World leaders and regular people gathered Tuesday in South Africa to honor Nelson Mandela — a man who was labelled a terrorist by the US until 8 years ago, a friend of China and Cuba, and now a symbol of hope and reconciliation for millions. We also look at Saudi Arabia’s interest in its own human genome project, one of the most extreme zipline rides in the world, and a video game where the villian is alcoholism. All that and more, in today’s Global Scan.