1986 - research trainee, IBISS, University of Belgrade 1989 - research assistant, IBISS, University of Belgrade 1998 - research associate, IBISS, University of Belgrade 2001 - assistant professor, Faculty of Biology, University of Belgrade 2006 - senior research associate, IBISS, University of Belgrade 2008 - associate professor, Faculty of Sciences and Mathematics, University of Niš 2011 - principal research fellow, IBISS, University of Belgrade 2013 - professor, Faculty of Sciences and Mathematics, University of Niš