Introduction
Studies about hominoid evolution have consumed anthropologists and evolutionary biologists for many years. Studies of our ancient primate locomotor behaviors and their adaptive adaptations focus mainly on the shoulder girdle’s scapula. The researchers of the 2016 study “Standing on the Shoulders of Apes: Analyzing the Form and Function of the Hominoid Scapula Using Geometric Morphometrics and Finite Element Analysis” demonstrated their aim to investigate the evolutionary along with biomechanical elements shaping hominoid shoulder blades. The research implements GM with FEA for analyzing how hominoid shoulder structures have evolved through the evolutionary processes of form and function, (Conaway & Von Cramon‐Taubadel, 2022).
The upper limb mobility together with stability depends critically on the correct functioning of the scapula. Scientists link distinct locomotion patterns in primates to different scapular morphological features which occur during brachiation, climbing and quadrupedal walking. The study of scapular morphology enables scientists to deduce prehistoric and modern locomotor behaviors together with their environmental evolutionary pressures. Workers in the field have constantly struggled to determine whether morphology stems from natural selection or is inherited from past ancestors. This study uses GM and FEA analyses to separate the factors behind scapular forms and performance characteristics, (García‐Martínez & De Castro, 2021).
Summary of Journal Article
The analysis of biological structures relies on geometric morphometrics which lets researchers both quantify shape differences in addition to performing statistical evaluation. The authors utilized GM methods to measure scapulae anatomical features across a wide range of hominoids by processing their landmark-based three-dimensional data. Analysts conducted shape data investigations alongside phylogenetic familial patterns to measure ancestral and non-ancestral elements in the observed morphological differences. The study of scapulae through morphological analysis received additional assessment from Püschel and Sellers who integrated finite element analysis into their approach. Computational models implementing FEA tested postural stability scenarios from static positions that recognized the typical external forces on scapulae when performing different locomotor actions. The authors used this approach to determine the biomechanical success of the shapes as they operated under various functional demands, (Lee & Rainbow, 2023).
The research data provided significant insights for analysis. The GM analysis demonstrated that scapular shape contained distinct heritable traits which produced most of the morphological variations between species. Without evolutionary ancestry the scapular morphology would extend beyond functional adaptation during development. FEA results revealed that the relationship between biomechanical performance follows directly from scapular shape. The constraints of phylogenetic heritage do not prevent scapular form from incorporating elements resulting from functional optimization processes. The research data establishes that biological heritage together with mechanical requirements jointly determine the development of anatomical traits. Although subject to evolutionary adaptations the scapula develops through integration of requirements for manual dexterity and received ancestral structural frameworks, (Püschel Chamberlain, 2020).
Conclusion
Through their combination of shape analysis with functional modelling the study creates a connection between these two domains to build more complete knowledge about anatomical evolutionary patterns. The research method establishes an important guideline which upcoming studies can follow when applying interdisciplinary approaches to study different bone structures. The research conducted by Püschel and Sellers demonstrates essential knowledge about the evolutionary development and functional elements of hominoid shoulder blades. Both phylogenetic backgrounds and biomechanical functions should be evaluated during scientific analysis of skeletal structures according to this research. Research on primate anatomy will continue to reveal evolutionary secrets through investigations that focus on shoulder blades to explain human evolution.
References
Conaway, M., & Von Cramon‐Taubadel, N. (2022). Morphological integration of the hominoid postcranium.. Journal of human evolution, 171, 103239. https://doi.org/10.1016/j.jhevol.2022.103239.
García‐Martínez, D., Green, D., & De Castro, J. (2021). Evolutionary development of the Homo antecessor scapulae (Gran Dolina site, Atapuerca) suggests a modern-like development for Lower Pleistocene Homo. Scientific Reports, 11. https://doi.org/10.1038/s41598-021-83039-w.
Lee, E., Young, N., & Rainbow, M. (2023). A comparative approach for characterizing the relationship among morphology, range-of-motion and locomotor behaviour in the primate shoulder. Proceedings of the Royal Society B: Biological Sciences, 290. https://doi.org/10.1098/rspb.2023.1446.
Püschel, T., Marcé‐Nogué, J., Chamberlain, A., Yoxall, A., & Sellers, W. (2020). The biomechanical importance of the scaphoid-centrale fusion during simulated knuckle- walking and its implications for human locomotor evolution. Scientific Reports, 10. https://doi.org/10.1038/s41598-020-60590-6.
Spear, J. (2024). Phylogenetic comparative analysis of suspensory adaptations in primates. Journal of human evolution, 198, 103616. https://doi.org/10.1016/j.jhevol.2024.103616.
Urciuoli, A., Zanolli, C., Beaudet, A., Dumoncel, J., Santos, F., Moyà-Solà, S., & Alba, D. (2020). The evolution of the vestibular apparatus in apes and humans. eLife, 9. https://doi.org/10.7554/eLife.51261.
