On Trails, the wonderful debut of the American writer Robert Moor, is now out in paperback (Aurum Press). The book is “on” trails in two senses: it’s the fruit of miles of walking and years of research. He starts with the trails left by organisms of the Ediacaran biota, which became extinct about 541 million years ago, and ends with the longest hiking trail in the world, a global footpath, a collective effort, that’s very much the offspring of the internet. (It’s the International Appalachian Trail — I’d never heard of it until I read his book).

In between, he considers the trails made by insects, animals and man, and the purposes to which they have been put, from finding food to building empires. While the Appalachian Trail, which prompted his inquiry, provides a main line, he branches off it, hiking everywhere from Canada to Morocco and considering the trail as everything from a means of recreation to a metaphor for life. You can now read an extract on Deskbound Traveller.