蜥蜴体色在反捕食防御策略和性选择中的作用

Animal body coloration is a consequence of the compensation between natural and sexual selection. Theoretically, sexual selection will result in conspicuous body coloration, whereas natural selection will lead inconspicuous body coloration. One of the challenges biologists have been facing is to the degree of which the compensation between natural and sexual selection has to be conspicuous enough for sexual signaling but also cryptic enough for avoiding predators. Currently, there are 462 reptile species in China, of which, 188 are Sauria. They are mainly distributed in tropical and sub-tropical regions. Most importantly, they exhibit a variety of body colors. Surprisingly, no study has been conducted to explore the functional significance of lizard coloration in China. In this proposed study, from an eye’s view of predators, prey and mates, we aim to examine the diversity of lizard coloration and its role in anti-predator defence and sexual selection using an approach integrating field survey, spectrometry, visual modeling and behavioral experiments. We believe that our results will provide evidence and new perspectives for theories on animal sexual selection, mimesis and cryptic coloration. In the perspective of application prospect, cryptic and aposematic coloration of animals are of enormous significance for the application of bionics, military, and materials science.

动物体色的鲜艳与否是自然选择与性选择在漫长的进化过程中相互妥协的结果。理论上性选择会导致动物的体色越来越鲜艳，而自然选择却导致动物的体色越来越隐蔽。因此，长期困扰进化生物学家的问题是，自然选择与性选择是如何在进化过程中相互妥协使动物的体色对捕食者来说是足够的隐蔽，而对配偶而言又是足够的鲜艳。我国爬行动物现有462种，其中蜥蜴目188种，见于温暖到寒冷气候区，体色丰富多变。目前，国内很少学者研究爬行动物的体色及其生物学意义。本项目拟以我国海南热带地区常见的丽棘蜥为模式，通过运用和整合光谱分析、视觉模型、捕食及求偶交配行为学实验的方法，从捕食者及配偶的角度探讨蜥蜴的体色是否是自然选择与性选择相互妥协的结果, 进而检验蜥蜴体色的视觉信号假说及隐蔽色与警戒色等假说。本项目的研究结果将为动物性选择及保护色理论提供依据和新的观点。在应用上，动物的隐蔽保护色也可给仿生学、军事、材料科学提供极大参考价值。

在自然选择与性选择双重压力下，爬行动物丰富多样的体色一直是生物学家关注的热点。随着生物科学技术的不断发展，已知动物色彩视觉与人类存在显著差异，因此，从动物视觉系统的角度重新评估动物体色的功能与适应性意义更为准确和客观。本实验以海南地区常见种变色树蜥为研究对象，通过对动物体色反射率测量与动物色彩视觉模型的定量分析，比较捕食者与猎物两类视觉信号接收者眼中的蜥蜴体色变化与差异，检验捕食关系中的隐蔽色和拟态色假说。实验结果表明，鬣蜥科变色树蜥存在性二型现象；在捕食者眼中，雌性隐蔽色功能优于雄性，雄性蜥蜴被捕食风险更高；在猎物眼中，雄性蜥蜴更易被猎物察觉，雌性蜥蜴捕食成功率更高。该研究结果为已有的体色功能假说提供了重要科学依据，进一步加深对自然选择和性选择演化理论的理解和认知。