title: Worldwide invasion by the little fire ant: routes of introduction and eco-evolutionary pathways.
abstract: Biological invasions are generally thought to occur after human aided migration to a new range. However, human activities prior to migration may also play a role. We studied here the evolutionary genetics of introduced populations of the invasive ant Wasmannia auropunctata at a worldwide scale. Using microsatellite markers, we reconstructed the main routes of introduction of the species. We found three main routes of introduction, each of them strongly associated to human history and trading routes. We also demonstrate the overwhelming occurrence of male and female clonality in introduced populations of W. auropunctata, and suggest that this particular reproduction system is under selection in human-modified habitats. Together with previous researches focused on native populations, our results suggest that invasive clonal populations may have evolved within human modified habitats in the native range, and spread further from there. The evolutionarily most parsimonious scenario for the emergence of invasive populations of the little fire ant might thus be a two-step process. The W. auropunctata case illustrates the central role of humans in biological change, not only due to changes in migration patterns, but also in selective pressures over species.
authors.affiliation: INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Montferrier-sur-Lez cedex, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Foucaud
authors.affiliation: Université de Toulouse, UPS, EDB (Laboratoire Evolution et Diversité Biologique) Toulouse, France ; CNRS, EDB (Laboratoire Evolution et Diversité Biologique) Toulouse, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Orivel
authors.affiliation: INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Montferrier-sur-Lez cedex, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Loiseau
authors.affiliation: Laboratório de Mirmecologia, CEPEC-CEPLAC & UESC Itabuna, Bahia, Brazil.
authors.forename: Jacques H C
authors.initials: JH
authors.lastname: Delabie
authors.affiliation: INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Montferrier-sur-Lez cedex, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Jourdan
authors.affiliation: INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Montferrier-sur-Lez cedex, France.
authors.forename: Djoël
authors.initials: D
authors.lastname: Konghouleux
authors.affiliation: Department of Zoology, Tel-Aviv University Tel-Aviv, Israel.
authors.forename: Merav
authors.initials: M
authors.lastname: Vonshak
authors.affiliation: Département de biologie des organismes animaux, Faculté des sciences de l'université de Douala Douala, Cameroun.
authors.forename: Maurice
authors.initials: M
authors.lastname: Tindo
authors.affiliation: Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 6035, Faculté des Sciences et Techniques Tours, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Mercier
authors.affiliation: Laboratoire d'Ethologie Expérimentale et Comparée, CNRS UMR 7153 Université Paris 13, Villetaneuse, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Fresneau
authors.affiliation: Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 6035, Faculté des Sciences et Techniques Tours, France.
authors.forename: Jean-Bruno
authors.initials: JB
authors.lastname: Mikissa
authors.affiliation: Department of Biology, University of San Diego San Diego, CA, USA.
authors.forename: Terry
authors.initials: T
authors.lastname: McGlynn
authors.affiliation: Section of Integrative Biology, University of Texas Austin, TX, USA.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Mikheyev
authors.affiliation: Biologie I, Universität Regensburg Regensburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Oettler
authors.affiliation: INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Montferrier-sur-Lez cedex, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Estoup
keywords: Wasmannia auropunctata; biological invasion; introduction routes; parthenogenesis; reproduction system