No announcement yet.

Quadruped to biped . Not possible in terrestrial apes .

  • Filter
  • Time
  • Show
Clear All
new posts

  • Quadruped to biped . Not possible in terrestrial apes .

    It has just struck me that the evolution of bipedalism among tree climbing /terrestrial apes is not really a feasible theory . This is because of the enormous disadvantage that a bipedal male is at ,compared to a quadruped of equal size , when it comes to fighting for mates/territory , unless weapons can be used decisively . I do not see anyway past this evolutionary problem for terrestrial quadrupeds to give rise to bipeds . Any thoughts ?

    Here is an exert from a post of mine on podiatry arena -

    "One of the major problems in moving from quadrupedalism to bipedalism is a greatly reduced ability to fight rival males unless weapons are used .

    If you are a biped , it's a lot harder to get upright after a fall . Also ,if you are a naked bipedal male and an a quadruped with long fangs approaches , you have every right to feel very vulnerable .
    Imagine standing in your birthday suit as an angry ,very large ( same weight as you ), pit bull ,runs at you looking for something to bite through !
    Worse , imagine a pit bull with fangs and 2 pairs of grasping feet rather than paws .

    Moving from quadruped to biped could not happen anywhere other than the tree tops .

    Gerrard Farrell


    scotfoot, 18 minutes ago

  • #2
    Re: Quadruped to biped . Not possible in terrestrial apes .

    A good few years ago a paper was produced which claimed to illustrate why standing up to fight would give an advantage to a male with these characteristics when it came to sexual selection (D CARRIER 2001). It was suggested that this led to a commitment to bipedalism .
    To my mind the paper demonstrated why a biped is at a huge DISADVANTAGE in a fight with a quadruped of the same weight .

    If you look at the paper ( see link below ) ,which is open access , focus on figure 2 . Look at the target height for each of the two strike conditions , quadruped and biped . The standing target is raised to above the height of any attacking quadruped .
    Although the standing position allows greater strike power to a lifted target it does not allow that strike power to be transmitted to a lower ( quadruped ) target . A standing position also makes it much harder to bite an opponent but makes it far easier for a quadruped opponent to inflict its own bites .

    So great is the disadvantage , when it comes to fighting , that a quadruped ape could never evolve into a biped without an evolutionary excursion into the tree tops and brachiation .

    Therefore , out go theories like seeing over grass ,radiation and overheating brains , food collection , standing to feed , etc . Terrestrial quadruped to biped ? Not a hope .

    The Advantage of Standing Up to Fight and the Evolution of Habitual ...
    Background Many quadrupedal species stand bipedally on their hindlimbs to fight. This posture may provide a performance advantage by allowing the forelimbs to strike an opponent with the range of motion that is intrinsic to high-speed running, jumping, rapid braking and turning; the range of motion over which peak force and power can be produced. Methodology/Principal Findings To test the hypothesis that bipedal (i.e., orthograde) posture provides a performance advantage when striking with the forelimbs, I measured the force and energy produced when human subjects struck from “quadrupedal” (i.e., pronograde) and bipedal postures. Downward and upward directed striking energy was measured with a custom designed pendulum transducer. Side and forward strikes were measured with a punching bag instrumented with an accelerometer. When subjects struck downward from a bipedal posture the work was 43.70