Callum F Ross, David A Reed, Rhyan L Washington, Alison Eckhardt, Fred Anapol, Nazima Shahnoor
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引用次数: 55
Abstract
The biomechanical determinants of the scaling of chew cycle duration are important components of models of primate feeding systems at all levels, from the neuromechanical to the ecological. Chew cycle durations were estimated in 35 species of primates and analyzed in conjunction with data on morphological variables of the feeding system estimating moment of inertia of the mandible and force production capacity of the chewing muscles. Data on scaling of primate chew cycle duration were compared with the predictions of simple pendulum and forced mass-spring system models of the feeding system. The gravity-driven pendulum model best predicts the observed cycle duration scaling but is rejected as biomechanically unrealistic. The forced mass-spring model predicts larger increases in chew cycle duration with size than observed, but provides reasonable predictions of cycle duration scaling. We hypothesize that intrinsic properties of the muscles predict spring-like behavior of the jaw elevator muscles during opening and fast close phases of the jaw cycle and that modulation of stiffness by the central nervous system leads to spring-like properties during the slow close/power stroke phase. Strepsirrhines show no predictable relationship between chew cycle duration and jaw length. Anthropoids have longer chew cycle durations than nonprimate mammals with similar mandible lengths, possibly due to their enlarged symphyses, which increase the moment of inertia of the mandible. Deviations from general scaling trends suggest that both scaling of the jaw muscles and the inertial properties of the mandible are important in determining the scaling of chew cycle duration in primates.
期刊介绍:
The American Journal of Physical Anthropology (AJPA) is the official journal of the American Association of Physical Anthropologists. The Journal is published monthly in three quarterly volumes. In addition, two supplements appear on an annual basis, the Yearbook of Physical Anthropology, which publishes major review articles, and the Annual Meeting Issue, containing the Scientific Program of the Annual Meeting of the American Association of Physical Anthropologists and abstracts of posters and podium presentations. The Yearbook of Physical Anthropology has its own editor, appointed by the Association, and is handled independently of the AJPA. As measured by impact factor, the AJPA is among the top journals listed in the anthropology category by the Social Science Citation Index. The reputation of the AJPA as the leading publication in physical anthropology is built on its century-long record of publishing high quality scientific articles in a wide range of topics.