title: Empirical evidence supporting frequent cryptic speciation in epiphyllous liverworts: a case study of the Cololejeunea lanciloba complex.
abstract: Cryptic species are frequently recovered in plant lineages, and considered an important cause for divergent of morphological disparity and species diversity. The identification of cryptic species has important implications for the assessment of conservation needs of species aggregates. The mechanisms and processes of the origin of cryptic species diversity are still poorly understand based on the lack of studies especially in context of environment factors. Here we explored evidence for cryptic species within the epiphyllous liverworts Cololejeunea lanciloba complex based on two loci, the plastid trnL-F region and the nuclear ribosomal ITS region. Several analytic approaches were employed to delimit species based on DNA sequence variation including phylogenetic reconstruction, statistical parsimony networks analysis and two recently introduced species delimitation criteria: Rosenberg's reciprocal monophyly and Rodrigo's randomly distinct. We found evidence for thirteen genetically distinct putative species, each consisting of more than one haplotype, rather than four morphologically-circumscribed species. The results implied that the highly conserved phenotypes are not congruent with the genetic differentiation, contributing to incorrect assessments of the biodiversity of epiphyllous liverworts. We hypothesize that evolution of cryptic species recovered may be caused by selection of traits critical to the survival in epiphyllous habitats combined with limited developmental options designed in the small body.
authors.affiliation: Department of Biology, East China Normal University, Shanghai, China ; Department of Life Science, Natural History Museum, London, United Kingdom.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Georg-August-Universität, Göttingen, Germany ; Department of Biology, Systematic Botany and Mycology, University of Munich (LMU), Munich, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Heinrichs
authors.affiliation: Department of Biology, East China Normal University, Shanghai, China ; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai, China.
authors.forename: Rui-Liang
authors.initials: RL
authors.lastname: Zhu
authors.affiliation: Department of Life Science, Natural History Museum, London, United Kingdom ; The State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Harald
authors.initials: H
authors.lastname: Schneider
mesh_terms: D017753:Ecosystem; D019143:Evolution, Molecular; D049810:Genetic Speciation; D014644:Genetic Variation; D035926:Hepatophyta / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D012098:Reproduction