Gai Zhikun

Biography

Developmental biologists had been working in parallel to solve the same problem, but by comparing the embryology of living jawless and jawed vertebrates, hoping to explain the difference between these two evolutionary grades of organisation in terms of changed temporal and spatial domains of expression of regulatory genes. They concluded that jawless vertebrates lack jaws because the migratory cells from which jaws develop are prevented from migrating to the site of jaw development by the peculiar nose that sits in the middle of the face of jawless vertebrates. By virtue of the synchrotron tomography beamline, we show that in galeaspid‘Shuyu’ – and by implication, the ancestor of jawed vertebrates - the paired nasal organs had separated, removing this nasal blockage, but since galeaspids lacked jaws, it was presumably the consequence of a different selective drive, most likely enhanced olfaction

Research Interest

The origin of jawed vertebrates represents that last major overhaul of vertebrate anatomy in our deep evolutionary ancestry. Our research sought to better understand the gradual changes in the organisation of the head through this formative episode in evolutionary history. We achieved this chiefly by elucidating the anatomy of the head of a group of extinct fossil fishes called the galeaspids which reflect the nature of the immediate ancestors of jawed vertebrates.