I am walking across the world. I set out on foot from Herto Bouri, an early site of Homo sapiens fossils in the Rift Valley of Ethiopia, to retrace the pathways of the first anatomically modern humans who colonized the planet at least 60,000 years ago. At the walk’s start in the Horn of Africa, one of the last habitable places on earth where automobiles remain scarce, walking was a near-universal activity. But once I crossed the Red Sea on a camel boat to the Middle East, where car ownership explodes to 300 or more vehicles per 1,000 citizens, I’d entered a region subjugated utterly by the vulcanized rubber tire. … Continue reading Paul Salopek