title: Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100.
abstract: Arctic animals face dramatic habitat alteration due to ongoing climate change. Understanding how such species have responded to past glacial cycles can help us forecast their response to today's changing climate. Gray whales are among those marine species likely to be strongly affected by Arctic climate change, but a thorough analysis of past climate impacts on this species has been complicated by lack of information about an extinct population in the Atlantic. While little is known about the history of Atlantic gray whales or their relationship to the extant Pacific population, the extirpation of the Atlantic population during historical times has been attributed to whaling. We used a combination of ancient and modern DNA, radiocarbon dating and predictive habitat modelling to better understand the distribution of gray whales during the Pleistocene and Holocene. Our results reveal that dispersal between the Pacific and Atlantic was climate dependent and occurred both during the Pleistocene prior to the last glacial period and the early Holocene immediately following the opening of the Bering Strait. Genetic diversity in the Atlantic declined over an extended interval that predates the period of intensive commercial whaling, indicating this decline may have been precipitated by Holocene climate or other ecological causes. These first genetic data for Atlantic gray whales, particularly when combined with predictive habitat models for the year 2100, suggest that two recent sightings of gray whales in the Atlantic may represent the beginning of the expansion of this species' habitat beyond its currently realized range.
authors.affiliation: Department of Biology, York College, City University of New York, 94-20 Guy R. Brewer Blvd, Jamaica, NY, 11415, USA; CUNY Graduate Center, 365 Fifth Avenue, New York, NY, 10016, USA; American Museum of Natural History, Sackler Institute for Comparative Genomics, 79th St and Central Park West, New York, NY, 10024, USA.
authors.forename: S Elizabeth
authors.initials: SE
authors.lastname: Alter
authors.forename: Matthias
authors.initials: M
authors.lastname: Meyer
authors.forename: Klaas
authors.initials: K
authors.lastname: Post
authors.forename: Paul
authors.initials: P
authors.lastname: Czechowski
authors.forename: Peter
authors.initials: P
authors.lastname: Gravlund
authors.forename: Cork
authors.initials: C
authors.lastname: Gaines
authors.forename: Howard C
authors.initials: HC
authors.lastname: Rosenbaum
authors.forename: Kristin
authors.initials: K
authors.lastname: Kaschner
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Turvey
authors.forename: Johannes
authors.initials: J
authors.lastname: van der Plicht
authors.forename: Beth
authors.initials: B
authors.lastname: Shapiro
authors.forename: Michael
authors.initials: M
authors.lastname: Hofreiter
mesh_terms: D000818:Animals; D001110:Arctic Regions; D001267:Atlantic Ocean; D057231:Climate Change; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D005580:Fossils; D014644:Genetic Variation; D006239:Haplotypes; D008954:Models, Biological; D008969:Molecular Sequence Data; D058974:Phylogeography; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D014907:Whales / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: ancient DNA; climate change; last glacial maximum; marine mammal