Variability and the form–function framework in evolutionary biomechanics and human locomotion

Abstract

The form-function conceptual framework, which assumes a strong relationship between the structure of a particular trait and its function, has been crucial for understanding morphological variation and locomotion among extant and fossil species across many disciplines. In biological anthropology, it is the lens through which many important questions and hypotheses have been tackled with respect to relationships between morphology and locomotor kinematics, energetics, and performance. However, it is becoming increasingly evident that the morphologies of fossil hominins, apes, and humans can confer considerable locomotor diversity and flexibility, and can do so with a range of kinematics depending on soft tissue plasticity and environmental and cultural factors. This complexity is not built in to traditional biomechanical or mathematical models of relationships between structure and kinematics or energetics, limiting our interpretation of what bone structure is telling us about behaviour in the past. The nine papers presented in this Special Collection together address some of the challenges that variation in the relationship between form and function pose in evolutionary biomechanics, to better characterize the complexity linking structure and function and to provide tools through which we may begin to incorporate some of this complexity into our functional interpretations.

Anterior diaphyseal curvature of the femur and tibia has biomechanical consequences during unloaded uphill locomotion

“…However, the importance of redundancy in the musculoskeletal system was clear, enabling different solutions to perform the same function by structurally different bones. The implications of such variability in the relationship between structure and function has become increasingly recognized in biological anthropology and in evolutionary biomechanics more specifically (Holowka et al, 2022;McClymont et al, 2022;Murray, 2022;Wallace et al, 2022). MSk modeling has been a crucial tool in highlighting this, as it enables the incorporation of various sources of individual morphological variation to better understand their impact on function (Sylvester et al, 2021).…”

New insights into patterns of integration in the femur and pelvis among catarrhines

“…Importantly, also, employing PC/rPC scores to assess their integration with CSG provides clear and precise representation of the specific morphological variations on the skeleton associated with distinct variation in structural properties (Figures 2 and 3). Therefore, morpho-structural integration between PC/rPC and CSG represents a promising approach to understanding complex anatomical variations, offering future perspectives for a comprehensive examination of the form-function relationship (Murray, 2022).…”