Abstract Detail



Macroevolution

Karimi, Nisa [1], Hernandez, Adriana [2], Rodriguez Contreras, Aaron [3], Eifler, Evan [4], Chan, Patricia [5], Landis, Jacob [6], Lemmon, Alan [7], Lemmon, Emily [7], Strickler, Susan [8], Specht, Chelsea [9], Givnish, Thomas [10].

Phylogenomics, patterns of species diversity and co-occurrence in the mariposa lilies (Calochortus; Liliaceae).

Geographic variation in species diversity within a lineage reflects both evolutionary processes (speciation, extinction, geographic spread, selection for reproductive and ecological isolation) and ecological processes (e.g., the ability of individual pairs of competing species to coexist).The number of locally co-occurring species in any given area should reflect the net rates of species diversification in the lineages found there, the amount of time since divergence, the extent of pre-existing reproductive barriers, and the range of local environmental conditions that can be partitioned. The genus Calochortus (~68 spp.) provides an outstanding opportunity to test these ideas. Here we investigate whether the number of species co-occurring locally is predicted by increasing environmental heterogeneity (e.g., elevational and climatic ranges) and/or base chromosome numbers, which presumably provides the basis for immediate reproductive isolation. We test these ideas using the first nuclear phylogeny for the genus Calochortus based on targeted sequence capture of hundreds of loci. Results suggest the six major lineages within Calochortus correspond to broad geographic areas and have diverged in climate and other environmental conditions. As predicted, the number of species co-occurring locally increases with both environmental heterogeneity and number of chromosomal clades. In addition, the extent of species overlap in geographic distribution increases with phylogenetic distance, supporting the idea that local sympatry occurs after secondary contact following divergence in climate or fine-scale patterns of habitat distribution. Hotspots of Calochortus diversity – within the California Floristic Province (CFP) and the mountain ranges of central Mexico – are marked by substantial elevational and climatic diversity. The most diverse regions for Calochortus – in parts of the CFP – correspond to areas where several clades of differing chromosome numbers overlap in range, and where substantial topographic relief provides a wide range of environmental conditions to be partitioned.


1 - University of Wisconsin - Madison, Department of Botany, 430 Lincoln Drive, Madison, WI, 53714
2 - Cornell University, School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Ithaca, NY, 14853, United States
3 - University of Guadalajara, Mexico
4 - UW Madison, Botany, 430 Lincoln Dr., Madison, WI, 53706, United States
5 - University Of Wisconsin Madison, Botany, Birge Hall, Madison, WI, 53703, United States
6 - Cornell University
7 - Florida State University, Center for Anchored Phylogenomics
8 - Boyce Thompson Institute For Plant Research , 533 Tower Road, Ithaca, NY, 14853, United States
9 - Cornell University, Plant Biology, Plant Science, 236 Tower Road, Ithaca, NY, 14851, United States
10 - University Of Wisconsin-Madison, Department Of Botany, 315 Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, United States

Keywords:
Calochortus
Phylogeography
species richness
Diversity
California
environmental heterogeneity.

Presentation Type: Oral Paper
Number: MACRO II002
Abstract ID:268
Candidate for Awards:None


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