Distal Part of the Human Hand: Study of Form Variability and Sexual Dimorphism Using Geometric Morphometrics
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Periodical |
| Magazine / Source | Anthropologia Integra |
| MU Faculty or unit | |
| Citation | |
| web | https://journals.muni.cz/anthropologia_integra/article/view/2411 |
| Field | Archaeology, anthropology, ethnology |
| Keywords | Human hand; shape; form variability; sexual dimorphism; hand proximodistal shear variability |
| Description | Traditionally, the human hand has been analyzed by measuring and comparing individual segments (fingers, phalanges, metacarpals) without considering their mutual spatial relationships. The present study aimed to analyze intra-population variability of the human hand form in the region of fingers as whole with special focus given to sexual dimorphism and the association between shape and size. Right hands of 99 females and 70 males, mostly college students, were scanned with a document scanner in standardized position from the palmar side. For each image 2-D coordinates of 16 landmarks were recorded and variability between configurations of landmarks were studied using geometric morphometrics. To understand patterns of variability, shape spaces were decomposed into affine and non-affine subspaces and further studied separately. The prevalence of the total variability was associated with affine shape change identical for the whole studied region of the hand. Its major portion was represented by shearing in proximodistal direction and to a lesser extent by straining in the relative hand width. The strain also strongly correlated with size of the hand. Intersexual differences were represented by affine change in which the proximodistal shearing was inextricably tied with the differences in relative hand width. Local non-affine sex differences were found in specific phalanges and might be associated with differences in finger length ratios. We presume that separating global and local sexually dimorphic features of the hand might shed light on the origin/onset of the dimorphism during early ontogeny – the more local the feature, the later differentiated, and thus influenced by different ontogenetic factors than global features. |
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