Abstract Detail

Systematics Section/ASPT

MCDADE , LUCINDA ANN [1], KIEL, Carrie [2], FISHER, Amanda [3], TRIPP, ERIN A [4].

Now that we have a date for our clade:  Using the calibrated phylogeny for Acanthaceae to test hypotheses about tempo, mode and drivers of evolution.

As a phylogenetic framework for Acanthaceae has taken shape over the last 15 years, the patterns of relationships revealed have pointed to many intriguing hypotheses about the tempo, modes and drivers of diversification in the group. Now that we have calibrated the phylogenetic history of the family, we are able to begin testing these hypotheses. After briefly reviewing this calibrated phylogeny, we will examine the timing of intercontinental dispersal events in the context of Earth history (dispersal is largely favored over land bridges). We will test whether the timing of diversification of New World Ruellia (Ruellieae) is consistent with a hypothesis of diffuse co-evolution of hummingbirds (it is not). A temporal framework for the evolution of African Blepharis (Acantheae) sheds light on the paleoclimatic context in which C4 photosynthsis evolved in the clade. Finally, the calibrated phylogeny for the Tetramerium lineage (Justiceae) allows us to examine the temporal pattern of diversification that has led the New World clade to surpass its Old World sister group in species richness by close to an order of magnitude, as well as to seek evidence of differential extinction rates. Phylogenies calibrated based on well documented evidence and by rigorous methods promise to provide remarkable insight that will enrich our perspectives on evolution by adding biotic and abiotic correlates to the phylogenetic patterns.

1 - Rancho Santa Ana Botanic Garden, Department Of Botany, 1500 N. College Avenue, Claremont, CA, 91711, USA
2 - Rancho Santa Ana Botanic Garden, 1500 North College Ave., Claremont, CA, 91711, USA
3 - Rancho Santa Ana Botanic Garden, 1500 N. College Ave., Claremont, CA, 91711, USA
4 - University Of Colorado Boulder, C105, Ramaley Hall, Boulder, CO, 80309, USA

Keywords:
Acanthaceae
calibrated phylogeny
land bridge
long-distance dispersal
diffuse co-evolution
C4 photosynthesis
Evolution
diversification.

Presentation Type: Oral Paper:Papers for Sections
Session: 33
Location: River Fork/Grove
Date: Wednesday, July 30th, 2014
Time: 11:30 AM
Number: 33013
Abstract ID:640
Candidate for Awards:None