SEASON PREMIERE: These are very personal stories, as Gates, with help from genealogists and DNA testing, uncovers the past of his celebrity guests, working back through many, many generations. This season, he’ll uncover some amazing facts about Bill O’Reilly and Bill Maher (including something they have in common), and even more amazing ones about Bill Hader – but tonight, his guests include Donna Brazile and Modern Family star Ty Burrell (pictured), who in this Season 3 opener gets to learn about his not-so-modern family. For a full story, see David Hinckley’s All Along the Watchtower. Check local listings.