Abstract Detail

Biogeography

Penagos Zuluaga, Juan Carlos [1], Queenborough, Simon A. [1], Comita, Liza S. [1], Donoghue, Michael [2].

Advances in the biogeographic history of the Supraocotea (Lauraceae).

Functional traits can potentially influence diversification rates, thereby affecting plant population's ability to expand to new ecological regions. Breeding system directly impacts the evolution of lineages, adapting the frequency of sexes and facilitating the radiation of phenotypes. In tropical woody plants, dimorphic breeding systems such as dioecy and gynodioecy are more frequent in lowland and mid-elevation forests.
Supraocotea (Lauraceae) contains hermaphroditic, dioecious, and gynodioecious species. Although dioecy is common in Amazonian species, all three breeding systems coexist in multiple ecosystems thought the Neotropics. However, it is not clear whether a transition to a dimorphic breeding system was advantageous in different geographical areas and whether shifts in the breeding system impacted diversification rates.
Here, we tested whether a shift in breeding system is associated with a shift to new geographical areas or biomes, and whether or not these shifts affected diversification rates in Supraocotea (Lauraceae).
METHODS: We developed an ancestral reconstruction for geographical area, biome, and breeding system using a molecular phylogeny for 143 species of the Supraocotea, a clade containing 950 species, and 17 genera of Lauraceae, mainly distributed in the Neotropics.
We tested for changes in diversification rates and evaluated whether shifts in breeding system were correlated with shifts in diversification rates or facilitated changes in biome or area.
KEY RESULTS: We found relationships between lineages restricted to the northern hemisphere, Macaronesia-Afro-Malagasy, and the Neotropics, suggesting a northern hemisphere colonization. Results also showed five independent radiations in the Neotropics from South American or Central American–Chocó ancestors.
Two major clades of Supraocotea converged independently in the same biomes. Dioecy and gynodioecy occur in more than a biome. However, once a lineage established within a biome, it was more likely to diversify within it than to shift into a new biome, independently of the breeding system. Finally, shifts in diversification rates were independent of breeding system or geographical area.
CONCLUSIONS: In Supraocotea, lineages often diversify within the same biome, suggesting that niche conservation could describe the infrequent shifts of lineages into a biome. Shifts in diversification rates are rare in Supraocotea and do not correlate with changes in geographical area, biome, or breeding system.

1 - Yale university, School of the Environment, 195 Prospect St, New Haven, CT, 06511, USA
2 - Yale University, Department Of Ecology And Evolutionary Biology, 21 Sachem St., New Haven, CT, 06511, United States

Keywords:
Ocotea complex
Gynodioecy
Radiation.

Presentation Type: Oral Paper
Number:
Abstract ID:712
Candidate for Awards:None