PMC

Statistical (99%) parsimony network of haplotypes in the trans-Arctic Clupea pallasii mtDNA clade. Concatenated cyt-b+CR data. Color codes refer to population groups as in Figure . Solid line refers to substitution in cyt-b, dashed line refers to substitution in CR.

Sampling localities for Clupea pallasii (dots) and C. harengus (circles). For locality codes see Table . Color codes reflect genetic population groupings (cf. Figures , ). Observations of historical herring occurrence along the Siberian coast in the warm period of 1930s-1940s [] are indicated with stars.

MDS ordination of the NE European Clupea pallasii samples and one from the Bering Sea. Ordination based on pairwise inter-population Φ_ST distances from the concatenated cyt-b+CR sequence data. For locality codes see Table . Kandalaksha spring spawning populations are indicated with asterisks. Color codes refer to population groups as in Figure .

Mitochondrial diversity in two herring species. Neighbor-joining trees from GTR+I+Γ distances (a) from cyt-b data only (1131 bp) (b) from concatenated cyt-b+CR data (1617 bp). The numbers are observed frequencies of haplotypes found in multiple individuals; haplotypes shared between localities are indicated with asterisks. Color codes refer to population groups as in Figure , core haplotypes A-D as in Figure .

Comparison of mitochondrial haplotype networks of trans-Arctic clades for three zoogeographically analogous amphi-boreal taxa. (a) 99% statistical parsimony network of the trans-Arctic Clupea pallasii lineage (cyt-b data only). (b) Median-joining network of Mytilus trossulus (control region; redrawn from []).The branch lengths correspond to the number of substitutions but unobserved haplotypes are not marked here (c) 99% statistical parsimony network of Macoma balthica (COIII gene; []). Note the similar trans-Arctic distributions and signatures of expansion in the dominant Atlantic haplotypes.

Mismatch distributions and Bayesian skyline (BSL) plots reflect population size history. Mismatch data in the two left panels, BSL plots in the two panels to the right. Results are presented for various putatively demographically coherent subsets of the data, for the cyt-b and CR data separately. Divergence and age estimates of inferred demographic events evaluated from these plots are presented in Additional file : Table S1. The BSL scales for N_e (y-axis) and operational timescales (x-axis) are based on 0.75% My^-1 (cyt-b) and 2.7% My^-1 (CR) per site mutation rates and a 4-year generation interval (see Additional file ). Black lines are median estimates of N_e, blue lines are the 95% HPD limits. End points of the lines represent the median estimate of the basal coalescence.