Sharks are primordial animals, unchanged for over 400 million years of evolution—or at least that is the received wisdom of television documentaries and science textbooks alike. Sharks and their relatives have long been looked to as a model for the primitive form of the vertebrates—animals with backbones, a diverse group spanning everything from humans and elephants, to dinosaurs, bony fishes, and sharks. This owes in part to the fact that sharks lack a bony skeleton and sport a host of other traits thought to be vestiges of vertebrate ancestry.
In this talk, Dr Martin Brazeau will describe how new fossil discoveries are challenging this view and how the fossil record is providing a unique window into the ancestry of vertebrate animals that simply can’t be extrapolated from the information found in genomes of living species. Dr Brazeau and his team of collaborators recently discovered 410-million-year-old fossil fish from Mongolia, that shows that a bony skeleton may well pre-date our last common ancestor with sharks. We will explore the meaning of this for our understanding of modern vertebrate species, how vertebrate skeletons evolved and generated new structures like jaws and teeth that allowed them to explore new ecologies, and even our understanding of the evolution of vertebrate genomes.
Martin Brazeau is Senior Lecturer in Ecology & Evolution in the Department of Life Sciences at Imperial College and a Scientific Associate at the Natural History Museum, UK. He earned his Bachelor of Science in Biology from McGill university in 2004 and his PhD in Evolutionary Organismal Biology in 2009 from Uppsala University. Since then, he has held fellowships at the Museum für Naturkunde in Berlin, Germany and Naturalis Biodiversity Centre in Leiden, The Netherlands. His research combines exploratory fieldwork and 3D imaging techniques to expose the evolutionary foundations of vertebrate animals and reveal how new, complex body plans and anatomies have originated. In the past decade, he has developed a conducted fieldwork in Mongolia and in northern Canada that is bringing to light unexpected early vertebrates that shed new light on the group’s origins and diversification.
Science Breaks is a virtual event series showcasing the impact and relevance of Imperial’s research and work taking place at the College.