Abstract Detail

Systematics Section

De-Nova, Arturo [1], Magallon, Susana [2], Medina, Rosalinda [3], Montero, Juan Carlos [3], Weeks, Andrea [4], Rosell, Julieta [5], Olson, Mark [6], Eguiarte, Luis [7].

Evolutionary Diversification in Species-Rich Mesoamerican Seasonally Dry Tropical Forests: Bursera (Burseraceae, Sapindales) as a Case Study.

Mesoamerican arid biomes epitomize Neotropical rich and complex biodiversity. To document some of the processes underlying the vast species richness of Mesoamerican Seasonally Dry Tropical Forests (SDTFs), and to evaluate specific predictions about the age, geographical structure and niche conservatism of SDTF-centered woody plant lineages, we consider the genus Bursera as a case study. Using a nearly complete species-level phylogeny from nuclear and plastid genomic markers, we estimate divergence times, test for phylogenetic and temporal diversification heterogeneity, test for geographical structure, and reconstruct habitat shifts. Bursera split from Commiphora in the earliest Eocene, and by the middle Eocene, its major lineages were distinct. Most living species of Bursera originated during independent early Miocene consecutive radiations that took place in SDTFs, uncoupled from habitat shifts. The late Miocene average age of Bursera species, their geographical structure and strong conservatism to SDTFs conform to expectations derived from South American SDTF-centered lineages. Nevertheless, Bursera's geographical structure is comparatively weak, suggesting that SDTF attributes that shape the evolution of SDTF-centered lineages are relaxed in Mesoamerica. The Miocene diversifications of Bursera are congruent with enhanced aridity in Mesoamerica resulting from global cooling and rain shadows caused by increased orogeny.

Broader Impacts:

1 - Universidad del Mar, Puerto Escondido, Instituto de Genetica, Ciudad Universitaria Km. 3.5, Carr. Puerto Escondido-Sola de Vega, Distrito de San Pedro Mixtepec, Puerto Escondido, Oaxaca, 71980, Mexico
2 - Instituto De Biologia, Universidad Nacional Autonoma De Mexico, 3er Circuito De Ciudad Universitaria, Del. Coyoacan, A.P. 70-233, Mexico City, Mexico D.F., N/A, 04510, Mexico
3 - Universidad Nacional Autonoma de Mexico, Instituto de Biologia, 3er Circuito de Ciudad Universitaria, Del. Coyoacan, Mexico City, Mexico D.F., 04510, Mexico
4 - George Mason University, 4400 University Drive MSN 5F2, Fairfax, VA, 22030, USA
5 - Club America 8-1, Villa Lazaro Cardenas, Mexico, D.F., 14370, México
6 - 5084 Santa Susana Place, Santa Barbara, CA, 93111, USA
7 - Instituto De Ecología, UNAM,, Apartado Postal 70-275, C.U., Coyoacán, México, C.P. 04510, Mexico

Keywords:
Seasonally Dry Tropical Forests
diversification
niche conservatism
dated phylogenies
geographical structure.

Presentation Type: Oral Paper:Papers for Sections
Session: 29
Location: Lindell B/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 9:15 AM
Number: 29004
Abstract ID:264