Cenozoic colonization and diversification patterns of tropical American palms: evidence fromAstrocaryum(Arecaceae)

Abstract

With 788 species in 67 genera in the Neotropics, Arecaceae are an important ecological and economic component of the region. We review the influence of geological events such as the Pebas system, the Andean uplift and the land connections between South and Central/North America, on the historical assembly of Neotropical palms. We present a case study of the palm genus Astrocaryum (40 species) as a model for evaluating colonization and diversification patterns of lowland Neotropical taxa. We conducted a Bayesian dated phylogenetic analysis based on four low‐copy nuclear DNA regions and a biogeographical analysis using the dispersal, extinction and cladogenesis model. Cladogenesis of Western Amazonian Astrocaryum spp. (c. 6 Mya) post‐dated the drainage of the aquatic Pebas system, supporting the constraining role of Pebas on in situ diversification and colonization. The ancestral distribution of Astrocaryum spp. in the Guiana Shield supported the hypothesis of an old formation that acted as a source area from which species colonized adjacent regions, but an earliest branching position for Guianan species was not confidently recovered. A twofold increase in diversification rate was found in a clade, the ancestor of which occupied the Guiana Shield (c. 13 Mya, a time of climatic change and Andean uplift). © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ●●, ●●–●●.

Adaptive radiation, correlated and contingent evolution, and net species diversification in Bromeliaceae

“…Our findings confirm the widespread pattern for many Neotropical plant groups to have diversified mostly since the Middle Miocene, associated with uplift of the northern Andes and the Serro do Mar and nearby ranges in southeastern Brazil (Givnish et al, 2004(Givnish et al, , 2007(Givnish et al, , 2011Hughes and Eastwood, 2006;Antonelli et al, 2009;Antonelli and Sanmartin, 2011;Arakaki et al, 2011;Hoorn et al, 2010;Nagalingum et al, 2011;Drew and Sytsma, 2013;Perret et al, 2013;Roncal et al, 2013;cf. Rull, 2008;Lohmann et al, 2013).…”

Niche conservatism drives a global discrepancy in palm species richness between seasonally dry and moist habitats

“…The expansion of savanna and other seasonal ecosystems during the dry periods of glaciation cycles in South America and Africa might have increased in situ diversification events of seasonal drought‐ and fire‐adapted clades (Linder, ; Simon et al, ), which might result in turnover patterns. Increases in diversification that coincide with seasonally dry ecosystem development, in fact, have been reported for Neotropical palms, such as Astrocaryum (Roncal, Kahn, Millan, Couvreur, & Pintaud, ) and Attalea (Freitas et al, ). Moreover, niche conservatism leads to low lineage exchange between distinct habitats (Wiens et al, ), which might also contribute to the turnover patterns (Eiserhardt, Svenning, Baker, Couvreur, & Balslev, ).…”

Renewed diversification following Miocene landscape turnover in a Neotropical butterfly radiation

“…For example, in the palm genus Astrocaryum (Arecaceae), the upper Amazonian clade started to diversify only c . 6 Ma (Roncal, Kahn, Millán, Couvreur, & Pintaud, ). In Taygetis butterflies, Amazonian lineages show rapid diversification during the last 7–8 Myr (Matos‐Maraví, Peña, Willmott, Freitas, & Wahlberg, ).…”