:40:31 PM PDT by Consort
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To: bondserv
Those organisms that had slightly clearer eye tissues had a survival advantage over those with slightly cloudier eye tissues, because the former could see better. -coloradan

The proper question is; How did an undirected natural force know how to clear an eye lens up, before knowing clarity is an issue? Did it call a temp enzyme service to check which did the trick?

Or even another question...how would a cloudy eye tissue survive over a billion years (since it would be useless) and "evolve" into a clear lens? Can't have it both ways, you know

198 posted on 09/15/2003 8:24:50 AM PDT by HalfFull (1Thess 5:21)
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