Genetic diversity (π), inbreeding coefficients, genetic relatedness, ROHs distribution, LD, and selective sweeps of Phoebastria immutabilis and P. nigripes. (A) Genetic diversity (π) assessed across species of different IUCN categories. Genetic diversity data are adopted from Robinson et al. (2016). The genetic diversities estimated for P. immutabilis and P. nigripes are highlighted by horizontal dotted lines. Both albatross species are currently classified as near threatened. (B) Inbreeding coefficient of P. immutabilis and P. nigripes. Genetic relatedness among pairwise individuals of (C) P. immutabilis and (D) P. nigripes. Distribution of ROHs for (E) P. immutabilis and (F) P. nigripes based on unlinked SNPs, with minimum windows sizes of 50 SNPs and 1 kb, allowing for five missing sites and five heterozygous sites. (G) LD decay based on the r2 index. (H) Signal of selective sweep in P. immutabilis and P. nigripes. Each genome was scanned for regions with outliers of high LD and low Tajima's D, along sliding-windows of 100 kb size and 50 kb step. The LD (upper blue lines) and Tajima's D (lower red lines) values are shown on the left and right y-axes, respectively. Pseudochromosomes (top panel) and scaffolds (bottom panel) are shown on the x-axis. Only pseudochromosomes 18, 20, 22, 26, 28, and 33 are shown here. Candidate genomic windows with signature of selective sweeps are highlighted in dark gray. The largest candidate windows (300–450 kb), located on scaffolds 7 and 226, are shown in detail with their gene content. Positions on the scaffold are shown on the y-axis. DD, data deficient; LC, least concern; NT, near threatened; VU, vulnerable; EN, endangered; CR, critically endangered; EW, extinct in the wild.
