It all started with a Hob Nob. As Dr Matt Morgan, an intensive care consultant, examined a patient who had suffered a cardiac arrest after inhaling some biscuit crumbs, he saw a flock of birds fly past the window. They must inhale objects all the time when flying, how do they survive? he thought to himself.

This began an investigation that spanned continents, species and millennia. For animal science has so much to teach us about human medicine. While some of the overlaps and parallels are obvious - we know how much DNA we share with primates, the first pig heart has been...