Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
J R Soc Interface. 2012 Dec 7;9(77):3240-8. doi: 10.1098/rsif.2012.0473. Epub 2012 Aug 15.
Among a myriad of spider web geometries, the orb web presents a fascinating, exquisite example in architecture and evolution. Orb webs can be divided into two categories according to the capture silk used in construction: cribellate orb webs (composed of pseudoflagelliform silk) coated with dry cribellate threads and ecribellate orb webs (composed of flagelliform silk fibres) coated by adhesive glue droplets. Cribellate capture silk is generally stronger but less-extensible than viscid capture silk, and a body of phylogenic evidence suggests that cribellate capture silk is more closely related to the ancestral form of capture spiral silk. Here, we use a coarse-grained web model to investigate how the mechanical properties of spiral capture silk affect the behaviour of the whole web, illustrating that more elastic capture spiral silk yields a decrease in web system energy absorption, suggesting that the function of the capture spiral shifted from prey capture to other structural roles. Additionally, we observe that in webs with more extensible capture silk, the effect of thread strength on web performance is reduced, indicating that thread elasticity is a dominant driving factor in web diversification.
在众多的蜘蛛网几何形状中，圆网呈现出一种迷人的、精致的建筑和进化范例。根据用于建筑的捕捉丝，圆网可以分为两类：具栉状附属丝的圆网（由拟栉状丝组成），附有干燥的栉状线；而不具栉状附属丝的圆网（由丝状纤维组成），附有粘性胶滴。具栉状附属丝的捕捉丝通常比粘性捕捉丝更强但弹性更小，并且系统发育证据表明，具栉状附属丝的捕捉丝与祖先形式的捕捉螺旋丝更为密切相关。在这里，我们使用一种粗粒化的蛛网模型来研究螺旋捕捉丝的机械性能如何影响整个蛛网的行为，结果表明，更具弹性的捕捉螺旋丝会导致蛛网系统能量吸收减少，这表明捕捉螺旋丝的功能从捕捉猎物转移到其他结构角色。此外，我们还观察到，在具有更具弹性捕捉丝的网中，线强度对线性能的影响减小，这表明线弹性是蛛网多样化的主导驱动因素。
