Evolution, Development, and Ecology of Biomineralized Tissues

骨骼和牙齿的进化是一个适应性的突破，导致了脊椎动物的辐射。它们不仅提供支持，能量和增加功能能力，骨骼和牙齿还通过生物矿化过程中形成的生长标记和化学成分的变化记录了动物的生活史。该记录用于推断生活史特征，如生长速率、繁殖时间和存活率，以及生态特征，如食物网中的饮食偏好和营养水平。幸运的是，这些记录也可以在化石化的遗骸中捕捉到，从而可以根据现存动物的模式来解释灭绝动物的生活史特征和生态学。然而，这些生长标记的显微解剖结构及其在活体动物中的形成和变化尚未完全了解，特别是季节性和有限资源等环境因素如何影响生物矿化。该研究计划的长期目标是整合古生物学，进化发育生物学（Evo-Devo），生态学和地质学领域的数据，通过检查骨骼和牙齿超微结构来解释灭绝脊椎动物的生活史和生态位。该研究计划将在未来五年内培训12名HQP，包括实验室和现场工作。将使用不同类型的成像和显微镜，包括计算机断层扫描和光学显微镜，并使用透射电子显微镜在纳米级上研究脊椎动物化石的相对较新的方法。详细表征的生物矿化组织中的生长标志，从宏观到纳米级的活爬行动物（豹壁虎和绿色anoles）将阐明这些结构如何形成，它们形成的速度，以及在什么条件下。只有到那时，从现存动物身上收集到的信息才能对灭绝动物的生态学进行有意义的解释。此外，分析活体动物中生物矿化组织的化学成分对于分离化石材料中的生物化学特征和成岩特征至关重要。然后，从个体收集的数据可以在长达百万年的时间尺度上进行比较，以确定脊椎动物生活史与环境变化之间的关系。

The evolution of bones and teeth is an adaptive breakthrough that led to the radiation of vertebrate animals. Not only do they provide support, energy, and increase functional capability, bones and teeth also capture a record of an animal's life history through the formation of growth marks and changes in chemical composition during biomineralization. This record is used to infer life history traits such as growth rates, time of reproduction, and survivorship, and ecological traits such as dietary preference and trophic levels in food webs. Fortuitously, this record can also be captured in fossilized remains, thereby allowing for an interpretation of life history traits and ecology in extinct animals based on patterns in living animals. However, the microanatomical structure of these growth marks and their formation and variation in living animals is not fully understood, especially how environmental factors like seasonality and limited resources impact biomineralization. The long-term objective of this research program is to integrate data from the fields of paleontology, evolutionary developmental biology (Evo-Devo), ecology, and geology to interpret the life history and ecological niche of extinct vertebrates through examination of bone and tooth ultrastructure. This research program will train 12 HQP over the next five years in both lab and field work. Different types of imaging and microscopy will be used, including computed tomography and optical microscopy, with a relatively new approach to studying vertebrate fossils at the nanoscale using transmission electron microscopy. Detailed characterization of growth marks in biomineralized tissues from the macro- to the nanoscale in living reptiles (leopard geckos and green anoles) will elucidate how these structures form, the rate at which they form, and under what conditions. Only then, armed with the information gathered from living animals, can meaningful interpretations of extinct animal ecology from fossilized growth marks be undertaken. Furthermore, analyzing the chemical composition of the biomineralized tissue in living animals is paramount to separating biological chemical signatures from diagenetic signatures in fossil material. Data collected from individuals can then be examined in a comparative context over long, million-year timescales to determine relationships between vertebrate life history and environmental change in deep time.