Estimates of genomic TMRCA.

Estimates of average genomic TMRCA for black, brown and polar bear lineages, and average population TMRCA for brown bears and polar bears estimated from our data, using three calibration methods (calibrated notes are listed in italics). Estimates are scaled based on an average pairwise distance between sampled brown bears and polar bears of 1 (Figure 2A). Method A assumes divergence between the giant panda and polar bear lineage 12±4 Mya [4]. Method B assumes an average TMRCA between brown bears and black bears 3.9–6.48 Mya [33]. Method C assumes a mammalian mutation rate of 1×10−9 substitutions/site/year, the basis for the very old estimates presented in [6].