Evolution of Postural Diversity in Primates as Reflected by the Size and Shape of the Medial Tibial Facet of the Talus
Evolution of Postural Diversity in Primates as Reflected by the Size and Shape of the Medial Tibial Facet of the Talus
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DOI：
10.1002/ajpa.22702
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发表时间：
2015-05-01
影响因子：
2.8
通讯作者：
Seiffert, Erik R.
中科院分区：
文献类型：
--
作者：
Boyer, Doug M.;Yapuncich, Gabriel S.;Seiffert, Erik R.
目的：对于灵长类动物及其近亲，距骨（=黄芪）内侧胫骨小关节（MTF）的形状和比例缺乏全面的量化。在这项研究中，MTF形式的各个方面进行了量化，并用于测试其功能和系统发育意义的假设。以下假设影响了对灵长类进化历史的看法，但需要更严格的评估：1）相对较大的MTF区分原猴亚目（strepsirrhines和眼镜猴）; 2）原猴类MTF的独特形式与运动倾向相关，其强调使用垂直和小直径支撑物以及倒置、外展的足姿势;方法：使用三维（3D）扫描来创建距骨（n = 378个标本，122个物种）的比例数字模型，从该模型中计算三种类型的变量来捕获MTF形式的方面：1）MTF面积相对于身体质量和外突小面面积; 2）MTF形状（椭圆形与非椭圆形）;以及3）MTF背侧限制在距骨体上（即，非关节区域的广泛暴露与最小暴露）。数据进行了分析，使用系统发育和传统的比较方法，包括系统发育广义最小二乘法，普通最小二乘法，ANCOVA，方差分析，贝叶斯祖先状态重建（ASR）。MTF面积（而不是形状或背侧限制）与距骨的腓骨小关节角（FFa）相关，这也被认为反映了习惯性的踏板倒置。在strepsirrhines中，更频繁/有效地进行抓握跳跃的类群似乎比不那么杂技的类群具有相对较大的MTF。进化变化的方向模型比其他模型更好地描述MTF变异的系统发育分布。ASR显示1）MTF沿着灵长类干的变化不大，2）独立的进化相对较大的和dorsoplantarly深MTF在基础haplorhines和strepsirrhines，和3）重新进化的形态类似于非euprimates在prosimians.Conclusions：结果支持这一假设，即MTF形式之间的差异prosimians和prosimians反映更多地使用倒置脚姿势和抓跳跃在后者组。虽然化石prosimians没有极端MTF尺寸的特点，许多现存的杂技跳跃，这些变量本身提供了一点额外的行为分辨率在个人化石的水平，由于强大的系统发育信号。ASR表明，一些专业化的使用倒置的脚姿势（如需要在一个细分支生态位）和修改抓取跳跃独立的基础strepsirrhine和haplorhine血统。美国物理人类学杂志157：134-177，2015年。(c)2015 Wiley Periodicals，Inc.
Objectives:Comprehensive quantification of the shape and proportions of the medial tibial facet (MTF) of the talus (=astragalus) has been lacking for Primates and their closest relatives. In this study, aspects of MTF form were quantified and employed to test hypotheses about their functional and phylogenetic significance. The following hypotheses influence perceptions of primate evolutionary history but are due for more rigorous assessment: 1) A relatively large MTF distinguishes prosimians (strepsirrhines and tarsiers) from anthropoids and non-primate euarchontans; 2) the distinctive form of the prosimian MTF is a correlate of locomotor tendencies that emphasize use of vertical and small diameter supports in conjunction with inverted, abducted foot postures; and 3) the prosimian MTF form arose along the primate stem lineage and was present in the euprimate common ancestor.Methods:Three-dimensional (3D) scanning was used to create scale digital models of tali (n = 378 specimens, 122 species) from which three types of variables capturing aspects of MTF form were computed: 1) MTF area relative to body mass and ectal facet area; 2) MTF shape (elliptical vs. non-elliptical); and 3) MTF dorsal restriction on the talar body (i.e., extensive vs. minimal exposure of non-articular area). Data were analyzed using both phylogenetic and traditional comparative methods including Phylogenetic Generalized Least Squares, Ordinary Least Squares, ANCOVA, ANOVA, and Bayesian Ancestral State Reconstruction (ASR).Results:Extant prosimians are generally distinct from anthropoids and non-primate euarchontans in our quantitative representations of MTF form. MTF area (but not shape or dorsal restriction) correlates with fibular facet angle (FFa) of the talus, which has also been argued to reflect habitual pedal inversion. Among strepsirrhines, taxa that engage in grasp-leaping more frequently/effectively appear to have a relatively larger MTF than less acrobatic taxa. Directional models of evolutionary change better describe the phylogenetic distribution of MTF variation than do other models. ASR shows 1) little change in the MTF along the primate stem, 2) independent evolution of relatively large and dorsoplantarly deep MTFs in basal haplorhines and strepsirrhines, and 3) re-evolution of morphologies similar to non-euprimates in anthropoids.Conclusions:Results support the hypothesis that differences in MTF form between anthropoids and prosimians reflect greater use of inverted foot postures and grasp-leaping in the latter group. Although fossil prosimians do not have the extreme MTF dimensions that characterize many extant acrobatic leapers, these variables by themselves provide little additional behavioral resolution at the level of individual fossils due to strong phylogenetic signal. ASR suggests that some specialization for use of inverted foot postures (as required in a fine-branch niche) and modifications for grasp-leaping evolved independently in basal strepsirrhine and haplorhine lineages. Am J Phys Anthropol 157:134-177, 2015. (c) 2015 Wiley Periodicals, Inc.