Our species started in Africa, but what was the last habitable landmass we reached? CrowdScience presenters Marnie Chesterton and Geoff Marsh team up to investigate how and when our species journeyed around the world and settled its most far flung landmasses. Geoff heads to some ancient caves in Israel to investigate the ‘false starts’ humans made out of Africa, and Marnie speaks with Professor Lisa Matisoo-Smith in New Zealand, uncovering the development of Polynesian sailing canoes and how they enabled the last landmasses to be found by people. This is a story spanning over seventy thousand years, huge changes in culture and technology, and the repeated remodelling of the earth thanks to the ice ages. Produced by Rory Galloway (Photo: Polynesian canoeists at sunset. Credit: Richmatts/Getty Images)