title: Population connectivity buffers genetic diversity loss in a seabird.
abstract: BACKGROUND
  Ancient DNA has revolutionized conservation genetic studies as it allows monitoring of the genetic variability of species through time and predicting the impact of ecosystems' threats on future population dynamics and viability. Meanwhile, the consequences of anthropogenic activities and climate change to island faunas, particularly seabirds, remain largely unknown. In this study, we examined temporal changes in the genetic diversity of a threatened seabird, the Cory's shearwater (Calonectris borealis).
  
  
  RESULTS
  We analysed the mitochondrial DNA control region of ancient bone samples from the late-Holocene retrieved from the Canary archipelago (NE Atlantic) together with modern DNA sequences representative of the entire breeding range of the species. Our results show high levels of ancient genetic diversity in the Canaries comparable to that of the extant population. The temporal haplotype network further revealed rare but recurrent long-distance dispersal between ocean basins. The Bayesian demographic analyses reveal both regional and local population size expansion events, and this is in spite of the demographic decline experienced by the species over the last millennia.
  
  
  CONCLUSIONS
  Our findings suggest that population connectivity of the species has acted as a buffer of genetic losses and illustrate the use of ancient DNA to uncover such cryptic genetic events.
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Ramírez
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Gómez-Díaz
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Olalde
authors.affiliation: Research Unit of Biodiversity (UO-CSIC-PA), Oviedo University, Asturias, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Illera
authors.affiliation: Departamento de Biología Animal (UDI Zoología), Universidad de La Laguna, La Laguna, Tenerife, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Rando
authors.affiliation: Institut de Recerca de la Biodiversitat and Departament de Biologia Animal, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Jacob
authors.initials: J
authors.lastname: González-Solís
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Lalueza-Fox