How did Flight evolve in the animal kingdom ?

[markearthling]

It seems likely this would have to start with something small and

light (insect ?) which could be lifted into the air by a strong wind/breeze and which would develop bud like appendages

which later develop into full blown wings in later generations ?

 

The question is , what is the impetus or trigger which causes

the immature wing buds to confer some kind of benefit

or advantage to the individual so it is more successfull

and survives to procreate and so wings get larger,

develop and become more and more successful and

usefull ?

 

Some animals which have the power of some kind of

flight are various insects, pteradactyl/dino etc.,

birds, gliding animals and flying fish.

 

 

[ydoaPs]

Flight is an example of convergent evolution. Insects and birds evolved flight separately. Birds evolved from gliding feathered dinosaurs.

 

If you're going towards the use of "half a wing" (which your previous thread suggests is quite likely), then I'll let Dr Dawkins answer since you're familiar with him:

What use is half a wing? How did wings get their start? Many animals leap from bough to bough, and sometimes fall to the ground. Especially in a small animal, the whole body surface catches the air and assists the leap, or breaks the fall, by acting as a crude aerofoil. Any tendency to increase the ratio of surface area to weight would help, for example flaps of skin growing out in the angles of joints. From here, there is a continuous series of gradations to gliding wings, and hence to flapping wings. Obviously there are distances that could not have been jubped by the earliest animals with proto-wings. Equally obviously, for any degree of smallness or crudeness of ancestral air-catching surfaces, there must be some distance, however short, which can be jumped with the flap and which cannot be jumped without the flap.

 

Or, if prototype wingflaps worked to break the animal's fall, you cannot say 'Below a certain size the flaps would have been no use at all'. Once again, it doesn't matter how small and un-winglike the first wingflaps were. There must be some height, call it h, such that an animal would just break its neck if it fell from that height, but would just survive if it fell from a slightly lower height. In this critical zone, any improvement in the body surface's ability to catch the air and break the fall, however slight that improvement, can make the difference between life and death. Natural selection will then facour slight, prototype wingflaps. When these small wingflaps have become the norm, the critical height h will become slightly greater. Now a slight further increase in the wingflaps will make the difference between life and death. And so on, until we have proper wings.

 

There are animals alive today that beautifully illustrate every stage in the continuum. There are frogs that glide with big webs between their toes, tree-snakes with flattened bodies that catch the air, lizards with flaps along their bodies; and several different kinds of mammals that glide with membranes stretched between their limbs, showing us the kind of way bats must have got their start. Contrary to the creationist literature, not only are animals with 'half a wing' common, so are animals with a quarter of a wing, three quarters of a wing, and so on. The idea of a flying continuum becoes even more persuasive when we remember that very small animals tend to float gently in the air, whatever their shape. The reason this is persuasive is that there is an infinitesimally graded continuum from small to large.

Edited June 9, 2011 by ydoaPs

[markearthling]

What Mr Dawkins has to say is interesting but not entirely

convinceing.

 

Quote/Extract Dr Dawkins (above)

 

Natural selection will then favour slight, prototype wingflaps.

When these small wingflaps have become the norm, the critical height h

will become slightly greater. Now a slight further increase in the wingflaps

will make the difference between life and death. And so on, until we have proper wings.

 

there is a continuous series of gradations to gliding wings,

and hence to flapping wings.

 

End Quote

 

If a creature has proto wing flaps and falls and damages

itself then I can't see how this confers any benefit

which would help the creature get around or survive

to procreate. So how would natural selection then favour

undeveloped wings ?

 

There is a vast difference between the structure and function

of gliding and flapping wings. This is only one example

of where Mr Dawkins tends to draw a very long bow

with his material (to the point of not being credible).

 

If proto wings damage their owner where is the impetus

or trigger for them to keep developing ?

 

 

 

[ydoaPs]

If a creature has proto wing flaps and falls and damages

itself then I can't see how this confers any benefit

which would help the creature get around or survive

to procreate. So how would natural selection then favour

undeveloped wings ?

It didn't die. This allows it to live longer and thus have a higher chance of reproducing than a similar creature with no wings in a similar situation.

 

On a side note, it'd be awesome if you could use the quote feature. We have a tutorial showing how to use many of the site's functions.

[markearthling]

Why would proto wing flaps develop in the first place ?

What would trigger this ?

 

If a creature is damaged by a fall but does not die

this does not mean it would then survive to procreate.

In fact it may die later from it's injuries for many

reasons. Your argument is not water tight.

 

Also why have other gliding animals not then developed

flapping wings as Mr Dawkins suggests ?

 

 

[ydoaPs]

Why would proto wing flaps develop in the first place ?

What would trigger this ?

The same thing that caused bacteria in Japan to be able to digest nylon-mutations.

 

If a creature is damaged by a fall but does not die

this does not mean it would then survive to procreate.

In fact it may die later from it's injuries for many

reasons. Your argument is not water tight.

Not all need survive till procreation for creatures with the mutated gene to become more prevalent in the population than the ones without. The important part is that those with the mutation are more likely to survive a fall at height h than those without. Higher probability of survivors coupled with a large number of occurrences yields more potential mates than their non-winged breeding competitors.

 

Also why have other gliding animals not then developed

flapping wings as Mr Dawkins suggests ?

The ones which have not had species split off have adapted to their niche so well as to out-compete their mutated competitors.

[markearthling]

Which of the following has more potential breeding ability :

 

1. A winged creature with proto wings which falls and damages

itself.

 

2. A non winged creature on the ground which doesn't

fall and injure itself.

 

And you are saying the one with proto wings necessarily

has some kind of advantage.

 

This is not logical.

[mississippichem]

Which of the following has more potential breeding ability :

 

1. A winged creature with proto wings which falls and damages

itself.

 

2. A non winged creature on the ground which doesn't

fall and injure itself.

 

And you are saying the one with proto wings necessarily

has some kind of advantage.

 

This is not logical.

 

What if the creature's food source is located at the tops of very high trees? Then it makes a lot of sense.

 

I think you don't understand the basic concepts of evolution. Evolution is not conscious, it does not follow logic. Most mutations are not favorable, but those organisms tend to not reproduce or tend to not have a reproductive advantage. Every now and then, a mutation occurs that just so happens to be favorable. Those with the favorable mutation tend to reproduce more.

[ydoaPs]

Which of the following has more potential breeding ability :

 

1. A winged creature with proto wings which falls and damages

itself.

 

2. A non winged creature on the ground which doesn't

fall and injure itself.

 

And you are saying the one with proto wings necessarily

has some kind of advantage.

 

This is not logical.

Invalid comparison. The valid comparison is as follows.

 

Which of the following has more potential breeding ability :

 

1. A winged creature with proto wings which falls and damages

itself.

 

2. A non winged creature which falls and dies.

[markearthling]

I am not asking evolution to be logical. I am asking you to be logical. You say what if a food source is high up in trees.

I say so what. This is not the case for all animals with or without

proto wings.

 

So what are you trying to say ?

 

An animal with proto wings which falls and damages itself

has no breeding advantage over a ground dwelling

animal with no proto wings. That is what I am saying.

 

Also one point mutation is not likely to confer any

procreational advantage to a creature.

If mutations were cumulative then something could change

to benefit an individual but this is unlikely.

 

If you have any links I would be happy to read the material.

[ydoaPs]

I am not asking evolution to be logical. I am asking you to be logical. You say what if a food source is high up in trees.

I say so what. This is not the case for all animals with or without

proto wings.

 

So what are you trying to say ?

 

An animal with proto wings which falls and damages itself

has no breeding advantage over a ground dwelling

animal with no proto wings. That is what I am saying.

I'm saying you're the one who is not being logical. If you'd like to make a valid comparison, then I'll discuss this further with you. If not, then we're done. As it stands, you're trying to compare apples and oranges.

 

Also one point mutation is not likely to confer any

procreational advantage to a creature.

Any given mutation is likely to have zero effect at all.

 

If mutations were cumulative

They are.

 

If you have any links I would be happy to read the material.

Go to the Khan Academy I linked to above.

[Edtharan]

If there are a lot of creatures on the ground, then there is an advantage in getting a food source that is not being use by any other creature.

 

 

Thus, if there are only creatures without wings and falling kills them, then they will live on the ground.

 

But as that food source on the ground becomes completely use, then any creature that could climb (even with the risk of falling) has an advantage. As these climbers have the advantage they will evolve to be better climbers and fall less often.

 

However, one can never eliminate the chance of falling, so once you have climbing creatures, then they have a chance to fall. If some mutation made a creature less likely to be injured (say small protuberances that allowed stability in the fall, or that provide air resistance) then these creatures would survive more often and come to dominate the gene pool because of their advantage.

 

Over time, the creatures with the protuberances that allow them to survive more often will come to dominate the gene pool, and this will cause the evolution of protuberances into proto-wingflaps, and then on into wings.

 

Each step provides some degree of advantage to the organism, from climbing, to protuberances to proto-wingflaps to wings. Each giving it access to more food, or survive better.

[mooeypoo]

Which of the following has more potential breeding ability :

 

1. A winged creature with proto wings which falls and damages

itself.

 

2. A non winged creature on the ground which doesn't

fall and injure itself.

 

And you are saying the one with proto wings necessarily

has some kind of advantage.

 

This is not logical.

 

It doesn't matter. Evolution doesn't operate as a long-term benefit, but rather short-term mutation benefit that ADD UP towards long term changes.

 

For that matter, the human body has quite a few NON benefitial design flaws in us. In fact, if a house would have been designed with the human body's waste piping design schematics, you'd sue the architect.

 

that said, your assumptions are somewhat weird to me. Isn't it more logical to have a winged creature that can ESCAPE predators and protect itself when falling from large height (where there are much fewer predators)?

 

Nothing will be logical if you frame it to not be logical. Seems to me you're not really interested in being convinced by science or evidence,but rather push your own agenda. I am willing to be open minded and weigh the evidence you shall present objectively. Can you really say you can do the same?

 

~mooey

[markearthling]

Noone here has presented any examples from the supposed literature

which support their arguments. All I get is quotes from Richard Dawkins

who tells a ripping yarn/story by the way.

 

An explanation is not evidence from a scientific literature which is published based

on actual research work.

 

My mind is open and the only agenda here is getting at the truth.

 

If we both climbed a tall tree and I had small winglike protuberances on my back

and you didn't I am sure we would both likely die in a fall or both be seriously

injured to the extent we could die later or not be healthy enough to maybe have kids later.

 

To say that proto wings would save more animals from falls than not is simply

a gross assumption. Where is the research which backs this assumption up ?

And I am the one who is being illogical.

 

Also noone bothered to respond to my question above regarding gliding and

flapping wings. They are vastly different in form/structure and function

and yet according to Richard Dawkins there is an evolutionary progression

from gliding wing to flapping. I would also like to see the research whixch has been

done on this one.

 

It isn't real science until you can present conclusive evidence in the literature.

 

So go ahead, surprise me.

[mississippichem]

So go ahead, surprise me.

 

Follow this link: Evolution of Wings, put on your surprise hat. By the way, you are the one making claims contrary to mainstream science, the burden of proof is on you. That's why this pseudoscientific nonsense spreads so fast. It's easy for you to post random rantings about how you don't understand things implying that we are somehow wrong (this is also a logical fallacy). It requires effort to put to rest your senseless line of questioning.

Edited June 9, 2011 by mississippichem

[markearthling]

Oh now I understand, you are the omniscient and omnipotent ones

who have no need to demonstrate or present any real evidence

regarding what you believe in.

 

You are so in love with your precious theory of evolution

and you are quite deluded by it.

 

You can just sweep any logical argument under the carpet can't you.

 

Present your evidence from the scientific literature or keep your

psuedo science to yourself.

 

Thanks for the link. My surprise hat is on.

 

I hope it's not another bedtime story from our dear Dr Dawkins

or one of his colleagues.

 

 

[mississippichem]

I hope you have enough free time to read the hundreds of thousands of peer reviewed articles that I linked you to.

 

You wanted evidence from the literature, you got it...know what is the problem?

[Moontanman]

I know what the problem is, markearthling, if you really want to understand evolution I can connect you to some really informative and scientifically accurate videos by some really impressive people but do you really want to know or are you just looking to ask an unanswerable question?

Edited June 9, 2011 by Moontanman

[mooeypoo]

I know what the problem is, markearthling, if you really want to understand evolution I can connect you to some really informative and scientifically accurate videos by some really impressive people but do you really want to know or are you looking to ask an unanswerable question?

 

No question so far was unanswerable. He just doesn't want to accept the answers.

Or even read about them for himself, it seems.

[Moontanman]

If he really wants an answer I do have some stuff to show him, this amounts to considerable time on my part spent looking up this stuff and while I do enjoy it for it's own sake having some one just ignore me or worse yet just move the goal posts by redefining the question each time is a bit of a... hmmm, how to say it....

[mooeypoo]

If he really wants an answer I do have some stuff to show him, this amounts to considerable time on my part spent looking up this stuff and while I do enjoy it for it's own sake having some one just ignore me or worse yet just move the goal posts by redefining the question each time is a bit of a... hmmm, how to say it....

 

Frustrating? Annoying? Unfair? Not-meant-as-a-science-inquiry? Intellectually Dishonest?

[Moontanman]

Yes, that last one would seem to be the most accurate, good thing there is some humor mixed in or it wouldn't be fun at all....

[Arete]

I'm a PhD student in evolutionary biology. I don't "believe" in Evolution per se - I believe in the most parsimonious explanation of observations. Currently, the best supported theory is that organisms diversify due to the accumulation of random genetic mutations resulting in differential phenotypes. A diverse array of environmental pressures mean that some phenotypes are able to reproduce and therefore pass their genetic information to the next generation better than others. As environments are complex, temporally and spatially dynamic, a number of phenotypes can be simultaneously successful.

 

This theory has been tested in a scientific framework countless times, with even more replications, by thousands of people all over the globe and not once has there been a result which significantly rejects the fundamental principles of the theory. That's an exceptionally large body of support... however if you or someone else could find an empirically supported alternative that better explains our large body of observations, demonstrate that it works and how it works - it would mean all us evolutionary biologists would have a fair bit of hat eating to do, but on the flip side it would make it a very interesting time to be working in the field.

 

It seems you're tangling up a few anti-evolution arguments in one. The first - the argument of irreducible complexity. The wing is actually a good example of how the argument of irreducible complexity is flawed as there are several extant - gliding possums, gliding lizards, gliding seed pods, parachuting spiders, jet propelled squid, flying fish, etc and so on... and extinct - Longisquama, Archaeopteryx, Microraptor etc. where intermediatory methods of flight are selectively advantageous. A membrane, or inefficient flapping wing which allows you to get to the next fruit bearing tree or remain airborne longer than something intent on eating you - even if it's a controlled fall more or less, is better than none at all in certain environments.

 

Next - argumentum ignoratum. You don't comprehend how a gliding structure can evolve into a flapping wing and thus conclude it cannot be done. This is an argument from incredulity - and thus a logical fallacy. If we look at the evolution of bird wings for e.g. the shoulder and elbow joints are residual from that limb being first a leg, then an forelimb. When furnished with a plane of feathers, bending and straitening that limb can generate lift. As such, the manipulation of the limb is residual - a happy coincidence for the bird and speculatively - a reason for their exceptional evolutionary success.

[crazynutsx]

you cant conclude anyting evolved into anything beacuse you cant know that a fossil gave birth to any children let alone something different to itself

[Arete]

you cant conclude anyting evolved into anything beacuse you cant know that a fossil gave birth to any children let alone something different to itself

 

You can't prove that the sun will rise tomorrow either. You can theorize that the earth and the sun are both spheres, the earth revolves around the sun whilst simultaneously spinning, meaning that for approximately 12 hrs tomorrow, the sun will be visible from the point on earth on which you stand. Based on theory and past events, we can be pretty sure that it will rise tomorrow.

 

We can, in a similar fashion be reasonably certain, given the prima facie evidence that the organisms represented in the fossil record were capable of reproduction.

Edited June 9, 2011 by Arete