Evolutionary of history of North Pacific humpback whales

North Pacific Humpback Whales breed on winter grounds at Hawaii, Mexico and Okinawa, and summer on feeding grounds in northern Temperate and sub-Arctic waters. Re-sighting records of photographically identified individual humpback whales suggest that breeding grounds are not isolated. Later genetic studies by Palumbi & Baker (1994) and Baker et al. (1998) inferred male-mediated gene flow between wintering breeding in Mexico and Hawaii. The result was based upon a 10-fold higher rate of gene flow estimated from bi-parentally inherited nuclear markers compared to the rate of gene flow estimated from maternally transmitted mitochondrial nucleotide sequences. In this study we re-test the notion of male-based gene flow among North Pacific winter breeding areas. We sequenced the mitochondrial control region and genotyped 6 hyper-variable microsatellite loci in 342 North Pacific Humpback whales; 109 samples from Hawaii, 77 from Alaska, 84 from Mexico and 74 from Japan. The preliminary estimates of standard population genetic divergence indices are similar to those reported by Baker et al. (1998), and analyses are on progress to determine if those are due to male-biased gene flow.