Diversification of the phaseoloid legumes: effects of climate change, range expansion and habit shift

Abstract

Understanding which factors have driven the evolutionary success of a group is a fundamental question in biology. Angiosperms are the most successful group in plants and have radiated and adapted to various habitats. Among angiosperms, legumes are a good example for such successful radiation and adaptation. We here investigated how the interplay of past climate changes, geographical expansion and habit shifts has promoted diversification of the phaseoloid legumes, one of the largest clades in the Leguminosae. Using a comprehensive genus-level phylogeny from three plastid markers, we estimate divergence times, infer habit shifts, test the phylogenetic and temporal diversification heterogeneity, and reconstruct ancestral biogeographical ranges. We found that the phaseoloid lineages underwent twice dramatic accumulation. During the Late Oligocene, at least six woody clades rapidly diverged, perhaps in response to the Late Oligocene warming and aridity, and a result of rapidly exploiting new ecological opportunities in Asia, Africa and Australia. The most speciose lineage is herbaceous and began to rapidly diversify since the Early Miocene, which was likely ascribed to arid climates, along with the expansion of seasonally dry tropical forests in Africa, Asia, and America. The phaseoloid group provides an excellent case supporting the idea that the interplay of ecological opportunities and key innovations drives the evolutionary success.

Targeting legume loci: A comparison of three methods for target enrichment bait design in Leguminosae phylogenomics

“…C) support Shuteria as sister to Kennedia , a finding also discovered by Li et al. (), whereas ASTRAL (Fig. B) and the concatenated chloroplast loci (Fig.…”

Phylogenetics and Biogeography of Apios (Fabaceae) Inferred from Sequences of Nuclear and Plastid Genes

“…Thus, our DNA sequence data support Apios as a monopyletic group. In addition, Apios diverges early in the phaseoloid group, which is consistent with the phylogenetic placement of Apios by previous studies (Kajita et al 2001;Wojciechowski et al 2004;Lavin et al 2005;Stefanovic et al 2009;Li et al 2013).…”

“…Two areas of endemism were used on the basis of the distribution of the extant species: EAS and ENA. The outgroup was included in the S-DIVA analysis and was coded as EAS since a recent study of phaseoloid legumes has inferred EAS as the most likely ancestral area of the sister group to Apios (Li et al 2013). …”

Range expansion and habitat shift triggered elevated diversification of the rice genus (Oryza, Poaceae) during the Pleistocene

“…Some studies have indicated that life history shifts are responsible for increased rates of diversification of many groups, such as Lupinus [ 55 ] and the phaseoloid legumes [ 61 ]. Our ancestral state reconstruction suggests that perennial life history is the ancestral state in Oryza , whereas annual life history has independently evolved at least four times (Fig.…”