title: Long live the alien: is high genetic diversity a pivotal aspect of crested porcupine (Hystrix cristata) long-lasting and successful invasion?
abstract: Studying the evolutionary dynamics of an alien species surviving and continuing to expand after several generations can provide fundamental information on the relevant features of clearly successful invasions. Here, we tackle this task by investigating the dynamics of the genetic diversity in invasive crested porcupine (Hystrix cristata) populations, introduced to Italy about 1500 years ago, which are still growing in size, distribution range and ecological niche. Using genome-wide RAD markers, we describe the structure of the genetic diversity and the demographic dynamics of the H. cristata invasive populations and compare their genetic diversity with that of native African populations of both H. cristata and its sister species, H. africaeaustralis. First, we demonstrate that genetic diversity is lower in both the invasive Italian and the North Africa source range relative to other native populations from sub-Saharan and South Africa. Second, we find evidence of multiple introduction events in the invasive range followed by very limited gene flow. Through coalescence-based demographic reconstructions, we also show that the bottleneck at introduction was mild and did not affect the introduced genetic diversity. Finally, we reveal that the current spatial expansion at the northern boundary of the range is following a leading-edge model characterized by a general reduction of genetic diversity towards the edge of the expanding range. We conclude that the level of genome-wide diversity of H. cristata invasive populations is less important in explaining its successful invasion than species-specific life-history traits or the phylogeographic history in the native source range.
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066, Blindern, NO-0316, Norway.|Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Vienna, Austria.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Trucchi
authors.affiliation: INRA, UMR1062, CBGP, Avenue du Campus Agropolis, 34980, Montferrier-sur-Lez, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Facon
authors.affiliation: Department of Primatology, Max Planck Institute for Evolutionary Biology, Deutscher Platz 6, 04130, Leipzig, Germany.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gratton
authors.affiliation: Department of Agriculture, Forest and Food Science, University of Turin, L.go P. Braccini 2, 10095, Grugliasco, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Mori
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066, Blindern, NO-0316, Norway.
authors.forename: Nils Chr
authors.initials: NC
authors.lastname: Stenseth
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066, Blindern, NO-0316, Norway.|Department of Natural Sciences, University of Agder, 4604, Kristiansand, Norway.
authors.forename: Sissel
authors.initials: S
authors.lastname: Jentoft
mesh_terms: D000352:Africa, Northern; D000818:Animals; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D058865:Introduced Species; D007558:Italy; D058974:Phylogeography; D046328:Porcupines / Q000235:genetics*; D013019:South Africa
chemical_list: D005819:Genetic Markers
keywords: RAD sequencing; gene surfing; inbreeding; invasive species; population dynamics