Format: ORAL

Jens J. Ringelberg 1, Moabe F. Fernandes 2, Anne Bruneau 3, R. Toby Pennington 2,4, Colin E. Hughes 5, Juliana Gastaldello Rando 6, Edeline Gagnon 7, Joseph T. Miller 8, Dario I. Ojeda 9, Manuel de la Estrella 10

1 University of Edinburgh, Edinburgh, United Kingdom 2 University of Exeter, Exeter, United Kingdom 3 Université de Montréal, Montréal, Canada 4 Royal Botanic Garden Edinburgh, Edinburgh, United Kingdom 5 University of Zurich, Zurich, Switzerland 6 Universidade Federal do Oeste da Bahia, Barreiras, Brazil 7 University of Guelph, Guelph, Canada 8 Global Biodiversity Information Facility, Copenhagen, Denmark 9 Norwegian Institute of Bioeconomy Research, Ås, Norway 10 Universidad de Córdoba, Córdoba, Spain

One of the central aims in evolutionary biology is explaining why some lineages are more evolutionarily successful than others, for example in terms of species richness, ecological versatility, and geographic distribution. Direct comparisons of lineages are complicated by the impacts of confounding factors such as differences in age and evolutionary relatedness. The six subfamilies of the legume family provide an ideal natural experiment to determine why some lineages are more successful than others. Since the origin of Leguminosae is a phylogenomic tangle which gave rise to all subfamilies within a very short time frame, the subfamilies are nearly identical in terms of age and relatedness. Notwithstanding these similar starting conditions, this natural experiment yielded vastly different results, ranging from subfamily Duparquetioideae, consisting of a single African species, to subfamilies Caesalpinioideae and Papilionoideae, which have respectively circa 4,700 and over 14,000 species across the globe. The other three subfamilies, Cercidoideae, Detarioideae, Dialioideae, are also widely distributed but harbour lower numbers of species. Here we assemble a legume-wide quality-controlled occurrence dataset to compare distribution patterns across the six subfamilies. We quantify differences between subfamilies in areas of species richness, ecological versatility, and geographic extents, to investigate links between richness and distribution. Furthermore, by combining this new geographic dataset with existing legume-wide and subfamily-specific phylogenies, we compare rates of long-distance dispersal and niche shifting through time to examine the roles of evolvability and phylogenetic conservatism in generating species richness. Our analyses reveal important differences between subfamilies in terms of their main centres of diversity, ecological versatility, and biogeographical evolvability through time. Notably, invasion of the temperate zone in Papilionoideae played a key role in generating its extreme species richness, whereas other subfamilies are largely constrained by tropical niche conservatism. These results shed new light on why some lineages are more successful than others.