Re: Time Frame: Early Hominids

Patricia Lynn Sothman (plsothma@artsci.wustl.edu)
8 May 1995 18:10:19 GMT

Phil Nicholls (pn8886@thor.albany.edu) wrote:

: Pat,
BTW, call me Trisha, I do not go by Pat.

: What is your opinion of the OH 62 stuff? I mean, my impression is
: that OH 62 is a rather small individual and the use of molar size
: (i.e. small buccolingual diameters) sets off these alarms in my
: head. Unfortunately we can't do allometric scaling when we have
: such lousy data on body size.

OH 62 was small, about the size of AL-288 (Lucy). Estimating body size
parameters from molar dimensions in a group of hominids which display
post-canine megadontia (having relatively large posterior teeth) should
not be done. I feel more confident when body size is estimated based
upon actual weight-bearing elements. However, attempting body size
reconstructions with fragmentary material is iffy at best. The latest
estimates of the australopithecines, demonstrate almost complete
overlapping. Getting back to the dental dimensions of OH 62, when I went
back to re-read the paper, I found it interesting that these teeth are
really large for the limb dimensions. Their comparision of OH 62 to some
of the Koobi Fora remains reminded me of a paper I saw in Toronto by JMA
Miller. He did an analysis of the mandibular remains from Koobi, and in
his results, it seemed as though half of the "habilis" mandibles fit
better allometrically with boisei. He concluded that dental dimensions
of these early hominids overlapped, and perhaps some have been
misclassified as "habilis" when they should be female boisei. I keep
coming back to the same basic question in my head: How much variation
should one expect in closely related fossil taxa?

: Also, did you notice that Johanson didn't even mention OH62 in
: his NOVA show?

That was interesting. I still think that many scientists ignore OH 62
because it does not "fit" with their conceptions of how human evolution
proceeded.

: --
: Phil Nicholls "To ask a question you must first
: Department of Anthropology know most of the answer."
: SUNY Albany -Robert Sheckley
: pn8886@cnsunix.albany.edu SEMPER ALLOUATTA

Patricia L. Sothman
Department of Anthropology
WASH U., St. Louis