Aristotle on the magnetosphere

If yours is one of 3000 family names listed in a current glossy magazine two-page ad (Abbot to Zimmerman—no Siscoe), $30 brings you a “GENEALOGICAL and HISTORICAL study of (your) family from earliest times.” (Prompt orders get a specially designed Ancestry Chart, free!) We have a built-in thirst to know our pedigree; how else could genealogy pay? Why else would people visit ancestral homesites? And what else let Alex Haley parlay a scholarly study of ship manifests and slave transactions into a best selling novel? Roots symbolizes a literary genre, which includes Oliver Twist and The Prince and the Pauper, that exploits deep emotions evoked by issues of heritage. The genre admits humor; the Mikado's Pooh-Bah traces his ancestry back to a “protoplasmic primordial atomic globule.”