高原鼠兔食谱和牙齿微形貌地理差异和种群分化

In addition to abiotic factors such as climate and soil, interspecific interactions (such as nutrient relationships) are also driving forces for species evolution. Exploring the adaptation of species to interspecific relationships is both the task of evolutionary biology and the frontier of ecology. Small herbivores are limited by their ability to migrate, and their diet is easily restricted by plant communities. Differences in diet can affect the morphology and structure of herbivores. Therefore, it can be hypothesized that the composition of plant communities may be the evolutionary driving force of small herbivores. However, for a long time, it has been difficult to determine 1) quantitative diet and 2) the relationship between diet and morphological structure. This research plans to use high-throughput sequencing and DNA-barcode technologies to determine the quantitative diet, use dental micromorphology as a morphological feature linking diets and species evolution, proposed by exploring the relationship betwwen diets and teeth microtopography of pika from different habitats in the northeast of qinghai-tibet plateau plateau, clear the influence of the diets for teeth microtopography , verify the role of diet differences in species diversity differentiation. The expected results of the project can increase the understanding of the driving force of species evolution and its mechanism, have important theoretical significance. Moreover, it can also establish a set of models to predict diets through the micromorphology of teeth, which has application value.

除了气候和土壤等非生物因子外，种间相互作用（例如营养关系）也是影响物种演化的驱动力。探索物种对种间关系的适应，既是进化生物学的任务，也是生态学的研究前沿。小型食草动物受限于迁徙能力，其食谱易受植物群落限制，而食谱差异能影响食草动物的形态和结构。因此，可以假设，植物群落的组成可能是小型食草动物演化驱动力。然而，长期以来，1)定量食谱确定困难、2)食谱与形态结构关系难以确定，目前相关的实证案例极少。本研究计划使用高通量测序技术和基因条形码技术明确定量食谱，使用牙齿微形貌作为联系食谱和物种演化的形态特征，拟通过探究青藏高原东北部不同栖息地高原鼠兔食谱与牙齿微形貌的关系，明确食谱对牙齿微形貌的影响，验证食谱差异在物种多样性分化中的作用。项目预期结果不仅可以增加对物种演化的驱动力及其作用机制的理解，具有重要的理论意义，还可以建立一套通过牙齿微形貌预测食谱的模型，具有应用价值。

本课题研究了食谱差异在特定广食性哺乳动物的多样化过程中的作用，验证了食性生态位变化在帮助物种环境适应的功能。本研究利用DNA条形码分析探索了高原鼠兔的食谱结构和消化道菌群结构，并利用牙齿微磨痕定量分析技术，分析了不同生境和历史时期哺乳动物的食性生态位变化。首先，结果表明海拔高度与食谱、摄食偏好和地点间微生物群落差异有显著相关性，暗示食谱适应是高原适应的必要组成部分。其次，研究发现，肠道菌群结构通过摄食偏好与食谱结构相关，且肠道菌群对海拔高度也有显著响应，提示肠道菌群发挥了增加食谱灵活性的作用，从而有助于高原鼠兔适应不同海拔的生境。最后，研究结果证明，牙齿微磨痕结构与食谱密切相关，牙齿微磨痕分析的结果反映食草动物可以通过灵活的食谱在一定程度上抵抗长期气候变化和近期环境变化，来维持其种群规模。本研究的结论验证了DNA条形码和牙齿磨痕分析技术在食性生态位研究中的可行性，强调了食性生态位变化在广食性哺乳动物多样化和环境适应中的贡献，为哺乳动物的高海拔适应机制提供了新的视角，为评估野生动物对环境变化的响应提供了新的见解。