title: Phylogeography and evolutionary history of the Crocidura olivieri complex (Mammalia, Soricomorpha): from a forest origin to broad ecological expansion across Africa.
abstract: BACKGROUND
  This study aims to reconstruct the evolutionary history of African shrews referred to the Crocidura olivieri complex. We tested the respective role of forest retraction/expansion during the Pleistocene, rivers (allopatric models), ecological gradients (parapatric model) and anthropogenic factors in explaining the distribution and diversification within this species complex. We sequenced three mitochondrial and four nuclear markers from 565 specimens encompassing the known distribution of the complex, i.e. from Morocco to Egypt and south to Mozambique. We used Bayesian phylogenetic inference, genetic structure analyses and divergence time estimates to assess the phylogenetic relationships and evolutionary history of these animals.
  
  
  RESULTS
  The C. olivieri complex (currently composed of C. olivieri, C. fulvastra, C. viaria and C. goliath) can be segregated into eight principal geographical clades, most exhibiting parapatric distributions. A decrease in genetic diversity was observed between central and western African clades and a marked signal of population expansion was detected for a broadly distributed clade occurring across central and eastern Africa and portions of Egypt (clade IV). The main cladogenesis events occurred within the complex between 1.37 and 0.48 Ma. Crocidura olivieri sensu stricto appears polyphyletic and C. viaria and C. fulvastra were not found to be monophyletic.
  
  
  CONCLUSIONS
  Climatic oscillations over the Pleistocene probably played a major role in shaping the genetic diversity within this species complex. Different factors can explain their diversification, including Pleistocene forest refuges, riverine barriers and differentiation along environmental gradients. The earliest postulated members of the complex originated in central/eastern Africa and the first radiations took place in rain forests of the Congo Basin. A dramatic shift in the ecological requirements in early members of the complex, in association with changing environments, took place sometime after 1.13 Ma. Some lineages then colonized a substantial portion of the African continent, including a variety of savannah and forest habitats. The low genetic divergence of certain populations, some in isolated localities, can be explained by their synanthropic habits. This study underlines the need to revise the taxonomy of the C. olivieri complex.
authors.affiliation: Institut de Systématique, Évolution, Biodiversité, ISYEB UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle, Sorbonne Universités, 57 rue Cuvier, CP 51, 75005, Paris, France. fr.jacquet@gmail.com.
authors.forename: François
authors.initials: F
authors.lastname: Jacquet
authors.affiliation: Institut de Systématique, Évolution, Biodiversité, ISYEB UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle, Sorbonne Universités, 57 rue Cuvier, CP 51, 75005, Paris, France. denys@mnhn.fr.
authors.forename: Christiane
authors.initials: C
authors.lastname: Denys
authors.affiliation: Royal Belgian Institute of Natural Sciences, Operational Direction Taxonomy and Phylogeny, Molecular Laboratory, Vautierstraat 29, 1000, Brussels, Belgium. everheyen@naturalsciences.be.|Biology Department, University of Antwerpen, Evolutionary Ecology Group, Groenenborgerlaan 171, 2020, Antwerpen, Belgium. everheyen@naturalsciences.be.
authors.forename: Erik
authors.initials: E
authors.lastname: Verheyen
authors.affiliation: Institute of Vertebrate Biology ASCR, Academy of Sciences of the Czech Republic, Květná 8, 603 65, Brno, Czech Republic. bryja@brno.cas.cz.|Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. bryja@brno.cas.cz.
authors.forename: Josef
authors.initials: J
authors.lastname: Bryja
authors.affiliation: Zoologisches Forschungmuseum Alexander Koenig, Adenauerallee 160, D-53113, Bonn, Germany. R.Hutterer@zfmk.de.
authors.forename: Rainer
authors.initials: R
authors.lastname: Hutterer
authors.affiliation: College of Professional Studies, Roosevelt University, 430 S Michigan Avenue, Chicago, IL, 60605, USA. jkerbis@fieldmuseum.org.|Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA. jkerbis@fieldmuseum.org.
authors.forename: Julian C
authors.initials: JC
authors.lastname: Kerbis Peterhans
authors.affiliation: Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA. wstanley@fieldmuseum.org.
authors.forename: William T
authors.initials: WT
authors.lastname: Stanley
authors.affiliation: Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA. sgoodman@fieldmuseum.org.|Association Vahatra, BP 3972, Antananarivo, 101, Madagascar. sgoodman@fieldmuseum.org.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Goodman
authors.affiliation: Génoscope, Centre National de Séquençage, 2 rue Gaston Crémieux, CP5706, 91057, Evry Cedex, France. acouloux@genoscope.cns.fr.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Couloux
authors.affiliation: Université de Rennes 1, CNRS, UMR 6553 Ecobio, Station Biologique, 35380, Paimpont, France. Marc.Colyn@univ-rennes1.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Colyn
authors.affiliation: Institut de Systématique, Évolution, Biodiversité, ISYEB UMR 7205 - CNRS, MNHN, UPMC, EPHE, Muséum National d'Histoire Naturelle, Sorbonne Universités, 57 rue Cuvier, CP 51, 75005, Paris, France. vnicolas@mnhn.fr.
authors.forename: Violaine
authors.initials: V
authors.lastname: Nicolas
mesh_terms: D000349:Africa; D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D004463:Ecology; D017753:Ecosystem; D065928:Forests; D040961:Genetic Drift; D049810:Genetic Speciation; D014644:Genetic Variation; D010802:Phylogeny; D058974:Phylogeography; D012788:Shrews / Q000145:classification / Q000235:genetics*