DNA分析揭示，至今仍生存在西班牙坎塔布连山一带的濒危动物棕熊是一种曾经繁盛的欧洲种群的后代，而且在该种群史上，棕熊可能是首个遗传隔离的一代。
相关论文3月17日在线发表于美国《国家科学院院刊》（PNAS）上。（来源：EurekAlert!中文版）
生物谷推荐原始出处：
（PNAS），doi：10.1073/pnas.0712223105，Cristina E. Valdiosera，Anders Götherström
Surprising migration and population size dynamics in ancient Iberian brown bears (Ursus arctos)
Cristina E. Valdiosera*,, José Luis García-Garitagoitia, Nuria Garcia*, Ignacio Doadrio, Mark G. Thomas, Catherine Hänni¶, Juan-Luis Arsuaga*,, Ian Barnes||, Michael Hofreiter**, Ludovic Orlando¶, and Anders Götherström
*Centro Mixto, Universidad Complutense de Madrid–Instituto de Salud Carlos III de Evolución y Comportamiento Humanos, c/Sinesio Delgado 4 Pabellon 14, 28029 Madrid, Spain; Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, c/José Gutierrez Abascal 2, 28006 Madrid, Spain; Department of Biology, University College London, Wolfson House, 4 Stephenson Way, London NW1 2HE, England; ¶Paléogénétique et Evolution Moléculaire, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Institut Fédératif Biosciences Gerland Lyon Sud, Université Lyon 1, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5242, Institut National de la Recherche Agronomique, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cédex 07, France; ||School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, England; **Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany; and Evolutionary Biology Center, Uppsala University, Norbyvägen 18, SE-752 36 Uppsala, Sweden
Contributed by Juan-Luis Arsuaga, January 29, 2008 (sent for review December 10, 2007)
Abstract
The endangered brown bear populations (Ursus arctos) in Iberia have been suggested to be the last fragments of the brown bear population that served as recolonization stock for large parts of Europe during the Pleistocene. Conservation efforts are intense, and results are closely monitored. However, the efforts are based on the assumption that the Iberian bears are a unique unit that has evolved locally for an extended period. We have sequenced mitochondrial DNA (mtDNA) from ancient Iberian bear remains and analyzed them as a serial dataset, monitoring changes in diversity and occurrence of European haplogroups over time. Using these data, we show that the Iberian bear population has experienced a dynamic, recent evolutionary history. Not only has the population undergone mitochondrial gene flow from other European brown bears, but the effective population size also has fluctuated substantially. We conclude that the Iberian bear population has been a fluid evolutionary unit, developed by gene flow from other populations and population bottlenecks, far from being in genetic equilibrium or isolated from other brown bear populations. Thus, the current situation is highly unusual and the population may in fact be isolated for the first time in its history.
