Spatio‐temporal evolution of Fosterella (Bromeliaceae) in the Central Andean biodiversity hotspot

Abstract

Aim To reconstruct the spatio‐temporal evolution of Fosterella (Bromeliaceae), a genus characterized by a high degree of endemism in the Central Andes, and to account for contemporary patterns of diversity and distribution within the genus. Location Fosterella has its centre of diversity in the Central Andes (24 species), where it occurs in two major biomes: the Yungas and seasonally dry tropical forests (SDTF). The genus displays three major disjunctions: Amazonia (one species), Central America (one species), and the Brazilian Shield (five species). Methods Phylogenetic relationships within Fosterella were inferred based on six plastid DNA regions. Parsimony and likelihood methods, a Bayesian relaxed molecular clock, ancestral area reconstructions, and diversification rate analyses were used to infer the spatio‐temporal evolution of Fosterella. Results The origin of extant lineages of Fosterella was placed in the late Miocene (c. 9.6 Ma) during the last rapid Andean uplift. SDTF and azonal lowland sites were inferred as the most likely ancestral habitats. The Yungas were colonized several times independently from c. 4.7 Ma onwards. Only one clade diversified in the Yungas, indicative of an ecological shift to moister and cooler conditions. Two recent long‐distance dispersals to Central America and to Amazonia were inferred. Diversification rates within Fosterella were found to be constant through time and comparatively low (0.4 species Myr−1). Main conclusions Allopatric speciation is the main mode of diversification in Fosterella. The isolated distribution of suitable habitats fostered the evolution of a high degree of endemism. The low speciation rates in Fosterella contrast with high diversification rates of Andean high‐elevation taxa but are similar to other Andean low‐ to mid‐elevation taxa. The last rapid Andean uplift did not leave a detectable signature in the diversification rates of Fosterella.

Phylogenetic insights into Andean plant diversification

“…In the Andean genus Fosterella (Bromeliaceae), allopatric speciation associated with the Andean uplift was invoked to explain the diversification of this genus, whose origin was dated to Middle Miocene age (Wagner et al, 2013). Outside the Andes (SDTF and Yungas), Fosterella has some species distributed in azonal rock outcrops of the Brazilian highlands, lowlands of central Amazonia and Central America; the latter three areas were reached in different and recent colonization events after the Andean diversification of the group (Wagner et al, 2013). Figure 3B summarizes divergence time estimates for all these inner-Andean clades.…”

Reproduction biology and chloroplast inheritance in Bromeliaceae: a case study in Fosterella (Pitcairnioideae)

“…Our recent biogeographical studies indicated that the genus had originated about 9.6 million years ago (Mya) in the Andean seasonally dry tropical forests of Bolivia (Wagner et al 2013). Based on chloroplast DNA (cpDNA) sequence data, six well-supported lineages were discerned within the genus (Rex et al 2009;Wagner et al 2013). Of these, the socalled micrantha group is of particular interest for evolutionary studies, because its three morphologically very similar species show different distribution patterns .…”

“…1d, h). According to cpDNA sequences, the diversification of the group began only 1.3 Mya (Wagner et al 2013). Delimitation of taxa by phenotypical characters is difficult: all three species have a similar growth habit and small whitish flowers (Fig.…”

“…is restricted to C America (see below), and F. batistana Ibisch, Leme & J.Peters is the only species known from Amazonia in Brazil (Peters et al 2008;). Our recent biogeographical studies indicated that the genus had originated about 9.6 million years ago (Mya) in the Andean seasonally dry tropical forests of Bolivia (Wagner et al 2013). Based on chloroplast DNA (cpDNA) sequence data, six well-supported lineages were discerned within the genus (Rex et al 2009;Wagner et al 2013).…”

“…1l). It is most likely that F. micrantha reached this area via long distance dispersal about 0.8 Mya (Wagner et al 2013). Fosterella villosula (Harms) L.B.Sm.…”