菊头蝠科蝙蝠适应辐射的感官生态机制研究

Why do some lineages comprise many species and a wide range of ecological variation, while others encompass only few species that vary little from one another? Current evidences show that ecological opportunity unlocked by morphological innovations of species plays a key role in triggering adaptive radiation of lineages. However, no final conclusion has been reached on whether sensory phenotypic innovations can also trigger the progress of adaptive radiation. Moreover, the function of innovative phenotype performance in exploiting and adapting to ecological opportunity is uncertain. Finally, the role of ecological divergent selection in speciation is significant, but whether the similar pattern occurs in sensory drive model is unclear. To address these problems, here, we analyse large and comprehensive datasets summarizing sensory phenotype, phenotype performance and habitat traits, and relate these traits to diversi?cation rates throughout the evolutionary history of an ecologically diverse family of mammals (Chiroptera: Rhinolophidae) to elucidate evolution and relationship of traits and test the hypothesis that the evolution of habitat traits and a sensory phenotype that improved phenotype performance is associated with increasing diversi?cation rates in this family, and then to reveal divers and mechanisms of adaptive radiation. Consequently, the study will show the innovative achievements in sensory ecology and evolutionary biology and profound significance and implication for the mechanism of sensory drive speciation, the origin of ecological adaptations, and the genesis of biological diversity, and thus can provide science countermeasures and basis for biodiversity conservation in bats.

为什么一些世系含有丰富的物种多样性且具有广泛的生态变化，而另一些仅包括很少量的物种且生态多样性极低？目前的证据表明物种借助"形态革新"并抓住"生态机会"是触发世系适应辐射的关键。然而，感官表型的革新是否也能触发适应辐射尚无定论；革新表型的性能对物种开拓和适应"生态机会"的作用仍不确定；感官推动的物种形成模式是否参与适应辐射的过程尚不清楚。本项目针对上述科学问题，在多学科交叉的基础上，通过对菊头蝠科蝙蝠的感官表型、表型性能和生境特征的综合比较，结合菊头蝠物种的分子系统发育历史，阐明3个性状的进化及关系，验证生境特征和提高菊头蝠表型性能的感官表型的进化将与物种分歧速率的增加相关这一假说，揭示菊头蝠科蝙蝠适应辐射的驱动力和机制，将在进化生物学和感官生态学领域取得创新性成果，对揭示物种形成的感官推动机制、生态适应性的起源和生物多样性的进化具有重要意义，为蝙蝠生物多样性保育提供科学对策和依据。

适应辐射由新物种形成和候选物种对多样化生态位的适应两个过程构成，其内容是桥连生态和进化的最重要过程。本项目以菊头蝠科和蹄蝠科蝙蝠为研究对象，综合物理声学、生态学和遗传进化等的理论和方法，通过行为实验、种群间和种间比较，试图阐明菊头蝠科蝙蝠物种形成的过程和机制。研究发现菊头蝠科蝙蝠感官表型（鼻腔和外耳）能更好地预测其回声定位声波频率的变化。且普氏蹄蝠鼻叶运动能动态地调控其回声定位声波的发射和声场。这些结果证实菊头蝠科和蹄蝠科蝙蝠感官表型（鼻叶、鼻腔和外耳）和其表型性能（回声定位声波）之间存在紧密联系。这种表型的“形态革新”使菊头蝠科和蹄蝠科蝙蝠发出有别于其他蝙蝠类群的恒频型回声定位声波，能够在复杂的森林环境中捕食振翅的昆虫，进而成功地抓住“生态机会”。以代表物种马铁菊头蝠和大蹄蝠为研究对象，发现其种群间回声定位的分歧受文化漂变和生态选择的驱动。同时，以隐藏种大耳菊头蝠复合体为典型研究对象，证实大耳菊头蝠复合体具有复杂的进化历史，包括体型和回声定位声波均显著差异的两个物种。揭示更新世冰期循环导致了种群分化和异域物种形成，冰期后种群间发生了二次联系和基因渗入。上述结果阐明菊头蝠科蝙蝠物种形成的基本过程，即环境变化可能同时或次序地促使形态改变和信号分歧，并进一步促进交配隔离和物种形成。本研究在进化生物学和感官生态学领域取得创新性成果，验证和发展了物种形成的感官驱动假说，丰富了物种形成理论，为蝙蝠生物多样性保育提供科学对策和依据。