Protoart

Well, at first a terrestrial coelurosaur needed to expand its range.

There was a discussion of this in the "Dinosaur Mailing List" in June of '08. You might want to read it. http://dml.cmnh.org/2008Jun/msg00141.html

The subtitle of " On the Origin of Species by Means of Natural Selection" by Charles Darwin is: right there on the cover: "Preservation of Favoured Races in the Struggle for Life". Think how sexual reproduction works. Something changes that benefits survival, and is carried on.

Of course, feathers, scales, fur or external color or pattern are needed for species recognition and mating display. But, these are visual in nature and not immediatly functional enough to benefit survival. "Form follows function."

Who says or where's your evidence that feathers arose for mating displays. It's far more likely that feathers were for thermal protection for small endothermic bodies. These are fluffy "down" type feathers and are not flight feathers!

Reply to iNow The NOVA show realy didn't discuss the "ground-up" or "tree-down" origin of flight. The show was about the use of the leg feathers on "microraptor." The conclusion was that the legs held straight back gave a good lift to drag ratio and that the splayed out leg position was a mistake. I still belive the the origin of flight was "bank jumping" because the trial and error failure of diving is not harmful and explains the fisrt exaptation, the aerodynamic use of the tail. This theory is also not mutually exclusive to what was demonstrated on the show.

Thanks for bumping the thread. Lets keep the discussion of my theory of "The Aerodynamic Origin of Bird Flight" going. Which is available at: http://protobird.blogspot.com Lucaspa wrote: (why, I do not know!) "So where is your first use of wings in diving as an aerodynamic feature? As I stated, in diving having forelimbs outstretched is detrimental, not advantageous." I write: >The first use of "wings" follows the first use of "fins" which were for the purpose of guidance. "Not in terms of wings or flight do you mention exaptation. Where is the exaptation for that? You only talk adaptation there." >I guess you finally read that section. "Dial is clear it is not a "defensive failure", but at least a "defensive success". Avoiding predators and reaching refuge so that you are not eaten contributes to reproductive success. Of course, we have the problem of your mischaracterization of natural selection into false categories. There are no categories such as you have tried to divide natural selection into "offensive" and "defensive". For natural selection, anything that gives an edge in the competition for survival and reproduction is a "success". A gazelle able to outrun and outturn a lion has a beneficial trait, whether you consider it "defensive" or not. >Defensive success comes passively. Offence is trial and error. How does a stalked animal evolve better sight, hearing, smell or camoflage to escape being eaten. The old and slow are eaten first. Survival of the fittest rules. "Humans have no tails but are able to control rotation during headfirst dives. This falsifies the necessity of a tail for a headfirst diver." >Humans in no way can control rotation after they left the diving board or platform. Are you blind? "But it still takes more energy than simply wading out into a stream. Remember, most of the attempts are going to end in failure. A wader doesn't have to climb back out when it misses; it just stands there. Therefore diving is going to be selected against in a population living along a bank." >Nonsense, If the fish won't come you, you have to go to them. Zebras don't come to the lion. "Only in a situation where the organism has to go looking for fish in the ocean and then dive on them is diving going to be used. But you need flight to go looking!" >As I wrote there are many places where you can see fish from the shore. "Cormorants dive for fish" >Cormorants swim on the surface and dive to bottom looking for fish. Terns dive from above for fish they can see. "Even if I made the mistake between cormorants and terns (which I didn't), it doesn't change the validity of the argument. You didn't address the argument. As I said, cormorants fly around looking for fish. The success of their dives (in terms of catching fish) depends on the density of fish. In order for your diving hypothesis to be correct, you would have to have a very constant (over thousands of generations) high density population of fish in a stream. And, of course, you don't get any aerodynamic benefit from having wings to dive from a low bank, do you? If you then move to higher banks and then cliffs, then the ecological requirement for a very dense fish population in a stream adjacent to cliffs (with water deep enough to allow diving) becomes even less likely." >The American Bald Eagle takes a fish with its talons one fish at a time. Birds take more tonnage of aquatic animals than they take in seeds, fruit, rodents, insects, etc. "BTW, did you notice that cormorants do NOT have tails? So tails are not necessary for controlling a dive. By your theory, the first birds would have been tail less. However, the fossil record shows that to be in error." >Cormorant have tails. You are blind (sorry)! You wrote: "Mimicking isn't part of natural selection." I wrote: "Then how do aquire an instinct?" You wrote "By natural selection." >??? I'm not going to respond to anymore of your statements. You are completely incoherant. BTW, Ken Dial sent me his new paper in "Nature". If you send me your email address I'll send it to you. He no longer refers to why OTW/WAIR was necessary, just "locomotive behavoir". My email address is protoart@gmail.com and is on the bottom my blogpost at: http://protobird.blogspot.com P.S. The first aerodynamic success that aided survival and that natural selection will promote is "bank diving." No other theory has a cogent initial act. Try challenging my premise. Art

"Please define ""first incremental success that aided survival"." > The first use of an anatomical feature aerodynamically, that natural selection will keep. "You don't mention exaptation at all." >Yes I do! Didn't you read this: "The tail is the first exaptation. Early rockets had a stick tied to them to keep their flight path more consistent for aiming purposes. The function of the tail will change from a balance control to an attitude control. A headfirst diver will need to control its rotation to keep its aim straight." "The running of the birds up inclines is NOT "defensive failure"." >In Dial's own words, please read within the first paragraph of each: http://dbs.umt.edu/flightlab/documents/BundleDialJEB2003.pdf http://www.aibs.org/bioscience-press-releases/resources/s15-0506.pdf Look for "reach refugia" in the first and "escape performance" in the second. "Let's look at some of what you stated: "Small wings or fins will be useful only if there is major airspeed to achieve any kind of incremental success."" > I think I explain this very well, please re-read" "But the tail is already present as a means of balancing a theropod dino as they run on two legs. Theropod dinos had tails a hundred million years before one species got flight." >I repeat what you didn't read again. "The tail is the first exaptation. Early rockets had a stick tied to them to keep their flight path more consistent for aiming purposes. The function of the tail will change from a balance control to an attitude control. A headfirst diver will need to control its rotation to keep its aim straight." "Protobird was a diver! Protobird dove for a fish, swam back to shore and climbed back up to the spot from where it dove, and waited for another fish to come by." "That's a lot of energy to spend for food. That climb takes lots of energy for the distance you are looking at." >A bank is a short walk from behind. "Cormorants are that accurate today, but then they fly around looking for fish! >You have confused Terns for Cormorants. "You are proposing a condition that, for thousands of generations, there is something worth diving for adjacent to a cliff. Not very likely." >Please re-read the part about meandering rivers. Banks are everywhere" "This new technique would be mimicked by others, maybe the young." "Mimicking isn't part of natural selection." >Then how do aquire an instinct? "That's Lamarckism. For natural selection to work the diver must get more food than those that don't. Therefore have more children to pass the alleles for diving to. More children that have alleles for diving than there are children of non-divers." >Huh? Traits that work produce more offspring. "If you wade, you don't have to dive. Look at bears and storks today. They wade, then dart their forelimbs or their necks underwater to grab fish. That's a more efficient way to earn a living by catching fish than climb up a cliff so you can dive." >Extending one's hunting range is instictive. You also didn't read this: "Protobird would expand its wading area by adding the edges and the areas that were normally bypassed where the water was too deep." "As I said, you put a lot of thought into this. But when you propose a theory, then you have to be prepared to give it up if the evidence is against it. Don't get too attached to your theory. >I love my theory. Nothing that you have said is mutually exclusive to its accuracy. "The highest authorities in the field in the evolutionary biology havn't concluded any such thing. Read this... http://www.ucmp.berkeley.edu/vertebr...ht/evolve.html Did you read the article beyond its saying there are a number of hypotheses? For instance, the article states "Scientists generally agree that wings must have been exaptations; they were used by the ancestor for one function, and became useful for flight among the descendants (if they weren't exaptations, then they were adaptations, which would mean that they were wings already used for powered flight; a circular argument)."" >I submit that the forelimb fins adapted to wings after their feathers got longer. Adaption is a change in form. Exaption is a change in function. "How do wings aid diving? They don't! All divers put their forelimbs against their body in order to enter the water. If they don't, then the force of hitting the water breaks the bones!" >Do you recall I said protobird may belly-in. Lots of birds land on their bellies or feet and don't fold their wings. "Now, did you look at the date of the webpages? If they were written before Dial (as was most of the stuff at the Wiki site, since Dial is the latest reference) then you are getting a controversy that existed in the past. For instance, if you only looked at papers more than 3 years ago, you would see a "controversy" over whether birds evolved from dinos or both birds and dinos had a common reptilian ancestor. That controversy has been settled. The Wiki site uses reference prior to Dial to say what the state of the situation was then -- and then there was a controversy." >The evolution of dinos to birds is different than the evolution of bird flight! My theory is "The Aerodynamic Origin of Bird Flight" and is available at: http://protobird.blogspot.com/ Enjoy, Art

...your basic suggestion seems to be that the first flying birds were water-fowl, which is fine, but without any reference to the fossil record it is an untestable supposition. >>>Some think the protoavis period ( before archeopterix) might be 75 million years. If the initial area where flight originated is gone, what are we supposed to do? ...It is also fairly unnecessary considering the solid fossil-based alternatives that have already been proposed. >>>For what species became birds, not for how flight originated. ...There also seem to be some definite errors in your logic. Your three "drives" for natural selection are a bit problematic. For which of those reasons did the tetrapod limb evolve, for example? Ultimately all selection is for features that increase reproductive success, either by increasing survivorship or simply increasing the animal's sexiness. That's probably a better way to look at natural selection. >>>Surviving includes feeding, not being eaten and reproduction. Does camouflage make one sexy? ...You make a bit of a strawman of "ground-up" and "tree-down," too. You paint them as suggesting that the evolution of flight was a directed process, with every incremental step being for flight-related reasons. >>>Good point. Someone else said "flight for flights sake." I already revised my blog post. ...As Lucaspa pointed out, that is not the case. The fact that hard ground might be more "dangerous" to fall on is absolutely irrelevant. A) That's not necessarily the case, water can be very hard if approached with sufficient speed; >>> One doesn't jump cliffs until they have masterd banks. ...B) There's no requirement that evolution happen somewhere "safe." If falling to the ground is fatal, then that's just a stronger selective agent; and >>> Harmful failure does not promote natural selection. ...C) The whole question is moot if birds were able to successfully keep airborne from the very inception of their flightedness. >>>When pigs fly! Micro evolutionary adaptations over over millions of years is universally accepted.

The highest authorities in the field in the evolutionary biology havn't concluded any such thing. Read this... http://www.ucmp.berkeley.edu/vertebrates/flight/evolve.html or this... http://wiki.cotch.net/index.php/Learning_to_Fly:_How_Birds_Took_to_the_Air But what do you think of my aerodynamic theory?

But what do you think about my aerodynamic theory?

I've read Dial and have seen the video. It looks like a skateboard stunt. It does not explain the first incremental success that aided survival. Defensive failure does not promote natural selection. Please read the whole piece. I do mention the first exaptation.

Much has been written to try to explain the evolution of bird flight. The discussion today revolves around two theories, the "ground-up" and the "tree-down." These theories and their variants have serious flaws as pointed out by the opposite camps. There is another way! My new theory is available now at: protobird.blogspot.com I think you will find it cogent and persuasive. I explain why, how and where flight evolved. I do avoid the fossil record because I'm no paleontologist. But, nothing I propose is contrary to archaeopteryx or the recent finds in China. Please give it a read.