Re: Neandertal skull features
Phil Nicholls (pnich@globalone.net)
Sun, 27 Aug 1995 16:36:38 GMT
jimf@vangelis.FtCollins.NCR.com (Jim Foley) wrote:
>I have a book which claims that the Neandertal facial morphology could
>be caused by environmental effects, rather than being genetic in origin.
>As support, it quotes the following paragraphs from Klein's "The Human
>Career":
> The full functional interpretation of Neanderthal facial structure is a
> matter of ongoing debate, but there are some points of broad agreement.
> The forward placement of Neanderthal jaws and the large size of the
> incisors probably reflect habitual use of the anterior dentition as a
> tool, perhaps mostly as a clamp or vise. Such para- or nonmasticatory
> use for gripping is implied by the high frequency of enamel chipping and
> microfractures on Neanderthal incisors, by nondietary microscopic
> striations on incisor crowns, and by the peculiar, rounded wear seen on
> the incisors of elderly individuals. Similar, though less extensive
> damage occurs on the teeth of Eskimos, who also tend to use their
> anterior jaws extensively as clamps.
> Biomechanically, the forces exerted by persistent, habitual,
> nonmasticatory use of the front teeth (= "massive anterior dental
> loading") could account in whole or in part for such well-known
> Neanderthal features as the long face, the well-developed supraorbital
> torus, and even the long, low shape of the cranium. Massive anterior
> dental loading could further explain the unique Neanderthal
> occipito-mastoid region which perhaps provided the insertions for
> muscles that stabilized the mandible and head during dental clamping.
>Now, I would have interpreted that to mean that Neandertals evolved
>facial features to handle the stresses of using teeth and jaws for
>non-eating purposes. But Klein's wording is vague enough (especially in
>the first sentence, second paragraph) that I can't rule out the
>alternative explanation that dental loading could directly cause these
>facial features in an individual with no genetic predisposition towards
>them.
>What is Klein saying here? And what do others think?
>--
>Jim (Chris) Foley, jim.foley@symbios.com
>Assoc. Prof. of Omphalic Envy Research interest:
>Department of Anthropology Primitive hominids
>University of Ediacara (Australopithecus creationistii)
I think that very often evolutionary explanations are phrased in print
in such a way that they have a Lamarkian sound to them. As I read the
passage from Klein that is what I see. Klein is outlining a
hypothesis put forward a few years ago by Yoel Rak. That's all.
Phil (Chris) Nicholls [pnich@globalone.net]
Institute for Hydrohominoid Studies
University of Ediacara
Semper Alouatta!
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