Doubting Didymus

Please clarify. The fish has eye structures. The eye structures do not function. I do not understand the difference between under developed eye structures and a useless eye.

By what standard do you call them a non-organ anyway? But more to the point, what difference does it make whether the eye is classified as an organ or not? The heart of the matted is that the fish would be improved by having no eye structures. The development would be more efficient and the fishes resources would be better spent.

Yes, if you insist, I suppose that the regression of the eye structures is technically a reduction in the creatures maximum possible territory (i.e. it can no longer function as well outside of caves). However, as per my previous comments, this is exactly what evolution expects. Natural selection can only effect mutations that have a measurable effect on the net fitness of an individual, so it is expected that unused features will degrade. There is no problem for evolution here, as the net fitness of the organism in its habitat has not decreased.

Yes, I think I agree with you. The fish would technically be more fit if it had eyes, as it could theoretically survive in the light as well as in caves. However, if the fish never left its cave, or had a reduced chance of survival when outside, then natural selection would NOT favour eyed fish. Natural selection would be NEUTRAL with respect to eyes. Therefore, any mutation (even negative mutations) could affect the eye and not be screened out. Under these conditions, the eye is expected to reduce.

It is presicely because natural selection is NOT a person and does NOT make conscious value judgements that degradation can occur in unused features.

Well, I agree that it makes sense to avoid an unused organ, but it does NOT make sense to leave half of the organ there, as is the case. The eyes you see in the pictures are not just black spots on the skin, they are near-compete eye cups without a lens or a retina. From a design perspective, this is a waste. Also, the organisms would still have large eye holes in their skulls, when a design perpective should suggest that leaving the eyes out completely and covering the holes would be appropriate.

IF the specimens in question did not have eye structures, AND did not have unneccesary holes in its skull, then you might be justified in refuting the 'bad design' argument. As it is, you must explain how they constitute better design than leaving them off.

Happy Wonderer

Permit me to paraphrase:
On why evolution isn't a person and it is therefore a bad thing to lose eye function:
My paraphrase:
On why it is a good thing to not have eye function:


So the argument is now:
Compelling...

HW

[ October 14, 2002: Message edited by: Happy Wonderer to get formatting somewhat decent.]

[ October 14, 2002: Message edited by: Happy Wonderer ]</p>

Nat

"Clearly, the cave fish is eye-less. It does NOT have eyes at all, so it is nonsense to comment on their function. The eyes never developed. Useless eyes are different from not having eyes at all. Yes, the remnants of embryonic eye forms are (apparently) present, but they are non-organs. So, we could hardly call these "useless" eyes. "

Yet there is certainly something there - something that has the appearance of being eyes in development. Don't you agree?

"Despite your later clarification on "selection", it would seem that blindness is an evolutionary regression."

No such thing - evolution is simply a change in the allele frequency in a population - it does not regress or progress, it just happens.

"Macroevolution, if it is in operation, is a non-person. It would therefore be unable to make value judgments and assessments, or "decide" among the potential benefits of alternatives. But you and I are persons capable of such things. As such, we can see that it is a degradation to move from complex, sophisticated functions to retarded or absent functions."

Is it a degradation to eliminate extraneous and vulnerable parts that provide no value within a certain ecological niche but most certainly provide some cost (e.g. the energy cost of their development, costs related to increased vulnerability, etc.)?

"We may also examine the issue from the ID perspective, and consider the role of a designer who is varying a general specification."

Sure, but this is simply an unfalsifiable position. Your designer could have done this, but there is no reason to think that such a designer (an undefined complex entity) is necessary given the power of the ToE to explain the slow disappearance of eyes in animals living in lightless environments.

"From this perspective, it seems quite sensible to avoid or curtail the production of an organ that will not be used."

Yet, the whole point of this topic is to point out that it would be even more sensible for a designer to design animals in lightless environments to not even have remnants of eyes or eyelike structures.

"As you suggest, it would be appropriate for the development of an eye to be removed from the specification of the cave-dwelling fish."

Yes, it would, but the fact is that many animals in lightless environments have not only remnants of eyes but whole structures that are absolutely useless in their ecological niche. Seems strange for a designer to design a cave based fish or salamander to have useless eye structures that for all appearances seem to be simply under-developed versions of their lighted environment counterpart's eyes. Why would they even have these limited yet still useless and vulnerble structures?

"If this is the case, then the animal does not possess any extraneous organs, and the flexibility of the designer is demonstrated."

Sure, if you define useless under-developed eye structures as not being organs, but you must admit that these animals do have structures that are seemingly useless and greatly resemble under-developed eyes.

"I wouldn't be surprised to discover that many of the examples of those "sub-optimal" designs are of this nature.

Of what nature? Of a nature that are explainable by contortionist movements of an ID/OEC who posits an unseen tinkering diety that pops in every once and a while and makes changes to the genomes of animals that look remarkably like the changes predicted by the ToE?

By the way, I don't think the ID folks out there would like you using their name for your beliefs. Behe and Dembski would certainly agree that the slow elimination of eyes in lightless environment animals is most certainly the result of mutation and natural selection because it doesn't rise to the "level" of their supposedly detectable design (i.e. it is not irreduciably complex and it involves no change in complex specified information). They would be right on the side of the mainstream evolutionary biologists on this one.

Valentine Pontifex

To bad that only posts to talk.origins can be nominated for a Chez Watt. Vanderzyden's statement gets my nomination for most silly
statement by a creationist for this week. One would have thought he would have used the old "it's just microevolution" ploy on this one.

Folks, I suggest people cease and desist discussing eyes with this guy. One would have never have thought that someone would argue that eyes are not useless because they are not eyes. I guess next we will hear that the developed inner wings trapped behind the fused outer wings in some flightless beatles are not wings. And the teeth that develop and are latter reabsorbed in toothless whales are not teeth. One can "explain" almost any feature with such "logic."

How desperate can he get?

Doubting Didymus

Actually, I find my current exchange to be quite purposeful and stimulating. I think that we are actually progressing towards some kind of conclusion.

Feel free to ignore him yourself, of course. Or insult him. Thats a sure fire way to end your discussions with him.

Happy Wonderer

That is a good one, but I nominate this science lesson:

HW

Edited to add: the choice is difficult, this one should get honorable mention:

[ October 14, 2002: Message edited by: Happy Wonderer ]</p>

Albion

What's this stuff aobut blind animals being suuddenly born of sighted ones? When did this start turning into a discussion about saltation, anyway?

Vanderzyden, there's a good reason, evolution-wise, for useless body parts to be degraded over time. Species don't have infinite (or even great) capacity for adding and adding and adding features. First, the genome is a particular length, and second, there's a requirement for energy expenditure to keep all these body parts first growing and then maintained. If a gene coding for some property of the eye is mutated so that it instead encodes an enzyme which has another function better suited to life in a dark cave, that mutation will tend to get fixed in the population at the expense of slightly or even somewhat impaired sight. If a gene is duplicated and one of them is mutated, so that the fish can see and has that extra other function, then whether that fish is more fit than the one with the impaired sight is decided on the basis of whether the extra energy (i.e., food) needed to keep more functions going is more efficient than simply ditching a function. If it's more efficient to ditch a useless function, then that's what happens. Evolution works in the present, it doesn't plan for the future. Your intelligent designer may do that, but the natural process doesn't.

Vanderzyden

Positive, specific mutation is the "big" assumption in your scenario.

Sustitute for "configured" or "altered" for "mutated" and explain why the Creator would be incapable of bringing this about from a basic "body blueprint".

Vanderzyden

[ October 14, 2002: Message edited by: Vanderzyden ]</p>

Doubting Didymus

We are not saying that a designer is impossible here, vander. In fact, we are hypothetically assuming that one exists.

Yes, a designer could have dug out his old 'fish' blueprints and scribbled on them, removing the lens and the retina, and adding a skin flap. The question is: why didn't he just scrap the whole eye and cover the hole with skull? Of the two theories, we ask which explains the prescence of useless eyes better: the theory that useless eyes are inherited from seeing fish, and degenerated due to lack of use or the theory that a designer left them there from an old plan, apparently forgetting to remove them.

Let me ask: if you yourself were given a blueprint for a fish, and wanted to change it to make a blind cave fish, wouldn't you remove the eyes completely and cover the hole with bone? What possible reason would you have to leave the skull hole (what is the technical term for that?) and half the eye there? Are you a lazy designer? An incompetent designer? Or are you everyones favourite: an inscrutable, unknowable designer?

These are not flippant questions. they are genuine problems that need answers, if the ID hypothesis is to be taken seriously.

Albion

No, you're missing all the cases where mutations have caused changes unsuitable to the environment and the individuals haven't survived. And it doesn't have to be a specific mutation. A mutation that's a step on the path to a better sense of smell would be just as likely to be selected over a functioning eye as would a mutation that's a step on the path to gerater immunity against whatever parasites live in caves but not in the open. Doesn't make a bit of difference. The point is that the situation is closer to a zero-sum game than to an open-ended continual addition, because a given species can't just add and add and add.

The creator would be capable. Nobody ever said otherwise. The thing is that the creator is capable of anything - including instantaneously creating totally eyeless fish that live in the total dark without having to go through the tedious process of dismantling the eye step by step. Evolution isn't. And yet we only tend to see things that evolution IS capable of producing - along with ones the creator is capable of producing on a bad day as well as on a good day - like fish with partial eyes and all the other things on Oolon's list.