The unfortunately named Hagfish or Slime Eel reveals a lot about how fish evolved, remaining fairly similar to its form 300 million years ago. It has gills, but doesn't need them to breathe, so what are they for?Rewilding is the protection of natural habitat by reintroduction of native plants and animals and exclsuion of exotic species. But will it save our ecosystems?The Astronomy and Light Festival at Scienceworks in August is part of Science Week and the International Year of Light. Find out more by listening in to the show.