In this May 2012 photo provided by Bryce Barker, University of Southern Queensland archaeologist Bryce Barker investigates Aboriginal rock art in a cave in the Australian Outback. Prof. Barker said Monday, June 18, 2012 that tests show the Aboriginal rock art in the cave was made 28,000 years ago, making it the oldest in Australia and among the oldest in the world. (AP Photo/Bryce Barker) EDITORIAL USE ONLY