Network Modularity Middle Ear Evolution

We have studied the anatomical transformations in the mammalian middle ear evolution using Anatomical Network Analysis (AnNA). With our network models, we have tested the role of the bone disconnection trend as the most plausible Evo-Devo mechanism underlying this evolutionary transition. We have identified three types of network modules relating to the jaw-otic complex of synapsids, and five evolutionary stages throughout the mammalian middle ear evolution. We identify two modularity changes, pointing out two developmental events as the key factors in the middle ear evolution: the ossification and posterior degradation of the Meckel's cartilage, and the full disconnection of middle ear bones from their mandibular origin.