3D geometric morphometric analysis of variation in the human lumbar spine
[Objectives]: The shape of the human lumbar spine is considered to be a consequence of erect posture. In addition, several other factors such as sexual dimorphism and variation in genetic backgrounds also influence lumbar vertebral morphology. Here we use 3D geometric morphometrics (GM) to analyze the 3D morphology of the lumbar spine in different human populations, exploring those potential causes of variation.
The torso integration hypothesis revisited in Homo sapiens: Contributions to the understanding of hominin body shape evolution.
Objectives: Lower thoracic widths and curvatures track upper pelvic widths and iliac blades curvatures in hominins and other primates (torso integration hypothesis). However, recent studies suggest that sexual dimorphism could challenge this assumption in Homo sapiens. We test the torso integration hypothesis in two modern human populations, both considering and excluding the effect of sexual dimorphism. We further assess covariation patterns between different thoracic and pelvic levels, and we explore the allometric effects on torso shape variation. Material and Methods: A sex-balanced sample of 50 anatomically connected torsos (25 Mediterraneans, 25 Sub-Saharan Africans) was segmented fro…
Geometric Morphometric Studies in the Human Spine
This chapter overviews the theoretical basics of geometric morphometrics (GM) and reviews its potential for the study of hominin vertebrae and vertebral columns. We show that challenges are related to seriality and the metameric nature of the spine. Measuring a series of vertebrae is a time-consuming process because the necessary sample sizes need to be multiplied by the number of vertebrae composing the spine or its anatomical parts. This is particularly true when measuring 3D semilandmarks of curves and surfaces in virtual anthropology. The lack of independence among vertebral series of a skeleton and the complex conceptual relation between the shape of vertebrae (parts) and the effect of…