title: Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum.
abstract: Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact.
authors.affiliation: Museum of Zoology, Senckenberg Dresden, A. B. Meyer Building, 01109 Dresden, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kehlmaier
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, OT Golm, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Barlow
authors.affiliation: Virginia Museum of Natural History, 21 Starling Avenue, Martinsville, VA 24112, USA.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Hastings
authors.affiliation: Museum of Zoology, Senckenberg Dresden, A. B. Meyer Building, 01109 Dresden, Germany.
authors.forename: Melita
authors.initials: M
authors.lastname: Vamberger
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, OT Golm, Germany.
authors.forename: Johanna L A
authors.initials: JL
authors.lastname: Paijmans
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Steadman
authors.affiliation: National Museum of The Bahamas, Marsh Harbour, Abaco, The Bahamas.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Albury
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Franz
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, OT Golm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hofreiter
authors.affiliation: Museum of Zoology, Senckenberg Dresden, A. B. Meyer Building, 01109 Dresden, Germany ufritz@senckenberg.de.
authors.forename: Uwe
authors.identifier: 0000-0002-6740-7214
authors.initials: U
authors.lastname: Fritz
mesh_terms: D000349:Africa; D000818:Animals; D001267:Atlantic Ocean; D017691:Caribbean Region; D000072441:DNA, Ancient / Q000032:analysis*; D004272:DNA, Mitochondrial / Q000235:genetics; D004484:Ecuador; D053476:Extinction, Biological; D054629:Genome, Mitochondrial; D006801:Humans; D062312:Islands; D010802:Phylogeny; D013020:South America; D014329:Tropical Climate; D014426:Turtles / Q000235:genetics*
chemical_list: D000072441:DNA, Ancient; D004272:DNA, Mitochondrial
keywords: Bahamas; biogeography; extinction; palaeontology; phylogeny