The biogeography of the austral, subalpine genus Ourisia (Plantaginaceae) based on molecular phylogenetic evidence: South American origin and dispersal to New Zealand and Tasmania

Abstract

Molecular phylogenetic analyses of 26 of the 28 species of Ourisia , including eight of ten subspecies and two purported natural hybrids, are presented and used to examine the biogeography of the genus, which is distributed in subalpine to alpine habitats of South America, New Zealand and Tasmania. Gondwanan vicariance, often cited as the cause of this classic austral biogeographical pattern, was rejected by parametric bootstrapping of our combined dataset. Alternatively, various lines of evidence are presented in favour of a South American origin of Ourisia and subsequent dispersal to Australasia. Specifically, the genus likely arose in the Andes of central Chile and spread to southern Chile and Argentina, to the north-central Andes, and finally to Tasmania and New Zealand. The ancestor of the New Zealand species probably first arrived on the South Island, where the New Zealand species of Ourisia are most diverse, and migrated to the North and Stewart Islands. Because the Tasmanian and New Zealand species are sister to one another, the direction of dispersal between these two areas is equivocal. These results agree with other molecular phylogenetic studies that show that past dispersal between southern hemisphere continents has played an important role in the evolutionary history of many high-elevation austral plants. Our data also show that within South America, many of the geographical barriers (with the exception of the Atacama Desert) that have played a role in the evolution of other plant groups have not affected Ourisia species. Within New Zealand, the phylogeny and biogeography of species of Ourisia coincide with the geological history of the country and patterns of other alpine plants.

Phylogenetic insights into Andean plant diversification

“…In the genus Perezia (Asteraceae, Figure 1B), Simpson et al (2009) suggest that the genus colonized high-elevation habitats from low-elevation ancestors in the Southern Andes and subsequently migrated northwards along the Andes to eventually diversify in the Central Andes. An essentially parallel hypothesis is provided by Meudt and Simpson (2006) based on data on Ourisia (Plantaginaceae), which clearly originated in the Southern Andes and subsequently dispersed to the Central and Northern Andes, where further speciation took place. In Chuquiraga (Asteraceae), distributed from Patagonia to Venezuela along the Andes (Ezcurra, 2002;Gruenstaeudl et al, 2009), a southern origin was inferred (Gruenstaeudl et al, 2009).…”

New World Origins of Southwest Pacific Gesneriaceae: Multiple Movements Across and Within the South Pacific

“…However, subtropical Coronanthereae might have been unsuited for the cool climate and extreme seasonality of Antarctica, which finally became inhospitable to woody plants ;15 Ma (Hill and Scriven 1995). The findings in numerous molecular studies now support the hypothesis that current biotic patterns in the southern Pacific are influenced by dispersal (Swenson and Bremer 1997;Hurr et al 1999;Wagstaff et al 2000Wagstaff et al , 2002Mummenhoff et al 2001;Gemmill et al 2002;Winkworth et al 2002b;Howarth et al 2003;Nepokroeff et al 2003;Smissen et al 2003;Berry et al 2004;Clement et al 2004;Mummenhoff 2004;Albach et al 2005;Bartish et al 2005;Cronk et al 2005;Motley et al 2005;Meudt and Simpson 2006;Clark et al 2008Clark et al , 2009Pfeil and Crisp 2008;Smith et al 2008;Tay et al 2010). The inference of dispersal has been most obvious for species on oceanic islands of recent origin but less so for those on continental islands.…”

“…Many plant genera found in temperate South America, Australia, and New Zealand give at least the impression of Gondwanic vicariance, e.g., Veronica sect. Hebe (Wagstaff et al 2002, as Hebe and relatives), Fuchsia (Berry et al 2004, in Australia as fossils only), Ourisia (Meudt and Simpson 2006), Oreobolus (Seberg 1988), Tetrachondra (Wagstaff et al 2000), and Abrotanella (Swenson and Bremer 1997). However, in the past 20 years, molecular ages (Wagstaff et al 2002(Wagstaff et al , 2007Smissen et al 2003;Pfeil and Crisp 2008;Tay et al 2010) have indicated that many southern disjunct plant groups are too recent for their distributions to be explained by Gondwanic vicariance.…”

“…For instance, in Veronica, the grade of taxa basal to the Australasian clade (subg. Pseudoveronica) is found in Eurasia (Albach and Meudt 2010), whereas the grades of taxa basal to the Australasian clades of Ourisia and Fuchsia are found in South America (Berry et al 2004;Meudt and Simpson 2006).…”

The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level

“…Many studies have tested Gondwanan vicariant patterns using an area cladogram approach, in both plants (e.g. Swenson et al 2001;Ladiges et al 2003;Cook and Crisp 2005;Meudt and Simpson 2006) and animals (e.g. Griswold and Ledford 2001;Daniels et al 2004;Sparks and Smith 2004;Kuntner 2006).…”