Holloway's question

alex duncan (aduncan@mail.utexas.edu)
7 Aug 1995 02:00:42 GMT

In article
<Pine.SUN.3.91.950805190246.3276A-100000@bonjour.cc.columbia.edu> Ralph L
Holloway, rlh2@columbia.edu writes:

>A question for Alex and Harry: What happens when you confine your
>cladistic analyses for Siva, Pongo, Giganto, etc., to purely mandibular
>characters? Isolated teeth and mandibles are ALL that is known to exist
>for Giganto.

That is what I've been encouraging Harry to do. While the data base is
impressive, it does include characters that in general are not used in
cladistic analysis, as well as characters that are unknown in
Gigantopithecus. I've already posted about the second category. In the
first category are features such as body size (too difficult to determine
polarity, and obviously a very labile character), geographic and temporal
position, diet (can we really KNOW this for a fossil species, or are we
extrapolating from dental and masticatory anatomy, in which case the data
should already been in there?).

Until good cranial material was discovered for Ouranopithecus, it was
often included in a clade with the sivapithecines, and was even placed in
the same genus (I think) by Simons & Pilbeam (1967?). The mandibles and
mandibular dentition are very similar to Siva, and I think many of the
other character states were assumed to be similar or identical to those
seen in Siva & Pongo.

A similar state of affairs exists today for Gigantopithecus. I suspect
that the evidence for Giganto belonging to the Siva/Pongo clade is better
than it was for Ouranopithecus. Kelley suggests that S. parvada is a
reasonable precursor for Gigantopithecus. But, given the general
similarity of the mandibles of the thick-enamelled hominoids, is it
really outrageous to suggest that Giganto might have evolved from
Ouranopithecus? I don't think that is the case, but if we begin our
exercise by assuming Giganto IS a member of the Siva/Pongo clade, and go
ahead and put characters in the database that are unknown -- but are
similar to what we see in Siva/Pongo -- then we'll never prove anything
about Giganto other than what we already "know."

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086