Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom.
University of Oxford Botanic Garden, Oxford OX1 4AZ, United Kingdom.
Proc Natl Acad Sci U S A. 2023 Sep 19;120(38):e2306268120. doi: 10.1073/pnas.2306268120. Epub 2023 Sep 7.
Carnivorous pitcher plants () are a striking example of a natural pitfall trap. The trap's slippery rim, or peristome, plays a critical role in insect capture via an aquaplaning mechanism that is well documented. While the peristome has received significant research attention, the conspicuous variation in peristome geometry across the genus remains unexplored. We examined the mechanics of prey capture using pitcher plants with divergent peristome geometries. Inspired by living material, we developed a mathematical model that links the peristomes' three-dimensional geometries to the physics of prey capture under the laws of Newtonian mechanics. Linking form and function enables us to test hypotheses related to the function of features such as shape and ornamentation, orientation in a gravitational field, and the presence of "teeth," while analysis of the energetic costs and gains of a given geometry provides a means of inferring potential evolutionary pathways. In a separate modeling approach, we show how prey size may correlate with peristome dimensions for optimal capture. Our modeling framework provides a physical platform to understand how divergence in peristome morphology may have evolved in the genus in response to shifts in prey diversity, availability, and size.
食虫猪笼草（）是天然陷阱的一个显著例子。陷阱的光滑边缘，或口盖，通过水滑机制在昆虫捕获中起着关键作用，该机制已有充分的记录。虽然口盖已经受到了大量的研究关注，但该属中口盖几何形状的明显变化仍然没有得到探索。我们使用具有不同口盖几何形状的猪笼草研究了猎物捕获的力学。受活体材料的启发，我们开发了一个数学模型，将口盖的三维几何形状与牛顿力学定律下的猎物捕获物理学联系起来。将形式和功能联系起来使我们能够测试与特征（如形状和装饰、在重力场中的方向）的功能相关的假设，以及“牙齿”的存在，而对给定几何形状的能量成本和收益的分析则提供了一种推断潜在进化途径的方法。在另一种建模方法中，我们展示了猎物大小如何与口盖尺寸相关，以实现最佳捕获。我们的建模框架为理解口盖形态的差异如何在属中进化提供了一个物理平台，以应对猎物多样性、可获得性和大小的变化。
