Re: An alternative to ST and AAT

Susan S. Chin (susansf@netcom.com)
Sun, 17 Nov 1996 04:28:51 GMT

John Waters (jdwaters@dircon.co.uk) wrote:
: > : JW: This morphology enables bipedalism, but is not as
: efficient
: > : for long distance walking. In this sense, the
: australopithicene
: > : bipedalism was less efficient than modern Hss.

Susan S. Chin <susansf@netcom.com> wrote in article
: <susansfE0nzAv.7rp@netcom.com>...
: > I haven't read any of the later research on
: Australopithecine locomotion,
: > can you cite a source and some specifics for the less
: efficient biped claim?
: > What part of the Australopithecine anatomy make them less
: efficient? Thanks.

: JW: I cannot site any source or references in respect of
: early Australopithicenes, and I doubt if anyone else can
: either. I say this because the really early
: Australopithicene fossils only comprise teeth and jawbones.
: As far as middle Australopithicenes are concerned (e.g.
: Lucy), my references are pretty ancient, but as far as I am
: aware they have not yet been seriously contradicted.

Actually, A. anamensis does have a proximal tibia preserved which show
a bipedally-adapted anatomy. This early Australopithecine species is
dated at 3.8-4.2myo making it the earliest known hominid (at the moment).

Also, I'm not really questioning that early Australopithecines were not
as well adapted bipeds as later hominids. That would be expected. But
Lucy and other afarensis were still fully functional bipeds from its
anatomy.

: Jolly and Plog determined that Lucy's walking resembled
: more of _a pigeon toed and lurching gait_. Perhaps this is
: where Paul got his idea of a waddling Lucy.

I'd be interested to know on what basis they came to this pigeon toed
lurching biped conclusion. It is also interesting to note that Jolly
is a Primatologist while Plog's specialty is Archeology.

On the other side of the bipedalism story, C. Owen Lovejoy, who
reconstructed the Lucy pelvis (flattened and distorted taphonomically),
calls Lucy a fully functional biped. She may not be as efficient or
elegant a strider as later hominids, but neither did she struggle in her
bipedal locomotion. I'd like to hear what those who think otherwise
explain the evidence of afarensis' bipedal gait from the Laetoli footprints.

The same evidence (pelvis, knee joint) can be interpreted differently by
various investigators. In this instance, I'd put more stock in a
specialist in hominid biomechanics and locomotion such as Lovejoy.

: Ref: Jolly, Clifford J and Fred Plog. (1987) Physical
: Anthropology and Archaeology. New York. Alfred A. Knopf.

: The part of the Australopithicene anatomy which is most
: likely to make them less efficient is the heel. Modern
: humans gain their bipedal efficiency from the ligaments of
: the lower leg which attach to the ankle via the achilles
: tendon.

: John.

Is this what Jolly and Plog state in their 1987 textbook? What
Australopithecine calcaneus are they referring to if this is so? I'm
not aware of such evidence. And what anatomical characteristics of the
Australopithecine calcaneus and fibia/tibia would cause this inefficiency?

Susan

-- 
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