Abstract Detail


Cacho, N. Ivalu [1], McIntyre, Patrick [2], Jose-Zacatula, Daniel [1], Piña de la Rosa, Itzel A [1], Lopez-Marmolejo, Clara [1], Vazquez-Ibarra, Marlene S [1], Medina-Rodriguez, Max D [1], Caraballo, Marcos [3].

Investigating the interplay between convergence and divergence in the Caribbean ring-species Euphorbia tithymaloides.

A complex geological history coupled with vicariance, migration and in situ diversification contribute to the high diversity of the Caribbean region and its iconic examples of speciation and adaptative radiation.  Here we explore the interplay between convergence and divergence among populations of a plant ring species that colonized the Caribbean basin through the Greater Antilles and the Lesser Antilles independently. We review patterns of morphological and genetic divergence in Euphorbia tithymaloides in the context of its colonization of the Caribbean basin from Mexico and Guatemala, which is supported as having occurred along two geographic fronts. We also show that there is evidence for convergence towards shorter inflorescences in this species-complex, which has been recognized as undergoing active speciation. We then examine evidence from our ongoing work on factors that may underly the evolution of progressively shorter inflorescences in Antillean populations of E. tithymaloides, including:  a) possible transitions to selfing or higher selfing rates, b) shifts from hummingbird to insect pollination or towards mixed pollination, and c) shifts in traits of hummingbirds, which are smaller in the Antilles.

1 - Institute of Biology, UNAM, Mexico City, 04510
2 - NatureServe, 1680 38th Street, Suite 120, Boulder, CO, 80301
3 - Temple University, igem, Philadelphia, PA, 19122

floral morphology

Presentation Type: Oral Paper
Session: BIOG2, Biogeography II
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 12:45 PM
Number: BIOG2002
Abstract ID:593
Candidate for Awards:None

Copyright © 2000-2020, Botanical Society of America. All rights reserved