title: Integrating Paleodistribution Models and Phylogeography in the Grass-Cutting Ant Acromyrmex striatus (Hymenoptera: Formicidae) in Southern Lowlands of South America.
abstract: Past climate changes often have influenced the present distribution and intraspecific genetic diversity of organisms. The objective of this study was to investigate the phylogeography and historical demography of populations of Acromyrmex striatus (Roger, 1863), a leaf-cutting ant species restricted to the open plains of South America. Additionally, we modeled the distribution of this species to predict its contemporary and historic habitat. From the partial sequences of the mitochondrial gene cytochrome oxidase I of 128 A. striatus workers from 38 locations we estimated genetic diversity and inferred historical demography, divergence time, and population structure. The potential distribution areas of A. striatus for current and quaternary weather conditions were modeled using the maximum entropy algorithm. We identified a total of 58 haplotypes, divided into five main haplogroups. The analysis of molecular variance (AMOVA) revealed that the largest proportion of genetic variation is found among the groups of populations. Paleodistribution models suggest that the potential habitat of A. striatus may have decreased during the Last Interglacial Period (LIG) and expanded during the Last Maximum Glacial (LGM). Overall, the past potential distribution recovered by the model comprises the current potential distribution of the species. The general structuring pattern observed was consistent with isolation by distance, suggesting a balance between gene flow and drift. Analysis of historical demography showed that populations of A. striatus had remained constant throughout its evolutionary history. Although fluctuations in the area of their potential historic habitat occurred during quaternary climate changes, populations of A. striatus are strongly structured geographically. However, explicit barriers to gene flow have not been identified. These findings closely match those in Mycetophylax simplex, another ant species that in some areas occurs in sympatry with A. striatus. Ecophysiological traits of this species and isolation by distance may together have shaped the phylogeographic pattern.
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Viçosa, Minas Gerais, 36570-000, Brazil.|Departamento de Biodiversidade, Evolução e Meio Ambiente/ICEB, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, Minas Gerais, 35400-000, Brazil.|Zoology / Evolutionary Biology, Universitätstrasse 31, Universität Regensburg, 93040, Regensburg, Deutschland.
authors.forename: Maykon Passos
authors.initials: MP
authors.lastname: Cristiano
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Viçosa, Minas Gerais, 36570-000, Brazil.|Departamento de Genética, Setor de Ciências Biológicas, Universidade Federal do Paraná, Rua Francisco H. dos Santos, 100, Jardim das Américas, Curitiba, Paraná, 81530-000, Brazil.|Zoology / Evolutionary Biology, Universitätstrasse 31, Universität Regensburg, 93040, Regensburg, Deutschland.
authors.forename: Danon
authors.initials: D
authors.lastname: Clemes Cardoso
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Viçosa, Minas Gerais, 36570-000, Brazil.
authors.forename: Tânia Maria
authors.initials: TM
authors.lastname: Fernandes-Salomão
authors.affiliation: Zoology / Evolutionary Biology, Universitätstrasse 31, Universität Regensburg, 93040, Regensburg, Deutschland.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Heinze
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001000:Ants / Q000145:classification / Q000235:genetics*; D001118:Argentina; D001938:Brazil; D057231:Climate Change; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017753:Ecosystem; D014644:Genetic Variation; D006239:Haplotypes; D008957:Models, Genetic; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D058974:Phylogeography; D012372:ROC Curve; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D004247:DNA