Portraits of Muhammad Ali, Marilyn Monroe and other silk-screen prints that arguably sparked the birth of pop culture will be on display at the Tucson Museum of Art, 140 N. Main Ave., as part of the touring exhibition Andy Warhol Portfolios: Life and Legends.  The museum is open Tuesday through Saturday, 10 a.m. to 4 p.m. and Sunday, noon to 4 p.m.  Admission is $8.  Visit www.tucsonmuseumofart.org or call 624-2333 for more information.