No brain expansion in Australopithecus boisei
Article first published online: 16 AUG 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 146, Issue 2, pages 155–160, October 2011
How to Cite
Hawks, J. (2011), No brain expansion in Australopithecus boisei. Am. J. Phys. Anthropol., 146: 155–160. doi: 10.1002/ajpa.21420
- Issue published online: 12 SEP 2011
- Article first published online: 16 AUG 2011
- Manuscript Accepted: 10 SEP 2010
- Manuscript Received: 22 APR 2010
- Graduate School of the University of Wisconsin-Madison
- brain evolution;
- robust australopithecines;
- temporal trends
The endocranial volumes of robust australopithecine fossils appear to have increased in size over time. Most evidence with temporal resolution is concentrated in East African Australopithecus boisei. Including the KNM-WT 17000 cranium, this sample comprises 11 endocranial volume estimates ranging in date from 2.5 million to 1.4 million years ago. But the sample presents several difficulties to a test of trend, including substantial estimation error for some specimens and an unusually low variance. This study reevaluates the evidence, using randomization methods and a related test using an explicit model of variability. None of these tests applied to the A. boisei endocranial volume sample produces significant evidence for a trend in that species, whether or not the early KNM-WT 17000 specimen is included. Am J Phys Anthropol, 2011. © 2011 Wiley-Liss, Inc.