DOCUMENTARY MINISERIES PREMIERE: This new three-part nature series, shown in March on BBC One, premieres on BBC America tonight, with Liz Bonnin and a team of scientists visiting nature’s most famous archipelago, the virtual birthplace of Darwinism. Episode one, “Cauldron of Life,” starts with the volcanically active Western islands, and includes a search for a rare species close to extinction: the pink iguana.