DNA (deoxyribonucleic acid) is a molecule that encodes the genetic information within every species of life on earth. The information contained within the sequence of base pairs determines how any given organism develops and biologically functions.

DNA is not just limited to the biological world, but is also now being utilised in palaeontology. But why is DNA not normally preserved? What's the oldest DNA we can recover? And what can we learn about fossil animals from their DNA? We spoke to ancient DNA expert Dr Ross Barnett in order to get answers.