The sheer scale and diversity of life on this planet is absolutely staggering.
From the smallest micro-organisms to the largest animals, life always seems to find a way to adapt in order to give it the best chance of surviving.
And the way we, or other creatures, come into this world is just one example of this.
While most of the animal kingdom lays eggs, we and almost all other mammals, have taken a different route.
Dr Elsa Panciroli, Research Fellow at the Oxford University Museum of Natural History & author of ‘Beasts Before Us: The Untold Story of Mammal Origins and Evolution’ joined Jonathan to disuss the evolution of mammalian life and what makes a mammal a mammal in the first place.