title: Who's getting around? Assessing species diversity and phylogeography in the widely distributed lichen-forming fungal genus Montanelia (Parmeliaceae, Ascomycota).
abstract: Brown parmelioid lichens comprise a number of distinct genera in one of the most species-rich families of lichen-forming fungi, Parmeliaceae (Ascomycota). In spite of their superficial similarity, a number of studies of brown parmelioids have provided important insight into diversification in lichen-forming fungi with cosmopolitan distributions. In this study we assess species diversity, biogeography and diversification of the genus Montanelia, which includes alpine to temperate saxicolous species. We sampled each of the five known species, four of which are known from broad, intercontinental distributions. In order to identify potential biogeographical patterns, each broadly distributed species was represented by individuals collected across their intercontinental distributions. Molecular sequence data were generated for six loci, including three nuclear protein-coding markers (MCM7, RPB1, and RPB2), two nuclear ribosomal markers (ITS and nrLSU), and a fragment of the mitochondrial small subunit. We used three sequence-based species delimitations methods to validate traditional, phenotype-based species and circumscribe previously unrecognized species-level lineages in Montanelia. Relationships among putative lineages and divergence times were estimated within a coalescent-based multi-locus species tree framework. Based on the results of the species delimitation analyses, we propose that the genus Montanelia is likely comprised of six to nine species-level lineages, including previously unrecognized species-level diversity in the nominal taxa M. panniformis and M. tominii. In contrast, molecular sequence data suggest that M. predisjuncta may be conspecific with the widespread taxon M. disjuncta in spite of distinct morphological differences. The rate-based age estimation of the most recent common ancestor of Montanelia (ca. 23.1Ma) was similar to previous estimates based on the fossil record. Furthermore, our data suggest that diversification in Montanelia occurred largely during the Neogene. At least three Montanelia species are broadly distributed throughout Asia, Europe, and North America with no evidence of phylogeographic substructure. In contrast to broadly distributed Montanelia species, our study suggests Pleistocene-dominated diversification and complex biogeographic history in the M. tominii group. Our analyses provide additional insight for understanding diversification and uncovering cryptic diversity in cosmopolitan species of lichen-forming fungi.
authors.affiliation: Committee on Evolutionary Biology, University of Chicago, Chicago, IL, USA; Science & Education, The Field Museum, Chicago, IL, USA. Electronic address: sleavitt@fieldmuseum.org.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Leavitt
authors.affiliation: Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid E-28040, Spain.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Divakar
authors.affiliation: Department of Botany, National Museum of Nature and Science, 4-1-1 Amaklubo, Tsukuba, Ibaraki 305-0005, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ohmura
authors.affiliation: Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan 650201, China.
authors.forename: Li-Song
authors.initials: LS
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences #2715, North Dakota State University, PO Box 6050, Stevens Hall, Fargo, ND 58108-6050, USA.
authors.forename: Theodore L
authors.initials: TL
authors.lastname: Esslinger
authors.affiliation: Science & Education, The Field Museum, Chicago, IL, USA.
authors.forename: H Thorsten
authors.initials: HT
authors.lastname: Lumbsch
mesh_terms: D001483:Base Sequence; D001499:Bayes Theorem; D004271:DNA, Fungal / Q000032:analysis; D008969:Molecular Sequence Data; D000068837:Parmeliaceae / Q000145:classification* / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D058974:Phylogeography; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal
keywords: ABGD; Cosmopolitan species; Fungi; GYMC; PTP; Species delimitation