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Re: COMPARATIVE BIPEDALISM

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  • m3dodds
    ... It is a remarkable feat ... an a ingenious way of evading a predator. The form of bipedalism involved is not unique by any means, as a number of small
    Message 1 of 12 , Dec 13, 2009
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      --- In AAT@yahoogroups.com, "Renato" <bender_renato@...> wrote:
      >
      > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
      >



      It is a remarkable feat ... an a ingenious way of evading a
      predator. The form of bipedalism involved is not unique by
      any means, as a number of small lizards evade predators by
      raising themselves up on their hind limbs and sprinting out
      of reach of a predator, but doing it on water is an
      amazing feat.

      A feat that aids them in evading predators.
      Wading and swimming are too slow in comparison to running
      bipedally across the surface of the water.

      Small lizards evade predation by sprinting bipedally on
      their hind limbs. Dinosaurs became successful predators
      chasing their prey on two legs.

      Would early hominids in a woodland habitat have evaded a
      predator by sprinting for a nearby tree on two legs?




      > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
      >


      As I understand it they use a combination of speed, gait and
      the way the foot hits the surface of the water.

      Apparently the foot slaps the surface so hard that it pushes
      aside the water (molecules) to create a cushion of air to
      support the foot (seemingly each foot only penetrates into
      the water surface just one or two centimeters).

      If they get it wrong, or if the foot gets covered by the
      water they can be dragged under.

      It could easily have evolved from the way small lizards evade
      predators by sprinting on their hind legs, first as a way
      of running over soft sand as you say, then extended to
      water ... possibly by moving even faster.

      Small lizards sprinting upright on their hind legs, are
      said to be ancestors of the dinosaurs




      > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
      >


      A quadruped gait is said to constrain lung function, an a
      upright bipedal posture removes that constraint among
      mammals.



      > For instance, I saw once a documentary in which a small crocodile
      > began to jump very fast like a big frog to reach the water;
      > a rather amazing locomotion.
      >


      Perhaps the crocodiles had ancestors that were small enough to
      evade predators (or prey), by sprinting upright on their
      hind limbs.




      > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
      >


      Possibly if some small lizards can raise themselves up on their
      hind limbs to sprint, they can also leap like a frog in some
      circumstances. (were not some bipedal dinosaurs capable of
      leaping onto their prey, using their powerful hind limbs?)



      > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
      > Renato
      >



      Perhaps if they ran fast enough across the surface of the water
      (like some birds today)they would obtain enough lift, to fly, but
      they would they need wings to lift off the water, so how would
      the first wings have evolved?

      Still I like the idea that birds first learnt (evolved) to fly
      on water. That the first birds were seabirds ...


      --- Bill (m3d)







      > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
      > >
      > >
      > > ----- Original Message -----
      > > From: Marc Verhaegen
      > > To: AAT@yahoogroups.com
      > > Sent: Saturday, December 12, 2009 6:13 PM
      > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
      > >
      > >
      > >
      > >
      > > > COMPARATIVE BIPEDALISM - how the rest of the animal
      > > > kingdom walks on two legs
      > > > Philip Dhingra
      > > > Prof. Jablonski
      > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
      > > > Published on Philosophistry
      > > > May 25, 2004
      > > > http://www.philosophistry.com/static/bipedalism.html
      > > > "In the case of the basilisk lizard, bipedalism also
      > > > allows for running over water." [quote]
      > >
      > > > Which I guess would be a bit quicker than
      > > > wading through it ... --- Bill (m3d)
      > >
      > > Yes.
      > >
      > > Thanks, Bill.
      > >
      > >
      > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
      > >
      > > wade through anyway. Anyone got any gen on that?
      > >
      > >
      > >
      > > Elaine
      > >
      > >
      > > [Non-text portions of this message have been removed]
      > >
      >
    • Renato
      ... The emergence of this bipedalism is probably connected to land bipedalism and bipedalism on the water surface over a very short distance. This would be
      Message 2 of 12 , Dec 17, 2009
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        --- In AAT@yahoogroups.com, "m3dodds" <dons3148@...> wrote:
        >
        >
        >
        > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
        > >
        > > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
        > >
        >
        >
        >
        > It is a remarkable feat ... an a ingenious way of evading a
        > predator. The form of bipedalism involved is not unique by
        > any means, as a number of small lizards evade predators by
        > raising themselves up on their hind limbs and sprinting out
        > of reach of a predator, but doing it on water is an
        > amazing feat.
        >
        > A feat that aids them in evading predators.
        > Wading and swimming are too slow in comparison to running
        > bipedally across the surface of the water.

        The emergence of this bipedalism is probably connected to land bipedalism and bipedalism on the water surface over a very short distance. This would be enough to give the crucial advangate to escape from predators; the bipedal locomotion on water over many meters was the natural development of this initial behavior, increased through natural selection.
        >
        > Small lizards evade predation by sprinting bipedally on
        > their hind limbs. Dinosaurs became successful predators
        > chasing their prey on two legs.
        >
        > Would early hominids in a woodland habitat have evaded a
        > predator by sprinting for a nearby tree on two legs?

        I do not see this as very probable. Babbons for instance, if they want to move fast in shallow water (for instance to hunt aquatic birds), they move on four legs. Bipedal in water is very slow.
        >
        >
        >
        >
        > > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
        > >
        >
        >
        > As I understand it they use a combination of speed, gait and
        > the way the foot hits the surface of the water.
        >
        > Apparently the foot slaps the surface so hard that it pushes
        > aside the water (molecules) to create a cushion of air to
        > support the foot (seemingly each foot only penetrates into
        > the water surface just one or two centimeters).
        >
        > If they get it wrong, or if the foot gets covered by the
        > water they can be dragged under.
        >
        > It could easily have evolved from the way small lizards evade
        > predators by sprinting on their hind legs, first as a way
        > of running over soft sand as you say, then extended to
        > water ... possibly by moving even faster.
        >
        > Small lizards sprinting upright on their hind legs, are
        > said to be ancestors of the dinosaurs
        >
        >
        >
        >
        > > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
        > >
        >
        >
        > A quadruped gait is said to constrain lung function, an a
        > upright bipedal posture removes that constraint among
        > mammals.
        >
        >
        >
        > > For instance, I saw once a documentary in which a small crocodile
        > > began to jump very fast like a big frog to reach the water;
        > > a rather amazing locomotion.
        > >
        >
        >
        > Perhaps the crocodiles had ancestors that were small enough to
        > evade predators (or prey), by sprinting upright on their
        > hind limbs.
        >
        > I think that the topic is very complex. For instance, it can be that young crocodiles are confronted with similar biomechanical and physiological constraints as other medium-sized reptiles, and they developed specific strategies to overcome these constraints. Young crocodiles have other strategies to escape from predators as the adult ones (that are normally the hunters, rarely hunted).
        >
        >
        > > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
        > >
        >
        >
        > Possibly if some small lizards can raise themselves up on their
        > hind limbs to sprint, they can also leap like a frog in some
        > circumstances. (were not some bipedal dinosaurs capable of
        > leaping onto their prey, using their powerful hind limbs?)
        >
        But it is very peculiar that a reptil is jumping aroung like a frog. I can imagine that this has something to do with an arboreal adaptation, as some small reptiles use the hind limbs simultaneously to climb on trees, for instance the Polychrus marmoratus. This behavior was described by Hans Böker in his interesting work "Vergleichende biologische Anatome der Wirbeltiere" (2 volumes, 1935, vol. 1, p. 63-64).
        >
        >
        > > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
        > > Renato
        > >
        >
        >
        >
        > Perhaps if they ran fast enough across the surface of the water
        > (like some birds today)they would obtain enough lift, to fly, but
        > they would they need wings to lift off the water, so how would
        > the first wings have evolved?

        This is exactly the problem with this hypothesis: you need already a kind wing to produce at least some lift...
        >
        > Still I like the idea that birds first learnt (evolved) to fly
        > on water. That the first birds were seabirds ...
        >
        >
        > --- Bill (m3d)
        >
        >
        >
        >
        >
        >
        >
        > > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
        > > >
        > > >
        > > > ----- Original Message -----
        > > > From: Marc Verhaegen
        > > > To: AAT@yahoogroups.com
        > > > Sent: Saturday, December 12, 2009 6:13 PM
        > > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
        > > >
        > > >
        > > >
        > > >
        > > > > COMPARATIVE BIPEDALISM - how the rest of the animal
        > > > > kingdom walks on two legs
        > > > > Philip Dhingra
        > > > > Prof. Jablonski
        > > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
        > > > > Published on Philosophistry
        > > > > May 25, 2004
        > > > > http://www.philosophistry.com/static/bipedalism.html
        > > > > "In the case of the basilisk lizard, bipedalism also
        > > > > allows for running over water." [quote]
        > > >
        > > > > Which I guess would be a bit quicker than
        > > > > wading through it ... --- Bill (m3d)
        > > >
        > > > Yes.
        > > >
        > > > Thanks, Bill.
        > > >
        > > >
        > > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
        > > >
        > > > wade through anyway. Anyone got any gen on that?
        > > >
        > > >
        > > >
        > > > Elaine
        > > >
        > > >
        > > > [Non-text portions of this message have been removed]
        > > >
        > >
        >
      • williamabond
        ... A small lizard can only run on water because of its very small size. It just like spiders who can walk on water because they are so small and light. Apart
        Message 3 of 12 , Dec 17, 2009
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          > It could easily have evolved from the way small lizards evade
          > predators by sprinting on their hind legs, first as a way
          > of running over soft sand as you say, then extended to
          > water ... possibly by moving even faster.
          >
          > Small lizards sprinting upright on their hind legs, are
          > said to be ancestors of the dinosaurs

          A small lizard can only run on water because of its very small size. It just like spiders who can walk on water because they are so small and light. Apart of Jesus Christ i don't know of any man who can walk or run on water.

          You would have to compare us with a animal of the same size, like a Cheetah, that can sprint a lot faster than us on four legs.

          William Bond


          --- In AAT@yahoogroups.com, "m3dodds" <dons3148@...> wrote:
          >
          >
          >
          > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
          > >
          > > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
          > >
          >
          >
          >
          > It is a remarkable feat ... an a ingenious way of evading a
          > predator. The form of bipedalism involved is not unique by
          > any means, as a number of small lizards evade predators by
          > raising themselves up on their hind limbs and sprinting out
          > of reach of a predator, but doing it on water is an
          > amazing feat.
          >
          > A feat that aids them in evading predators.
          > Wading and swimming are too slow in comparison to running
          > bipedally across the surface of the water.
          >
          > Small lizards evade predation by sprinting bipedally on
          > their hind limbs. Dinosaurs became successful predators
          > chasing their prey on two legs.
          >
          > Would early hominids in a woodland habitat have evaded a
          > predator by sprinting for a nearby tree on two legs?
          >
          >
          >
          >
          > > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
          > >
          >
          >
          > As I understand it they use a combination of speed, gait and
          > the way the foot hits the surface of the water.
          >
          > Apparently the foot slaps the surface so hard that it pushes
          > aside the water (molecules) to create a cushion of air to
          > support the foot (seemingly each foot only penetrates into
          > the water surface just one or two centimeters).
          >
          > If they get it wrong, or if the foot gets covered by the
          > water they can be dragged under.
          >
          > It could easily have evolved from the way small lizards evade
          > predators by sprinting on their hind legs, first as a way
          > of running over soft sand as you say, then extended to
          > water ... possibly by moving even faster.
          >
          > Small lizards sprinting upright on their hind legs, are
          > said to be ancestors of the dinosaurs
          >
          >
          >
          >
          > > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
          > >
          >
          >
          > A quadruped gait is said to constrain lung function, an a
          > upright bipedal posture removes that constraint among
          > mammals.
          >
          >
          >
          > > For instance, I saw once a documentary in which a small crocodile
          > > began to jump very fast like a big frog to reach the water;
          > > a rather amazing locomotion.
          > >
          >
          >
          > Perhaps the crocodiles had ancestors that were small enough to
          > evade predators (or prey), by sprinting upright on their
          > hind limbs.
          >
          >
          >
          >
          > > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
          > >
          >
          >
          > Possibly if some small lizards can raise themselves up on their
          > hind limbs to sprint, they can also leap like a frog in some
          > circumstances. (were not some bipedal dinosaurs capable of
          > leaping onto their prey, using their powerful hind limbs?)
          >
          >
          >
          > > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
          > > Renato
          > >
          >
          >
          >
          > Perhaps if they ran fast enough across the surface of the water
          > (like some birds today)they would obtain enough lift, to fly, but
          > they would they need wings to lift off the water, so how would
          > the first wings have evolved?
          >
          > Still I like the idea that birds first learnt (evolved) to fly
          > on water. That the first birds were seabirds ...
          >
          >
          > --- Bill (m3d)
          >
          >
          >
          >
          >
          >
          >
          > > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
          > > >
          > > >
          > > > ----- Original Message -----
          > > > From: Marc Verhaegen
          > > > To: AAT@yahoogroups.com
          > > > Sent: Saturday, December 12, 2009 6:13 PM
          > > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
          > > >
          > > >
          > > >
          > > >
          > > > > COMPARATIVE BIPEDALISM - how the rest of the animal
          > > > > kingdom walks on two legs
          > > > > Philip Dhingra
          > > > > Prof. Jablonski
          > > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
          > > > > Published on Philosophistry
          > > > > May 25, 2004
          > > > > http://www.philosophistry.com/static/bipedalism.html
          > > > > "In the case of the basilisk lizard, bipedalism also
          > > > > allows for running over water." [quote]
          > > >
          > > > > Which I guess would be a bit quicker than
          > > > > wading through it ... --- Bill (m3d)
          > > >
          > > > Yes.
          > > >
          > > > Thanks, Bill.
          > > >
          > > >
          > > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
          > > >
          > > > wade through anyway. Anyone got any gen on that?
          > > >
          > > >
          > > >
          > > > Elaine
          > > >
          > > >
          > > > [Non-text portions of this message have been removed]
          > > >
          > >
          >
        • m3dodds
          ... No one is making a bipedal comparison with a lizard that can run on the surface of water ... It has only got a mention because of an intriguing quote in
          Message 4 of 12 , Dec 18, 2009
          • 0 Attachment
            --- In AAT@yahoogroups.com, "williamabond" <wabond@...> wrote:
            >
            > > It could easily have evolved from the way small lizards evade
            > > predators by sprinting on their hind legs, first as a way
            > > of running over soft sand as you say, then extended to
            > > water ... possibly by moving even faster.
            > >
            > > Small lizards sprinting upright on their hind legs, are
            > > said to be ancestors of the dinosaurs
            >
            > A small lizard can only run on water because of its very small
            > size. It just like spiders who can walk on water because they
            > are so small and light. Apart of Jesus Christ i don't know of
            > any man who can walk or run on water.
            >



            No one is making a bipedal comparison with a lizard that
            can run on the surface of water ...

            It has only got a mention because of an intriguing quote
            in the article on comparative bipedalism (that compares
            bipedalism and the origins of bipedalism in different
            species) ...

            Comparative Bipedalism
            http://www.philosophistry.com/static/bipedalism.html

            Human habitual bipedalism - may simply have result from
            the necessity to cover considerable distances while
            foraging (when it comes to walking distances, the
            human upright bipedal gait is more efficient than
            that of a chimpanzee).




            > You would have to compare us with a animal of the same
            > size, like a Cheetah, that can sprint a lot faster than
            > us on four legs.
            >
            > William Bond
            >


            Cheetahs are twice as fast as a human when sprinting, but
            cheetahs can only maintain their burst of speed over short
            distances.

            Being larger, heavier and a quadruped would rule out animals
            like cheetahs from mastering the skill of that little lizard
            that can run upright on two legs on water. They are too
            heavy and have too many legs ... to master the amazing
            skill of that little lizard.

            Spiders an the like are light enough to take advantage
            of the surface tension of water, whereas the lizard in
            question has actually mastered the skill of running
            bipedally on water - which is something entirely
            different.


            --- Bill (m3d)








            > --- In AAT@yahoogroups.com, "m3dodds" <dons3148@> wrote:
            > >
            > >
            > >
            > > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
            > > >
            > > > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
            > > >
            > >
            > >
            > >
            > > It is a remarkable feat ... an a ingenious way of evading a
            > > predator. The form of bipedalism involved is not unique by
            > > any means, as a number of small lizards evade predators by
            > > raising themselves up on their hind limbs and sprinting out
            > > of reach of a predator, but doing it on water is an
            > > amazing feat.
            > >
            > > A feat that aids them in evading predators.
            > > Wading and swimming are too slow in comparison to running
            > > bipedally across the surface of the water.
            > >
            > > Small lizards evade predation by sprinting bipedally on
            > > their hind limbs. Dinosaurs became successful predators
            > > chasing their prey on two legs.
            > >
            > > Would early hominids in a woodland habitat have evaded a
            > > predator by sprinting for a nearby tree on two legs?
            > >
            > >
            > >
            > >
            > > > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
            > > >
            > >
            > >
            > > As I understand it they use a combination of speed, gait and
            > > the way the foot hits the surface of the water.
            > >
            > > Apparently the foot slaps the surface so hard that it pushes
            > > aside the water (molecules) to create a cushion of air to
            > > support the foot (seemingly each foot only penetrates into
            > > the water surface just one or two centimeters).
            > >
            > > If they get it wrong, or if the foot gets covered by the
            > > water they can be dragged under.
            > >
            > > It could easily have evolved from the way small lizards evade
            > > predators by sprinting on their hind legs, first as a way
            > > of running over soft sand as you say, then extended to
            > > water ... possibly by moving even faster.
            > >
            > > Small lizards sprinting upright on their hind legs, are
            > > said to be ancestors of the dinosaurs
            > >
            > >
            > >
            > >
            > > > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
            > > >
            > >
            > >
            > > A quadruped gait is said to constrain lung function, an a
            > > upright bipedal posture removes that constraint among
            > > mammals.
            > >
            > >
            > >
            > > > For instance, I saw once a documentary in which a small crocodile
            > > > began to jump very fast like a big frog to reach the water;
            > > > a rather amazing locomotion.
            > > >
            > >
            > >
            > > Perhaps the crocodiles had ancestors that were small enough to
            > > evade predators (or prey), by sprinting upright on their
            > > hind limbs.
            > >
            > >
            > >
            > >
            > > > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
            > > >
            > >
            > >
            > > Possibly if some small lizards can raise themselves up on their
            > > hind limbs to sprint, they can also leap like a frog in some
            > > circumstances. (were not some bipedal dinosaurs capable of
            > > leaping onto their prey, using their powerful hind limbs?)
            > >
            > >
            > >
            > > > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
            > > > Renato
            > > >
            > >
            > >
            > >
            > > Perhaps if they ran fast enough across the surface of the water
            > > (like some birds today)they would obtain enough lift, to fly, but
            > > they would they need wings to lift off the water, so how would
            > > the first wings have evolved?
            > >
            > > Still I like the idea that birds first learnt (evolved) to fly
            > > on water. That the first birds were seabirds ...
            > >
            > >
            > > --- Bill (m3d)
            > >
            > >
            > >
            > >
            > >
            > >
            > >
            > > > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
            > > > >
            > > > >
            > > > > ----- Original Message -----
            > > > > From: Marc Verhaegen
            > > > > To: AAT@yahoogroups.com
            > > > > Sent: Saturday, December 12, 2009 6:13 PM
            > > > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
            > > > >
            > > > >
            > > > >
            > > > >
            > > > > > COMPARATIVE BIPEDALISM - how the rest of the animal
            > > > > > kingdom walks on two legs
            > > > > > Philip Dhingra
            > > > > > Prof. Jablonski
            > > > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
            > > > > > Published on Philosophistry
            > > > > > May 25, 2004
            > > > > > http://www.philosophistry.com/static/bipedalism.html
            > > > > > "In the case of the basilisk lizard, bipedalism also
            > > > > > allows for running over water." [quote]
            > > > >
            > > > > > Which I guess would be a bit quicker than
            > > > > > wading through it ... --- Bill (m3d)
            > > > >
            > > > > Yes.
            > > > >
            > > > > Thanks, Bill.
            > > > >
            > > > >
            > > > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
            > > > >
            > > > > wade through anyway. Anyone got any gen on that?
            > > > >
            > > > >
            > > > >
            > > > > Elaine
            > > > >
            > > > >
            > > > > [Non-text portions of this message have been removed]
            > > > >
            > > >
            > >
            >
          • m3dodds
            ... Would agree. Small reptiles millions of years ago turned this method of avoiding a predator by running upright on their hind legs to their advantage, and
            Message 5 of 12 , Dec 19, 2009
            • 0 Attachment
              --- In AAT@yahoogroups.com, "Renato" <bender_renato@...> wrote:
              >
              >
              >
              > --- In AAT@yahoogroups.com, "m3dodds" <dons3148@> wrote:
              > >
              > >
              > >
              > > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
              > > >
              > > > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
              > > >
              > >
              > >
              > >
              > > It is a remarkable feat ... an a ingenious way of evading a
              > > predator. The form of bipedalism involved is not unique by
              > > any means, as a number of small lizards evade predators by
              > > raising themselves up on their hind limbs and sprinting out
              > > of reach of a predator, but doing it on water is an
              > > amazing feat.
              > >
              > > A feat that aids them in evading predators.
              > > Wading and swimming are too slow in comparison to running
              > > bipedally across the surface of the water.
              >
              > The emergence of this bipedalism is probably connected to land bipedalism and bipedalism on the water surface over a very short distance. This would be enough to give the crucial advangate to escape from predators; the bipedal locomotion on water over many meters was the natural development of this initial behavior, increased through natural selection.
              >


              Would agree.
              Small reptiles millions of years ago turned this method of
              avoiding a predator by running upright on their hind legs
              to their advantage, and went on to dominate life on Earth
              for hundreds of thousands of years as dinosaurs ...

              Incidentally the equivalent speed in human terms of this
              method of locomotion over water (utilized by this small
              lizard), would be close to a human running at 104 kph ...




              > > Small lizards evade predation by sprinting bipedally on
              > > their hind limbs. Dinosaurs became successful predators
              > > chasing their prey on two legs.
              > >
              > > Would early hominids in a woodland habitat have evaded a
              > > predator by sprinting for a nearby tree on two legs?
              >
              > I do not see this as very probable. Babbons for instance, if they want to move fast in shallow water (for instance to hunt aquatic birds), they move on four legs. Bipedal in water is very slow.
              > >



              Wading is a very slow way way to move bipedally, water
              having a density close to that of the human body impedes
              movement.




              > > > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
              > > >
              > >
              > >
              > > As I understand it they use a combination of speed, gait and
              > > the way the foot hits the surface of the water.
              > >
              > > Apparently the foot slaps the surface so hard that it pushes
              > > aside the water (molecules) to create a cushion of air to
              > > support the foot (seemingly each foot only penetrates into
              > > the water surface just one or two centimeters).
              > >
              > > If they get it wrong, or if the foot gets covered by the
              > > water they can be dragged under.
              > >
              > > It could easily have evolved from the way small lizards evade
              > > predators by sprinting on their hind legs, first as a way
              > > of running over soft sand as you say, then extended to
              > > water ... possibly by moving even faster.
              > >
              > > Small lizards sprinting upright on their hind legs, are
              > > said to be ancestors of the dinosaurs
              > >
              > >
              > >
              > >
              > > > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
              > > >
              > >
              > >
              > > A quadruped gait is said to constrain lung function, an a
              > > upright bipedal posture removes that constraint among
              > > mammals.
              > >
              > >
              > >
              > > > For instance, I saw once a documentary in which a small crocodile
              > > > began to jump very fast like a big frog to reach the water;
              > > > a rather amazing locomotion.
              > > >
              > >
              > >
              > > Perhaps the crocodiles had ancestors that were small enough to
              > > evade predators (or prey), by sprinting upright on their
              > > hind limbs.
              > >
              > > I think that the topic is very complex. For instance, it can be that young crocodiles are confronted with similar biomechanical and physiological constraints as other medium-sized reptiles, and they developed specific strategies to overcome these constraints. Young crocodiles have other strategies to escape from predators as the adult ones (that are normally the hunters, rarely hunted).
              > >



              Crocodiles are an ancient lineage, said to have changed little
              since the time of the dinosaurs. Being apex predators, they
              probably have no predators now - other than human ones.




              > > > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
              > > >
              > >
              > >
              > > Possibly if some small lizards can raise themselves up on their
              > > hind limbs to sprint, they can also leap like a frog in some
              > > circumstances. (were not some bipedal dinosaurs capable of
              > > leaping onto their prey, using their powerful hind limbs?)
              > >
              > But it is very peculiar that a reptil is jumping aroung like a frog. I can imagine that this has something to do with an arboreal adaptation, as some small reptiles use the hind limbs simultaneously to climb on trees, for instance the Polychrus marmoratus. This behavior was described by Hans Böker in his interesting work "Vergleichende biologische Anatome der Wirbeltiere" (2 volumes, 1935, vol. 1, p. 63-64).
              > >



              Could be an adaption of their running gait. The human running
              gait could be simply described as leaping from one leg to the
              other (making running more expensive - in terms of energy -
              than walking).

              The human bipedal gait appears to be an adaption
              for distance walking.




              > > > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
              > > > Renato
              > > >
              > >
              > >
              > >
              > > Perhaps if they ran fast enough across the surface of the water
              > > (like some birds today)they would obtain enough lift, to fly, but
              > > they would they need wings to lift off the water, so how would
              > > the first wings have evolved?
              >
              > This is exactly the problem with this hypothesis: you need already a kind wing to produce at least some lift...
              > >


              Or webbed forelimbs like a bat ...


              --- Bill (m3d)












              > > Still I like the idea that birds first learnt (evolved) to fly
              > > on water. That the first birds were seabirds ...
              > >
              > >
              > > --- Bill (m3d)
              > >
              > >
              > >
              > >
              > >
              > >
              > >
              > > > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
              > > > >
              > > > >
              > > > > ----- Original Message -----
              > > > > From: Marc Verhaegen
              > > > > To: AAT@yahoogroups.com
              > > > > Sent: Saturday, December 12, 2009 6:13 PM
              > > > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
              > > > >
              > > > >
              > > > >
              > > > >
              > > > > > COMPARATIVE BIPEDALISM - how the rest of the animal
              > > > > > kingdom walks on two legs
              > > > > > Philip Dhingra
              > > > > > Prof. Jablonski
              > > > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
              > > > > > Published on Philosophistry
              > > > > > May 25, 2004
              > > > > > http://www.philosophistry.com/static/bipedalism.html
              > > > > > "In the case of the basilisk lizard, bipedalism also
              > > > > > allows for running over water." [quote]
              > > > >
              > > > > > Which I guess would be a bit quicker than
              > > > > > wading through it ... --- Bill (m3d)
              > > > >
              > > > > Yes.
              > > > >
              > > > > Thanks, Bill.
              > > > >
              > > > >
              > > > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
              > > > >
              > > > > wade through anyway. Anyone got any gen on that?
              > > > >
              > > > >
              > > > >
              > > > > Elaine
              > > > >
              > > > >
              > > > > [Non-text portions of this message have been removed]
              > > > >
              > > >
              > >
              >
            • dons3148
              Comparative Bipedalism: Conclusions UNIFYING PATTERNS AND CONCLUSION A major unifying trait of bipedalism is that it is associated with occasional but critical
              Message 6 of 12 , Dec 27, 2009
              • 0 Attachment
                Comparative Bipedalism: Conclusions



                UNIFYING PATTERNS AND CONCLUSION

                A major unifying trait of bipedalism is that it is associated
                with occasional but critical cursorial movements. Lizards, which
                are quadrupedal most of the time, switch to bipedal running in
                order to escape predators (or catch prey). In hominids, during
                the deforestations after the Miocene Epoch (twenty-four to five
                million years ago) bipedalism was critically useful to migrate
                to new locations for food. Flamingos, likewise, will do the
                same thing, occasionally shifting between lakes.

                Another unifying trait in bipedalism is the two general ways in
                which it has developed. In the case of thecodonts, lizards, and
                the non-primate mammals, bipedalism evolved for its advantages
                to speed in either escaping prey or pursuing predators. In the
                case of primates and birds, bipedalism evolved because the
                forelimbs were highly specialized for other purposes. [Quote]

                http://www.philosop histry.com/ static/bipedalis m.html



                __________________________________________





                Would appear because in primates the forelimbs were favoured
                for other purposes, a facultative bipedal gait was favoured
                when on the ground in the primal forest ... 21 - 14 Mya.

                A trait reinforced when foraging in the woodland habitat
                of the P/H-LCA 6 Mya ... as primal forest gave way to
                open woodland.

                A trait reinforced further in the ancestors of Homo 4.5 Mya
                when foraging in the open and on the shore as their woodland
                habitat gave way to open grassland, a habitat change that
                would necessitate covering considerable distances on foot
                when foraging habitually walking upright.

                Those that foraged on the shore thrived, those that
                remained inland perished as new predators evolved
                to dominate life on the new open grasslands.


                --- Bill (m3d)













                ---------- original message ----------




                --- In AAT@yahoogroups.com, "m3dodds" <dons3148@...> wrote:
                >
                >
                >
                >
                > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
                > >
                > >
                > >
                > > --- In AAT@yahoogroups.com, "m3dodds" <dons3148@> wrote:
                > > >
                > > >
                > > >
                > > > --- In AAT@yahoogroups.com, "Renato" <bender_renato@> wrote:
                > > > >
                > > > > The bipedalim of these animals (genus Basiliscus)is amazing. It seems that the feet of heavy adult males sink too deeply when strinking the water and the retraction speed is not fast enough to be out before the air cavity collapses. That means that the capacity to run over water depends on the body mass (but also on the stride frequency and the speed of the slapping feet). I always thought that weight support has something to do with surface tension, but it is not: it is achieved by slapping the water surface (see Rand and Marx 1967 in "Copeia" 1, 230-233, summarised in Videler, quoted below, pp. 102-103). I do not know from any observation about different locomotion connected to shallow / deep water. But I am almost sure that they do NOT wade bipedal in shallow water, if this is what you mean.
                > > > >
                > > >
                > > >
                > > >
                > > > It is a remarkable feat ... an a ingenious way of evading a
                > > > predator. The form of bipedalism involved is not unique by
                > > > any means, as a number of small lizards evade predators by
                > > > raising themselves up on their hind limbs and sprinting out
                > > > of reach of a predator, but doing it on water is an
                > > > amazing feat.
                > > >
                > > > A feat that aids them in evading predators.
                > > > Wading and swimming are too slow in comparison to running
                > > > bipedally across the surface of the water.
                > >
                > > The emergence of this bipedalism is probably connected to land bipedalism and bipedalism on the water surface over a very short distance. This would be enough to give the crucial advangate to escape from predators; the bipedal locomotion on water over many meters was the natural development of this initial behavior, increased through natural selection.
                > >
                >
                >
                > Would agree.
                > Small reptiles millions of years ago turned this method of
                > avoiding a predator by running upright on their hind legs
                > to their advantage, and went on to dominate life on Earth
                > for hundreds of thousands of years as dinosaurs ...
                >
                > Incidentally the equivalent speed in human terms of this
                > method of locomotion over water (utilized by this small
                > lizard), would be close to a human running at 104 kph ...
                >
                >
                >
                >
                > > > Small lizards evade predation by sprinting bipedally on
                > > > their hind limbs. Dinosaurs became successful predators
                > > > chasing their prey on two legs.
                > > >
                > > > Would early hominids in a woodland habitat have evaded a
                > > > predator by sprinting for a nearby tree on two legs?
                > >
                > > I do not see this as very probable. Babbons for instance, if they want to move fast in shallow water (for instance to hunt aquatic birds), they move on four legs. Bipedal in water is very slow.
                > > >
                >
                >
                >
                > Wading is a very slow way way to move bipedally, water
                > having a density close to that of the human body impedes
                > movement.
                >
                >
                >
                >
                > > > > As water is a "unstable" underground, it can be that the bipedalism in Baliscus evolved in a similar (but not identical) way as the bipedalism of several species of small mammals able to jump like a kangaroo (e.g., the Pale Kangaroo Mouse (Microdipodous pallidus). This animal and several other (also not close related) species developed this locomotion in connection with a sandy ground. Probably they are able to escape faster from predators using the hind legs simoultaneously. We can imagine that moving fast in a sandy underground would be a preadaptation to moving on water.
                > > > >
                > > >
                > > >
                > > > As I understand it they use a combination of speed, gait and
                > > > the way the foot hits the surface of the water.
                > > >
                > > > Apparently the foot slaps the surface so hard that it pushes
                > > > aside the water (molecules) to create a cushion of air to
                > > > support the foot (seemingly each foot only penetrates into
                > > > the water surface just one or two centimeters).
                > > >
                > > > If they get it wrong, or if the foot gets covered by the
                > > > water they can be dragged under.
                > > >
                > > > It could easily have evolved from the way small lizards evade
                > > > predators by sprinting on their hind legs, first as a way
                > > > of running over soft sand as you say, then extended to
                > > > water ... possibly by moving even faster.
                > > >
                > > > Small lizards sprinting upright on their hind legs, are
                > > > said to be ancestors of the dinosaurs
                > > >
                > > >
                > > >
                > > >
                > > > > But another important factor to be considered here is connected to the respiratory problems that lizards have when they run on four legs. As R. M. Alexander explains (in "Exploring Biomechanics", 1992, pp. 50-51)explains, lizards "run by fits and starts, stopping briefly between bursts of about 2 to 12 strides". Mammals do not have this constrains of breathing during locomotion. It can be that lizards run bipedal to overcome this problem, but I am not sure if this is the only or even the main reason for most extant and extinct bipeal reptiles.
                > > > >
                > > >
                > > >
                > > > A quadruped gait is said to constrain lung function, an a
                > > > upright bipedal posture removes that constraint among
                > > > mammals.
                > > >
                > > >
                > > >
                > > > > For instance, I saw once a documentary in which a small crocodile
                > > > > began to jump very fast like a big frog to reach the water;
                > > > > a rather amazing locomotion.
                > > > >
                > > >
                > > >
                > > > Perhaps the crocodiles had ancestors that were small enough to
                > > > evade predators (or prey), by sprinting upright on their
                > > > hind limbs.
                > > >
                > > > I think that the topic is very complex. For instance, it can be that young crocodiles are confronted with similar biomechanical and physiological constraints as other medium-sized reptiles, and they developed specific strategies to overcome these constraints. Young crocodiles have other strategies to escape from predators as the adult ones (that are normally the hunters, rarely hunted).
                > > >
                >
                >
                >
                > Crocodiles are an ancient lineage, said to have changed little
                > since the time of the dinosaurs. Being apex predators, they
                > probably have no predators now - other than human ones.
                >
                >
                >
                >
                > > > > E.O. Wilson wrote in one of his books that a small lizard jumped like a frog in a terrestrial environment, without given any reference or even the species (Nicole asked him last years personally if he still know which animal he was refering, but he did not remember any more that he wrote something like this - he wrote a lot, and he not getting younger with the time).
                > > > >
                > > >
                > > >
                > > > Possibly if some small lizards can raise themselves up on their
                > > > hind limbs to sprint, they can also leap like a frog in some
                > > > circumstances. (were not some bipedal dinosaurs capable of
                > > > leaping onto their prey, using their powerful hind limbs?)
                > > >
                > > But it is very peculiar that a reptil is jumping aroung like a frog. I can imagine that this has something to do with an arboreal adaptation, as some small reptiles use the hind limbs simultaneously to climb on trees, for instance the Polychrus marmoratus. This behavior was described by Hans B�ker in his interesting work "Vergleichende biologische Anatome der Wirbeltiere" (2 volumes, 1935, vol. 1, p. 63-64).
                > > >
                >
                >
                >
                > Could be an adaption of their running gait. The human running
                > gait could be simply described as leaping from one leg to the
                > other (making running more expensive - in terms of energy -
                > than walking).
                >
                > The human bipedal gait appears to be an adaption
                > for distance walking.
                >
                >
                >
                >
                > > > > Something special is what the Dutch ornithologist John J. Videler (in Avian Flight, 2006, pp. 102-116) suggested. He think that the first birds began to fly in a similar way like the Baliscus today. This could be an explanation, even if it sounds somehow bizar... He called this idea "Jesus- Christ hypothesis" (the Baliscus species are also called Jesus-Christ lizards).
                > > > > Renato
                > > > >
                > > >
                > > >
                > > >
                > > > Perhaps if they ran fast enough across the surface of the water
                > > > (like some birds today)they would obtain enough lift, to fly, but
                > > > they would they need wings to lift off the water, so how would
                > > > the first wings have evolved?
                > >
                > > This is exactly the problem with this hypothesis: you need already a kind wing to produce at least some lift...
                > > >
                >
                >
                > Or webbed forelimbs like a bat ...
                >
                >
                > --- Bill (m3d)
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                > > > Still I like the idea that birds first learnt (evolved) to fly
                > > > on water. That the first birds were seabirds ...
                > > >
                > > >
                > > > --- Bill (m3d)
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > >
                > > > > --- In AAT@yahoogroups.com, "Elaine Morgan" <elaine@> wrote:
                > > > > >
                > > > > >
                > > > > > ----- Original Message -----
                > > > > > From: Marc Verhaegen
                > > > > > To: AAT@yahoogroups.com
                > > > > > Sent: Saturday, December 12, 2009 6:13 PM
                > > > > > Subject: Re: [AAT] COMPARATIVE BIPEDALISM
                > > > > >
                > > > > >
                > > > > >
                > > > > >
                > > > > > > COMPARATIVE BIPEDALISM - how the rest of the animal
                > > > > > > kingdom walks on two legs
                > > > > > > Philip Dhingra
                > > > > > > Prof. Jablonski
                > > > > > > Anth. Sci. 131/231 - Primate Evolution, Stanford University
                > > > > > > Published on Philosophistry
                > > > > > > May 25, 2004
                > > > > > > http://www.philosophistry.com/static/bipedalism.html
                > > > > > > "In the case of the basilisk lizard, bipedalism also
                > > > > > > allows for running over water." [quote]
                > > > > >
                > > > > > > Which I guess would be a bit quicker than
                > > > > > > wading through it ... --- Bill (m3d)
                > > > > >
                > > > > > Yes.
                > > > > >
                > > > > > Thanks, Bill.
                > > > > >
                > > > > >
                > > > > > I seem to rememver seeing a picture of this happening and it looked like water too deep to
                > > > > >
                > > > > > wade through anyway. Anyone got any gen on that?
                > > > > >
                > > > > >
                > > > > >
                > > > > > Elaine
                > > > > >
                > > > > >
                > > > > > [Non-text portions of this message have been removed]
                > > > > >
                > > > >
                > > >
                > >
                >
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