Rhesus monkeys 27-year-old Canto, on a restricted diet (left), and 29-year-old Owen, a control subject on an unrestricted diet (right), were photographed at the Wisconsin National Primate Research ... more 
Rhesus monkeys 27-year-old Canto, on a restricted diet (left), and 29-year-old Owen, a control subject on an unrestricted diet (right), were photographed at the Wisconsin National Primate Research Center at the University of Wisconsin-Madison less 
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LiveScience.com | Photo By Jeff Miller, University Communications, UW-Madison
Tue, Apr 1, 2014 12:40 PM EDT