The Pleistocene epoch has been a time of climatic fluctuation with various effects on species distribution and survival. Currently we have little knowledge on how these changes affected the genetic diversity of the populations that survive until today. Here we attempt to investigate the genetic contribution of ancient to modern brown bear populations by analysing whole genome sequencing (WGS) data . We have already generated WGS data for ancient brown bear individuals from Central Europe (Austria, Germany) dating to the Late Pleistocene and Early Holocene. We will compare these data with those available for modern brown bear populations in attempt to determine the level of ancient brown bear genomic diversity surviving in today's brown bear populations. We will apply population genomic and phylogenomic analyses and results will be assessed based on current knowledge on climatic fluctuations throughout the Quaternary period and interspecific interactions between bear species.