The relationship between microhabitat use, allometry and functional variation in the eyes of Hawaiian Megalagrion damselflies
The relationship between microhabitat use, allometry and functional variation in the eyes of Hawaiian Megalagrion damselflies
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DOI：
10.1111/1365-2435.12479
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发表时间：
2016-03-01
影响因子：
5.2
通讯作者：
Butler, Marguerite A.
中科院分区：
文献类型：
--
作者：
Scales, Jeffrey A.;Butler, Marguerite A.
1.视觉系统的进化是由环境、动物眼睛的大小和分辨率敏感度权衡所施加的物理限制所施加的视觉要求所引导的。给定一个特定的眼睛表面积，分辨率和灵敏度不能同时最大化：分辨率的提高，眼睛检测细节的能力，将以灵敏度为代价，捕获光子的能力，反之亦然，而不会增加眼睛的大小。这种约束如何与生态相互作用，以及它是否允许微调的视觉系统，以较小规模的栖息地异质性仍然是一个未充分研究的问题，在视觉生态学。2.在这里，我们使用密切相关的物种豆娘在夏威夷属Megalagrion不同的生态测试分辨率敏感性权衡的变化是否是缩放或微生境使用的差异的进化结果。我们使用回归分析和系统发育比较的方法来研究的大小和微生境的使用特性相关的光敏感性和视觉分辨率的影响。3.我们发现，眼睛的大小是密切相关的身体大小在这些豆娘，但其他视觉形态特征相关的光敏感性和分辨率与微生境类型。此外，大小和形态的关系各不相同的微生境，和性能相关的分辨率往往比光敏感性的变化更保守。4.此外，较小的物种在视觉上具有挑战性的微栖息地有更多的区域化的眼睛比物种更大的眼睛在开放，光线充足的地区。因此，眼睛的区域化允许大小和形态/性能的解耦，使得即使是小的昆虫物种也可以利用视觉上具有挑战性的栖息地。这些结果表明，在视觉性能的变化的结果，从眼睛的几何形状以及大小的变化。这些形态变化可能是适应微生境的差异，表明微生境的变化，即使在小尺度上，也可以在视觉系统的进化中发挥重要作用。
1. The evolution of visual systems is guided by visual requirements imposed by the environment, the size of the animal's eyes, and physical limitations imposed by the resolution-sensitivity trade-off. Given a particular eye surface area, resolution and sensitivity cannot be simultaneously maximized: gains in resolution, the ability of the eye to detect detail, will come at the cost of sensitivity, the ability to capture photons, and vice versa, without an increase to eye size. How this constraint interacts with ecology and whether it allows the fine-tuning of the visual system to smaller scale habitat heterogeneity remains an understudied question in visual ecology. 2. Here, we use closely-related species of damselflies in the Hawaiian genus Megalagrion which differ in ecology to test whether variation in the resolution-sensitivity trade-off is the evolutionary result of scaling or differences in microhabitat use. We use regression analyses and phylogenetic comparative methods to examine the effects of size and microhabitat use on traits related to light sensitivity and visual resolution. 3. We find that eye size is tightly associated with body size in these damselflies, but other visual morphology traits related to light sensitivity and resolution are associated with microhabitat type. Furthermore, size and morphology relationships vary across microhabitats, and performance related to resolution tends to be more conserved than to variation in light sensitivity. 4. Additionally, smaller species in visually challenging microhabitats have more regionalized eyes than species with larger eyes in open, well-lit areas. Thus, regionalization of the eye allows a decoupling of size and morphology/performance so that even small insect species can exploit visually challenging habitats. These results suggest that variation in visual performance results from changes in eye geometry as well as size. These morphological changes are likely adaptive to differences in microhabitat, indicating that variation in microhabitat use, even at small scales, can play an important role in the evolution of visual systems.