Modular color evolution facilitated by a complex nanostructure in birds
Modular color evolution facilitated by a complex nanostructure in birds
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DOI：
10.1111/evo.12575
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发表时间：
2015-02-01
期刊：
影响因子：
3.3
通讯作者：
Shawkey, Matthew D.
中科院分区：
文献类型：
--
作者：
Eliason, Chad M.;Maia, Rafael;Shawkey, Matthew D.
一个复杂性状的变化和进化方式受到其亚单位的独立性或模块性的严重影响。模块化设计如何促进表型多样化在非装饰性（例如，慈鲷科的颌），但不是观赏性状。鸟类羽毛的不同颜色是由色素的光吸收和/或纳米结构的光散射产生的。这样的结构颜色是确定性相关的纳米结构，产生它们，因此是很好的系统来研究模块化和多样性的观赏性状。阐明这些纳米结构是否以及如何促进颜色多样性依赖于理解纳米结构特征如何协变，以及这些特征如何映射到颜色。这两种情况在进化背景下仍然是未知的。大多数鸭子（鸭科）有一个明显的翅膀补丁与彩虹色的颜色造成的二维光子晶体的小（100-200纳米）黑素体。在这里，我们问这个复杂的纳米结构如何影响颜色属性的模块化。使用电子显微镜，分光光度计和比较方法的组合，我们表明，纳米结构的复杂性导致功能解耦，使不同的颜色性状的独立进化。这些结果表明，纳米结构的功能促进了颜色的多样性，并可能解释为什么有些鸟类比其他鸟类更具有颜色多样性。
The way in which a complex trait varies, and thus evolves, is critically affected by the independence, or modularity, of its subunits. How modular designs facilitate phenotypic diversification is well studied in nonornamental (e.g., cichlid jaws), but not ornamental traits. Diverse feather colors in birds are produced by light absorption by pigments and/or light scattering by nanostructures. Such structural colors are deterministically related to the nanostructures that produce them and are therefore excellent systems to study modularity and diversity of ornamental traits. Elucidating if and how these nanostructures facilitate color diversity relies on understanding how nanostructural traits covary, and how these traits map to color. Both of these remain unknown in an evolutionary context. Most dabbling ducks (Anatidae) have a conspicuous wing patch with iridescent color caused by a two-dimensional photonic crystal of small (100-200 nm) melanosomes. Here, we ask how this complex nanostructure affects modularity of color attributes. Using a combination of electron microscopy, spectrophotometry, and comparative methods, we show that nanostructural complexity causes functional decoupling and enables independent evolution of different color traits. These results demonstrate that color diversity is facilitated by how nanostructures function and may explain why some birds are more color-diverse than others.