Morphological disparity and evolutionary rates of cranial and postcranial characters in sloths (Mammalia, Pilosa, Folivora)

Sloth morphological evolution has been widely studied qualitatively, with comparative anatomy and morpho-functional approaches, or through quantitative assessments of morphological variation using morphometrics. Only recently, however, have folivoran morphological disparity and evolutionary rates begun to be evaluated using discrete character data. Nonetheless, patterns of morphological evolution in separate character partitions have not been investigated, neither the relative influence of, on the one hand, phylogeny, and on the other, dietary and locomotory adaptations of sloths. Here we evaluate those patterns using a phylomorphospace approach, quantifying morphological disparity and evolutionary rates, and investigating possible drivers of morphological evolution for cranial and postcranial characters in Folivora. The evolution of the morphology in those partitions is associated with distinct patterns of disparity among clades and ecological groups, even though the two partitions do ..., DATA Phylogenetic data (sloths_data.nex & sloths_tree.tre) was obtained from the published study of Casali et al. 2022 (doi.org/10.1093/zoolinnean/zlac092). Classification of each tip and node into phylogenetic, ecological and convergence hypotheses' groups (sloths_info.csv) was obtained from the literature (see Supplementary Table S2 for a detailed account), or was defined for this study according to the results obtained estimating ancestral states and evaluating phylomorphospace patterns. The 'ggphylomorpho' R fuction is available in GitHub (https://github.com/wabarr/ggphylomorpho, v.0.2), being modified for this study. The data files are meant to be opened in the R programming environment with a custom R_script.R file. Â SUPPLEMENTARY INFORMATION Eigenvalues and eigenvectors resulting from Principal Coordinate Analyses are provided as Supplementary Information., The custom R_script.R file reproduces all analyses carried in the study. The following files are necessary to run the script, and must be in the user R working directory: 1 - sloths_data.nex - morphological dataset with 510 discrete characters from Casali et al. 2022 (doi.org/10.1093/zoolinnean/zlac092) 2 - sloths_tree.tre - time-calibrated tree (chronogram) from Casali et al. 2022 (doi.org/10.1093/zoolinnean/zlac092) 3 - sloths_info.csv - comma-delimited file classifying each tip and node according to phylogenetic, ecological and convergence hypotheses' groups. 4 - ggphylomorpho_mod - a modified version of the code for the R function ggphylomorpho v.0.2 (https://github.com/wabarr/ggphylomorpho).树懒的形态演化长期以来被广泛开展定性研究，研究手段涵盖比较解剖学、形态功能学方法，或是通过形态计量学对形态变异开展定量评估。直至近年，学界才开始利用离散特征（discrete character）数据评估叶懒亚目（Folivora）的形态差异度与演化速率。但迄今为止，学界既未针对不同特征分区的形态演化模式展开研究，也未探讨系统发育，以及食性与运动适应性二者对树懒形态演化的相对影响。本研究采用系统发育形态空间（phylomorphospace）方法开展相关评估，量化形态差异度与演化速率，并探究叶懒亚目颅骨与颅后骨骼离散特征的形态演化潜在驱动因素。尽管两类特征分区并未呈现一致的演化模式，DATA 系统发育数据（sloths_data.nex 与 sloths_tree.tre）源自Casali等人2022年发表的研究（doi.org/10.1093/zoolinnean/zlac092）。 各支系末端与节点的分类信息，即按系统发育、生态及趋同演化假说分组的数据集（sloths_info.csv），要么引自已发表文献（详细说明参见补充表S2），要么基于本研究估算祖先状态并分析系统发育形态空间模式的结果自行定义。 本研究对GitHub平台开源的R函数`ggphylomorpho`（版本v.0.2，仓库地址：https://github.com/wabarr/ggphylomorpho）进行了定制修改。 本数据集的所有数据文件需配合自定义R脚本`R_script.R`在R编程环境中使用。 【补充材料】 本研究主坐标分析（Principal Coordinate Analyses）得到的特征值与特征向量已作为补充材料提供。 自定义R脚本`R_script.R`可复现本研究开展的所有分析。 运行该脚本所需的全部文件需置于用户的R工作目录下，具体包括： 1. sloths_data.nex：源自Casali等人2022年研究的形态学数据集，包含510个离散特征； 2. sloths_tree.tre：源自Casali等人2022年研究的时间校准系统发育树（年代树）； 3. sloths_info.csv：以逗号分隔的分类文件，用于按系统发育、生态及趋同演化假说分组对各支系末端与节点进行归类； 4. ggphylomorpho_mod：本研究修改后的`ggphylomorpho` v.0.2版R函数代码（原仓库地址：https://github.com/wabarr/ggphylomorpho）。