Abstract Detail

The flora of Madagascar: uncovering mechanisms for diversification

Shimu, Tahsina [1], Machkour M'Rabet, Salima [2], Hanes , Margaret Mae [1].

Investigating mechanisms of population differentiation and speciation in Megistostegium (Hibisceae: Malvaceae) in Southern Madagascar.

The dynamic evolution of the Malagasy endemic genus Megistostegium (Malvaceae) has likely been influenced by a complex combination of biological processes. Two, or even all three, of the recognized species, can co-occur at a single site, yet they remain morphologically distinct despite flowering synchronously. SNPs throughout the genome of 80 individual plants encompassing the three species were collected via RADseq. We estimate a number of historical parameters for the data and identify the subset that represents the most important biological processes in the evolution of the genus. We assess population divergence, gene flow, population size, and changes in population size among individuals from sampled populations of each focal species. Species distribution models were also used to predict bioclimate and soil parameters for each population in order to uncover the potential abiotic factors that led to the divergence within and between species. The most widely distributed species have high values of niche overlap and we predict a model of niche conservatism for diversification of the genus. We hope this framework will inspire further inquiries into the general and recurring patterns of diversification throughout xeric southern Madagascar.

1 - Eastern Michigan University, Biology, 441 Mark Jefferson Science Complex, Ypsilanti, MI, 48197, USA
2 - El Colegio de la Frontera Sud, Laboratorio de Ecología Molecular y Conservación, Chetumal, Quintana Roo, MX

Keywords:
RADseq
Madagascar
Malvaceae
Phylogeography
population genomics
Species Distribution Modelling.

Presentation Type: Colloquium Presentations
Session: C08, The flora of Madagascar: uncovering mechanisms for diversification
Location: 101/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 4:00 PM
Number: C08010
Abstract ID:680
Candidate for Awards:None