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Phylogeography and divergence date estimates of a lichen species complex with a disjunct distribution pattern
Author(s) -
Otálora Mónica A. G.,
Martínez Isabel,
Aragón Gregorio,
Molina M. Carmen
Publication year - 2010
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.0900064
Subject(s) - biology , disjunct , disjunct distribution , biological dispersal , species complex , lichen , phylogeography , evolutionary biology , ecology , phylogenetic tree , biogeography , divergence (linguistics) , genetic divergence , genetic diversity , population , gene , biochemistry , linguistics , philosophy , demography , sociology
Disjunct species distributions may result from a combination of geologic events and long‐distance dispersal. The foliose lichen species complex Leptogium furfuraceum ‐ L. pseudofurfuraceum has an intercontinental disjunction pattern. Populations of this species complex are found in western North America, southern South America, Africa, and southern Europe. We conducted a phylogenetic study to reconstruct the biogeographic history of this species complex using two ribosomal genes (ITS and LSU) and a protein‐coding gene (partial RPB2 ). Results indicated that the complex comprises four geographically restricted genetic lineages. A sister relationship was found between populations from the same hemispheres, incongruent with previous data derived from morphological characteristics and geographical classification schemes. Incorporating Bayesian ancestral area reconstruction and Bayesian divergence time estimation, we proposed an evolutionary hypothesis for the species complex. The results suggested that processes of biotic expansion via transoceanic dispersal were responsible for the species divergence and distribution patterns observed today. This study also expands the view that cryptic speciation is not a rare phenomenon among fungi and lichens.