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Evolution Under Scrutiny


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#1 Springer

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Posted 04 October 2005 - 07:38 AM

In validating any scientific hypothesis, it is far more critical to look at the hostile evidence than the positive evidence. In mathematics, for example, a theorem can be disproven by finding one exception where it is invalid. It is not necessary for skeptics of evolutionary theory to answer every “positive” piece of evidence put forth by evolutionists. Rather, all that needs to be done is point out a fatal flaw in the theory.
In my view, the greatest fallacy of evolutionary thinking is the glossing over of critical flaws in the theory, fixating only on what is deemed “positive evidence”
Charles Darwin himself recognized the vulnerability of his theory, when he stated,
"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."

There are numerous examples that could be given in which gradualistic changes by natural selection are conceptually impossible, not to mention empirically unsubstantiated.
I will give a few examples and would challenge any evolutionist to respond…

1. The evolution of flight in bats. (specifically, what would a bat ancestor look like and how could natural selection favor an early non functioning wing over a fully functional forelimb?) A similar challenge could be made for flying reptiles and birds.
2. The evolution of the lens
3. The evolution of binary code transmission via the optic nerve.
The evolution of hemoglobin or any other complex molecule essential to life.

#2 chance

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Posted 04 October 2005 - 01:50 PM

In validating any scientific hypothesis, it is far more critical to look at the hostile evidence than the positive evidence. In mathematics, for example, a theorem can be disproven by finding one exception where it is invalid. It is not necessary for skeptics of evolutionary theory to answer every “positive” piece of evidence put forth by evolutionists. Rather, all that needs to be done is point out a fatal flaw in the theory.


I agree, finding a Dinosaur, Human or Mammal in undisturbed Devonian strata would be a good example, as evolutionary theory predicts that such a situation is impossible.

But I’m not sure to what degree one looks at hostile evidence V’s positive. However if you are defending creationism, how does one answer every bit of evidence that points to an old earth without countering it? IMO you are in the same boat as I am on that account.


In my view, the greatest fallacy of evolutionary thinking is the glossing over of critical flaws in the theory, fixating only on what is deemed “positive evidence”


If such “critical flaws” exist, and IMO they do not, then it is up to the person making such claims to make their case, if accepted science would have no recourse but to accept whatever theory is in need of revision, or trashing. IMO this forum has been dealing with such claims as it’s focus.


Charles Darwin himself recognized the vulnerability of his theory, when he stated,
"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."


I agree. But I’m having a bit of difficulty in imagining how such a demonstration would be carried out, perhaps when examining a lenes of an eye, if one finds an engraving on it “Manufactured in Taiwan”, I would think that would disprove that that lens evolved.

There are numerous examples that could be given in which gradualistic changes by natural selection are conceptually impossible, not to mention empirically unsubstantiated.
I will give a few examples and would challenge any evolutionist to respond…

1. The evolution of flight in bats. (specifically, what would a bat ancestor look like and how could natural selection favor an early non functioning wing over a fully functional forelimb?) A similar challenge could be made for flying reptiles and birds.
2. The evolution of the lens
3. The evolution of binary code transmission via the optic nerve.
4. The evolution of hemoglobin or any other complex molecule essential to life.


Hmmm, I’ve seen all these except No 3, basically the same old “it’s too complex to have evolved”. Before I examine these in detail, I will ask you to respond to these questions first.

What would you consider as:

a. positive evidence for evolution for the cases you made, (after all if I am going to answer I need to focus in the area you require that will satisfy you as a proof) and
b. how can you justify your claims above constitute as ‘evidence’ against evolution. Because this is the first hurdle that must be crossed, i.e. is the challenge valid?

#3 Springer

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Posted 06 October 2005 - 09:13 AM

Chance:

In the first place, there is no positive evidence that the lens evolved. The only "evidence" sited is that the lens exists, therefore it must have evolved. THis kind of thinking is rampant in evolutionary thought.

It's not just a matter of comlexity... it's the fact that there is no way that such adaptations could have evolved through natural selection because functional intermediates are impossible to even coneptualize. In the case of the lens, any precursor would have been a hindrance to vision. Another example is the evolution of the feather from a scale. There would have to have been innumerable intermediates which would not have been functional in achievement of powered flight. I've seen conceptualized drawings of "pro-avis", and they are laughable. How could a reptile gradually develop feathers that had no functional purpose, and how could such evolution proceed directionally for presumably millions of years? This completely defies any credible explanation. Another example is the wing of a bat. I would challenge you to draw a bat precursor with elongated partially webbed phylanges and explain to me how such an ungainly creature could have possibly had any sort of slective advantage over its ancestors prior to the acquisiiton of flight, either gliding or powered. Such a creature would have had to sacrifice its forelimb function prior to achievement of flight. This runs completely counter to natural selection. How about the evolution of the avian lung? How can you gradually go from an in and out "bellows" system of resiration to a continuous unidirectional lung through functional intermediates? Again, it is impossible to even imagine.

I have been totally frustrated attempting to argue these points, because all I receive are extremely speculative vague explanations which are only convincing to someone already emotionally attached to evolutionary theory.

Back to the example of the bat... if there is no empiric evidence that a bat's wing evolved, then the least you can do is explain how such an adaptation could have possibly evolved through natural selection through credible hypothetical functional intermediates. Such an explantion needs to conform to known laws of probabilty. You can flip a coin five times and, yes, it's possible to get five heads. But it's impossible to get one million heads in sequence. No viable scientific hypothesis can be based on vast improbabilities.

#4 chance

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Posted 06 October 2005 - 02:45 PM

In the first place, there is no positive evidence that the lens evolved. The only "evidence" sited is that the lens exists, therefore it must have evolved. THis kind of thinking is rampant in evolutionary thought.


The lens evolving is no different to any other bodily part, the record of gradual change, (fragmentary as it is) in the fossil record is testament that simple life evolved into more complex. Now if you feel the record does not show this ‘progression’ you will need to overthrow old earth, and evolution.

It's not just a matter of comlexity... it's the fact that there is no way that such adaptations could have evolved through natural selection because functional intermediates are impossible to even coneptualize.


Why is it ‘impossible’ to conceptualise, I feel you are making an argument from incredulity.



In the case of the lens, any precursor would have been a hindrance to vision.


I disagree, please explain how you arrive at that conclusion.


Another example is the evolution of the feather from a scale. There would have to have been innumerable intermediates which would not have been functional in achievement of powered flight.


You are assuming the purpose of a feather (proto feather) has a purpose, namely flight.



I've seen conceptualized drawings of "pro-avis", and they are laughable. How could a reptile gradually develop feathers that had no functional purpose, and how could such evolution proceed directionally for presumably millions of years? This completely defies any credible explanation.


Get rid of thinking that there is purpose in the equation.



Another example is the wing of a bat. I would challenge you to draw a bat precursor with elongated partially webbed phylanges and explain to me how such an ungainly creature could have possibly had any sort of slective advantage over its ancestors prior to the acquisiiton of flight, either gliding or powered. Such a creature would have had to sacrifice its forelimb function prior to achievement of flight. This runs completely counter to natural selection.


Gliding squirrels seem to manage quite well in the trees, not so good on the ground however!



How about the evolution of the avian lung? How can you gradually go from an in and out "bellows" system of resiration to a continuous unidirectional lung through functional intermediates? Again, it is impossible to even imagine.


Again you are looking at situation that has fragmentary history in the fossil record, in this case recent discoveries have uncovered the possibility that some (raptor) dinosaurs had the avian lung. But I am not too familiar with this perticuler example, so I’ll see if can dig something up :)



I have been totally frustrated attempting to argue these points, because all I receive are extremely speculative vague explanations which are only convincing to someone already emotionally attached to evolutionary theory.


Well lets see what it’s like in this forum, I’ll do my best to answer your questions sincerely.
Part of the frustration is often cause by initial assumption in the question.


Back to the example of the bat... if there is no empiric evidence that a bat's wing evolved, then the least you can do is explain how such an adaptation could have possibly evolved through natural selection through credible hypothetical functional intermediates. Such an explantion needs to conform to known laws of probabilty. You can flip a coin five times and, yes, it's possible to get five heads. But it's impossible to get one million heads in sequence. No viable scientific hypothesis can be based on vast improbabilities.


Careful now, probabilities have a nasty habit of proving things are possible. There is a common phrase that there are 3 types of lies, “Lies, dammed lies and statistics”. The critical point about statistics is that it can be manipulated by unscrupulous to prove a point, just by omitting to include or exclude a some data. It is absolutely vital to understand the question before collecting data.

#5 Springer

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Posted 06 October 2005 - 04:58 PM

Why is it ‘impossible’ to conceptualise, I feel you are making an argument from incredulity.

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Chance, I'd be a fool to "believe" in something that made absolutely no scientific sense... call that incredulity if you will.
As far as a "purpose" to evolution, my point is that evolution requires selection pressure... Specialized structures can't evolve without some "purpose" or factor that's selecting them for survival.
Your response, quite frankly, typifies evolutionary thinking. Again, you are grossly minimizing the barriers required to go from a non-flying rodent to a bat. I would challenge anyone to draw a series of functional intermediates in bat evolution. I've never been able to find such illustrations, because they would be absurd. In simple terms, how is a forelimb going to gradually evolve into a wing? Gradual elongation of phylanges with interphylangeal webbing in early stages would have to have some survival advantage for natural selection to work. Any mutation toward a wing in early stages would immediately be selected out because it would incapacitate the forelimbs. If you disagree, then draw me a hypothetical example.
In the case of the lens, a "proto-lens" would obstruct vision and would be totally useless until it was fully developed and capable of accomodation.

#6 chance

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Posted 06 October 2005 - 08:01 PM

Chance > Why is it ‘impossible’ to conceptualise, I feel you are making an argument from incredulity.

, I'd be a fool to "believe" in something that made absolutely no scientific sense... call that incredulity if you will.


Evolution is supported by some the best available evidence there is. The only people who make the claim that evolution makes no sense are those who’s theology conflicts with the science. E.g do you have any problem with accepting the science of medicine or navigation?



As far as a "purpose" to evolution, my point is that evolution requires selection pressure... Specialized structures can't evolve without some "purpose" or factor that's selecting them for survival.


The only ‘purpose’ is that of successful reproduction, if one must specify that evolution has ‘purpose’. That is the selective pressure.
Any feature wing, eye, leg is the way it is because of it’s survival advantage, not because of some artificial purpose like flying.



Your response, quite frankly, typifies evolutionary thinking. Again, you are grossly minimizing the barriers required to go from a non-flying rodent to a bat. I would challenge anyone to draw a series of functional intermediates in bat evolution. I've never been able to find such illustrations, because they would be absurd.


Why the bat specifically? Is it because you know that there are no fossils of the bat precursor, and that me not being able to produce one somehow invalidates evolution? Or are you trying to make a special case for bats and are perfectly willing to accept evolution for an animal that is better represented? However, to speculate – I would expect some intermediate ancestor to pass through a gliding stage. It’s not that difficult to imagine a wing evolving from a for limb, birds did it, so did some reptiles. Lets not let the incompleteness of the fossil record become the focal of the argument, because it’s a never ending “fossil of the gaps” game. I produce an intermediary, you say “but what cam between it”!

In simple terms, how is a forelimb going to gradually evolve into a wing? Gradual elongation of phylanges with interphylangeal webbing in early stages would have to have some survival advantage for natural selection to work. Any mutation toward a wing in early stages would immediately be selected out because it would incapacitate the forelimbs. If you disagree, then draw me a hypothetical example.


I do disagree, long legs are an advantage in the trees, any small amount of gliding ability would aid the animal in not requiring it to cross dangers on the ground. Basically, skin flaps first, then longer limbs.

In the case of the lens, a "proto-lens" would obstruct vision and would be totally useless until it was fully developed and capable of accomodation.


Nonsense, any eye is better than none, any lens (no matter how inefficient by modern standards) is better than no focal ability at all.

#7 Springer

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Posted 07 October 2005 - 06:49 AM

[quote name='chance' date='Oct 6 2005, 08:01 PM']
[/quote]

Evolution is supported by some the best available evidence there is. The only people who make the claim that evolution makes no sense are those who’s theology conflicts with the science.

View Post

[/quote]
You are grossly mistaken if you believe that evolutionists base their beliefs of objective science and creationists are ignoring facts and relying on theology. After studying biology in college in was convinced that evolutionary theory was true. However, after going through medical school and studying embryology and other basic sciences, I reversed my position. The facts of nature speak for ID. Evolutionary thinking requires a retreat from pure empiricism. Acceptance of evolutionary theory requires a preconceived theology of secular humanism, and you demonstrate this in your arguments. You prefer to minimize or completely ignore glaring facts which amount to hostile evidence against evolution, relying on your imagination rather than science to resolve the questions at hand.

You have again evaded my challenge on constructing bat intermediates. You’ve suggested that just because we can’t fill in all the gaps we should focus on the “positive” evidence of evolution. The original point of this thread was that a fatal flaw will debunk evolutionary theory [as Darwin himself conceded], and now you’re trying to ignore the flaws. The example of bat evolution is but one of innumerable examples that demonstrates the fundamental fallacy of evolutionary theory… To simply state that there was a gliding precursor begs the question. Again, try to draw on paper five or six fully functional intermediate forms showing varying degrees of wing development, and explain to me in specific terms how each precursor could have possibly developed through the laws of natural selection. At some point, the non-flying precursor would have had to sacrifice its forelimbs to further evolve into wings… how is this possible through natural selection? In reality, I don’t expect you to actually do this, because I know that it is impossible to envision such a continuum that would have any semblance of realism.

#8 chance

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Posted 11 October 2005 - 01:56 PM

You are grossly mistaken if you believe that evolutionists base their beliefs of objective science and creationists are ignoring facts and relying on theology.


From what I’ve experienced in debates, and general observation, I believe what I have stated is factual. Science must be objective and review it’s position periodically, else traditional wisdom can never be challenged, indeed it is a requirement of the scientific method. Contrast that with AiG’s statement of faith ‘extract’

By definition, no apparent, perceived or claimed evidence in any field, including history and chronology, can be valid if it contradicts the Scriptural record

. By any definition, that's about as anti-science as it’s possible to be!



After studying biology in college in was convinced that evolutionary theory was true. However, after going through medical school and studying embryology and other basic sciences, I reversed my position.


Interesting, I can only suggest that whatever has changed your view be analysed to see what caused you to change your mind. These forums explore some of the topics.


The facts of nature speak for ID.


I disagree totally on this point, and have stated my reasoning on this in several topics on this forum.


Evolutionary thinking requires a retreat from pure empiricism. Acceptance of evolutionary theory requires a preconceived theology of secular humanism, and you demonstrate this in your arguments. You prefer to minimize or completely ignore glaring facts which amount to hostile evidence against evolution, relying on your imagination rather than science to resolve the questions at hand.


Again, I totally disagree with that POV, and challenge you that the ‘facts’ you allude to are in error. The only way to reach consensus on this is to begin to dissect any given point ‘evidence’ in detail.

You have again evaded my challenge on constructing bat intermediates. <moved this bit> To simply state that there was a gliding precursor begs the question. Again, try to draw on paper five or six fully functional intermediate forms showing varying degrees of wing development, and explain to me in specific terms how each precursor could have possibly developed through the laws of natural selection. At some point, the non-flying precursor would have had to sacrifice its forelimbs to further evolve into wings… how is this possible through natural selection? In reality, I don’t expect you to actually do this, because I know that it is impossible to envision such a continuum that would have any semblance of realism.


I suggested something analogous of a flying squirrel.

to speculate – I would expect some intermediate ancestor to pass through a gliding stage. It’s not that difficult to imagine a wing evolving from a for limb, birds did it, so did some reptiles

so that would be:

Evolution of (in order):

Skin flaps,
Longer limbs,
Lightness,
gradual and continued reliance/specialisation on flight
musculature for better flight,
Forelimbs become gradually specialised for flight, bats spend there life in the environment that moulded them, loss of function as forelimbs limbs makes them effectively bipeds.


You’ve suggested that just because we can’t fill in all the gaps we should focus on the “positive” evidence of evolution. The original point of this thread was that a fatal flaw will debunk evolutionary theory [as Darwin himself conceded], and now you’re trying to ignore the flaws.


You are confusing a ‘gap in knowledge’ with ‘flaw’. E.g. it is quite sound to develop a theory on treating a disease with out knowing the root cause (you suspect a germ, but don’t know which one exactly).


The example of bat evolution is but one of innumerable examples that demonstrates the fundamental fallacy of evolutionary theory…


No, it a gap in the fossil record.

#9 Springer

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Posted 12 October 2005 - 12:00 PM

Evolution of (in order):

Skin flaps,
Longer limbs,
Lightness,
gradual and continued reliance/specialisation on flight
musculature for better flight,
Forelimbs become gradually specialised for flight, bats spend there life in the environment that moulded them, loss of function as forelimbs limbs makes them effectively bipeds.

View Post


You are showing a possible pathway, but you're not suggesting how each precursor would have a selective advantage, allowing for survival. The analogy of a flying squirrel to a bat precursor is irrelevant, because the mechanism of gliding is totally different.

#10 chance

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Posted 12 October 2005 - 02:15 PM

You are showing a possible pathway, but you're not suggesting how each precursor would have a selective advantage, allowing for survival.


OK, the ability to glide, further and further would give that animal several advantages:

Ability to escape from a predator that cannot fly/glide.
Saving of energy (IMO this is critical) to have the ability to get a free ride as opposed to climbing down, then running across the forest floor, then climbing up is significant.
If the subject were trapped in a climate that changed forest to savannah, the pockets of tree would slowly widen.

Basically when times get tough, it’s adapt (evolve) or die. Flying/gliding is just one solution.


The analogy of a flying squirrel to a bat precursor is irrelevant, because the mechanism of gliding is totally different.


It’s not totally different at all, the basic principles are the same i.e. Thrust V’s Drag, Lift V’s Gravity, the difference between gliding and powered flight is the thrust bit. As the ability to glide evolves one of the fist things I would imagine would be to control ones glide path (up down left right), increase musculature in appropriate areas would achieve this, it’s then only a small step to use ones strength to flap (the necessary evolutionary path would be for the skin membrane to become more taught for better control) the ambulatory mechanism of a shoulder ball joint is already in place.

#11 Guest_George R_*

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Posted 12 October 2005 - 06:00 PM

I think the sequence is:

Skin Flaps
- cause tripping and tangling when fleeing predators or hunting for food among brush/twigs
- co-incidently ... all selected skin flaps happen to be in areas that will be useful for flight by later generations

Longer limbs
- a "just so" advantage ... so why aren't we all 100 feet tall?
a. vast increased limb size removes limb from mouth unless articulation occurs
at a point less optimal for leverage required for motion
b. minor limb size change provides advantage which should be no
more of a selectable advantage than variation is eye size, mouth size, etc.
which do not lead to flight ... why this one advantage continues to
"direct" evolution along a path to flight is questionable

Lightness - I suppose you mean weight loss while limbs are getting longer and flappy skin is added - neat coincidence but the full range of possible combinations (light, lank, flappy) would not likely contain many that are relevant to flight

So lets take a wild guess... why would the small set of surviving lean lanky flappy creatures beat out all other variations and be "just so" for flight?

Maybe (it's just so that...) the surviving variations are all more "indigestible" and boost selection by predator avoidance
- maybe (it's just so that...) the surviving varaitions are sexy and cause increased mate possibilities (the lanky flappy light desirable solution)
- maybe (it's just so that...) the surviving variations are better provider to their offsping because they can reach tall tree limbs laden with nutritious food

Do you see the burden of proof being lifted from "show me how it is better than OTHER variations at all points and still leads to flight" to.... "give some scenario that might be true if I assume only variations that lead to flight".

I think a more complete analysis of variation possibilities make it difficult to "ratchet" each step of progress "towards" flight.

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Posted 12 October 2005 - 07:03 PM

I missed one part:

"Forelimbs become gradually specialised for flight, bats spend there life in the environment that moulded them, loss of function as forelimbs limbs makes them effectively bipeds."

Huh, More specialized for flight?

Why not more something else, like specialized for leap-frog or stamp collecting? Or at least cave-grub eating.

The loss of 4-pedalism to 2-pedalism is at least as much LOSS of incumbent possibilities as an opportunity to fly.

Of course, this cave-flying capability needs to be preceeded by cave radar to walk around in the dark with a flappy lanky light body... or was that strong musculature as well?

I am not trying to be facetious or negative .. I do believe that it is so much easier IN THE MIND to "target a one dimensional path" and make all the reasons why a given path of change is possible ... than to deal with the difficult ramifications of a full variations in a long string of intermediate generations.

Gradual variation explains everything.. and nothing. It is a tautology that is founded on single path extrapolation - always a dangerous logic tool.

We are at risk of believing "what we see" and extrapolating it to fill any gap.

1) We see selected "time lapse" diagrams... a sequence of hairy men with ape-chins becoming less hairy and less ape-like.

2) We see morphing... Software that manipulates 2-dimensional pictures through "Morphing" or "Special Effects" can provide the illlusion that gradual change can create anything.

Can it really?. In fact, gradual change with morph software only creates a 2-dimensional compromise that OUR MINDS supply structure and plausibility to.

If random change were instead
- made to a three-dimensional being... and
- each gradual stage had a stop-action "survival" segment - during which the changed entity had to continue living, gathering resources to do so, and
- many other variations were concurrently given a crack at the same resources
- alterations were not "directed" to a given goal, (like real life gradual random change)

So after that ... would we then find it easy to claim that gradual change leads to whatever we conceive?

#13 chance

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Posted 12 October 2005 - 07:18 PM

Skin Flaps
- cause tripping and tangling when fleeing predators or hunting for food among brush/twigs
- co-incidently ... all selected skin flaps happen to be in areas that will be useful for flight by later generations


All features have advantages and disadvantages, there is currently a squirrel glider with skin flaps so large that it indeed makes it look awkward in the trees when running around. Birds forelimbs are so specialised for flight they have almost no other use! A bird must use it’s beak for just about everything. The only criteria is that it survive, if a squirrel can flourish better by gliding, yet sacrifice some ground agility then so be it, as long as it works.

A skin flap in an area that hinders flight will be quickly weeded out of the population.



Longer limbs
- a "just so" advantage ... so why aren't we all 100 feet tall?
a. vast increased limb size removes limb from mouth unless articulation occurs
at a point less optimal for leverage required for motion
b. minor limb size change provides advantage which should be no
more of a selectable advantage than variation is eye size, mouth size, etc.
which do not lead to flight ... why this one advantage continues to
"direct" evolution along a path to flight is questionable 


Longer limbs increases wing surface area, more lift per body ratio.
Do you think there is an advantage to being 100ft tall, consider all the extra food you will need to consume, growing big costs, if resources dwindle, who do you think will die out first? E.g. island dwarfism is a topical point.


Lightness - I suppose you mean weight loss while limbs are getting longer and flappy skin is added - neat coincidence but the full range of possible combinations (light, lank, flappy) would not likely contain many that are relevant to flight 


The lighter you are the easier it is to fly/glide (simple energy budget Thrust Vs Gravity) for any given body size the proportionally lighter expends less energy.

So lets take a wild guess... why would the small set of surviving lean lanky flappy creatures beat out all other variations and be "just so" for flight?

Nice spin – but lets look at the alternate description for the same situation, why would an efficient, lanky, flying creature beat a heavy earthbound creature competing for the same dwindling resource.

Maybe (it's just so that...) the surviving variations are all more "indigestible" and boost selection by predator avoidance


This does happen, there are many creature that ‘advertise’ their indigestibility with prominent colouration, some salamanders, frogs, fish etc. The strategy works so well that some ‘tasty’ animals have evolved to mimic them. When these animals are accidentally introduced into an area where predators have not seen them before there is often big disruption to the existing environment.

- maybe (it's just so that...) the surviving varaitions are sexy and cause increased mate possibilities (the lanky flappy light desirable solution)
- maybe (it's just so that...) the surviving variations are better provider to their offsping because they can reach tall tree limbs laden with nutritious food


This also happens, the male peacock is actually slower when in breading plumage, yet the s@x Vs Risk trade off is worth it.
Ability to exploit a habitat once out of reach is of enormous benefit, how could this be a problem?


Do you see the burden of proof being lifted from "show me how it is better than OTHER variations at all points and still leads to flight" to.... "give some scenario that might be true if I assume only variations that lead to flight".

I think a more complete analysis of variation possibilities make it difficult to "ratchet" each step of progress "towards" flight.


If one looks at various arboreal life forms, one can see many solutions, not just flight or gliding, to think that a life in the trees automatically leading to flight is ‘better’ is wrong, there is nothing preventing one branch of the same animal leading to flight while another takes to “swinging in the trees”, while another changes it’s diet. One problem many solutions.

#14 Springer

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Posted 12 October 2005 - 07:34 PM

OK, the ability to glide, further and further would give that animal several advantages:

Ability to escape from a predator that cannot fly/glide.
Saving of energy (IMO this is critical) to have the ability to get a free ride as opposed to climbing down, then running across the forest floor, then climbing up is significant.
If the subject were trapped in a climate that changed forest to savannah, the pockets of tree would slowly widen.

View Post


I agree that a gliding form might have a selective advantage over a non-flying mammal. However, how do you get from a rodent-like mammal to a gliding form? How are the phylanges going to gradually elongate and develop webs? It would require numerous sequential small mutations, all unidirectional, to achieve a limb capable of any sort of gliding. In the innumerable generations prior to gliding, how could such a clumsy creature have any kind of selective advantage? This is the aspect of natural selection that is so blatantly absurd. I repeat my challenge: Draw five or six bat precursors leading up to the first gliding form, and demonstrate how each could have had a survival advantage over the former.

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Posted 12 October 2005 - 07:46 PM

chance

I don't think you are really countering what I said.

I am pointing out the difficulty of intermediate non-flying generations would have BEFORE flight in retaining the precursors to flight over many randomly-varying generations.

Of course once they are used for functioning flight they have a purpose ... that keeps them around much later because , well, flight is useful.

The question is: why would these specific variations, which end up being so great for flight, happen to be husbanded and thrive BEFORE flight, and compete so successfully WITHOUT FLIGHT against all other variations that don't happen co-incidently to be good for flight.

Maybe ... it is all too improbable and needs a "just so" story about a "happy ending" (flight) to seem even remotely possible. If so, the explanation carries no weight and is only an illusion of "how great these precursor changes were in hindsight".



BTW And of course any item can have a conceivable advantage. That doesnt make a specific explanation for an advantage true or useful... especially if a plethora of generic easy explanations can be randomly chosen and grafted as "an advantage" onto any specific variation named at random. That's why I chose stamp collecting as an advantage of bipedalism. It is so obvious that my grafted explanation explains nothing. It is less obvious that other grafted explanations equally explain nothing.

#16 Springer

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Posted 13 October 2005 - 12:58 PM

But I’m not sure to what degree one looks at hostile evidence V’s positive.  However if you are defending creationism, how does one answer every bit of evidence that points to an old earth without countering it? IMO you are in the same boat as I am on that account.

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There is no scientific proof that the earth is extremely old. All theories are based on unverified assumptions. It is literally impossible to verify the accuracy of radiometric dating. The issue at hand in this discussion is the fallacy of evolution, not the proving of a young earth. You must avoid the temptation to try to find a fatal flaw in creation theory in defense of ToE. The point I'm making is that evolutionary theory has fatal flaws. Even if the earth is extremely old as evolutionists insist, that fact doesn't justify a belief in Darwinism. I repeat... One does not have to offer an alternative theory to disprove a false one. Likewise, one cannot prove a theory by finding what he supposes to be a fatal flaw in an alternative theory.

#17 chance

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Posted 13 October 2005 - 06:40 PM

Springer

chance > OK, the ability to glide, further and further would give that animal several advantages:

Ability to escape from a predator that cannot fly/glide.
Saving of energy (IMO this is critical) to have the ability to get a free ride as opposed to climbing down, then running across the forest floor, then climbing up is significant.
If the subject were trapped in a climate that changed forest to savannah, the pockets of tree would slowly widen.

I agree that a gliding form might have a selective advantage over a non-flying mammal. However, how do you get from a rodent-like mammal to a gliding form? How are the phylanges going to gradually elongate and develop webs? It would require numerous sequential small mutations, all unidirectional, to achieve a limb capable of any sort of gliding. In the innumerable generations prior to gliding, how could such a clumsy creature have any kind of selective advantage? This is the aspect of natural selection that is so blatantly absurd. I repeat my challenge: Draw five or six bat precursors leading up to the first gliding form, and demonstrate how each could have had a survival advantage over the former.


Take a look at your own hands, notice the web joining the thumb, if we were forced to become aquatic, it’s not hard to imaging this feature being selected for (as for any feature).
WRT gliding, the first stages I would think would just be the animal stretching out, the next a flattening of the body (much like the gliding snake and frog). Then extra skin increases the surface area, and so on.
Mutation causes the changes, natural selection does the rest.

The evolving creature may indeed be clumsy as you say (compared to it’s ancestor), BUT not clumsy enough to negate the new advantage, it’s still better off for it.

Re your challenge – why do you keep repeating this, have I not done this to your satisfaction yet? What exactly are you asking for?


George R

chance

I don't think you are really countering what I said.

I am pointing out the difficulty of intermediate non-flying generations would have BEFORE flight in retaining the precursors to flight over many randomly-varying generations.

Of course once they are used for functioning flight they have a purpose ... that keeps them around much later because , well, flight is useful.


Forget purpose, there is only survival.
Forget perfection, there is only ‘good enough’.

If the intermediary of the bat was something like a gliding squirrel (not that unreasonable) the only question is, does the new attribute (various stages of gliding, to poor flight, to good flight) offer survival advantage. Basically, poor gliding was better than no gliding despite a trade-off in clumsiness.
Take a look at any animal around you it’s a mix of good and poor adaptation. Take for example the Tree Kangaroo, now if there was any animal that should not be in the trees this is it, one could think of it as a transitional form of marsupial ape. The Tree Kangaroo has only just started to evolve along the path to a life in the trees, so far it has evolved better grip in it’s paws, and has the ability to ‘walk’ it’s hind legs (no other roo can do this, their legs are ‘locked’ to hop only). Give it a few million years it could quite conceivably resemble Madagascan Lemurs, all it needs is the environment to shape it (e.g. increase in forestation, loss of grazing land).

The question is: why would these specific variations, which end up being so great for flight, happen to be husbanded and thrive BEFORE flight, and compete so successfully WITHOUT FLIGHT against all other variations that don't happen co-incidently to be good for flight.

Maybe ... it is all too improbable and needs a "just so" story about a "happy ending" (flight) to seem even remotely possible. If so, the explanation carries no weight and is only an illusion of "how great these precursor changes were in hindsight".


Because you make the mistake of thinking that poor flight or gliding, or even poor gliding, offer no survival advantage. Survival is for the hear and now, there is no headlong rush to achieve flight. You are thinking about evolution entirely in the wrong frame of mind.

BTW And of course any item can have a conceivable advantage. That doesnt make a specific explanation for an advantage true or useful... especially if a plethora of generic easy explanations can be randomly chosen and grafted as "an advantage" onto any specific variation named at random. That's why I chose stamp collecting as an advantage of bipedalism. It is so obvious that my grafted explanation explains nothing. It is less obvious that other grafted explanations equally explain nothing.


Lets remember that I am speculating WRT bat flight because you asked me to, I think it’s a reasonable scenario consistent with current knowledge (I am not claiming this is how it happened).
When you state that any item can have some advantage, you must remember that it need only be ‘enough to survive’, like the Tree Kangaroo it is living a precarious existence if we compared it to a modern ape, yet as it has no competition it muddles on just fine. Surviving is ralative.


Springer

QUOTE(chance @ Oct 4 2005, 01:50 PM)
But I’m not sure to what degree one looks at hostile evidence V’s positive.  However if you are defending creationism, how does one answer every bit of evidence that points to an old earth without countering it? IMO you are in the same boat as I am on that account.

There is no scientific proof that the earth is extremely old. All theories are based on unverified assumptions. It is literally impossible to verify the accuracy of radiometric dating.


Nonsense, however off topic I suggest you join a topic in the appropriate forum (in old/young earth)

The issue at hand in this discussion is the fallacy of evolution, not the proving of a young earth. You must avoid the temptation to try to find a fatal flaw in creation theory in defense of ToE.

Fair enough.


The point I'm making is that evolutionary theory has fatal flaws. Even if the earth is extremely old as evolutionists insist, that fact doesn't justify a belief in Darwinism. I repeat... One does not have to offer an alternative theory to disprove a false one. Likewise, one cannot prove a theory by finding what he supposes to be a fatal flaw in an alternative theory.


I agree with the way you have worded this (although I disagree that ToE has fatal flaws). You are quite correct in that to disprove a theory one need not replace it, in these cases the phenomena under investigation should remain in limbo, i.e. If Not X, then, Not X. and,

I also agree that disproof of an alternate theory adds no weight to an existing theory. I.e. If X is not true, then Y is not affected.

#18 Springer

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Posted 13 October 2005 - 07:46 PM

[quote name='chance' date='Oct 13 2005, 06:40 PM']
Springer

[/quote]

Take a look at your own hands, notice the web joining the thumb, if we were forced to become aquatic, it’s not hard to imaging this feature being selected for (as for any feature).
WRT gliding, the first stages I would think would just be the animal stretching out, the next a flattening of the body (much like the gliding snake and frog). Then extra skin increases the surface area, and so on.
Mutation causes the changes, natural selection does the rest.

The evolving creature may indeed be clumsy as you say (compared to it’s ancestor), BUT not clumsy enough to negate the new advantage, it’s still better off for it.

Re your challenge – why do you keep repeating this, have I not done this to your satisfaction yet? What exactly are you asking for?
George R
[/i]

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[/quote]
Initial stages of evolution, as you suggest, would offer no survival advantage until at least gliding was achieved. Every stage leading up to that would be a disadvantage. Taking your example of webbing between human fingers... what survival advantage would there be if a human were born with webbed fingers? They would be an incumberance. There is no new advantage until the specialization becomes fully developed. I can certainly imagine that a human possessed with modified forelimbs having the ability to glide (such as bat forelimbs) would have a survival advantage. But what about all of the stages leading up to that point? Webbing between the fingers offers no survival advantage, but rather would be rooted out by natural selection. It is inconceivable that every stage of bat evolution would have offered a survival advantage over the previous stage, even using your wildest imagination. That is the flaw seen in so much of evolutionary theory by natural selection. All steps leading up to a complex advantageous change would be disadvantageous, at least in many instances.

#19 chance

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Posted 16 October 2005 - 07:59 PM

Initial stages of evolution, as you suggest, would offer no survival advantage until at least gliding was achieved.  Every stage leading up to that would be a disadvantage. Taking your example of webbing between human fingers... what survival advantage would there be if a human were born with webbed fingers?  They would be an incumberance.  There is no new advantage until the specialization becomes fully developed.  I can certainly imagine that a human possessed with modified forelimbs having the ability to glide (such as bat forelimbs) would have a survival advantage.  But what about all of the stages leading up to that point?  Webbing between the fingers offers no survival advantage, but rather would be rooted out by natural selection.  It is inconceivable that every stage of bat evolution would have offered a survival advantage over the previous stage, even using your wildest imagination.  That is the flaw seen in so much of evolutionary theory by natural selection.  All steps leading up to a complex advantageous change would be disadvantageous, at least in many instances.

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Your putting the cart before the horse, evolution does not work that way at all. Firstly you must be in the (new) environment, where webbing would be an advantage, i.e. your island is slowly sinking, food on land is getting scarce and you turn to the sea for food, those that can swim the best (webbed fingers) survive. Same principle for the bat

#20 Springer

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Posted 17 October 2005 - 07:51 AM

Your putting the cart before the horse, evolution does not work that way at all.  Firstly you must be in the (new) environment, where webbing would be an advantage, i.e. your island is slowly sinking, food on land is getting scarce and you turn to the sea for food, those that can swim the best (webbed fingers) survive.  Same principle for the bat

Not at all the same principle. Webbed fingers wouldn't confer any advantage for survival in bat evolution until at least rudimentary gliding was achieved. They would be a hindrance. THat's my whole point... No survival advantage in early stages. Natural selection doesn't not provide any explanation as to how a bat's wing could evolve. Only generalizations are made, with complete slurring over of any specifics. As I said before, try illustrating five or six bat precursors prior to the gliding stage and attempt to justify their existence based on natural selection.




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