Re: New Ethiopian Find - Oldest Biped At 3.8-4 mya

From: Algis Kuliukas (algis_at_RiverApes.com)
Date: 03/18/05 

Date: 18 Mar 2005 14:24:35 -0800

Rick Wagler wrote:

> In this latest go-rouind all Jason is trying to do is establish
> the point that if you want to make a comparative argument
> you have to make a comparison between the types
> of locomotion at issue. Simple enough point I should have
> thoiught. Comparing humans in different substrates does
> not help you engage the issue that is your professed interest.
> All it does is prove that gravity is a real phenomenon and has
> measurable effects. Its good to establish the basics but don't
> get carried away with it.

Fine. I can see you have a point, Rick, but I do think that when
discussing the pros and cons of any given locomotion you must not
forget the substrate through which the animal is moving. There is a
great deal of difference between the energy required walking bipedally
on hard, hoof-worn grassland and walking through difficult bush. There
must be far less difference for a quadruped. This is more than an
assertion. I have performed some simple (but painful!) experiements to
test it and it appears to be correct. If one thinks about it for a
moment, it is rather obvious. Human bipedal efficiency is due to our
striding gait, which is ever more hindered the worse the substrate
gets. A quadruped is hindered too, but if it does not rely on an
inverted pendulum gait (and apes' certainly aren't), it is less likely
to be affected by substrate imperfections. Furthermore, a quadruped is
more stable on uneven surfaces or when stepping over low branches or
fallen logs whereas these obstacles would require costly changes in
posture whilst moving bipedally. Finally, where the bush is very thick
with foliage, as would be the case in a tropical rain forest, then
clearly the frontal profile area of the body is going be another factor
that will effect efficiency and probably actually favour the quadruped.

I can see that I was clearly very foolish to get into such an argument
with such a person. But I think I made a valid point and expected a far
more generous response from a scientist on a public disussion group
such as this. There is something about self-righteous egostical
personalities that brings out the worst in me and I admit that I have
become part of the problem there.

The really stupid thing is that I largely agree with Jason about the
energy efficiency argument. I only differ in thinking that wading was
the factor that started the process going in the first place. Whereas
Jason apparently thinks there was no energy rubicon to cross for the
earliest bipeds, I think that shallow water was the place where this
rubicon was eliminated. I also appear to differ from him in that I
think that such efficiencies could only have been selected for in
certain substrates whereas he seems to think it would be selected for
anyway no matter what substrates they moved through. These are, on the
whole, minor differences however, especially when one considers that I
am currently simultaneously arguing with Marc Verhaegen about the same
thing but over differnt aspects. We largely agree (I think) on the
earlier wading-climbing part but differ greatly in how that evolved in
the humanlike form. He thinks diving was the key factor there, I think
it was energy efficiency.

I am just sick of all the nasty harranging that goes on here. We're all
interested in human evolution. We're all Darwinists. Everyone has an
opinion and something to offer, so why does it always have to turn into
a pissing contest, leaving everyone smelling of the stench of urine?
Why is it that some people think that just because they hold certain
mainstream views it makes them not just a better scientist but, it
seems, a better person too, allowing them to treat adversaries as if
they were untermenschen, with impunity. No-one has a monopoly of being
right even if you hold a position that is in the majority.

Algis Kuliukas

Relevant Pages

  • Re: New Ethiopian Find - Oldest Biped At 3.8-4 mya
    ... >> qualifications you still choose to support the energy efficiency ... They made a comparison between two forms of locomotion. ... possibility that on other substrates the gap in efficiency might be ...
    (sci.anthropology.paleo)
  • Re: New Ethiopian Find - Oldest Biped At 3.8-4 mya
    ... "Algis Kuliukas" wrote in message ... > in our evolution, could it Michael? ... You've been whining about efficiency measures ... across substrates when the issue is something entirely different. ...
    (sci.anthropology.paleo)
  • Re: New Ethiopian Find - Oldest Biped At 3.8-4 mya
    ... >> efficiency. ... And, specifically, the assertion is that bipeds are ... chimps, I just compared humans in different substrates. ... considering substrates that are even more densely vegetated. ...
    (sci.anthropology.paleo)
  • Re: New Ethiopian Find - Oldest Biped At 3.8-4 mya
    ... McH paper is based on R & T's study of two young chimps and two young ... efficiency model for bipedal origins, I have argued for the wading ... > more efficient than chimps on a variety of substrates, ... *likely* to be less efficient than chimps whilst moving through thick ...
    (sci.anthropology.paleo)
  • Re: Motor speed stability
    ... could do it better with Calculus though. ... odometry and then correct the course accordingly, does this differ in any major way with respect to efficiency from just modifying the commanded velocity of the wheel that did not slow down? ...
    (comp.robotics.misc)