Abstract Detail


Melton, Anthony [1], Clinton, Matthew [1], Wasoff, Donald [1], Soltis, Douglas [2], SOLTIS, PAMELA S. [3].

Niche Evolution in Eastern Asia – Eastern North America Disjunct Lineages.

            The Eastern Asia – Eastern North America (EA-ENA) floristic disjunction has been of great interest to evolutionary biologists and biogeographers for over 250 years. Dozens of genera of seed plants have been identified as having this disjunction. Congeneric species across this disjunction often exhibit conservation in habitat, although Eastern Asia tends to be higher in species richness (known as the EA-ENA Species Anomaly). Although the two regions share similar climates, the environment of eastern Asia is more heterogeneous and has greater topological and climatic variation, leading to greater potential niche space, and hence may promote greater species richness. Our study aimed to test the hypotheses that disjunct sister lineages will exhibit ecological niche conservatism and that EA species will have a narrower niche breadth due to greater ecological heterogeneity and higher net diversification within the region. Presence points and climate data were downloaded from public databases for Ecological Niche Models (ENMs and Species Distribution Models (SDM) development using Maxent. ENMs were assessed for niche breadth (per hypervolume and the niche.breadth tool of ENMtools), and SDMs were used to estimate the geographic area occupied by each species. The symmetric background test of ENMtools was used to test for niche divergence between sister lineages. Results show that the niches of sister species across the disjunction have diverged and that there is a trend for ENA species to occupy a larger portion of their available niche space than their EA congeners. These results support the hypothesis that the EA taxa will occupy less of the overall available niche space, potentially as an effect of the EA-ENA Species Anomaly, and do not support the hypothesis of niche conservation between sister lineages.

1 - University of Florida, Dept. of Biology, 220 Bartram Hall, P.O. Box 118525, Gainesville, FL, 32611
2 - Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida, 32611, United States
3 - Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida, 32611, United States

eastern Asia-eastern North American disjunction
ecological niche modeling
Niche Evolution.

Presentation Type: Oral Paper
Abstract ID:497
Candidate for Awards:Ecological Section Best Graduate Student Paper

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