Parallel Miocene dispersal events explain the cosmopolitan distribution of the Hypogymnioid lichens

Abstract

Aim Contemporary species’ distributions are shaped by both geography and historical events, such as extinction, diversification in specific areas and long‐distance dispersals. In the most diverse family of lichen‐forming fungi, Parmeliaceae, the Hypogymnioid clade, is an example of an evolutionary lineage comprised of species occurring in temperate to subpolar regions in both hemispheres. Here, we elucidate the timing of diversification events and the impact of historical events on the species distribution in this lineage. Location Worldwide. Taxon Genera Arctoparmelia, Brodoa, Hypogymnia and Pseudevernia (Parmeliaceae). Methods Our sampling focused on the most diverse genus of the clade, Hypogymnia, including c. 70% of the described species. We reconstructed phylogenetic relationships using a multi‐locus data set, estimated divergence times, and inferred ancestral distributions. Results Our analyses suggest that the ancestor of the Hypogymnioid clade occurred in the Holarctic. In each of the four genera, all recovered as monophyletic here, diversification have occurred largely during the Miocene and Pliocene. A number of currently accepted species did not form monophyletic groups, especially in cases where specimens were collected from distinct geographic areas, with multiple, distinct clades corresponding to the geographic region of origin. Our results suggest that only a very few species in the Hypogymnioid clade have cosmopolitan distributions, all of which reproduces using vegetative propagules including both symbiotic partners. Main conclusions While the diversification occurred predominantly in the Northern Hemisphere during the Miocene, a long‐distance dispersal event from the Northern to the Southern Hemisphere, resulted in diversification of a clade of species largely restricted to the Southern Hemisphere. Similar to other groups in this diverse family, our study highlights the need for re‐evaluation of species boundaries among members of the Hypogymnioid clade.

Providing Scale to a Known Taxonomic Unknown—At Least a 70-Fold Increase in Species Diversity in a Cosmopolitan Nominal Taxon of Lichen-Forming Fungi

“…Based on current, limited sampling, we found a mix of a few cosmopolitan lineages and many local/regional endemics. Other lichen-forming fungi have shown similar patterns of complex intercontinental species distributions [ 82 , 83 , 84 , 85 ]. Presently, little is known of evolutionary processes that may give rise to reproductive isolation and ultimately speciation among populations in the L. polytropa clade.…”

A revision of species of theParmelia saxatiliscomplex in the Iberian Peninsula with the description ofP. rojoi, a new potentially relict species

“…Our results allow us to hypothesize that long-distance dispersal might have played a crucial role in colonizing transcontinental regions. In lichenized fungi, wide distributional ranges have often been attributed to long-distance dispersal (Geml et al 2010;Amo de Paz et al 2012;Del-Prado et al 2013;Leavitt et al 2013Leavitt et al , 2018Núñez-Zapata et al 2017;Cubas et al 2018;Divakar et al 2019). Distinguished by an absence of soralia and isidia, a uniformly dark brown thallus, laminal and marginal pseudocyphellae, nonsquarrose rhizines, and by containing protocetraric and ±lobaric acids as characteristic substances (Thell et al 2011).…”

Repeated Colonization Between Arid and Seasonal Wet Habitats, Frequent Transition Among Substrate Preferences, and Chemical Diversity in Western Australian Xanthoparmelia Lichens

“…A number of lichen species exhibit large distributional ranges, often being cosmopolitan, pantropical or antitropical (e.g., Galloway, 2008;Werth, 2011;Printzen et al, 2013;Leavitt and Lumbsch, 2016). However, molecular data have shown that many widely distributed species consist of separate lineages on different continents (Arguello et al, 2007;Otálora et al, 2010;Amo de Paz et al, 2012;Divakar et al, 2019). Species with worldwide distributional ranges usually are restricted to specific habitats -e.g., arctic species that occur in temperate regions are usually restricted to higher altitudes (Poelt, 1987).…”