Uncertainty and error …

… Book Review: The Half-Life of Facts - WSJ.com. (Hat tip, Dave Lull.)

Copying errors, it turns out, aren't uncommon and fall into characteristic patterns, such as deletions and duplications—exactly the sorts of mistakes that geneticists have identified in DNA. Using approaches adapted from genetics, paleographers—scientists who study ancient writing—use these accumulated errors to trace the age and origins of a document, much in the same way biologists use the accumulation of genetic mutations to assess how similar two species are to each other. For example, by analyzing the oddities and duplicated errors in the 58 surviving versions of "The Wife of Bath's Prologue" from Chaucer's "Canterbury Tales," researchers deduced the content of the original version.