Data from other loci are from either whales or seals, but not both. Intron sequence data collected to date. Data taken from the literature are underlined. Loci in progress have an asterisk. Although variation in intron divergence values across loci was greater than expected from binomial expectations in both seals and whales, there was no evidence that the variation could be explained by differences in nucleotide composition or in purifying selection.
Further work is needed on methods to detect the causes of rate heterogeneity.
Preliminary estimates of ancestral population size in elephant seals suggest that the contemporary southern species may provide a reasonable view of long-term population demography. As such, the southern elephant seal provides a suitable comparison with the northern elephant seal to judge the extent of genetic diversity loss experienced in the north from human harvests during the 19th century. It remains enigmatic to explain the lack of dramatic inbreeding depression in the northern elephant seals after suffering such a severe population bottleneck. Insufficient data are available for a preliminary test of right whale ancestral population size. A genetic estimate of ancestral population size in right whales.