Edel Carina, Rühr Peter T, Frenzel Melina, van de Kamp Thomas, Faragó Tomáš, Hammel Jörg U, Wilde Fabian, Blanke Alexander
Bonn Institute for Organismic Biology, University of Bonn, Bonn, Germany.
Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Karlsruhe, Germany.
Evolution. 2024 Dec 2;78(12):1958-1968. doi: 10.1093/evolut/qpae121.
Although species evolve in response to many intrinsic and extrinsic factors, frequently one factor has a dominating influence on a given organ system. In this context, mouthpart shape and function are thought to correlate strongly with dietary niche and this was advocated for decades, e.g., for insects. Orthoptera (grasshoppers, crickets, and allies) are a prominent case in this respect because mandible shape has been even used to predict feeding preferences. Here, we analyzed mandible shape, force transmission efficiency, and their potential correlation with dietary categories in a phylogenetic framework for 153 extant Orthoptera. The mechanical advantage profile was used as a descriptor of gnathal edge shape and bite force transmission efficiency in order to understand how mandible shape is linked to biting efficiency and diet, and how these traits are influenced by phylogeny and allometry. Results show that mandible shape, in fact, is a poor predictor of feeding ecology and phylogenetic history has a strong influence on gnathal edge shape. Being ancestrally phytophagous, Orthoptera evolved in an environment with food sources being always abundant so that selective pressures leading to more specialized mouthpart shapes and force transmission efficiencies were low.
尽管物种会因许多内在和外在因素而进化，但通常一个因素会对特定器官系统产生主导影响。在这种情况下，口器的形状和功能被认为与饮食生态位密切相关，几十年来人们一直主张这一点，例如对于昆虫来说。直翅目（蚱蜢、蟋蟀及相关物种）在这方面是一个突出的例子，因为下颚形状甚至被用来预测取食偏好。在这里，我们在一个系统发育框架内分析了153种现存直翅目的下颚形状、力传递效率及其与饮食类别的潜在相关性。机械优势剖面图被用作颚边缘形状和咬合力传递效率的描述符，以便了解下颚形状如何与咬合力效率和饮食相关联，以及这些特征如何受到系统发育和异速生长的影响。结果表明，事实上，下颚形状并不能很好地预测取食生态，系统发育历史对颚边缘形状有很大影响。直翅目在其祖先为植食性的情况下，是在食物来源一直丰富的环境中进化的，因此导致口器形状和力传递效率更加特化的选择压力较低。
