Global diversity and oceanic divergence of humpback whales (Megaptera novaeangliae).
Humpback whales (Megaptera novaeangliae) annually undertake the longest migrations between seasonal feeding and breeding grounds of any mammal. Despite this dispersal potential, discontinuous seasonal distributions and migratory patterns suggest that humpbacks form discrete regional populations within each ocean. To better understand the worldwide population history of humpbacks, and the interplay of this species with the oceanic environment through geological time, we assembled mitochondrial DNA control region sequences representing approximately 2700 individuals (465 bp, 219 haplotypes) and eight nuclear intronic sequences representing approximately 70 individuals (3700 bp, 140 alleles) from the North Pacific, North Atlantic and Southern Hemisphere. Bayesian divergence time reconstructions date the origin of humpback mtDNA lineages to the Pleistocene (880 ka, 95% posterior intervals 550-1320 ka) and estimate radiation of current Northern Hemisphere lineages between 50 and 200 ka, indicating colonization of the northern oceans prior to the Last Glacial Maximum. Coalescent analyses reveal restricted gene flow between ocean basins, with long-term migration rates (individual migrants per generation) of less than 3.3 for mtDNA and less than 2 for nuclear genomic DNA. Genetic evidence suggests that humpbacks in the North Pacific, North Atlantic and Southern Hemisphere are on independent evolutionary trajectories, supporting taxonomic revision of M. novaeangliae to three subspecies.
Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, 2030 SE Marine Science Drive, Newport, OR 97365, USA British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK jennifer.jackson@bas.ac.uk.
Jennifer A
JA
Jackson
British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
Debbie J
DJ
Steel
Department of Scientific Computing, Florida State University, Tallahassee, FL 32306, USA.
P
P
Beerli
School of Marine and Tropical Biology, James Cook University, Cairns, Queensland 4870, Australia.
Bradley C
BC
Congdon
School of Biological Sciences, Auckland University, 3a Symonds Street, Auckland 1010, New Zealand Fundación CEQUA, Punta Arenas, Chile.
Carlos
C
Olavarría
Ocean Giants Program, Global Conservation-Marine, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA Sackler Institute for Comparative Genomics, American Museum of Natural History, 79th Street and Central Park West, New York, NY, USA.
Matthew S
MS
Leslie
Ocean Giants Program, Global Conservation-Marine, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA Sackler Institute for Comparative Genomics, American Museum of Natural History, 79th Street and Central Park West, New York, NY, USA.
Cristina
C
Pomilla
Ocean Giants Program, Global Conservation-Marine, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA Sackler Institute for Comparative Genomics, American Museum of Natural History, 79th Street and Central Park West, New York, NY, USA.
Howard
H
Rosenbaum
Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, 2030 SE Marine Science Drive, Newport, OR 97365, USA School of Biological Sciences, Auckland University, 3a Symonds Street, Auckland 1010, New Zealand.
C Scott
CS
Baker
D000199:Actins / Q000235:genetics*; D000818:Animals; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D006239:Haplotypes; D050640:Humpback Whale / Q000235:genetics*; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D000199:Actins; D004272:DNA, Mitochondrial
cetacean; diversity; gene flow; genomic; mitochondrial; whale