Department of Evolutionary Anthropology, Duke University, Box 90383, Durham, NC, USA.
Department of Evolutionary Anthropology, Duke University, Box 90383, Durham, NC, USA.
J Hum Evol. 2019 Aug;133:23-31. doi: 10.1016/j.jhevol.2019.05.012. Epub 2019 Jun 17.
Given that most species of primates are predominantly arboreal, maintaining the ability to move among branches of varying sizes has presumably been a common selective force in primate evolution. However, empirical evaluations of the relationships between morphological variation and characteristics of substrate geometry, such as substrate diameter relative to an animal's body mass, have been limited by the lack of quantified substrate usage in the wild. Here we use recently published quantitative data to assess the relationships between relative substrate size and talar morphology in nine New World monkey species at the Tiputini Biodiversity Station, Ecuador. Within this sample, both fibular facet angle (the angle between the fibular facet and the trochlear rims) and body-mass-standardized area of the medial tibial facet decrease as average and maximum relative substrate size increases. Correlations between medial tibial facet area and relative substrate size are driven by the inclusion of callitrichids in this sample. Nevertheless, these findings strengthen the hypothesis that variation in fibular facet orientation and medial tibial facet area are functionally correlated with habitual degrees of pedal inversion. They also strengthen the notion that evolutionarily changing body mass could impact habitat geometry experienced by a lineage and thereby substantially impact major trends in primate morphological evolution. This study highlights the importance of empirical data on substrate use in living primates for inferring functional and evolutionary implications of morphological variation.
鉴于大多数灵长类动物主要是树栖动物，在进化过程中，能够在不同大小的树枝之间移动可能是一种常见的选择压力。然而，形态变异与基质几何特征（如基质直径相对于动物体重）之间关系的实证评估受到缺乏野外量化基质使用情况的限制。在这里，我们利用最近发表的定量数据，在厄瓜多尔的 Tiputini 生物多样性站评估了 9 种新世界猴物种中相对基质大小与距骨形态之间的关系。在这个样本中，腓骨面角（腓骨面与滑车边缘之间的角度）和内侧胫骨面标准化面积都随着平均和最大相对基质大小的增加而减小。内侧胫骨面面积与相对基质大小之间的相关性是由该样本中包括卷尾猴科引起的。尽管如此，这些发现还是加强了这样一种假设，即距骨面取向和内侧胫骨面面积的变化与习惯性的足趾内翻程度在功能上是相关的。它们还进一步证实了这样一种观点，即进化过程中体重的变化可能会影响谱系所经历的栖息地几何形状，并因此对灵长类动物形态进化的主要趋势产生重大影响。本研究强调了对生活中灵长类动物基质使用的实证数据的重要性，这些数据可用于推断形态变异的功能和进化意义。
