The humble sea sponge has been around for over 500 million years. We may think of them as ‘simple’ animals, with no brain, no nerves and no organs. But they have a pretty good party trick up their fleshy sleeves. Push a sponge through a mesh, until all that remains is a cloud of cells. Pour those cells into a tank, and watch as the cells reform themselves, like the terminator, back into a sponge.

Becky Ripley and Emily Knight ask: is it the same sponge it was before?

Featuring Professor Sally Leys from the University of Alberta, and Philosopher Charlie Huenemann from Utah State University.