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Frans_Jozef
Thursday, November 24th, 2005, 11:40 PM
Craniodental Variation in Paranthropus boisei:
A Developmental and Functional Perspective

Bernard Wood and Daniel E. Lieberman




ABSTRACT

What levels and patterns of craniodental variation among a fossil hypodigm are necessary to reject the null hypothesis that only a single species is sampled?

We suggest how developmental and functional criteria can be used to predict where in the skeleton of fossil hominins we should expect more, or less, within-species variation.

We present and test three hypotheses about the factors contributing to craniodental variation in extant primate taxa, and then apply these results to the interpretation of the P. boisei hypodigm. Within the comparative samples of extant Homo, Pan, Gorilla, Pongo, and Colobus, variables
from the cranial base, neurocranium, and face that are not subject to high magnitudes of strain have consistently lower levels of intraspecific variation than variables from regions of the face subject to high levels of strain.
Dental size variables are intermediate in terms of their reliability.
P. boisei is found to have a low degree of variability relative to extant primates for variables shown to be generally useful for testing taxonomic hypotheses.

Contrary to the claims of Suwa et al. ([1997] Nature 389:489–492), the recently discovered material from Konso falls within the range of variation of the “pre-Konso” hypodigm of P. boisei for available conventional metrical variables. Those aspects of the Konso material that appear to extend the range of the P. boisei hypodigm involve regions of the skull predicted to be prone to high levels of within-species variation.
The approach used in this study focuses on craniodental
data, but it is applicable to other regions of the
skeleton.
Am J Phys Anthropol 116:13–25, 2001.

Full Text:
http://www.fas.harvard.edu/~skeleton/pdfs/2001a.pdf

Frans_Jozef
Thursday, November 24th, 2005, 11:47 PM
Ref.:

http://www.mnh.si.edu/anthro/humanorigins/ha/bos.html

http://www.amonline.net.au/human_evolution/skulls/p_boisei.htm

http://www.kessler-web.co.uk/History/FeaturesAfrica/HominidChronology3.htm

Dr. Solar Wolff
Friday, November 25th, 2005, 02:29 AM
Isn't this the same Daniel Lieberman who published in the 1970s that Neanderthals couldn't talk because their vocal tracts were apelike?

Frans_Jozef
Friday, November 25th, 2005, 02:52 AM
Isn't this the same Daniel Lieberman who published in the 1970s that Neanderthals couldn't talk because their vocal tracts were apelike?

The very same Lieberman who insisted that the decrease of the spheroid bone's lenght lead to a shortening of the vocal tract, which enabled moderns in turn to develop speech.

Dr. Solar Wolff
Saturday, November 26th, 2005, 09:01 PM
The very same Lieberman who insisted that the decrease of the spheroid bone's lenght lead to a shortening of the vocal tract, which enabled moderns in turn to develop speech.

No, this involved the hyoid bone, the floating bone causing what we call the "adam's apple" in English. Lieberman said it was different as in apes with Neanderthals and placed in a higher position. This crowed the tongue and with the rather large, broad Neanderthal anatomy, it would have given Neanderthals a much different sounding voice and inability to made certain sounds. Of course the sphenoid was longer and less bent in Neanderthals which would cause some difference but the hyoid was the big deal. Later, a Neanderthal hyoid bone was found (in Israel I believe) which was perfectly human, shooting Lieberman's idea down.

Frans_Jozef
Sunday, November 27th, 2005, 09:37 AM
No, this involved the hyoid bone, the floating bone causing what we call the "adam's apple" in English. Lieberman said it was different as in apes with Neanderthals and placed in a higher position. This crowed the tongue and with the rather large, broad Neanderthal anatomy, it would have given Neanderthals a much different sounding voice and inability to made certain sounds. Of course the sphenoid was longer and less bent in Neanderthals which would cause some difference but the hyoid was the big deal. Later, a Neanderthal hyoid bone was found (in Israel I believe) which was perfectly human, shooting Lieberman's idea down.

Correction: he still postulate this theory to branch off Neanderthals from the sapiens lineage and therefore devaluating the significance of this fully "progressive" shaped hyoid in view of the change in cranio-facial configuration by sphenoid reduction.

http://www.personalmd.com/news/a1998051314.shtml