Could genetic diversity in eastern North Pacific gray whales reflect global historic abundance?

Abstract

In Reply: Palsbol et al. raise the possibility that our estimates of gray whale genetic diversity could reflect global diversity if a population of gray whales existed in the Southern Hemisphere. However, as they note, no evidence of gray whales has been discovered in the Southern Hemisphere. No fossils or subfossils have been reported, there are no accounts of this species from whaling records, and it is not known whether the specialized feeding requirements of gray whales could have been met in Southern Ocean areas. Although this lack of evidence does not eliminate the possibility of a gray whale population in the Southern Hemisphere, it does indicate a low probability that a large, widespread population existed there recently. In our paper on gray whale abundance before whaling (1), we use a new approach to evaluating “ghost” populations for their potential impact on the genetic diversity of current-day population diversity, as requested by the International Whaling Commission (2). Through a series of coalescent … *To whom correspondence should be addressed. E-mail: sealter{at}stanford.edu