POPULATION CHARACTERISTICS OF DNA FINGERPRINTS IN HUMPBACK WHALES (MEGAPTERA-NOVAEANGLIAE)

Humpback whales exhibit a remarkable social organization that is chara cterized by seasonal long-distance migration (> 10,000 km/year) betwee n summer feeding grounds in high latitudes and winter calving and bree ding grounds in tropical or near-tropical waters. All populations are currently considered endangered as a result of intensive commercial ex ploitation during the last 200 years. Using three hypervariable minisa tellite DNA probes (33.15, 3'HVR, and M13) originally developed for st udies of human genetic variation, we examined genetic variation within and among three regional subpopulations of humpback whales from the N orth Pacific and one from the North Atlantic oceans. Analysis of DNA e xtracted from skin tissues collected by biopsy darting from free-rangi ng whales revealed considerable variation in each subpopulation. The e xtent of this variation argues against a recent history of inbreeding among humpback whales as a result of nineteenth- and twentieth-century hunting. A canonical variate analysis suggested a relationship betwee n scaled genetic distance, based on similarities of DNA fingerprints, and geographic distance (i.e., longitude of regional subpopulation). S ignificant categorical differences were found between the two oceanic populations using a multivariate analysis of variance (MANOVA) with a modification of the Mantel nonparametric permutation test. The relatio nship between DNA fingerprint similarities and geographic distance sug gests that nuclear gene flow between regional subpopulations within th e North Pacific is restricted by relatively low rates of migratory int erchange between breeding grounds or assortative mating on common wint ering grounds.