The Evolution of Teeth (Summer Repeat)

Melvyn Bragg and guests discuss theories about the origins of teeth in vertebrates, and what we can learn from sharks in particular and their ancestors. Great white sharks can produce up to 100,000 teeth in their lifetimes. For humans, it is closer to a mere 50 and most of those have to last from childhood. Looking back half a billion years, though, the ancestors of sharks and humans had no teeth in their mouths at all, nor jaws. They were armoured fish, sucking in their food. The theory is that either their tooth-like scales began to appear in mouths as teeth, or some of their taste buds became harder. If we knew more about that, and why sharks can regenerate their teeth, then we might learn how humans could grow new teeth in later lives. With Gareth Fraser Assistant Professor in Biology at the University of Florida Zerina Johanson Merit Researcher in the Department of Earth Sciences at the Natural History Museum and Philip Donoghue Professor of Palaeobiology at the University of Bristol Producer: Simon Tillotson

Om Podcasten

Spanning history, religion, culture, science and philosophy, In Our Time from BBC Radio 4 is essential listening for the intellectually curious. In each episode, host Melvyn Bragg and expert guests explore the characters, events and discoveries that have shaped our world. History fans can learn about pivotal wars and societal upheavals, such as the rise and fall of Napoleon, the Sack of Rome in 1527, and the political intrigue of the Russian Revolution. Those fascinated by the lives of kings and queens can journey to Versailles to meet Marie Antoinette and Louis XIV the Sun King, or to Ancient Egypt to meet Cleopatra and Nerfertiti. Or perhaps you’re looking to explore the history of religion, from Buddhism’s early teachings to the Protestant Reformation. If you’re interested in the stories behind iconic works of art, music and literature, dive in to discussions on the artistic genius of Michelangelo's Sistine Chapel and Van Gogh’s famous Sunflowers. From Gothic architecture to the works of Shakespeare, each episode of In Our Time offers new insight into humanity’s cultural achievements. Those looking to enrich their scientific knowledge can hear episodes on black holes, the Periodic Table, and classical theories of gravity, motion, evolution and relativity. Learn how the discovery of penicillin revolutionised medicine, and how the death of stars can lead to the formation of new planets. Lovers of philosophy will find episodes on the big issues that define existence, from free will and ethics, to liberty and justice. In what ways did celebrated philosophers such as Mary Wollstonecraft and Karl Marx push forward radical new ideas? How has the concept of karma evolved from the ancient Sanskrit texts of Hinduism to today? What was Plato’s concept of an ideal republic, and how did he explore this through the legend of the lost city of Atlantis? In Our Time celebrates the pursuit of knowledge and the enduring power of ideas.