School of Life Sciences, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, China.
Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117, China.
Sci Rep. 2017 Sep 19;7(1):11837. doi: 10.1038/s41598-017-12090-3.
Phylogenetic inference typically invokes nocturnality as ancestral in primates; however, some recent studies posit that diurnality is. Here, through adaptive evolutionary analyses of phototransduction genes by using a variety of approaches (restricted branch/branch-site models and unrestricted branch-site-based models (BS-REL, BUSTED and RELAX)), our results consistently showed that ancestral primates were subjected to enhanced positive selection for bright-light vision and relatively weak selection for dim-light vision. These results suggest that ancestral primates were mainly diurnal with some crepuscularity and support diurnality as plesiomorphic from Euarchontoglires. Our analyses show relaxed selection on motion detection in ancestral primates, suggesting that ancestral primates decreased their emphasis on mobile prey (e.g., insects). However, within primates, the results show that ancestral Haplorrhini were likely nocturnal, suggesting that evolution of the retinal fovea occurred within ancestral primates rather than within haplorrhines as was previously hypothesized. Our findings offer a reassessment of the visual adaptation of ancestral primates. The evolution of the retinal fovea, trichromatic vision and orbital convergence in ancestral primates may have helped them to efficiently discriminate, target, and obtain edible fruits and/or leaves from a green foliage background instead of relying on mobile insect prey.
系统发育推断通常认为夜行性是灵长类动物的祖先特征；然而，一些最近的研究认为日行性才是。在这里，我们通过使用多种方法（受限分支/分支位点模型和无限制分支位点模型（BS-REL、BUSTED 和 RELAX））对光转导基因进行适应性进化分析，我们的结果一致表明，原始灵长类动物的强光视觉受到了增强的正选择，而弱光视觉受到了相对较弱的选择。这些结果表明，原始灵长类动物主要是昼行性的，具有一些黄昏性，并且支持从真兽亚纲到灵长类动物的日行性是原始特征。我们的分析表明，原始灵长类动物的运动检测受到了放松的选择，这表明原始灵长类动物减少了对移动猎物（例如昆虫）的重视。然而，在灵长类动物中，结果表明原始的简鼻亚目动物可能是夜行性的，这表明视网膜中央凹的进化发生在原始灵长类动物中，而不是以前假设的简鼻亚目中。我们的发现提供了对原始灵长类动物视觉适应的重新评估。视网膜中央凹、三色视觉和原始灵长类动物的眼眶会聚的进化可能帮助它们从绿色树叶背景中有效地识别、瞄准和获取可食用的果实和/或叶子，而不是依赖于移动的昆虫猎物。
