Historical biogeography of the predominantly Australian plant family Goodeniaceae

Abstract

Aim The plant family Goodeniaceae includes 12 genera, largely restricted to Australia. They are a diverse and conspicuous element of the country's ecosystems and an important clade to consider in the effort to reconstruct the historical biogeography of this continent. We used a time‐calibrated molecular phylogeny to perform ancestral‐area reconstructions for the family, in order to: (1) determine its area of origin; (2) test whether vicariance played a role in the history of lineages occupying the south‐western and south‐eastern regions; (3) trace diversification processes in the central arid zone; and (4) trace potential eastward dispersals into the Pacific. Location Australia and the Pacific. Methods We employed a previously published molecular dataset to develop a time‐calibrated phylogeny for the Goodeniaceae using beast 1.6.1 with both primary and secondary node calibrations. Ancestral areas were reconstructed via both dispersal–extinction–cladogenesis (DEC) and statistical dispersal–vicariance analysis (S‐DIVA). Results The Goodeniaceae split from Asteraceae + Calyceraceae c. 78 Ma, with the divergence of the Lechenaultia, Anthotium and Dampiera (LAD) clade from the remainder of the family c. 67 Ma. Although the geographical origin of the family is equivocal, the LAD clade originated in south‐western Australia, and the remainder of the family, especially Goodenia s.l., probably originated in the central Eremaean zone. The majority of Goodenia cladogenesis events occurred during the Miocene, with expansions to the north, south‐east and south‐west. The crown radiation of Scaevola s.l. occurred later, during the second half of the Miocene, and has involved several recent extra‐Australian dispersals into the Pacific. Main conclusions Although it is unclear where in Australia the family originated, our results support a south‐western origin for the LAD clade and considerable diversification of some clades within Goodenia s.l. and Scaevola s.l. in that zone. A relative paucity of mid‐Miocene sister relationships between south‐western and south‐eastern lineages suggests that the occupants of these regions were not affected by contemporary vicariance events. Instead, our results suggest that the aridifying Eremaean zone was an important source and sink for lineages, especially in Goodenia s.l. Dispersal is inferred for the extra‐Australian lineages due to their recent origins.

Phylogeny, evolution, and biogeographic history of Calandrinia (Montiaceae)

“…A decline in diversification rates has also been reported for other Australian plant lineages that had originally diversified and radiated during the mid‐Miocene, e.g., Tetratheca (Crayn and Rossetto, ), Goodeniaceae (Jabaily et al., ), Proteaceae (Sauquet et al., ; Mast et al., ), and Myrtaceae (Thornhill et al., ). Many of these lineages likely responded to extreme desertification of the continent during glacial maxima by retreating to refugia.…”

Evolutionary origin of the Asteraceae capitulum: Insights from Calyceraceae

“…The Goodeniaceae show a wide diversity of inflorescences, with different modifications of the basic thyrsoid ( Pentaptilon , Verreauxia ) or thyrsic ( Goodenia ) structure, sometimes condensed ( Anthotium , Brunonia , Dampiera wellsiana , and D. eriocephala ) or not, with or without mono/dichasial lateral first order branches (in the latter case, the inflorescence is a raceme as in Dampiera wellsiana , or a botryoid if there is a terminal flower), with or without one‐flowered lateral branches (i.e., a cyme, as in Velleia ). A preliminary molecular phylogeny of the Goodeniaceae (Jabaily et al, 2010) proposes two main clades: the Dampiera/Lechenaultia/Anthotium group and the Scaevola / Goodenia (including Verrauxia and Velleia )/ Coopernookia / Brunonia (plus other monotypic genera) group. Although it is not possible to choose a basalmost genus in the Goodeniaceae phylogeny (R. S. Jabaily, personal communication), we took the thyrse and the thyrsoid as the plesiomorphic structures for Goodeniaceae based on Rajput and Carolin (1988) and Carolin et al (1992).…”

“…Menyanthaceae and Goodeniaceae were coded following two criteria: with the plesiomorphic structure, and with all inflorescence diversity considered particularly for Goodeniaceae. Plesiomorphic states were based on Tippery et al (2008) for Menyanthaceae and on Carolin et al (1992), Jabaily et al (2010), and R. S. Jabaily (University of Wisconsin, personal communication) for Goodeniaceae. Inflorescence diversity of Menyanthaceae was taken from Troll (1964) and Troll and Weberling (1989), but we excluded the unusual one‐flowered inflorescence of Liparophyllum gunii .…”

Fire as a key driver of Earth's biodiversity

“…rainforest) into fire‐prone environments in 24 cases. The two exceptions are Scaevola (Goodeniaceae) where limited dispersal occurred more recently from fire‐prone Australia to the non‐fire‐prone Pacific rim (Jabaily et al, ), and a few species of Disa (Orchidaceae) dispersing from fire‐prone fynbos to rarely burnt riverbanks (Bytebier et al, ). On acquiring fire‐adapted traits, vast new habitats become available that create new speciation opportunities in terms of the altered physical environment (climate, soil, topography) and different plant–animal interactions (pollinators, herbivores, granivores) become possible (Lamont et al, ; Pausas & Lamont, ).…”

“…rainforest) may also present novel agents of selection in association with extensive new habitats and foster speciation. Nevertheless, migration to fire‐free habitats among essentially fire‐prone lineages is relatively recent and the comparatively low levels of speciation observed might simply be attributed to their restricted numbers (Bytebier et al, ; Jabaily et al, ; Lamont et al, ). Overall these results suggest that fire is as good, or an even more powerful, driver of diversification than the traditionally considered agents of selection (climate, soils, biogeography and species interactions; Pausas & Lamont, ).…”