Format: ORAL

Jeffrey P. Rose1,2, Ricardo Kriebel3, Mark A. Elvin4, Kenneth J. Sytsma1, Bryan T. Drew2

1 Department of Botany, University of Wisconsin-Madison, Madison, USA 2 Department of Biology, University of Nebraska at Kearney, Kearney, USA 3 California Academy of Sciences, San Francisco, USA 4 Department of Ecology and Evolutionary Biology, University of California Los Angeles, UCLA Herbarium, Los Angeles, USA

Mediterranean-like biomes across the globe are biodiversity hotspots for both animals and plants. However, because such climates have only existed since the mid-Miocene, lineages adapted to Mediterranean-like biomes have diverged relatively recently, making it difficult to make robust inferences of phylogenetic relationships. Moreover, apparent abiotic niche conservatism within these lineages often leads to high levels of range overlap among species, potentially obscuring their biogeographic history. In particular, it is possible that pulses of expansion and contraction of suitable habitat throughout the Pleistocene, especially contraction towards the present, mimics a scenario of sympatric speciation when in fact speciation was primarily allopatric. The California Floristic Province is the only area of Mediterranean-like biome in North America and is the center of diversity and potentially the area of origin for several clades of mints (Lamiaceae), including Lepechinia sect. Calycinae (5 species), Salvia subg. Audibertia (19 species), and Monardella ( 40 species). Prior studies have shown that all three clades have diversified since the mid-Miocene, although relationships within clades have been difficult to resolve. Using a phylogenomic hypothesis of relationships and a suite of biogeographic tools, including generating ecological niche models for all ancestors that originated in the last 5 million years, we test if all three clades (1) show similar temporal patterns of divergence, (2) show parallel patterns of area of origin and directionality of geographic spread, and/or (3) show evidence of sympatric speciation rather than allopatric speciation followed by secondary contact. Our results provide important insights into the origin and maintenance of species diversity within Mediterranean-like biomes.