Discuss the general trends in locomotion observed in the transition from water to land, as well as in the origins of amniotes and of mammals, with regards of the role of the vertebral column, the function of paired appendages, and limb posture. Refer back to the “big tree” cladogram (fig. 3.1) and plot these changes on a cladogram. Some of the key features are synapomorphies that we already discussed.Discuss the evolution of paired appendages. What is the structure of pectoral and pelvic fins in different groups of fishes? What structures of the tetrapod limb are homologous with structures in the fin of an early sarcopterygian fish? What does this tell us about the origin of the different components of the tetrapod limb?