The Twelfth Strand is the story of an oddly incongruous love affair between two remarkable people, Henry Cadence and Eva Chakluak. It is also a kind of owner's manual for life on earth, offering an explanation for one of the most baffling mysteries of humankind. Exactly how, and perhaps more importantly, when did Homo Sapiens make their startlingly rapid, almost overnight, cultural leap from primitive, cave-dwelling, hunter-gatherers to intellectually...