Abstracts (first author)
Phylogenetic patterns of diversification and community structure reveal the role of ecological factors in generating and shaping Neotropical mimetic butterfly diversity
The Neotropic is the most diverse region in the world. Identifying the causes underlying the observed diversity and spatial structure and unraveling how different factors interact remain outstanding questions. Addressing these questions in the Neotropics provides a unique opportunity to understand the processes that shape the structure of ecosystems. Recent advances in molecular phylogenetics, such as novel tests for diversification scenarios or community ecology phylogenetics, provide new insights into biodiversity questions. The Ithomiini tribe is a species-rich group of Neotropical butterflies, which consists of ca. 380 species widely distributed from the lowlands to 3000 m in the Andes. All species are involved in Müllerian mimicry, whereby different species protected by chemical defenses converge to share the same warning color patterns (mutualistic interactions). Here we combine phylogenetic, trait and species assemblage (community) data to investigate the effects of color patterns and adaptation to altitude in generating and shaping the diversity of Ithomiini.Comprehensive phylogenetic and trait analyses of several genera show that shifts in altitude and color patterns are both involved in diversification. In parallel, phylogenetic analyses of 15 communities along an altitudinal gradient show that both adaptation to altitude and mimetic interactions act as ecological filters and contribute in shaping species assemblages. Moreover, we find that both factors are not independent, and species that share color patterns also share altitudinal niche more often than predicted by phylogeny alone. The two approaches undertaken here are complementary and provide support for a similar scenario, whereby ecological factors, especially positive interactions, have been instrumental in generating and shaping biodiversity. Taking other types of positive interactions into consideration may shed light on why some groups have diversified dramatically, and why others have not.