Margaret Jenkins, whose troupe and work has been part of San Francisco’s DNA since the 1970s, presents four performances at the San Francisco JCC’s Kanbar Hall, Oct. 18–21, with dances from the company repertory as well as a preview of the new Time Bones, which she created with her eight dancers. Set to a score by Paul Dresher, it premieres in 2013 as part of the Margaret Jenkins Dance Company’s 40th anniversary season.