From Keith Pearce, Dursley, Gloucestershire, UK
Michael Marshall speculates about how seafaring was learned. Could it have developed incrementally as rising water levels turned a society’s accustomed range into a series of islands (where once there were hills), with the gaps between them developing from dry land to a swamp to a small waterway to a larger waterway and then finally to a sea? They would be motivated to cross by their knowledge of exploitable resources, and maybe cousins to trade with on the other side (31 January, p 32).
