Notices
Results 1 to 70 of 70
Like Tree42Likes
  • 1 Post By Lynx_Fox
  • 1 Post By Lynx_Fox
  • 3 Post By billvon
  • 6 Post By skeptic
  • 5 Post By pyoko
  • 1 Post By Neverfly
  • 2 Post By exchemist
  • 3 Post By exchemist
  • 1 Post By ukjojo
  • 2 Post By icewendigo
  • 2 Post By marnixR
  • 1 Post By skeptic
  • 1 Post By skeptic
  • 1 Post By John Galt
  • 1 Post By protoart
  • 1 Post By skeptic
  • 6 Post By spuriousmonkey
  • 1 Post By Paleoichneum
  • 1 Post By skeptic
  • 2 Post By RedPanda

Thread: Why would an animal evolve wings?

  1. #1 Why would an animal evolve wings? 
    Forum Freshman ukjojo's Avatar
    Join Date
    Nov 2013
    Posts
    14
    I was watching Attenborough's series again on TV and still find it extremely hard to blindly agree with the simplistic conventional wisdom of what was being taught on the show - for example - that some tree-dwelling creatures evolved to be gliders and then these evolved into birds. Why would any animal evolve wings? To make that statement sounds like implying that somehow evolution is like a conscious decision - like evolution somehow contemplates that flying is a good idea and so it decides to 'make' wings. I can't get my head around it at all. Why would any animal by either gradual minute evolutionary changes, or by huge genetic mutations, evolve wings that are physiologically such a radical innovation for any ground/tree dwelling animal to develop - and what was in between?

    It's fine that Attenborough says gliders evolved into winged birds, but how many intermediate examples are there to prove this is actually true and not simply speculation? Were these early proto-birds like flightless penguins that eventually evolved larger wings and learnt how to fly? This process makes no logical sense to me and so it would be great if someone could properly explain it all to me. It just seems to me that every stage in the process from having no wings, to having fully developed flying wings would actually disabled an animal and get in their way rather than being helpful; so what was the benefit to them that spurred evolution into continuing?

    Thank you.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,416


    Ninja Pancakes likes this.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  4. #3  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,416
    Though I don't see it mentioned much in biology classes it also helps that Earth's atmosphere was thicker which would made evolution of flight by larger animals less challenging.
    anticorncob28 likes this.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  5. #4  
    Forum Cosmic Wizard
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    2,222
    Quote Originally Posted by ukjojo View Post
    Why would any animal evolve wings?
    To escape predators. To run slightly faster than their prey. To get to better/more abundant food sources. To flee pursuers more effectively. To survive falls.

    To make that statement sounds like implying that somehow evolution is like a conscious decision - like evolution somehow contemplates that flying is a good idea and so it decides to 'make' wings.
    Nope. Animals with more skin across their "arms" survive falls a little better or run a little faster. Multiply that by ten million and you have wings.

    If you want to see that in action today, google "Idiurus macrotis." Note the new 'bone' evolving in its wing.

    and what was in between?
    Gliding animals (like flying squirrels) and/or running animals (like ostriches.)
    Reply With Quote  
     

  6. #5  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    To answer this question, you have to realise that the first wing precursor was not a wing. We know from the fossil record that birds came from dinosaurs, and we know that many dinosaurs had feathers. We know that those dinosaurs had fore limbs. We also know that feathers in modern day birds are frequently expanded as display items for sexual attraction.

    So here is a possibility. This is a f'rinstance speculation and not to be taken as truth. It is probably wrong, but there are so many possibilities that any speculation will probably be wrong.

    Imagine a dinosaur with feathers that climbed trees. It evolves feathers on its forelimbs as display items. It stands on a branch and spreads its forelimbs to display the large, brightly coloured feathers to attract a mate, like many birds do today. Obviously, the tree dinosaurs of this species that have the largest fore limbs, longest feathers, and brightest colours will be the most successful reproducers, since they will win the ladies. Thus, evolution leads to longer fore limbs and longer, brighter feathers on the forelimbs.

    Now let us imagine that this species sometimes has to jump out of that tree to escape a predator. The ones with those large forelimbs and feathers will fall more slowly and have a better chance at surviving. Natural selection leads to the growth of even longer forelimbs, and longer feathers on those forelimbs.

    If the feathers are slanted backwards, that fall will be directional, assisting escape. So evolution slowly leads to long feathers slanted backwards. Over a long time, that leads to gliding motion. The individuals that have strong forelimb muscles will be better at controlling those glides, so strong muscles evolve. Those stronger muscles allow for a flap to assist the jump off the branch. In time, the system evolves to the point where flapping flight becomes possible.

    Now, I do not want you, or anyone to take this story seriously. There are a thousand possible routes to evolving wings. The thing to note is that each change is small, and towards a "goal" which may have nothing to do with the end result - flight.
    Reply With Quote  
     

  7. #6  
    Forum Professor pyoko's Avatar
    Join Date
    Jun 2011
    Location
    Australia
    Posts
    1,094
    This might be worth a watch:



    Whilst the traditional view on the evolution of feathers was in relation to flight, new discoveries of feathered dinosaurs in China have changed this to focus on thermoregulation and display. Similarly, the evolutionary path from reptilian scales to bird feather has been turned on its head by tubular structures from the follicle.

    Certain organisations continue to parrot the phrase "no transitional fossils have ever been found". However, the list of species which possess transitional features continues to grow.

    Epidexipteryx hui, Protoavis, Protarchaeopteryx, Archeopteryx, Avimimus, Sinosauropteryx, Caudipteryx, Rahonavis, Shuvuuia, Sinornithosaurus, Beipiasaurus, Microraptor, Nomingia, Epidendrosaurus, Cryptovolans, Scansoriopteryx, Yixianosaurus, Dilong, Pedopenna, Jinfengopteryx, Sinocalliopteryx, Sinornis, Ambiortus, Hesperornis, Ichthyornis
    Reply With Quote  
     

  8. #7  
    Suspended
    Join Date
    Nov 2012
    Location
    Apocalyptic Paradise
    Posts
    6,613
    Quote Originally Posted by pyoko View Post
    This might be worth a watch:
    Watched all five parts and enjoyed it immensely. Thanks for posting that.
    pyoko likes this.
    Reply With Quote  
     

  9. #8  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by ukjojo View Post
    I was watching Attenborough's series again on TV and still find it extremely hard to blindly agree with the simplistic conventional wisdom of what was being taught on the show - for example - that some tree-dwelling creatures evolved to be gliders and then these evolved into birds. Why would any animal evolve wings? To make that statement sounds like implying that somehow evolution is like a conscious decision - like evolution somehow contemplates that flying is a good idea and so it decides to 'make' wings. I can't get my head around it at all. Why would any animal by either gradual minute evolutionary changes, or by huge genetic mutations, evolve wings that are physiologically such a radical innovation for any ground/tree dwelling animal to develop - and what was in between?

    It's fine that Attenborough says gliders evolved into winged birds, but how many intermediate examples are there to prove this is actually true and not simply speculation? Were these early proto-birds like flightless penguins that eventually evolved larger wings and learnt how to fly? This process makes no logical sense to me and so it would be great if someone could properly explain it all to me. It just seems to me that every stage in the process from having no wings, to having fully developed flying wings would actually disabled an animal and get in their way rather than being helpful; so what was the benefit to them that spurred evolution into continuing?

    Thank you.
    It always surprises me why people have so much trouble with wings on birds. Often I suspect they've read the same crap creationist tracts and haven't thought about it for themselves at all.

    Ask yourself: would you express the same incredulity regarding wings on insects? How do you think these arose? Do you think them just as problematic as wings on birds? If not, why not?

    And what about winged mammals, such as bats? Doesn't consideration of these and, say, flying squirrels, give you a clue as to the continuum that can exist between flight and non-flight adaptations?
    Neverfly and Bad Robot like this.
    Reply With Quote  
     

  10. #9  
    Suspended
    Join Date
    Nov 2013
    Posts
    99
    Its amazing the how lines of evolution compliment their environment like that.
    Reply With Quote  
     

  11. #10  
    Suspended
    Join Date
    Nov 2013
    Posts
    238
    I'm not an expert here but I am going to say "climbing trees gave a survival advantage". "Jumping from tree to tree gave a survival advantage". "Having skin webbed bewteen the limbs and body allowed for longer distance jumping, and gave a survival advantage". "Using musculuar power to generate lift with the webbing allowed for even longer distance jumping which gave a survival advantage". I could go on.
    Last edited by Ninja Pancakes; November 29th, 2013 at 02:45 AM.
    Reply With Quote  
     

  12. #11  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by Magic Pixel View Post
    Its amazing the how lines of evolution compliment their environment like that.
    Quite. There are many examples of convergent evolution, not just with flight, which has evolved at least 3 times independently as discussed above. My favourite is whales being descended from a common ancestor of hippos. Amazing, but when you stop and think it make perfect sense The eye is another (arthropods, molluscs, vertebrates).

    To me what this tells you is the power of evolutionary pressures to reinvent things, often several times over, in the course of biological time on Earth. But of course the creationist prefers (for either undisclosed theological reasons or due to rank stupidity - or a linear combination of the two) to throw his hands up and say it's unbelievable - the Argument from Personal Incredulity.
    KALSTER, Neverfly and Bad Robot like this.
    Reply With Quote  
     

  13. #12  
    Forum Freshman ukjojo's Avatar
    Join Date
    Nov 2013
    Posts
    14
    Quote Originally Posted by skeptic View Post
    To answer this question, you have to realise that the first wing precursor was not a wing. We know from the fossil record that birds came from dinosaurs, and we know that many dinosaurs had feathers. We know that those dinosaurs had fore limbs. We also know that feathers in modern day birds are frequently expanded as display items for sexual attraction...
    Thank you SKEPTIC - Your answer resonates with me and is the most sensible and obvious solution that I've ever read. This solution that you give has logical and rational sense to me and I'm very grateful to you; plus I don't know why I never thought of that myself seeing as I'm usually a lateral thinker.

    What you propose has to be far more realistic than the frankly 'fairytale-like' explanations pushed by convention, because even today we see many examples of birds enduring the most inconvenient adaptations for the sake of attracting mates, so to imagine that after scales 'frayed' into feather-like structures, thereafter colour and size rapidly evolved in them for mating success, followed by bony supportive structures - and voila! - flying wings are the result.

    Thanks so much for your insight that is much appreciated
    Bad Robot likes this.
    Reply With Quote  
     

  14. #13  
    Suspended
    Join Date
    Nov 2013
    Posts
    99
    Feathers were green but not colorfull, probably to blend in with trees. To bad the species no longer exists on this planet.
    Reply With Quote  
     

  15. #14  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    5,295
    What are you on about now?
    Reply With Quote  
     

  16. #15  
    Suspended
    Join Date
    Nov 2013
    Posts
    99
    Have a video link,only I misplaced it.
    Reply With Quote  
     

  17. #16  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,150
    Flying fishes remind me of a joke about 2 guys running from a bear

    Joe: Thank god I have my running shoes on!
    Jim: ouch, ouch, crap, but why? The bear is faster than you even with your running shoes, right?
    Joe: Yes but the only thing that really counts is that Im a tad faster than you!



    (EDIT: Added sidenote: note that mutations and changes do occur even when theres absolutely no rime or reason for them, theres no significant advantage of having 115 hair on your brow as opposed to 114 (or a unrelated reason like sexual differenciaton etc) , and some of these changes only take on the mantle of advantageous or disadvantageous when something in the environment changes/emerges when this attribute now makes a small (or big) difference. Like if some populations of human's T-Cells make them immune to HIV or some other virus, this might never be an advantage until a new virus come along that is particularily deadly for or inoffensive for those with that mutation/variation. Now if the situation makes it advantageous there might be more individuals with this characteristic and you may then multiply the variations of that T-cell configuration, etc ). So the wings can have precursors that are not necessairily advantageous for flight or advantageous for other reasons(mating, etc) or not advantageous at all.
    Last edited by icewendigo; November 29th, 2013 at 12:05 PM.
    Bad Robot and exchemist like this.
    Reply With Quote  
     

  18. #17  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    there's quite a few birds that use their wings whilst running to aid manoeuvrability (think road runner) or help in some other way with terrestiral locomotion (e.g. chukar partridges can negotiate 50 degree inclines right after hatching, 60 degree slopes at 4 days old, and at 20 days, can perform a vertical ascent whilst running and flapping their wings)

    another interesting thing is the swivel wrist common between birds and dromaeosaurs - the latter used the swivel action to capture prey (hence maniraptora), and it only turned out fortuitous that this is the same type of movement in a wing beat

    the following website is quite interesting in reply to your question : Origin of Flight
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  19. #18  
    precious sir ir r aj's Avatar
    Join Date
    Oct 2013
    Posts
    668
    Quote Originally Posted by marnixR View Post

    another interesting thing is the swivel wrist common between birds and dromaeosaurs - the latter used the swivel action to capture prey (hence maniraptora), and it only turned out fortuitous that this is the same type of movement in a wing beat

    Analogous organ - Evolution Tale.com
    Reply With Quote  
     

  20. #19  
    precious sir ir r aj's Avatar
    Join Date
    Oct 2013
    Posts
    668
    Quote Originally Posted by Lynx_Fox View Post
    Archaeopteryx - Wikipedia, the free encyclopedia
    Reply With Quote  
     

  21. #20  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by sir ir r aj View Post
    what ?!? we're not talking analogous structures here ! the semi-lunate carpal is a synapomorphy (or shared derived feature) between maniraptorans and birds



    (see The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs)
    Lynx_Fox and sir ir r aj like this.
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  22. #21  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    Quote Originally Posted by Magic Pixel View Post
    Feathers were green but not colorfull, probably to blend in with trees. To bad the species no longer exists on this planet.
    There is no evidence at all that feathers were green. Preserved melatonins in fossils have given indications of patterning and brown, black and gray tones.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  23. #22  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    besides, many modern feathers that appear green to us aren't really green but irridescent, so you wouldn't be able to pick that up from the fossil record
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  24. #23  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    Birds, and many reptiles, are able to see into the ultra violet. What appears to our limited vision to be drab is often irridescent under ultra violet. The common, and uncolourful starling positively glows under ultraviolet.
    Bad Robot likes this.
    Reply With Quote  
     

  25. #24  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by marnixR View Post
    there's quite a few birds that use their wings whilst running to aid manoeuvrability (think road runner) or help in some other way with terrestiral locomotion (e.g. chukar partridges can negotiate 50 degree inclines right after hatching, 60 degree slopes at 4 days old, and at 20 days, can perform a vertical ascent whilst running and flapping their wings)

    another interesting thing is the swivel wrist common between birds and dromaeosaurs - the latter used the swivel action to capture prey (hence maniraptora), and it only turned out fortuitous that this is the same type of movement in a wing beat

    the following website is quite interesting in reply to your question : Origin of Flight
    That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve. You have current traits explaining the origin of flight while they are subsequent to flight. Chukar chicks have growing wings and the instinct to use them and thus cannot be a precursor to flight.
    Reply With Quote  
     

  26. #25  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by protoart View Post
    That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve.
    Thus, if it extended a wing on one side only that would facilitate a rapid turn, more of a pivot, to that side. This would clearly be beneficial both for capturing prey and avoiding predators. Your objection is thus invalidated.

    You have current traits explaining the origin of flight while they are subsequent to flight.
    These are presented as behavioural analogies and explanatory illustrations. Do you have objections to their use in that way?

    So, how do you think flight evolved?
    Reply With Quote  
     

  27. #26  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,222
    That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve.
    And those that had an unusual configuration of those feathered forelimbs might get a bit of lift to get up and out of the way or up and able to leap-dive onto prey. If this tactic was successful in avoiding a common predator or in better feeding then more of this type would survive and the early version of short and limited flight would survive. So this feature would help a particular form of the species become more common, whether it was dominant in that location or whether it moved within the environment - with increased chances for a flighted species to develop.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  28. #27  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by adelady View Post
    That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve.
    And those that had an unusual configuration of those feathered forelimbs might get a bit of lift to get up and out of the way or up and able to leap-dive onto prey. If this tactic was successful in avoiding a common predator or in better feeding then more of this type would survive and the early version of short and limited flight would survive. So this feature would help a particular form of the species become more common, whether it was dominant in that location or whether it moved within the environment - with increased chances for a flighted species to develop.
    Interesting, Adelady.

    Do you of any theories as to how insect wings developed? This strikes me as just as remarkable, but seems for some reason to be far less discussed?
    Reply With Quote  
     

  29. #28  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by exchemist View Post
    Do you have any theories as to how insect wings developed?
    This is extracted from a recent PNAS paper.

    Despite accumulating efforts to unveil the origin of insect wings, it remains one of the principal mysteries in evolution. Currently, there are two prominent models regarding insect wing origin: one connecting the origin to the paranotal lobe and the other to the proximodorsal leg branch (exite). However, neither hypothesis has been able to surpass the other.
    Reply With Quote  
     

  30. #29  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by John Galt View Post
    Quote Originally Posted by exchemist View Post
    Do you have any theories as to how insect wings developed?
    This is extracted from a recent PNAS paper.

    Despite accumulating efforts to unveil the origin of insect wings, it remains one of the principal mysteries in evolution. Currently, there are two prominent models regarding insect wing origin: one connecting the origin to the paranotal lobe and the other to the proximodorsal leg branch (exite). However, neither hypothesis has been able to surpass the other.
    Thanks very much for this, John. Evidently this is an area where it will be interesting to watch for new information. Nice to see genetic analysis being used to support palaeontology and that it supports both of the leading hypotheses. But I confess the whole article is a bit hard for me to follow.
    Reply With Quote  
     

  31. #30  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by John Galt View Post
    Quote Originally Posted by protoart View Post
    That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve.
    Thus, if it extended a wing on one side only that would facilitate a rapid turn, more of a pivot, to that side. This would clearly be beneficial both for capturing prey and avoiding predators. Your objection is thus invalidated.

    You have current traits explaining the origin of flight while they are subsequent to flight.
    These are presented as behavioural analogies and explanatory illustrations. Do you have objections to their use in that way?
    What you describe is called drag steering and works in aircraft like the B-2 but not without constant thrust. If it uses its forelimbs for drag, the lift to drag ratio is less than 1 and you are evolving agility not speed. In any case, a quadrupedal model would be far more successful.
    The ground-up hypothesis for the origin of flight have long been invalidated by lack of increasing lift, thrust and control.
    Reply With Quote  
     

  32. #31  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by protoart View Post
    What you describe is called drag steering and works in aircraft like the B-2 but not without constant thrust. If it uses its forelimbs for drag, the lift to drag ratio is less than 1 and you are evolving agility not speed.
    Exactly. Many (probably most, possibly all) evolved features on organisms did not start out fulfilling their current function. A wing that evolved to provide agility might later be commandeered to permit flight. This is exaptation, a well recognised process within evolution.

    Quote Originally Posted by protoart View Post
    In any case, a quadrupedal model would be far more successful.
    What would be more successful is irrelevant. There are almost limitless examples of features that could be designed better. (One of the arguments against Intelligent Design.) If the combination of environment, initial anatomy and contingent mutations did not favour a route to a quadruped then no quadruped will evolve.

    Quote Originally Posted by protoart View Post
    The ground-up hypothesis for the origin of flight have long been invalidated by lack of increasing lift, thrust and control.
    1. Provide citations to support this assertion.
    2. Please answer my question. How do you think flight evolved?
    Reply With Quote  
     

  33. #32  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    If we look at present day vertebrates in the early stages of flight evolution (ie. currently gliding only), they all appear to be tree climbers. We have gliding lemurs, gliding squirrels, gliding lizards, and even a gliding snake. All are tree climbers and tree dwellers. I challenge those who favour a running origin to find a modern equivalent.

    For this reason, I think it is probable that the first feathered dinosaur to begin evolving towards birds was a tree climber and dweller also.

    A thought occurs to me in relation to the gliding snake. This beast has a membrane that spreads, so that when a large snake flicks itself off a branch, it falls at an angle, rather than vertically, and falls more slowly. It is actually a lousy effort at gliding (small snakes are better), and as such can be seen as earlier in the evolution towards flight. My point is that even a poor gliding effort, leading to a slower fall, and a fall at an angle instead of vertically, confers advantage.

    So my earlier proposal may have merit. The first feathered dinosaur tree climber evolved longer forelimb and forelimb feathers for sexual display. However, it came to use its forelimb and feathers in the same way the gliding snake does. From that point, further evolution would lead to greater gliding skill, and it is half way there.
    Last edited by skeptic; December 4th, 2013 at 02:23 PM.
    Bad Robot likes this.
    Reply With Quote  
     

  34. #33  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by skeptic View Post
    If we look at present day vertebrates in the early stages of flight evolution (ie. currently gliding only), they all appear to be tree climbers. We have gliding lemurs, gliding squirrels, gliding lizards, and even a gliding snake. All are tree climbers and tree dwellers. I challenge those who favour a running origin to find a modern equivalent.

    For this reason, I think it is probable that the first feathered dinosaur to begin evolving towards birds was a tree climber and dweller also.

    A thought occurs to me in relation to the gliding snake. This beast has a membrane that spreads, so that when a large snake flicks itself off a branch, it falls at an angle, rather than vertically, and falls more slowly. It is actually a lousy effort at gliding (small snakes are better), and as such can be seen as earlier in the evolution towards flight. My point is that even a poor gliding effort, leading to a slower fall, and a fall at an angle instead of vertically, confers advantage.

    So my earlier proposal may have merit. The first feathered dinosaur tree climber evolved longer forelimb and forelimb feathers for sexual display. However, it came to use its forelimb and feathers in the same way the gliding snake does. From that point, further evolution would lead to greater gliding skill, and it is half way there.
    What sorts of trees did they have in the Jurassic? I thought they were all unclimbable palm tree or fern types.
    Reply With Quote  
     

  35. #34  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,222
    Unclimbable?

    There's nothing to stop an animal the size of a mouse or a rat or a mole or a possum climbing anything much. Squirrels, bats and other little tree dwellers show us that. And there's nothing to stop some of those critters evolving during tens of millions of years into larger ones that can't climb or others of various sizes that can glide or fly.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  36. #35  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by adelady View Post
    Unclimbable?

    There's nothing to stop an animal the size of a mouse or a rat or a mole or a possum climbing anything much. Squirrels, bats and other little tree dwellers show us that. And there's nothing to stop some of those critters evolving during tens of millions of years into larger ones that can't climb or others of various sizes that can glide or fly.
    Suppose you're right. I keep forgetting there were lots of tiny dinosaurs……..
    Reply With Quote  
     

  37. #36  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    Plus you are missing out on the MASSIVE numbers of gymnosperms (cycads, cycadophytes, pinophtyes, and totally extinct conifer groups) which were living. Also palms are angiosperms and dont appear in the fossil record until the Eocene.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  38. #37  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by adelady View Post
    Unclimbable?

    There's nothing to stop an animal the size of a mouse or a rat or a mole or a possum climbing anything much. Squirrels, bats and other little tree dwellers show us that. And there's nothing to stop some of those critters evolving during tens of millions of years into larger ones that can't climb or others of various sizes that can glide or fly.
    Suppose you're right. I keep forgetting there were lots of tiny dinosaurs……..
    microraptor, anyone ?

    still, even if the flying may have started in the trees, the precursor on the ground clearly is the swivel wrist, which in its own right would have been useful in a different context

    anyone who keeps on using current utility to explain the origin of a trait will often be surprised + miss out on the beauty of exaptation
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  39. #38  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,317
    Quote Originally Posted by marnixR View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by adelady View Post
    Unclimbable?

    There's nothing to stop an animal the size of a mouse or a rat or a mole or a possum climbing anything much. Squirrels, bats and other little tree dwellers show us that. And there's nothing to stop some of those critters evolving during tens of millions of years into larger ones that can't climb or others of various sizes that can glide or fly.

    Suppose you're right. I keep forgetting there were lots of tiny dinosaurs……..
    microraptor, anyone ?

    still, even if the flying may have started in the trees, the precursor on the ground clearly is the swivel wrist, which in its own right would have been useful in a different context

    anyone who keeps on using current utility to explain the origin of a trait will often be surprised + miss out on the beauty of exaptation
    YES!! Thanks very much for this - how fascinating. But it seems from the diagram they weren't that "micro", being about the size of a smallish chicken. Quite a mass to keep aloft by gliding with feathers. Compared to a flying squirrel, I mean.
    Reply With Quote  
     

  40. #39  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by John Galt View Post
    Quote Originally Posted by protoart View Post
    What you describe is called drag steering and works in aircraft like the B-2 but not without constant thrust. If it uses its forelimbs for drag, the lift to drag ratio is less than 1 and you are evolving agility not speed.
    Exactly. Many (probably most, possibly all) evolved features on organisms did not start out fulfilling their current function. A wing that evolved to provide agility might later be commandeered to permit flight. This is exaptation, a well recognised process within evolution.

    Quote Originally Posted by protoart View Post
    In any case, a quadrupedal model would be far more successful.
    What would be more successful is irrelevant. There are almost limitless examples of features that could be designed better. (One of the arguments against Intelligent Design.) If the combination of environment, initial anatomy and contingent mutations did not favour a route to a quadruped then no quadruped will evolve.

    Quote Originally Posted by protoart View Post
    The ground-up hypothesis for the origin of flight have long been invalidated by lack of increasing lift, thrust and control.
    1. Provide citations to support this assertion.
    2. Please answer my question. How do you think flight evolved?
    >A wing that evolved to provide agility might later be commandeered to permit flight.
    The ostrich did the opposite.

    >This is exaptation, a well recognised process within evolution.


    Exaptation is a functional change, not a process. Adaptation is phenotypic change and is a process.


    > What would be more successful is irrelevant.
    That's not Darwinian.


    >If the combination of environment, initial anatomy and contingent mutations did not favour a route to a quadruped then no quadruped will evolve.
    If it pursued or fled it would have too. Random mutations that put the organism at a competitive disadvantage don't evolve.

    >
    How do you think flight evolved?

    If you have a comprehensive ground-up (or tree-down) evolutionary scenario for bird flight, what is it? I'll gladly point out the Lamarckian, million year leaps over thresholds, lunacies in it.




    Reply With Quote  
     

  41. #40  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    I'll respond to the rest of your misinterpretations later. First and for the third time of asking how do you think flight evolved?You may know something of flight. You clearly know almost nothing of evolution.
    Reply With Quote  
     

  42. #41  
    Forum Cosmic Wizard
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    2,222
    >>A wing that evolved to provide agility might later be commandeered to permit flight.
    >The ostrich did the opposite.

    Of course. Many phenotypes have come and gone as organisms fill new niches. Fish gain eyes, fish lose eyes. Birds gain flight, birds lose flight. Whatever better allows survival.

    >>This is exaptation, a well recognised process within evolution.

    >Exaptation is a functional change, not a process. Adaptation is phenotypic change and is a process.

    Both are processes resulting in functional changes. Adaptation refers to the process of changing to better suit one's environment; exaptation refers to the same process but enabled by a different prior adaptation unrelated to whatever drove the original adaptation.
    Reply With Quote  
     

  43. #42  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by protoart View Post
    >
    Quote Originally Posted by John Galt
    A wing that evolved to provide agility might later be commandeered to permit flight.

    The ostrich did the opposite.
    So what? The trajectory of evolution is contingent. Amphibians moved onto land full time. Mammals evolved and some of them moved back to the sea. Some of them moved into the air. The fact that the ostrich "did the opposite" is not an argument against the opposite.

    Quote Originally Posted by protoart View Post
    Quote Originally Posted by John Galt
    This is exaptation, a well recognised process within evolution.
    Exaptation is a functional change, not a process. Adaptation is phenotypic change and is a process.
    You seriously want to start a pointless argument over whether exaptation is a single event, or a series of events. You are avoiding the central point that there is no reason that the function of the wing could not change over time. I simply gave you a name to apply to that process.


    Quote Originally Posted by protoart View Post
    What would be more successful is irrelevant.
    That's not Darwinian.
    That is wholly Darwinian. If the mutations required to allow a "more successful" approach do not occur then nature will select for the most successful approach that is available. Nature has no way of identifying, in advance, what might be the best way of doing something. Certain options are thrown in the ring and selection makes its choice. You have to be in it, to win it.


    Quote Originally Posted by protoart View Post
    Quote Originally Posted by John Galt
    If the combination of environment, initial anatomy and contingent mutations did not favour a route to a quadruped then no quadruped will evolve.
    If it pursued or fled it would have too. Random mutations that put the organism at a competitive disadvantage don't evolve.
    Provide your justification for you implicit assertion that bipedal evolution and/or the evolution of wings put the recipient at a disadvantage. (Good luck with that!)

    Quote Originally Posted by protoart View Post

    >
    Quote Originally Posted by John Galt
    How do you think flight evolved?


    If you have a comprehensive ground-up (or tree-down) evolutionary scenario for bird flight, what is it? I'll gladly point out the Lamarckian, million year leaps over thresholds, lunacies in it.
    I'm asking you how you think flight evolved. You are vocal in your condemnation of current theory. So, what do you have to offer instead? I've now asked you four times. Will I have to make it five?
    exchemist likes this.
    Reply With Quote  
     

  44. #43  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by John Galt View Post
    I'm asking you how you think flight evolved. You are vocal in your condemnation of current theory. So, what do you have to offer instead? I've now asked you four times. Will I have to make it five?
    I've made no claim nor have asserted a hypothesis. You have no right to demand that I do.
    You asked for references, read this:
    Learning to Fly: How Birds Took to the Air - EvoWiki
    Reply With Quote  
     

  45. #44  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,416
    Quote Originally Posted by protoart View Post
    You asked for references, read this:
    Learning to Fly: How Birds Took to the Air - EvoWiki
    Science is about evaluating hypotheses put forth to explain observed phenomena. Rather than just dropping a generic summation of some of them, it would probably be better if you told us what your favorite one is and why? Or do you have an entirely different idea?
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  46. #45  
    AI's Have More Fun Bad Robot's Avatar
    Join Date
    Apr 2013
    Location
    Washington state
    Posts
    6,114
    Quote Originally Posted by skeptic View Post
    To answer this question, you have to realise that the first wing precursor was not a wing. We know from the fossil record that birds came from dinosaurs, and we know that many dinosaurs had feathers. We know that those dinosaurs had fore limbs. We also know that feathers in modern day birds are frequently expanded as display items for sexual attraction.

    So here is a possibility. This is a f'rinstance speculation and not to be taken as truth. It is probably wrong, but there are so many possibilities that any speculation will probably be wrong.

    Imagine a dinosaur with feathers that climbed trees. It evolves feathers on its forelimbs as display items. It stands on a branch and spreads its forelimbs to display the large, brightly coloured feathers to attract a mate, like many birds do today. Obviously, the tree dinosaurs of this species that have the largest fore limbs, longest feathers, and brightest colours will be the most successful reproducers, since they will win the ladies. Thus, evolution leads to longer fore limbs and longer, brighter feathers on the forelimbs.

    Now let us imagine that this species sometimes has to jump out of that tree to escape a predator. The ones with those large forelimbs and feathers will fall more slowly and have a better chance at surviving. Natural selection leads to the growth of even longer forelimbs, and longer feathers on those forelimbs.

    If the feathers are slanted backwards, that fall will be directional, assisting escape. So evolution slowly leads to long feathers slanted backwards. Over a long time, that leads to gliding motion. The individuals that have strong forelimb muscles will be better at controlling those glides, so strong muscles evolve. Those stronger muscles allow for a flap to assist the jump off the branch. In time, the system evolves to the point where flapping flight becomes possible.

    Now, I do not want you, or anyone to take this story seriously. There are a thousand possible routes to evolving wings. The thing to note is that each change is small, and towards a "goal" which may have nothing to do with the end result - flight.
    I'm solidly behind this idea as the leading probability for feathered animals. Winged insects and non-feathered winged animals could be a different probability entirely.
    Reply With Quote  
     

  47. #46  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by protoart View Post
    Quote Originally Posted by John Galt View Post
    I'm asking you how you think flight evolved. You are vocal in your condemnation of current theory. So, what do you have to offer instead? I've now asked you four times. Will I have to make it five?
    I've made no claim nor have asserted a hypothesis. You have no right to demand that I do. You asked for references, read this: Learning to Fly: How Birds Took to the Air - EvoWiki
    you have made a very specific claim - that conventional views on the origin of flight are wrong. You have offered no evidence in support, but continue to make unfounded assertions.On this science forum we do not accept unfounded assertions. Either provide specific support for your claims or offer your view of how flight evolved. I not only have a right to ask this, but a duty.
    Reply With Quote  
     

  48. #47  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by John Galt
    you have made a very specific claim - that conventional views on the origin of flight are wrong. You have offered no evidence in support, but continue to make unfounded assertions.On this science forum we do not accept unfounded assertions. Either provide specific support for your claims or offer your view of how flight evolved. I not only have a right to ask this, but a duty.
    It's not my, or anyone's, duty to provide an alternate theory as an argument to theories that are wrong. However, I should explain better why that conventional views on the origin of flight are wrong.

    I initially said "That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve. You have current traits explaining the origin of flight while they are subsequent to flight. Chukar chicks have growing wings and the instinct to use them and thus cannot be a precursor to flight." I stand by these statements, here's why.

    How much incremental increase in the feathered forelimb can a random mutation produce in one offspring? Not much. And why would this increase be able to thrust, drag or lift when the feathered forelimbs have never been successfully used this way?

    You have the success of a trait before you have the trait. This is Lamarckian evolution and does not work!

    Also, it cannot inherit. There is no guarantee that the random mutation will repeat.

    Evolution is; random mutation, competition and rejection of the traits, attributes or characteristics that put the organism at a disadvantage. This is called natural selection.
    Harold14370 likes this.
    Reply With Quote  
     

  49. #48  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    I find it unlikely that flight would evolve from the basis of a running animal. My reason is simply that we can see a number of gliding animals in today's world, which could be seen as a half way step towards true flight, and all of them are climbing animals. So I think it is far more likely that flight in vertebrates typically starts with an animal adapted to climbing.
    Bad Robot likes this.
    Reply With Quote  
     

  50. #49  
    Forum Cosmic Wizard
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    2,222
    Quote Originally Posted by protoart View Post
    I initially said "That birds use their wings "whilst running to aid manoeuvrability" is an erroneous assumption for the origin of flight. If an early maniraptora extended its feathered forelimbs while pursuing or fleeing then it would slow down from drag, thus not succeed and not evolve.
    That's an unsupported claim. People swing their arms when running. People who do so are faster than people who run with their arms behind their backs, thus minimizing drag. Thus, higher drag = faster in one animal.
    Reply With Quote  
     

  51. #50  
    AI's Have More Fun Bad Robot's Avatar
    Join Date
    Apr 2013
    Location
    Washington state
    Posts
    6,114
    Quote Originally Posted by skeptic View Post
    I find it unlikely that flight would evolve from the basis of a running animal. My reason is simply that we can see a number of gliding animals in today's world, which could be seen as a half way step towards true flight, and all of them are climbing animals. So I think it is far more likely that flight in vertebrates typically starts with an animal adapted to climbing.
    Again I think your right on. The video below shows a Roadrunner doing 26 miles an hour and not using any wings at all.

    Roadrunner 26 mph - YouTube
    Reply With Quote  
     

  52. #51  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    remember, we're not talking pure straight-line speed here : the arms would only come into effect if as a predator the animal needs to go fast and at the same time be able to swerve and change direction in order to capture a prey that tries to escape - at this stage the arms would help in changing direction without the need for the legs to do all the work

    my point was not so much that flight would have started from the ground up, but that evolution on the ground would have pre-adapted the body structure of a maniraptoran so that when some of them went into the trees, they would find some structures useful in managing a suitable gliding / flapping action
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  53. #52  
    Forum Cosmic Wizard spuriousmonkey's Avatar
    Join Date
    May 2005
    Posts
    2,191
    You know what is ever weirder? Why would any animal develop legs?

    Fish did pretty well swimming around in water. Why would they want to walk?

    No wait. You know what is even weirder. Why would any bacterium want to join some other cell to become an eukaryote cell??!?!?! He was doing perfectly fine by itself.

    No wait, why would any eukaryote cell decide he wants to live in a commune of cells. He was doing fine by itself. Just hanging around in the primal soup.


    You know what the answer is? i will tell you. Disbelief is not an argument against evolution. It is just a sign of lack of commitment to imagine there might be more to the story than your own preconceptions. It is a sign of a closed mind.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

    http://spuriousforums.com/index.php
    Reply With Quote  
     

  54. #53  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    We missed you.
    Reply With Quote  
     

  55. #54  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by spuriousmonkey View Post
    It is a sign of a closed mind.
    and lack of imagination
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  56. #55  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,795
    Is somebody saying evolution didn't happen? All protoart said is that one particular hypothesis is wrong or incomplete.
    Reply With Quote  
     

  57. #56  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    He is saying by means of unsubstantiated assertion, not provision of evidentially based argument.
    Reply With Quote  
     

  58. #57  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by Harold14370 View Post
    Is somebody saying evolution didn't happen? All protoart said is that one particular hypothesis is wrong or incomplete.
    no-one says evolution didn't happen - what protoart does is to disbelieve certain scenarios of how flight could have originated in dinosaurs, which is his good right, but then fails to go into any detail of why he finds the scenarios improbable + fails to present any arguments that in his view make more sense
    all he says is that he finds it unbelievable

    as such it's rather hard to have a fruitful discussion, since one party refuses to bring his arguments to the discussion
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  59. #58  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by marnixR View Post
    Quote Originally Posted by Harold14370 View Post
    Is somebody saying evolution didn't happen? All protoart said is that one particular hypothesis is wrong or incomplete.
    no-one says evolution didn't happen - what protoart does is to disbelieve certain scenarios of how flight could have originated in dinosaurs, which is his good right, but then fails to go into any detail of why he finds the scenarios improbable + fails to present any arguments that in his view make more sense
    all he says is that he finds it unbelievable

    as such it's rather hard to have a fruitful discussion, since one party refuses to bring his arguments to the discussion
    If a human had a fan in each hand, could he maneuver quicker or run faster? Absolutely not! This is testable and falsifiable. It's physics. So if a random mutation does not help it succeed then natural selection will remove it. Running off the ground is a Lamarckian lunacy.
    Reply With Quote  
     

  60. #59  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    Quote Originally Posted by protoart View Post
    Quote Originally Posted by marnixR View Post
    Quote Originally Posted by Harold14370 View Post
    Is somebody saying evolution didn't happen? All protoart said is that one particular hypothesis is wrong or incomplete.
    no-one says evolution didn't happen - what protoart does is to disbelieve certain scenarios of how flight could have originated in dinosaurs, which is his good right, but then fails to go into any detail of why he finds the scenarios improbable + fails to present any arguments that in his view make more sense
    all he says is that he finds it unbelievable

    as such it's rather hard to have a fruitful discussion, since one party refuses to bring his arguments to the discussion
    If a human had a fan in each hand, could he maneuver quicker or run faster? Absolutely not! This is testable and falsifiable. It's physics. So if a random mutation does not help it succeed then natural selection will remove it. Running off the ground is a Lamarckian lunacy.
    Out of curiosity why did you leave out the important third option? "if the random mutation does not help & does not harm, natural selection will NOT remove it"
    adelady likes this.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  61. #60  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by Paleoichneum View Post

    Out of curiosity why did you leave out the important third option? "if the random mutation does not help & does not harm, natural selection will NOT remove it"
    Neutral random mutations just hang around. Part of the ancestral probability package. Could be used for exaptation.
    Reply With Quote  
     

  62. #61  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    But in this conversation your not allowing for the quill like protofeathers that most theropods would have had to have been anything but a positive /negative factor when it comes to running.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  63. #62  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    As I understand it, most mutations are not really very potent, either for good or harm, and are not readily removed. However, a change in the environment may make a previously unimportant mutation into a powerful advantage. When that happens, the mutation rapidly increases in frequency in the gene pool.
    adelady likes this.
    Reply With Quote  
     

  64. #63  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by Paleoichneum View Post
    But in this conversation your not allowing for the quill like protofeathers that most theropods would have had to have been anything but a positive /negative factor when it comes to running.
    This is the latest artist conception of archaeopteryx. It has the quill like protofeathers you refer to. It probably ate insects and other things that it could swallow whole. They helped it catch prey but not by running.
    So you are trying to corner me as to how the flying phenotype evolved, aren’t you?
    Last edited by protoart; December 13th, 2013 at 10:40 PM.
    Reply With Quote  
     

  65. #64  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    What particular journal/palaeontologist is this illustration from?

    Also what article are you using for the feeding habits and prey preferences?
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  66. #65  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by Paleoichneum View Post
    What particular journal/palaeontologist is this illustration from?

    Also what article are you using for the feeding habits and prey preferences?
    Nature.
    Theory suggests iconic early bird lost its flight : Nature News & Comment
    Reply With Quote  
     

  67. #66  
    AI's Have More Fun Bad Robot's Avatar
    Join Date
    Apr 2013
    Location
    Washington state
    Posts
    6,114
    Quote Originally Posted by skeptic View Post
    As I understand it, most mutations are not really very potent, either for good or harm, and are not readily removed. However, a change in the environment may make a previously unimportant mutation into a powerful advantage. When that happens, the mutation rapidly increases in frequency in the gene pool.
    The main reason for feathers to develop was to maintain body heat, and learning to fly was a secondary benefit of feathers. As weather cooled the feathered animals had a powerful advantage that you mentioned and learning to fly was a bonus development.

    If birds descended from dinosaurs, why are they warm-blooded? › Ask an Expert (ABC Science)
    Reply With Quote  
     

  68. #67  
    parsimonious person protoart's Avatar
    Join Date
    Feb 2011
    Location
    San Diego
    Posts
    23
    Quote Originally Posted by Bad Robot View Post
    Quote Originally Posted by skeptic View Post
    As I understand it, most mutations are not really very potent, either for good or harm, and are not readily removed. However, a change in the environment may make a previously unimportant mutation into a powerful advantage. When that happens, the mutation rapidly increases in frequency in the gene pool.
    The main reason for feathers to develop was to maintain body heat, and learning to fly was a secondary benefit of feathers. As weather cooled the feathered animals had a powerful advantage that you mentioned and learning to fly was a bonus development.

    If birds descended from dinosaurs, why are they warm-blooded? › Ask an Expert (ABC Science)
    It's reasonable that flight evolved in maniraptora in a habitat marginally colder than exothermic reptiles lay eggs.
    Reply With Quote  
     

  69. #68  
    Time Lord Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    5,221
    Quote Originally Posted by protoart View Post
    Quote Originally Posted by Paleoichneum View Post
    What particular journal/palaeontologist is this illustration from?

    Also what article are you using for the feeding habits and prey preferences?
    Nature.
    Theory suggests iconic early bird lost its flight : Nature News & Comment
    Two main things to note with this:

    Its not the current major thinking on Archaeopteryx, rather its the suggestion of one biologist made as a conference presentation. I have been to a number of Geological society of America annual meetings, and know there is a major step between suggestions made during a talk and going through the actual process of peer review with the idea.

    The image itself is a stock image from Stocktrek images/Alamy and not actually by or based on Habib's hypothesis. Its also very inaccurate on the placement, amount and type of feathers that Archaeopteryx had based on the information we have from the eleven fossils that have been found so far.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  70. #69  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,810
    Quote Originally Posted by protoart View Post
    If a human had a fan in each hand, could he maneuver quicker or run faster? Absolutely not! This is testable and falsifiable. It's physics. So if a random mutation does not help it succeed then natural selection will remove it. Running off the ground is a Lamarckian lunacy.
    you clearly haven't read one of my earlier posts, which reads :

    Quote Originally Posted by marnixR View Post
    remember, we're not talking pure straight-line speed here : the arms would only come into effect if as a predator the animal needs to go fast and at the same time be able to swerve and change direction in order to capture a prey that tries to escape - at this stage the arms would help in changing direction without the need for the legs to do all the work

    my point was not so much that flight would have started from the ground up, but that evolution on the ground would have pre-adapted the body structure of a maniraptoran so that when some of them went into the trees, they would find some structures useful in managing a suitable gliding / flapping action
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  71. #70  
    ▼▼ dn ʎɐʍ sıɥʇ ▼▼ RedPanda's Avatar
    Join Date
    Aug 2012
    Location
    UK
    Posts
    2,737
    Quote Originally Posted by protoart View Post
    If a human had a fan in each hand, could he maneuver quicker or run faster? Absolutely not! This is testable and falsifiable. It's physics.
    Yes. Wings slow you down.
    There is no way that wings could make you go faster.
    And that is why the top 20 list of "fastest animals in the world" does not include any birds.

    Ostriches are terribly encumbered by their wings. They can barely keep up with Cheetahs.
    And don't get me started on the ponderously sedate pace of the Swift.


    No....wait.
    adelady and Bad Robot like this.
    SayBigWords.com/say/3FC

    "And, behold, I come quickly;" Revelation 22:12

    "Religions are like sausages. When you know how they are made, you no longer want them."
    Reply With Quote  
     

Similar Threads

  1. Shapes of birds’ wings
    By Nehushtan in forum Biology
    Replies: 3
    Last Post: March 19th, 2013, 12:07 PM
  2. Wings, is it possible?
    By Winged Teen in forum Biology
    Replies: 50
    Last Post: December 30th, 2008, 07:23 PM
  3. Replies: 13
    Last Post: July 9th, 2006, 08:41 PM
  4. Ant ripping off it's wings...?
    By CLaShiNgtAco in forum Biology
    Replies: 7
    Last Post: July 7th, 2006, 01:24 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •