0000000000068651
AUTHOR
Nicole Torres-tamayo
Sexual dimorphism in the vertebral wedging of the human lumbar vertebrae and its importance as a comparative framework for understanding the wedging pattern of Neanderthals
Lumbar lordosis is a key element of the upright posture, being interpreted as a consequence of bipedal locomotion. There is consensus that the generic modern human pattern of metameric vertebral body wedging is sexually dimorphic in modern humans. However, recently published studies have compared this pattern with other hominins, such as Neanderthals. These tried to establish whether the (male) Neanderthal lumbar vertebrae express a pattern that falls within or outside the range of modern human males. In the present study, data collected by 3D landmarks of the lumbar vertebrae of modern humans from different geographic regions and Neanderthals (Ntotal = 505 individual vertebrae) are used to…
Three-dimensional geometric morphometrics of thorax-pelvis covariation and its potential for predicting the thorax morphology: A case study on Kebara 2 Neandertal
The skeletal torso is a complex structure of outstanding importance in understanding human body shape evolution, but reconstruction usually entails an element of subjectivity as researchers apply their own anatomical expertise to the process. Among different fossil reconstruction methods, 3D geometric morphometric techniques have been increasingly used in the last decades. Two-block partial least squares analysis has shown great potential for predicting missing elements by exploiting the covariation between two structures (blocks) in a reference sample: one block can be predicted from the other one based on the strength of covariation between blocks. The first aim of this study is to test w…
Association between ribs shape and pulmonary function in patients with Osteogenesis Imperfecta
Graphical abstract
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…
In Vivo 3D Analysis of Thoracic Kinematics: Changes in Size and Shape During Breathing and Their Implications for Respiratory Function in Recent Humans and Fossil Hominins
The human ribcage expands and contracts during respiration as a result of the interaction between the morphology of the ribs, the costo-vertebral articulations and respiratory muscles. Variations in these factors are said to produce differences in the kinematics of the upper thorax and the lower thorax, but the extent and nature of any such differences and their functional implications have not yet been quantified. Applying geometric morphometrics we measured 402 three-dimensional (3D) landmarks and semilandmarks of 3D models built from computed tomographic scans of thoraces of 20 healthy adult subjects in maximal forced inspiration (FI) and expiration (FE). We addressed the hypothesis that…
Assessing thoraco-pelvic covariation in Homo sapiens and Pan troglodytes: A 3D geometric morphometric approach
[Objectives]: Understanding thoraco-pelvic integration in Homo sapiens and their closest living relatives (genus Pan) is of great importance within the context of human body shape evolution. However, studies assessing thoraco-pelvic covariation across Hominoidea species are scarce, although recent research would suggest shared covariation patterns in humans and chimpanzees but also species-specific features, with sexual dimorphism and allometry influencing thoraco-pelvic covariation in these taxa differently.