Processed Backgrounds Data 20 percent markers SUBMITTED r1.zip from Ancient insect vision tuned for flight among rocks and plants underpins natural flower colour diversity

Understanding the origins of flower colour signalling to pollinators is fundamental to evolutionary biology and ecology. Flower colour evolves under pressure from visual systems of pollinators, like birds and insects, to establish global signatures among flowers with similar pollinators. However, an understanding of the ancient origins of this relationship remains elusive. Here, we employ computer simulations to generate artificial flower backgrounds assembled from real material sample spectra of rocks, leaves and dead plant materials, against which to test flowers' visibility to birds and bees. Our results indicate how flower colours differ from their backgrounds in strength, and the distributions of salient reflectance features when perceived by these key pollinators, to reveal the possible origins of their colours. Since Hymenopteran visual perception evolved before flowers, the terrestrial chromatic context for its evolution to facilitate flight and orientation consisted of rocks, leaves, sticks and bark. Flowers exploited these pre-evolved visual capacities of their visitors, in response evolving chromatic features to signal to bees, and differently to birds, against a backdrop of other natural materials. Consequently, it appears that today's flower colours may be an evolutionary response to the vision of diurnal pollinators navigating their world millennia prior to the first flowers.

解析花色向传粉者传递信号的起源，是进化生物学与生态学领域的核心基础问题。花色会在鸟类、昆虫等传粉者的视觉系统选择压力下演化，从而在依赖同类传粉者的花卉间形成统一的视觉特征标识。然而，这一协同关系的远古起源仍难以厘清。本研究通过计算机模拟，以岩石、叶片与枯植物残体的真实样本光谱为基础构建人工花卉背景，以此测试花卉在鸟类与蜂类视觉中的可见性。研究结果揭示了在两类关键传粉者的视觉感知下，花色与背景在色彩强度上的差异，以及显著反射特征的分布规律，从而为解析花色的起源提供了可能的线索。由于膜翅目（Hymenopteran）的视觉感知系统演化早于开花植物，其为辅助飞行与定向而演化出的陆地色彩环境，由岩石、叶片、枯枝与树皮构成。花卉则利用了其传粉者此前已演化出的视觉能力，通过演化出适配自然背景的色彩特征，分别向蜂类与鸟类传递信号，且二者的信号模式存在差异。由此可见，现今的花色或许是对昼行性传粉者视觉系统的演化响应——而这类传粉者的视觉系统早在首批开花植物诞生数千年前，就已为了导航自身生存环境而演化完成。