Figure 2. Population structure of present-day and historical
blue whales from North Atlantic A . Map of sampling locations of
blue whales B. Principal component analysis (PCA) ten Northwest
Atlantic (NWA) blue whales, eight Northeast Atlantic (NEA) blue whales,
one Antarctic blue whale, seven fin whales from North Atlantic and two
sei whales using LASER. The circled sample represents the blue-fin
hybrid historical sample (NWa-CM1) C. PCA of seven NWA blue
whales, eight NEA blue whales and one Antarctic blue whale with LASER.D. Maximum likelihood tree using TREEMIX for NE, NW and
Antarctic blue whales with two migration edges, considering each
individual as a separate population and fin whale as the root. The
horizontal branch lengths are proportional to genetic drift along that
branch and the scale bar shows ten times the average standard error of
the entries in the sample covariance matrix. E. Individual
admixture proportions using NGSadmix for a single run from 10 runs of
k=2 and k=3 for present-day and historical sample from NWA, NEA and
Antarctic). The X-axis displays the proportion of ancestry and the
Y-axis displays blue whale samples.