The Book of General Ignorance round differs, in particular during the Christmas specials. During the course of the "B" Series special, Fry and Davies swapped places for "General Ignorance", with Fry attempting to answer questions ostensibly written by Davies to stump him. During "D"s Christmas Special, all the "GI" questions revolved around saints. "The Book of General Ignorance" contains a list of 230 questions, most of which previously appeared in episodes of "QI". Each question explains the correct answer, and usually attempts to show why people tend to make the wrong assumptions, or believe certain myths. Each book contains two forewords, one by Fry, the
Most recent common ancestor all of the modern population. Due to pedigree collapse, modern individuals may still exhibit clustering, due to vastly different contributions from each of ancestral population . Most recent common ancestor In biology and genealogy, the most recent common ancestor (MRCA, also last common ancestor (LCA), or concestor) of any set of organisms is the most recent individual from which all the organisms are directly descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree.