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Author Topic:   The Evolution of Flight.... why are some birds grounded?
Fred Williams
Member (Idle past 3412 days)
Posts: 310
From: Broomfield
Joined: 12-17-2001


Message 61 of 84 (58008)
09-26-2003 1:19 PM
Reply to: Message 48 by DC85
09-24-2003 11:29 PM


Re: bottom-up or top-down
quote:
DC85 wrote: there is no clear cut way to know how flight evolved however am pretty sure it happend(nothing is certain) But not knowing doesn't disprove piles of evidence.. as for the bible it has lets see....... 0? evidence to back it up

I have a series on flight:

www.evolutionfairytale.com/flight1.htm

I also have a page that touches on the overwhelming evidence that supports the Bible:

www.bibleevidences.com


This message is a reply to:
 Message 48 by DC85, posted 09-24-2003 11:29 PM DC85 has not yet responded

Replies to this message:
 Message 62 by Brian, posted 09-26-2003 1:34 PM Fred Williams has responded
 Message 63 by JonF, posted 09-26-2003 3:34 PM Fred Williams has not yet responded
 Message 64 by Rei, posted 09-26-2003 3:36 PM Fred Williams has not yet responded
 Message 65 by Cthulhu, posted 09-26-2003 5:23 PM Fred Williams has not yet responded

  
Brian
Member (Idle past 3516 days)
Posts: 4659
From: Scotland
Joined: 10-22-2002


Message 62 of 84 (58012)
09-26-2003 1:34 PM
Reply to: Message 61 by Fred Williams
09-26-2003 1:19 PM


Re: bottom-up or top-down
HI Fred,

Brian from Scotland, we chatted about Gerald Aardsma's 'Canaanites' (amongst other things) once before.

I am interested in you biblevidences references. Can you tell me why you never put the dates of publication in any if your book references? This seems quite a startling feature on your site.

The reason I ask is because your Nelson Glueck quote is very outdated and even retracted by Glueck himself in the follow up to 'Rivers in the Desert.' (The River Jordan 1968) Rivers in the Desert was written in 1959 for goodness sakes.

So why no publishing dates ?

Brian


This message is a reply to:
 Message 61 by Fred Williams, posted 09-26-2003 1:19 PM Fred Williams has responded

Replies to this message:
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JonF
Member
Posts: 6155
Joined: 06-23-2003
Member Rating: 1.9


Message 63 of 84 (58036)
09-26-2003 3:34 PM
Reply to: Message 61 by Fred Williams
09-26-2003 1:19 PM


Re: bottom-up or top-down
I have a series on flight:

Most amusing. An excellent parody of creationist lunacy. A few mis-spellings would help, though.


This message is a reply to:
 Message 61 by Fred Williams, posted 09-26-2003 1:19 PM Fred Williams has not yet responded

  
Rei
Member (Idle past 5569 days)
Posts: 1546
From: Iowa City, IA
Joined: 09-03-2003


Message 64 of 84 (58037)
09-26-2003 3:36 PM
Reply to: Message 61 by Fred Williams
09-26-2003 1:19 PM


Re: bottom-up or top-down
I should register "evolutionfairytalesfairytails.com"

quote:
The whole idea that an arm could evolve into a wing is patently absurd, since the arm would become completely useless and a hindrance long before it could possibly become a functional wing

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:
Even the leading evolutionist Stephen J. Gould recognizes evolution by gradual changes (neo-Darwinism) as a pipe-dream: "Of what possible use are the imperfect incipient stages of useful structures? What good is half a jaw or half a wing?

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."


This message is a reply to:
 Message 61 by Fred Williams, posted 09-26-2003 1:19 PM Fred Williams has not yet responded

  
Cthulhu
Member (Idle past 4408 days)
Posts: 273
From: Roe Dyelin
Joined: 09-09-2003


Message 65 of 84 (58062)
09-26-2003 5:23 PM
Reply to: Message 61 by Fred Williams
09-26-2003 1:19 PM


Re: bottom-up or top-down
The whole idea that an arm could evolve into a wing is patently absurd, since the arm would become completely useless and a hindrance long before it could possibly become a functional wing

*Cough* Archaeopteryx *cough*

------------------
Ia! Cthulhu fhtagn!


This message is a reply to:
 Message 61 by Fred Williams, posted 09-26-2003 1:19 PM Fred Williams has not yet responded

  
Fred Williams
Member (Idle past 3412 days)
Posts: 310
From: Broomfield
Joined: 12-17-2001


Message 66 of 84 (58066)
09-26-2003 5:42 PM
Reply to: Message 62 by Brian
09-26-2003 1:34 PM


Re: bottom-up or top-down
Brian, how the heck are you?

quote:
Can you tell me why you never put the dates of publication in any if your book references? This seems quite a startling feature on your site.

Yes I can. It was the first paper I wrote for the internet, some 8 years ago. I agree with you there should be dates with the citations. I've added a few minor changes since then and always included the dates. In fact, you can tell which ones I added post-original because sure enough they are the one’s with dates! I really never noticed this oversight and will correct it (it will go on a todo list that is quite large, so I probably won't get to right away).

quote:
The reason I ask is because your Nelson Glueck quote is very outdated and even retracted by Glueck himself in the follow up to 'Rivers in the Desert.' (The River Jordan 1968)

I’ll research this further. Any specifics you can provide would be appreciated (in another thread, or by email, since this would be off-topic. My email is fred@evolutionfairytale.com).

[This message has been edited by Fred Williams, 09-26-2003]


This message is a reply to:
 Message 62 by Brian, posted 09-26-2003 1:34 PM Brian has not yet responded

Replies to this message:
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DC85
Member (Idle past 321 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 67 of 84 (58117)
09-26-2003 11:35 PM
Reply to: Message 66 by Fred Williams
09-26-2003 5:42 PM


Re: bottom-up or top-down
Fred unfortunately That is not the first time I have seen that horrible series on flight of yours...... I think its the worst and sorry to say one of the dumbest things I have ever seen. its a Joke.(same goes for your swimming wolf)..... However since you think the flying was designed I would like you to answer the question why are Some birds grounded? I would REALLY like to know

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 Message 66 by Fred Williams, posted 09-26-2003 5:42 PM Fred Williams has not yet responded

  
Andya Primanda
Inactive Member


Message 68 of 84 (58141)
09-27-2003 5:55 AM
Reply to: Message 60 by mark24
09-26-2003 5:16 AM


Re: bottom-up or top-down
I assume that we're talking bird flight here, okay?

Okay, what other creatures _truly_ fly? Insects, bats, pterosaurs. IMHO, insects are small so I guess they evolved flight because they are likely to be blown off by strong wind, either from the ground or from a tree. They are bad analogy if we want to speculate about birds, because primitive bird ancestors are not that small.

Bats however are arboreal mammals, more likely to evolve from flying-squirrel-like ancestors[top down] than possible jumping/running 'ground-up' ancestors (kangaroo rat-like?). And pterosaurs... well their early forms (Dimorphodon, Rhamphorhynchus)suggest an arboreal lifestyle. Add the fact that all extant gliding reptiles (Draco, flying snake) are arboreal, so I presume that pterosaur flight also evolved from arboreal gliders. Hence, top-down flight.

And yes, Microraptor gui with four wings makes a plausible link in the arboreal archosaur>bird scenario. I don't understand why the describers shoehorned it into Dromaeosauridae. Four wings does not make it a good runner; it would be like running in a wedding dress?

As for why runners don't evolve to fliers, I would like to point out that the adaptation for quadrupedal running (cheetah, horse) would commit all four limbs just for that purpose, while tailed bipedal running (velociraptor, T.rex [if it really runs, that is]) reduces the front limbs and render them less likely to evolve to anything else like wings.


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 Message 60 by mark24, posted 09-26-2003 5:16 AM mark24 has responded

Replies to this message:
 Message 72 by mark24, posted 09-28-2003 3:01 PM Andya Primanda has not yet responded

  
some_guy
Inactive Member


Message 69 of 84 (58209)
09-27-2003 6:04 PM


I was wondering if someone would maybe give me a possible scenario in which flight would be disadvantage and so the need to evolve the abilty to run and to lose the ability to fly could happen.

Replies to this message:
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NosyNed
Member
Posts: 8933
From: Canada
Joined: 04-04-2003
Member Rating: 3.4


Message 70 of 84 (58212)
09-27-2003 6:15 PM
Reply to: Message 69 by some_guy
09-27-2003 6:04 PM


Here is my guess, I am not an expert.

Flight is energetically expensive. If it is not an advantage then a creature that doesn't try saves energy.

You might note that, again and again, when a bird gets into a enviroment with no predators then a flightless form evolves. The Dodo being a famous example. (most of pre human contact, New Zealand being another ).


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DC85
Member (Idle past 321 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 71 of 84 (58217)
09-27-2003 6:40 PM
Reply to: Message 69 by some_guy
09-27-2003 6:04 PM


mutations simple as that........ Evolution didn't set out to make an ostrich or a chicken

This message is a reply to:
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mark24
Member (Idle past 3752 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 72 of 84 (58319)
09-28-2003 3:01 PM
Reply to: Message 68 by Andya Primanda
09-27-2003 5:55 AM


Re: bottom-up or top-down
Andya,

You miss the point, I understand fully that flying fish aren't true flyers, yet gliding is a plausible, I think you will agree, precursor of flight. Flying fish have managed a surface up transition.

Given that we know that they have, then we also know it's not impossible.

And yes, Microraptor gui with four wings makes a plausible link in the arboreal archosaur>bird scenario.

But in the grand scheme, they are unlikely to be anything like the ancestral bird. Why? Bird legs, like Archaeopterix' articulate for running in a particular way, very similar to therapodan/dinosaurs. Microraptors legs don't, & it is found more recently than Archaeopterix fossils. This means that therapod hind limbs evolved into Microraptor like legs, & then back again. Or archaeosaurs evolved Microraptor legs, then bird/therapod like legs. I therefore put it to you that Microraptor gui is actually more derived than Archaeopterix, rather than possesses ancestral characters of all birds.

That said, the number of synapomorphies that birds & therapods share is amazing, & simply cannot be just written off to convergent evolution. I therefore put it to you that the large majority of evidence points to a therapod ancestor of birds. I'm happy to consider an arboreal therapod, of course. But haven't been convinced that the ground up hypothesis is sufficiently flawed enough to be considered inferior to the arboreal hypothesis.

I don't understand why the describers shoehorned it into Dromaeosauridae.

Presumably because it possessed dromaeosauridae/dinosaur characters & not archosaur?

Mark

[This message has been edited by mark24, 09-28-2003]

[This message has been edited by mark24, 09-28-2003]


This message is a reply to:
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Replies to this message:
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Rei
Member (Idle past 5569 days)
Posts: 1546
From: Iowa City, IA
Joined: 09-03-2003


Message 73 of 84 (58355)
09-28-2003 6:33 PM
Reply to: Message 69 by some_guy
09-27-2003 6:04 PM


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."


This message is a reply to:
 Message 69 by some_guy, posted 09-27-2003 6:04 PM some_guy has not yet responded

  
Dr Jack
Member (Idle past 661 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 74 of 84 (58497)
09-29-2003 12:06 PM
Reply to: Message 72 by mark24
09-28-2003 3:01 PM


Re: bottom-up or top-down
One point from Andya's post struck me as interesting, although not directly in the form posted. We would reasonably expect flight, or indeed gliding as a pre-cursor, to require a strong, and flexible, muscle structure in the (to-be-)flight limbs. These pre adaptions are, surely, more likely to develop in an arboreal creature than a bipedeal runner.

Since you seem to have a pretty solid grounding in this area, I'm wondering whether you think this is a worthwhile line of argument?


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Replies to this message:
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mark24
Member (Idle past 3752 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 75 of 84 (58512)
09-29-2003 12:56 PM
Reply to: Message 74 by Dr Jack
09-29-2003 12:06 PM


Re: bottom-up or top-down
Mr Jack,

There's nothing wrong with the argument, nor is it not worthwhile. We just don't know the size of, nor the relative front limb dimensions, of the bird ancestors. Dromaeosaurs aren't found in rocks older than Archaeoptery so we don't know what the so-called protodromaeosaur really looked like.

These pre adaptions are, surely, more likely to develop in an arboreal creature than a bipedeal runner.

It doesn't always follow that bipedalism reduces the forelimbs, of course, us for example. Particularly if you are using your feathered arms for rapid changes of direction whilst prey chasing, to increase your acceleration/top speed. The flying fish managed surface up gliding without any musculature in the fins themselves.

Mark


This message is a reply to:
 Message 74 by Dr Jack, posted 09-29-2003 12:06 PM Dr Jack has responded

Replies to this message:
 Message 76 by Andya Primanda, posted 09-30-2003 5:56 AM mark24 has responded
 Message 78 by Dr Jack, posted 09-30-2003 9:55 AM mark24 has responded

  
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