Abstract Detail

Macroevolution

Zuluaga, Alejandro [1], Cameron, Kenneth M. [2].

Exploring diversification rates in the monocot family Araceae.

The family Araceae (in the order Alismatales) is one of the most diverse monocot families with about 3500 described species, in contrast with the rest of the order, which includes twelve other families and ca. 500 species. It is especially abundant in the tropics, and exhibits remarkable morphological, anatomical, ecological, and geographical variation. A set of key innovations (e.g. inaperturate and exineless pollen, chemical defense), have been proposed to increase species diversification within Araceae, in particular in the subfamily Aroideae. Despite several recent phylogenetic studies, we still know rather little about the dynamics of lineage and species diversification across the family, or about the underlying drivers of diversification. First, we explored diversification rates of Araceae compared to the rest of the order Alismatales in two datasets: 1) a fossil calibrated phylogeny using Bayesian relaxed molecular clock methods (two genes, ca. 250 taxa); and a supermatrix (ten genes, ca 950 taxa). We used a Bayesian approach (BAMM), to evaluate the shifts of species diversification. Then, we combined results from ancestral state reconstructions and BiSSE birth–death models to evaluate if pollen traits are associated with shifts in species diversification. Additionally we studied, rates associated with transitions to and from water-associated life forms, or toward dry-land geophytes and epiphytes. We found dissimilar clade-specific processes that related to rates of species diversification in the family, and some shifts in diversification seem to be related to the traits previously hypothesized. We demonstrated that better sampled phylogenies that cover broad taxonomy and geographic ranges, and that are inferred from many genes, are promising for more accurate and precise modeling of rate shifts across aroids. In addition, assembly of equally densely sampled morphological, geographical and ecological datasets will be needed to properly test associations between these factors and clades showing different rates of species diversification

1 - University Of Wisconsin-Madison, 430 Lincoln Drive, UWisconsin-Department Of Botany, Madison, WI, 53706, USA
2 - University Of Wisconsin, Department Of Botany, 154 Birge Hall, 450 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
Araceae
diversification rates.

Presentation Type: Oral Paper:Papers for Topics
Session: 3
Location: Salon 3/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 10:30 AM
Number: 3010
Abstract ID:1219
Candidate for Awards:None