Figure 1: Map of sampling locations of the five killer whale types included in this study.
From: Genome-culture coevolution promotes rapid divergence of killer whale ecotypes
Sampling locations and inset photographs illustrating favoured prey species are colour-coded by ecotype: ‘transient’ (blue) and type B1 (purple) are predominantly mammal-eating; ‘resident’ (brown) and type C (orange) are predominantly fish-eating; type B2 (green) is known to feed on penguins. The map is superimposed on a colour grid of sea-surface temperature (SST). The Antarctic ecotypes primarily inhabit waters 8–16 °C colder than the North Pacific ecotypes. The relationship among these types and their estimated divergence times based on mitochondrial genomes are shown in the superimposed chronogram. Boxes 1–4 indicate pairwise comparisons spanning points along the ‘speciation continuum’ used to investigate the build up of genomic differentiation. (Photo credits: Dave Ellifrit, Center for Whale Research; Holly Fearnbach and Robert Pitman, SWFSC; SST measurements from NOAA Optimum Interpolation SST V2 long-term mean 1981–2010, www.esrl.noaa.gov/psd/repository courtesy of Paul Fiedler; killer whale illustrations courtesy of Uko Gorter.)
