Anand Jagatia heads to the rainbow nation of South Africa, to answer listener Lucy’s deceptively simple question. He follows the path of early human migration to understand the relationship between light skin and latitude, and find out how the world become more multi-coloured as people ventured further away from the equator. And he learns how our genes have helped us adapt to less sunny environments, hearing from the remote KhoeSan tribe in the Kalahari desert, who took part in a massive study aimed at giving scientists a better understanding of pigmentation.

Producer: Marijke Peters

(Image: Four diverse women’s arms holding each others wrists in a circle. Credit: Getty Images)