Dissertation Research: Evolution and Functional Morphology of the Theropod Foot

由于拇指（第一趾）对人类的抓握至关重要，第一趾（像人类的大脚趾）在鸟类中对栖息和抓住猎物至关重要。 尽管第一趾对鸟类很重要，但它的解剖、进化和功能尚未被研究。 这项研究将解决两个主要问题，这将导致更完整的了解鸟脚。 首先，通过与已知鸟类化石的比较，研究鸟类拇趾的早期进化。 其次，对活鸟类脚功能的研究将比较肌肉功能和力量输出，以深入了解可能塑造鸟类脚进化的功能因素。鸟类栖息足的进化似乎是生物学中一个相对普遍的现象，即结构复制的分化。 拥有一个结构的“额外”副本允许生物体用一个副本探索新的功能或行为领域，同时用另一个副本保持原始功能。 因此，更好地了解鸟类脚的进化将有助于了解其他结构的进化，如人类拇指，多余的下巴肌肉组织和鱼类摄食，以及基因复制，所有这些都是这种现象的例子。

As the thumb (digit I) is vital for grasping in humans, digit I (like the human big toe) in birds is critical for both their perching and holding prey. Despite the importance of digit I to birds, its anatomy, evolution, and function have not been studied. This study will address two primary questions, which will lead to a more complete understanding of the avian foot. First, the early evolution of the avian hallux will be investigated through comparisons of known avian fossils. Second, a study of foot function among living birds will compare muscle function and force output to lend insights into functional factors that may have shaped the evolution of bird feet. The evolution of the perching foot of birds appears to exemplify a relatively common phenomenon in biology, the differentiation of a structural copy. Having an "extra" copy of a structure allows the organism to explore a new functional or behavioral realm with one copy while maintaining the primitive function with another. Thus, a better understanding of avian foot evolution will contribute to understanding the evolution of other structures as diverse as the human thumb, redundant jaw musculature and fish feeding, and gene duplications, all of which are examples of this phenomenon.