By Leonard Doyle
TRAVELING by foot, National Geographic writer Paul Salopek is recreating the epic journey of humankind starting at its birthplace in Ethiopia and ending at the southern tip of South America. He walked in the scorching heat of the deserts of Ethiopia’s Rift Valley across the broiling barren landscape of Djibouti to the Red Sea coast. Stranded for weeks. There he encountered IOM's Chief of Mission Bakary Doumbia and a fascinating conversation ensued, much of it on Twitter after Paul moved on to Saudi Arabia.