Calibration of intra-specific divergences among Harp Seal clades.

<p>(a) ML clock-corrected estimates of the molecular distances to the MRCA for four hominines with established divergence dates < 1 MYA follow a power curve relationship T = 1.886 x (d)^1.21 (r² = 0.9983), where T = KYA and d = linearized ML substitution rates (semi-log plot). Sources of homine mtDNA genomes are given in Methods: San2 is in the L1 haplogroup that is the basal divergence from other extant <i>Homo</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134207#pone.0134207.ref001" target="_blank">1</a>], M vs N is the divergence between haplotypes in the U and A haplogroups, respectively [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134207#pone.0134207.ref009" target="_blank">9</a>]. (b) Dates of the MRCA of the major intra-specific <i>Pagophilus</i> clades estimated from the same power curve (linear plot).