A Statistic Method for Anatomical and Evolutionary Analysis

Abstract

Rules, formulas, and statistical tests have been widely used in studies that analyze continuous variables with the normal (Gaussian) distribution or deined parameters.Nevertheless, in some studies such as those in gross anatomy, only statistics with discrete or nominal variables are available. In fact, the existence or absence of an anatomical structure, its features and internal aspects, innervation, arterial and vein supplies, etc. can be analyzed as discrete and/or nominal variables. However, there have been no adequate methods, which allow transformation of data with qualitative/nominal variables in gross anatomy to those with quantitative variables. To resolve the issue, we have purposed a new method that allows, in order, descriptions based on numerical analyses, the statistical method for comparative anatomy (SMCA), and proposed the formula for comparison of groups of anatomical structures among diferent species that allows to infer evolutionary perspective. The important features of this method are as follows: (1) to allow to analyze numerical data, which are converted from discrete or nominal variables in morphological areas and (2) to quantitatively compare identical structures within the same species and across diferent species. The SMCA ills the lack of a speciic method for statistical works in comparative anatomy, morphology, in general, and evolutional correlations.

Comparative anatomy of the Sapajus sp. (bearded capuchin) hand with comments on tool use in a parallel evolution with the hominid pathway

“…These analyses reveal that the Sapajus hand more closely resemble those of arboreal primates (Aversi-Ferreira et al, 2014a), consistent with the findings of the current study and other studies comparing the primate blood supply (Aversi-Ferreira et al, 2020;Aversi-Ferreira et al, 2021b). However, linear hand proportion measurements suggest that capuchin hands are closer to those of humans than other primates (Almecíja et al, 2015).…”

“…According to the descriptive analysis and GCAI results (Tables 2, 3, 5), Sapajus hand muscles are similar to those of baboons. It is crucial to note that the vascularization of the hand is identical between capuchins and baboons but is different compared with the other primates (Aversi-Ferreira et al, 2007a;Aversi-Ferreira et al, 2007b;Aversi-Ferreira et al, 2007c;Aversi-Ferreira, 2009;Abreu et al, 2021;Aversi-Ferreira et al, 2021b), while innervation is identical in all of them (Marin et al, 2009), except for the (E) Schematic representation of a human hand, indicating the projection of the thumb over the plane of the hand; that is, the curved carpus and crossing parallel to the z-axis due to the anterior position of the trapezium bone (based on Aversi-Ferreira et al, 2014a;Aversi-Ferreira et al, 2014c).…”