Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK.
Nature. 2017 Oct 26;550(7677):469-474. doi: 10.1038/nature24285. Epub 2017 Oct 18.
Diverse forms of nanoscale architecture generate structural colour and perform signalling functions within and between species. Structural colour is the result of the interference of light from approximately regular periodic structures; some structural disorder is, however, inevitable in biological organisms. Is this disorder functional and subject to evolutionary selection, or is it simply an unavoidable outcome of biological developmental processes? Here we show that disordered nanostructures enable flowers to produce visual signals that are salient to bees. These disordered nanostructures (identified in most major lineages of angiosperms) have distinct anatomies but convergent optical properties; they all produce angle-dependent scattered light, predominantly at short wavelengths (ultraviolet and blue). We manufactured artificial flowers with nanoscale structures that possessed tailored levels of disorder in order to investigate how foraging bumblebees respond to this optical effect. We conclude that floral nanostructures have evolved, on multiple independent occasions, an effective degree of relative spatial disorder that generates a photonic signature that is highly salient to insect pollinators.
不同形式的纳米结构会在物种内部和物种之间产生结构色并执行信号功能。结构色是光从近似规则周期结构的干涉产生的结果；然而，在生物有机体中，结构无序是不可避免的。这种无序是功能性的，受到进化选择的影响，还是仅仅是生物发育过程中不可避免的结果？在这里，我们表明无序纳米结构使花朵能够产生对蜜蜂有明显作用的视觉信号。这些无序的纳米结构（在被子植物的大多数主要谱系中都有发现）具有不同的解剖结构，但具有趋同的光学特性；它们都产生角度依赖的散射光，主要在短波长（紫外线和蓝色）。我们制造了具有纳米结构的人工花朵，这些结构具有定制的无序程度，以研究觅食的熊蜂如何对这种光学效应做出反应。我们的结论是，花的纳米结构已经在多个独立的场合进化出了有效的相对空间无序程度，从而产生了对昆虫传粉者高度显著的光子特征。
