Format: ORAL

Carrie M. Tribble1,2, Fernando Alzate-Guarn3, Etelvina Gndara4, Araz Vartoumian1,5, J. Gordon Burleigh6, Rosana Zenil-Ferguson7, Chelsea D. Specht8, and Carl J. Rothfels2,9

1 School of Life Sciences, University of Hawai‘i at Manoa, Honolulu, USA 2 University Herbarium and Department of Integrative Biology University of California, Berkeley, USA 3 Grupo de Estudios Botánicos (GEOBOTA) and Herbario Universidad de Antioquia (HUA), Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia 4 Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico. 5 Department of Oral Biology, University of California, Los Angeles, USA 6 Department of Biology, University of Florida, Gainesville, FL 32611 USA 7 Department of Biology, University of Kentucky, Lexington KY 40506 USA 8 Section of Plant Biology and the L.H. Bailey Hortorium, School of Integrative Plant Science, Cornell University, Ithaca, USA 9 Intermountain Herbarium, Department of Biology, and Ecology Center, Utah State University, Logan, USA

Geological events such as mountain uplift affect how, when, and where species diversify, but measuring those effects is a longstanding challenge. Andean orogeny impacted the evolution of regional biota by creating barriers to gene flow, opening new habitats, and changing local climate. Bomarea (Alstroemeriaceae) are tropical plants with (often) small, isolated ranges; in total, Bomarea species occur from central Mexico to central Chile. This genus appears to have evolved rapidly and quite recently, and rapid radiations are often challenging to resolve with traditional phylogenetic inference. In this study, we apply phylogenomics—with hundreds of loci, gene-tree-based data curation, and a multispecies-coalescent approach—to infer the phylogeny of Bomarea. We used this phylogeny to untangle the potential drivers of diversification and biogeographic history. In particular, we test if Andean orogeny contributed to the diversification of Bomarea. We find that Bomarea originated in the central Andes during the mid-Miocene, then spread north, following the trajectory of mountain uplift. Furthermore, Andean lineages diversified faster than non-Andean relatives. Bomarea thus demonstrates that—at least in some cases—geological change rather than environmental stability has driven high species diversity in a tropical biodiversity hotspot. These results also demonstrate the utility (and danger) of genome-scale data for making macroevolutionary inferences.