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Author | Topic: The Evolution of Flight.... why are some birds grounded? | |||||||||||||||||||
Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
They didn't evolve useless wings. They're in the process of de-evolving wings from when they weren't flightless.
Again, the question goes back: Why would god create them? ------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
Wings on an F1 car don't give it speed. They're designed to trade forward speed in exchange for greater traction on the ground. An ostrich isn't going hundreds of miles per hour, and can much more easily get better traction simply with larger feet. They don't use their wings for this purpose anyway - when running, they tuck them into their sides to reduce drag.
------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
quote: Like the wonderous functions of the appendix, the liver fluke, or Near Earth Objects?
quote: What animals are supposedly having problems with balance? And a high-drag appendage is a good way to solve it?
quote: Yes, all of those feathers make cooling down so easy. Meanwhile, back in the real world, ostriches cool down by panting. In particularly hot weather, they'll use their wings to fan themselves - to try and undo all of the damage that having such a thick coat of feathers is doing.
quote: Yes, that frigid serengeti...
quote: And something else wouldn't be better at keeping one safe during falls? Oh, lets just say.... arms???
quote: Millions of other species get along just fine without their mating rituals involving body parts that work against them in every other aspect of their lives.
quote: This is the only one that has some truth in it - ostriches are "weird" enough looking that recently introduced predators to them often are afraid of them. However, predators in areas where they are traditionally found hunt and eat them all the same, so it's irrelevant in the long run.
quote: While ostriches do incubate their eggs, it's not done with their wings, it's done with the feathers and fatty tissue on the undersides of their bodies. Perhaps they're God's "ball and chain" on ostriches? Designed to make them compete more poorly? Better hope that no mutation kills off those wings, then! ------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
I'll skip the posts that you gave which don't come close to addressing what I mentioned.
quote: Yes, their tail can be used for balance and maneuverability, because it's quite long. If you take a long object and swing it around, you can get quite an accelerative force. Dwarved wings won't do that for you.
quote: Among other places, yes. Ostriches are east/central African/southwest asian in origin.
[quote]If arms and wings can do the same job does it matter which one?[quote]
Yes. Arms are far, far more effective at the job. A lot less drag while providing more length and a proper grip at the end - there's no contest. Falling with stubby wings and a long neck would be quite painful - it's questionable whether the wings would do anything for you.
quote: Well, it doesn't work on anything where they live any more. If you introduce a tiger to an ostrich, it'll tend to be afraid of it. But, tigers don't live near where ostriches do. Introduce a wild lion to an ostrich, it'll kill it off the bat. In short, it's completely ineffective where they live.
quote: Yes. But they're not. ------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
Where on earth did you get the assumption that scientists believe that flight was developed from running? That's an awful proposition for the development of flight - flight requires lightweight organisms, while fast runners tend to be bulky. Flight is believed to have come from tree and cliff dwellers - it came from jumping. And there are many intermediaries stages currently alive on this front.
------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
quote:quote:What about the Exodus? After all the Egyptians kept pretty good records, and they never mention either keeping Hebrew slaves or their departure. And the loss of most of their workforce, as it says in the Bible, would be something they would have noticed, don't you think? ... and Joshua, Judges, Samuel, Kings, Chronicles (mostly a retelling), etc... Not to mention Esther (the Persians kept pretty good records too - especially of their royalty!). They're still trying to find *something* anywhere in history that mentions King David and King Solomon in a contemporary context (you'd think a kingdom that was given 25 tons of gold per year - excluding tribute from all of the middle east - would draw *some* notice! ) (oh yeah... this is supposed to be about wings, right?) ------------------"Illuminant light, illuminate me." [This message has been edited by Rei, 09-26-2003]
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
I should register "evolutionfairytalesfairytails.com"
quote: Yes, that would never happen! Sugar gliders don't exist, right Fred? Nor the flying lizard? Nor snakes in the chrysopelea genus, right? Please, I would *love* to hear your explanation as to how either A) an intermediate form between them doesn't gain part of the advantages that they have, or B) there is no intermediate form.
quote: Ah, Fred, I thought you were better than to fall into the typical Creationist quote fallacy. As usual, this is a pathetically out of context quote. Here's the context (in a discussion about PE): "Of what possible use are the imperfect incipient stages of useful structures? What good is half a jaw or half a wing? The concept of preadaptation provides the conventional answer by permitting us to argue that incipient stages performed different functions. The half jaw worked perfectly well as a series of gill-supporting bones; the half wing may have trapped prey or controlled body temperature. I regard preadaptation as an important, even an indispensable, concept. But a plausible story is not necessarily true. I do not doubt that preadaptation can save gradualism in some cases, but does it permit us to invent a tale of continuity in most or all cases? I submit, although it may only reflect my lack of imagination, that the answer is no, and I invoke two recently supported cases of discontinuous change in my defense. {Snip discussion of boid snakes, pocket gophers, kangaroo rats and pocket mice} "If we must accept many cases of discontinuous transition in macroevolution, does Darwinism collapse to survive only as a theory of minor adaptive change within species? . . . {Snip discussion of non-Darwinian theories of discontinuous change in species.} "But all theories of discontinuous change are not anti-Darwinian, as Huxley pointed out nearly 120 years ago. Suppose that a discontinuous change in adult form arises from a small genetic alteration. Problems of discordance with other members of the species do not arise, and the large, favorable variant can spread through a population in Darwinian fashion. Suppose also that this large change does not produce a perfected form all at once, but rather serves as a "key" adaptation to shift its possessor toward a new mode of life. Continued success in this new mode may require a large set of collateral alterations, morphological and behavioral; these may arise by a more traditional, gradual route once the key adaptation forces a profound shift in selective pressures. } Also, the cite is wrong. It should be: Gould, Stephen J. 1980. "The Return of Hopeful Monsters" in The Panda's Thumb: More Reflections in Natural History. New York: W.W. Norton & Co. (paperback), p. 189. In short: This was a discussion about PE, more specifically, preadaptation vs. changes in selective factors. Do you know what preadaptation (which Gould is arguing against) is, correct? Fred, learn to do better research. And never, ever, ever trust a creationist quote book or quote list - they're about as accurate as Libya is glacial. If you want to use a quote, look it up yourself first. ------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
Flight gives a lot of disadvantages; one of the biggest is that you have to have a a brittle, easily damaged body because bone is heavy. Flight itself also takes a lot of energy, so if it isn't being used extensively, there's no reason to even keep all of the muscles necessary for it around. Of course, flight can often be very useful - it really just depends on the environment.
For example, look at diving owls versus emperor penguins. What if the penguins could still fly, and were more like diving owls? They wouldn't be able to have nearly as much insulation, so they wouldn't be able to handle such extreme climates. They wouldn't be nearly as sleek underwater for long dives. They wouldn't be able to hold as much breath. They would be an easier target for underwater predators. Etc. What would they gain? Not much. They don't have any land predators. Their biggest predators - killer whales and leopard seals - are ambush predators, so being able to "fly away" wouldn't help them much. They simply steadily progressed into an environment where flight was no longer that critical to them, but other traits were. ------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
A female orangutan's armspan gets upwards of 7 feet, while they're rarely much taller than 4 feet. Our armspan is typically roughly equivalent to our height. I'd say that a 40% reduction in forelimb length from a couple million year branch is quite significant. I'd additionally argue that one of the only reasons it's not worse than it is is that we are so dependent on dexterity compared to most animals.
------------------"Illuminant light, illuminate me."
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Rei Member (Idle past 7033 days) Posts: 1546 From: Iowa City, IA Joined: |
In our case, that is true.
------------------"Illuminant light, illuminate me."
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