Date of Award

2020

Degree Type

Restricted to Claremont Colleges Dissertation

Degree Name

Botany, PhD

Program

Botany

Advisor/Supervisor/Committee Chair

Travis Columbus

Dissertation or Thesis Committee Member

J. Mark Porter

Dissertation or Thesis Committee Member

Lucinda McDade

Terms of Use & License Information

Terms of Use for work posted in Scholarship@Claremont.

Rights Information

© 2020 Fabian Nicolas Medina Amaya

Subject Categories

Botany | Environmental Sciences

Abstract

Ficus (figs) is a hyper-diverse genus of tropical plants (> 800 species). No other group is comparable in terms of species richness, growth form (trees, shrubs, climbers, hemiepiphytes or stranglers), and ubiquity in tropical and subtropical regions. Figs also have a mutualistic relationship they have with their pollinators; little Agaonid wasps transport pollen, and develop and reproduce inside the figs. It is not uncommon for multiple species of figs to occur in sympatry, so this relationship was predicted to be “one- to-one”. However exceptions and hybrid figs have been widely reported. My study addresses the origin of species diversity of strangler figs in the Neotropics (Ficus sect. Americanae, ca. 120 species), and I make emphasis on the evolutionary role of hybridization. I base my investigation on field collections and molecular data (RADseq) of >400 samples (>80 species) from the entire range of the section. I apply these data to methods in phylogenetics, biogeography, and population genetics. In the first chapter, I analyze broad patterns of diversity of sect. Americanae. Ancestral range estimation places the origin of the section in Central America followed by dispersal in a north to south direction. BAMM and MiSSE analyses are unable to detect significant shifts in diversification rates, and estimates low extinction and high diversification rates. Convergence of leaf shape is common as the phylogeny reveals non- monophyly of three species complexes (F. americana, F. citrifolia, and F. pertusa). My second chapter addresses the evolutionary role that hybridization has played within Cuban strangler figs. I sampled seven species of Ficus sect. Americanae from Cuba, and despite reciprocal monophyly of species, genetic clustering and demographic modeling reveal extensive gene flow among these species. These findings suggest that the main consequence of hybridization within Ficus in Cuba is reinforcement of postzygotic reproductive barriers. Finally, in chapter three, I present the first draft genome of a strangler fig, F. velutina (sect. Americanae). I combined DNA reads from three sequencing platforms (PacBio Sequel II, Nanopore MinIon, and Illumina Miseq). With this data I was able to assemble 92% of the F. velutina genome. 56.4% of the genome was annotated with either gene predictions or repetitive elements. I also explore the applicability of this genome as a reference for restriction-site associated DNA sequencing datasets.

ISBN

9798664777284

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