Caroline Nolan, along with Professor Valerie Hall, and geologist Dr Mike Simms, travel back 16,000 years to a time when the vast ice sheets that gripped our landscape began to melt.

They imagine how the land stripped bare by the advancing glaciers might have looked and identify the early plant life which would have made its home on the rocky surface.

But how did those first plants get here? And how did they spread across an island scrubbed bare by thousands of years of advancing and retreating ice sheets?