Preface: Thoughts on doing science -- Introduction to mobile DNA -- Varieties of mobile DNA -- DNA transposons -- Mobile DNA of model organisms -- Exceptional scientists working on mobile DNA in lower organisms -- Role of bioinformatic in genome analysis -- The prologue -- "Welcome to th wonderful world of LINEs" -- An experimental breakthrough -- Reverse transcriptase to the rescue -- A quirk of L1 elements: a lousy 3' end is important for genome evolution -- A tour de force from Tom Eickbush -- "I don't believe all those colonies represent retrotransposition events." -- L1 encodes an endonuclease -- The jocks -- The mayor and the Frenchman -- Ostertag's coups -- The independent Canadian -- The musician scientist -- Young ladies in the Back Bay -- The brilliant young lady from China -- Hiroki's big surprises -- A young man with a purpose -- Other Mobile DNA in mammalian genomes -- Effects of retrotransposons on mammalian genomes -- Host factors involved in L1 retrotransposition -- Why mobile DNA? -- The future of mobile DNA research -- Predictions for Mobile DNA.