Figure 4. Inferred effective population sizes through time estimated from three blue whales (NWA and NEA whales and NE-Ar) and a fin whale using the PSMC analyses on genome sequences. The X-axis displays time (years) going backward from the present (log scale) and the Y-axis denotes the effective population size. The plot is scaled by a generation time of 30.8 years for the blue whales and 25.9 years for the fin whale with a mutation rate of 1.39 X 10 -8substitutions per nucleotide per generation (Árnason et al., 2018). Grey shaded areas demarcate interglacial periods in years before present: 0–14,000; 115,000–130,000; ~220,000–243,000; ~320,000–337,000; and ~400,000–424,000.