Abstract Detail



Macroevolution

Zenil-Ferguson, Rosana [1], Di Stilio, Veronica [2].

Phylogenetic patterns of trait evolution in Thalictrum: the role of integration, timing and interdependence in lineage diversification.

Shifts from insect pollination to wind pollination, from hermaphroditism to dioecy (separate sexes) and from diploidy to polyploidy represent major evolutionary transitions in flowering plants. Thalictrum (Ranunculaceae) is an ideal system in which to study the tempo and mode of evolution of these character transitions in the context of lineage diversification. We investigate patterns of correlated trait evolution (i.e., evolutionary integration), asking whether traits tend to change together (the degree of integration), whether they change in a consistent order (e.g., whether the evolution of separate sexes consistently follows the evolution of wind pollination), and whether rates of trait evolution depend on the background of other traits (e.g., higher rates of sexual and pollination system change on a background of polyploidy). To investigate associations of key traits and lineage diversification we fit a suite of models that integrate trait evolution, speciation, and extinction in a SSE framework. First, each trait - pollination mode, sexual syndrome, or ploidy level – is modeled as the sole factor that might explain shifts in diversification in Thalictrum. Later, we include hidden states in the models to accommodate other factors that can be confounding in the diversification process and affect speciation and extinction along our focal traits. Finally, we combine the traits and hidden states to accommodate potential evolutionary interactions amongst traits with and without hidden states. By taking a stepwise approach, interrogating the models iteratively with the suspected traits and hidden states in different combination we hope to unravel the complex evolutionary history of the genus. Furthermore, the use of the SSE models would allow us to infer important evolutionary hypotheses, like the timing of sexual system evolution and wind pollination in Thalictrum and its consequences.


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1 - University Of Hawaii, School Of Life Sciences, 2538 McCarthy Mall, Edmonson 309, Honolulu, HI, 96822, United States
2 - University Of Washington, Biology, PO Box 351800, Seattle, WA, 98195-1800, USA

Keywords:
SSE
phylogenetic comparative methods
sexual system
pollination mode
polyploidy
Dioecy
wind pollination
Ranunculid.

Presentation Type: Oral Paper
Number: MACRO2002
Abstract ID:513
Candidate for Awards:None


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