Opening Saturday: Work and how it's done is continually evolving, but in the end it always involves selling time and muscle -- mental or physical -- for money. While conditions have improved for many workers, especially in the United States and other "advanced" countries, they are still shockingly exploitative in many parts of the world, as documented by Minneapolis photographer David Parker, who has long tracked the plight of child workers. Parker's images will be showcased with more than 50 prints, drawings and other photos spanning the past 170 years including images of workers in fields, factories, laundries, garbage heaps, highways and myriad other sites by talents as diverse as Edgar Degas, Pierre Bonnard, Grant Wood, Elizabeth Catlett, Charles Sheeler, Jim Dine and Romare Bearden, whose 1942 "Factory Worker" gouache is shown here. (Free through Sept. 1. Minneapolis Institute of Arts, 2400 3rd Av. S., Mpls. 612-870-3000 or www.artsmia.org)