The pharynx is an important region of the vertebrate body that is involved in many key processes including feeding, respiratory and vascular functions, immune and endocrine activities. However, with the colonisation of land by vertebrates, the pharynx underwent substantial modification and it is this that we wish to understand. In this talk, I will discuss the development of the pharynx and how this has been altered to facilitate terrestrial life. To understand how the development of the pharynx has been modified through evolution, we take a comparative approach. This involves analysing pharyngeal development using a range of cellular and molecular approaches: immunostaining, in situ hybridisation, morpholino knockdowns, lineage tracing and pharmacological inhibition of signalling pathways, in embryos that are chosen for the phylogenetic position. These include shark, zebrafish, chick and mouse embryos. We have considered how features have been lost; the gills and their covering, the operculum, and how new structures; the parathyroid glands, have emerged. We find that although the gills were lost from the adult forms, the gill primordia persist in land vertebrates and that they have been transformed into the parathyroid glands. We further find that the operculum was also not completely lost but that it exists transiently at embryonic stages. This work is significant as it lays out the progressive nature of evolutionary change and shows that the modification underpinning the emergence of the tetrapods were not as abrupt as previously believed. Finally, this work also highlights the utility of comparative approaches involving embryos of multiple species to address key problems in vertebrate biology.