The wondrous world of burrows -- Beyond "cavemen" : a brief history of humans underground -- Kaleidoscopes of dug-out diversity -- Hadean dinosaurs and birds underfoot -- Bomb shelters of the Phanerozoic -- Terraforming a planet, one hole at a time -- Playing hide and seek for keeps -- Rulers of the underworld -- Viva la evolución : change comes from within -- Appendix: Genera and species mentioned in The evolution underground.