Re: Bipedalism and theorizing... was Re: Morgan and creationists

John Waters (
2 Oct 1996 02:22:27 GMT

WVanhou237 <> wrote in article
> In article <01bbad7c$edb2f960$>,
> Waters" <> writes:
> >I know you are still sceptical about this power to weight
> >business. However, it makes a lot of sense in the context of
> >marginal variant evolutionary change.

> I have been following your colloquy on this N.G. for a
> weeks. Fascinating!
> What I missed --- much as one who came in during the second
act of a play
> --- is exactly what is the "power to weight ratio"? Is it:

JW: In terms of physics, it is energy to mass ratio. In my
articles, it means the best combination of muscle
power/endurance for the least body weight. In this context, I
would say that a tortoise would have a relatively poor power to
weight ratio, while a wolf, or wild dog would have a relatively
good power to weight ratio. Maximum useful power for minimum
weight. Low fat and small boned. Endurance rather than brute
> 3. Body power to brain weight. Gracile vs Robustus

JW: In respect of this definition, I think paeleontologists use
the terms Gracile and Robustus to describe relative jaw sizes.
> Lastly, may I suggest the event that led to the creation
of the niche
> that allowed,
> even forced, the development of the bipedal hominids.--- The
> of the continental Rift ---- To the west,well watered and
forested. To the
> west, uplifted and arid. No proto-hominids to the west. No
chimps or
> gorillas to the east.
> Time: Beginning about 4M years B.P.
JW: Sounds fine, except for the timing. The earlist hominid
fossils have been dated to 4.6 million years B.P. Furthermore,
the ancestral hominid split from the ancestral gorilla/chimp
specie is estimated at more than 5 million years B.P. Perhaps
the Rift development was earlier. Are you sure about your dates

John Waters

John Waters is the author of "Helpless as a Baby",
a book concerned with general and human
evolution. It may be accessed at URL