Re: MOVING CREATURES

[Chris Campbell <sankarah@ou.edu>]

GSP1954@aol.com wrote:
> 
> Michael & Jonathon state that there are differences between the trot and
> pace. Of course there are. Read what I said carefully. I did not say they are
> identical. My statement that the gaits are functional equivalents and cannot
> be told apart in lateral silhouette. Compare plates 44 & 55 in Muybridge 1957
> and imagine that the figures are solid black, the trot and pace are the same
> in this view.
> 
> The canter is not as Jonathon suggested a separate level between the
> trot-pace on one hand and the gallop, it is basically a slow gallop. J also
> says that "I don't even pretend to understand how you can use the same
> technical term to describe the motion of a straddle-legged croc" and a dog.
> You also state you are not familiar with reptiles gaits. All those who have
> published on the fast crocodilian bound call it a gallop. It is very similar
> to the symmetrical gallop of squirrels etc. Don't get after me for using the
> commonly applied term.
> 
> The largest sample comparing energy consumption in reptiles, birds and
> mammals is the classic M Fedak & H Seeherman Reappraisal of energetics of
> locomotion....... Nature 282:713-716.
> 
> Jonathon does exactly what is the problem with this discussion. He asks an
> expert how fast elephants can move. The expert Haight then replies, with
> claims that sound fantastical. That elephants can sprint at 30 mph for a
> short distance, a speed way up into the mammalian galloping range, about 7
> mph faster than Carl Lewis, only 4 mph less than a racing greyhound, and 8
> mph less than the typical winner of a horse race. Haight provides no
> documentation of how these speeds were obtained, so they remain as
> unsubstantiated as they are implausible. What Jonathon should have asked
> Haight is something like "what are the maximum elephant speeds actually
> measured by reliable means, such as timed course, film analysis, or radar
> gun".  If Haight could cite studies or provide data then THAT would be
> interesting. As it is it's just arm waving. Saying that it is not feasible to
> accurately measure elephant speeds does not mean that we must take 20-30 mph
> speed claims seriously. Science is based upon accurate information, and lack
> of rigorous data is not a reason to accept unsubstantiated claims.

Similarly, though, we don't have enough data to dismiss all the
anecdotal evidence claiming elephants can indeed move faster than 12
mph.  We *do* have enough data to suspect that elephants might have some
way around the constraints given by our current view of biomechanics,
just as bumblebees get around conventional constraints of aerodynamics. 
We don't have data claiming this is absolutely the case, but the very
real possibility exists that elephants can move faster than anything of
their general size and build has a right to.  Because of this, we cannot
claim elephants *can't* move at the speeds published simply because we
don't know whether or not that's the case.  All we can claim with any
certainty whatsoever is that we need more data.  Anything else is
handwaving, no matter which side of the argument it comes from.

Chris