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Life in the slow lane revisited: Ontogenetic separation between Chimpanzees and humans†
Version of Record online: 12 DEC 2005
Copyright © 2005 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 129, Issue 4, pages 577–583, April 2006
How to Cite
Walker, R., Hill, K., Burger, O. and Hurtado, A. M. (2006), Life in the slow lane revisited: Ontogenetic separation between Chimpanzees and humans. Am. J. Phys. Anthropol., 129: 577–583. doi: 10.1002/ajpa.20306
- Issue online: 13 MAR 2006
- Version of Record online: 12 DEC 2005
- Manuscript Accepted: 16 MAR 2005
- Manuscript Received: 26 MAR 2004
- National Science Foundation
- University of New Mexico Latin American and Iberian Institute
- growth rates;
- Ache foragers;
- human life history
This study investigates the evolution of human growth by analyzing differences in body mass growth trajectories among three populations: the Ache of eastern Paraguay, the US (NHANES, 1999–2000), and captive chimpanzees. The relative growth statistic “A” from the mammalian growth law is allowed to vary with age and proves useful for comparing growth across different ages, populations, and species. We demonstrate ontogenetic separation between chimpanzees and humans, and show that interspecific differences are robust to variable environmental conditions. The human pattern of slow growth during the lengthened period from weaning to the beginning of the adolescent growth spurt is found among the Ache (low energy availability and high disease load) and also in the US (high energy availability and low disease load). The human growth pattern contrasts with that of the chimpanzee, where absolute growth rates and relative “A” values are faster and less prolonged. We suggest that selection has acted to decrease human growth rates to allow more time for increased cognitive development with lower body-maintenance costs. Am J Phys Anthropol, 2006. © 2005 Wiley-Liss, Inc.