Stöckl Anna, Grittner Rebecca, Taylor Gavin, Rau Christoph, Bodey Andrew J, Kelber Almut, Baird Emily
Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Würzburg, Germany.
Institute for Globally Distributed Open Research and Education (IGDORE), Ribeirão Preto, Brazil.
Proc Biol Sci. 2022 Jul 27;289(1979):20220758. doi: 10.1098/rspb.2022.0758.
Animals vary widely in body size within and across species. This has consequences for the function of organs and body parts in both large and small individuals. How these scale, in relation to body size, reveals evolutionary investment strategies, often resulting in trade-offs between functions. Eyes exemplify these trade-offs, as they are limited by their absolute size in two key performance features: sensitivity and spatial acuity. Due to their size polymorphism, insect compound eyes are ideal models for studying the allometric scaling of eye performance. Previous work on apposition compound eyes revealed that allometric scaling led to poorer spatial resolution and visual sensitivity in small individuals, across a range of insect species. Here, we used X-ray microtomography to investigate allometric scaling in superposition compound eyes-the second most common eye type in insects-for the first time. Our results reveal a novel strategy to cope with the trade-off between sensitivity and spatial acuity, as we show that the eyes of the hummingbird hawkmoth retain an optimal balance between these performance measures across all body sizes.
动物在物种内部和物种之间的体型差异很大。这对大型和小型个体的器官及身体部位的功能都有影响。这些器官及身体部位如何随着体型变化，揭示了进化投资策略，通常会导致功能之间的权衡。眼睛就是这些权衡的例证，因为它们在两个关键性能特征（灵敏度和空间敏锐度）上受到绝对大小的限制。由于昆虫复眼具有大小多态性，因此是研究眼睛性能异速生长缩放的理想模型。先前关于并列复眼的研究表明，在一系列昆虫物种中，异速生长缩放导致小型个体的空间分辨率和视觉灵敏度较差。在这里，我们首次使用X射线显微断层扫描技术来研究重叠复眼中的异速生长缩放，重叠复眼是昆虫中第二常见的眼型。我们的研究结果揭示了一种应对灵敏度和空间敏锐度之间权衡的新策略，因为我们发现蜂鸟鹰蛾的眼睛在所有体型中都能在这些性能指标之间保持最佳平衡。
