Geographical structure, narrow species ranges, and Cenozoic diversification in a pantropical clade of epiphyllous leafy liverworts. Issue 2 (20th December 2016)

• Record Type: Journal Article
• Authors: Bechteler, Julia; Schäfer‐Verwimp, Alfons; Lee, Gaik Ee; Feldberg, Kathrin; Pérez‐Escobar, Oscar Alejandro; Pócs, Tamás; Peralta, Denilson F.; Renner, Matthew A. M.; Heinrichs, Jochen
• Is Part Of: Ecology and evolution. Volume 7:Issue 2(2017:Feb.)
• Page Start: 638
• Page End: 653
• Publication Date: 2016-12-20
• Subjects: ancestral area estimation -- bryophyte -- cryptic speciation -- divergence time estimation -- epiphyte -- Leptolejeunea -- phylogeny; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2656
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: The evolutionary history and classification of epiphyllous cryptogams are still poorly known. Leptolejeunea is a largely epiphyllous pantropical liverwort genus with about 25 species characterized by deeply bilobed underleaves, elliptic to narrowly obovate leaf lobes, the presence of ocelli, and vegetative reproduction by cladia. Sequences of three chloroplast regions ( rbc L, trn L‐F, psb A) and the nuclear ribosomal ITS region were obtained for 66 accessions of Leptolejeunea and six outgroup species to explore the phylogeny, divergence times, and ancestral areas of this genus. The phylogeny was estimated using maximum‐likelihood and Bayesian inference approaches, and divergence times were estimated with a Bayesian relaxed clock method. Leptolejeunea likely originated in Asia or the Neotropics within a time interval from the Early Eocene to the Late Cretaceous (67.9 Ma, 95% highest posterior density [HPD]: 47.9–93.7). Diversification of the crown group initiated in the Eocene or early Oligocene (38.4 Ma, 95% HPD: 27.2–52.6). Most species clades were established in the Miocene. Leptolejeunea epiphylla and L. schiffneri originated in Asia and colonized African islands during the Plio‐Pleistocene. Accessions of supposedly pantropical species are placed in different main clades. Several monophyletic morphospecies exhibit considerable sequence variation related to a geographical pattern. The clear geographic structure of the Leptolejeunea crown group points to evolutionary processes including rare long‐distance dispersal and subsequent speciation. Leptolejeunea may have benefitted from the large‐scale distribution of humid tropical angiosperm forests in the Eocene. Abstract : Widespread polyphyly of supposedly pantropical species indicates an important role of morphologically cryptic or near‐cryptic speciation in the evolutionary history of the epiphyllous liverwort genus Leptolejeunea . The clear geographic structure of the Leptolejeunea crown group contradicts the hypothesis of global panmixis and points to evolutionary processes including rare long‐distance dispersal and subsequent speciation. Leptolejeunea may have benefitted from the large‐scale distribution of humid tropical angiosperm forests in the Eocene.