Nucleotide sequence data from the mitochondrial control region were used from a phylogenetic context to investigate the long-term history of a population of bowhead whales (Balaena mysticetus). In addition, the coalescence time of these sequences was used to estimate the age of the inferred patterns of population size change. The results indicate that mitochondrial genetic polymorphism was not affected by a recent bottleneck that occurred near the turn of the 20th century, thereby preserving the signature of historical population size change in the mitochondrial genome. Further analysis showed that this population underwent an expansion initiated in the Middle to Late Pleistocene. As such, early Holocene changes in Arctic sea ice distribution appear to have had little influence on patterns of genetic variability in this population.

Corresponding Editor: S. Karl