Everything we know to be true in the world, and indeed outside of it, can be attributed to our willingness to reach out into the unknown and ask the most important questions.

From the edges of the universe to the core of the Earth itself, our unerring curiosity can lead us to the most incredible, unlikely and sometimes, well, unpleasant areas.

Enter Andreas Hejnol - Evolutionary Biologist and research leader at the University of Bergen in Norway, as he discusses the evolution of the anus, where it comes from and why it is the way it is.

First aired 14/04/2018