BROOKLYN, N.Y. — Here are some things that did not yet exist when Susannah Mushatt Jones was born in Alabama on July 6, 1899: the Model T, and for that matter the Ford Motor Company. The teddy bear. Thumbtacks and tea bags. Puccini’s “Tosca” and Scott Joplin’s “Maple Leaf Rag.” The Flatiron Building and the subway system beneath it. Emma Morano, an Italian woman born four months later, who is today the only other living soul who was around before 1900.