Abstract Detail


Liston, Paige [1], Jud, Nathan [2].

Are variation in seed size and fruit morphology related to climate in Serjania (Sapindaceae)?

Adaptive radiations are characterized by the combination of rapid speciation in a monophyletic group relative to a larger parent clade, ecological separation of species, and adaptations to the environment shaped by natural selection. They serve as useful systems for understanding the process of evolution. Paullinieae are a diverse tribe of lianas distributed throughout the Neotropics. They constitute only 6 genera, but approximately 25% of species in the family Sapindaceae, the rest of which are self-supporting trees and shrubs. The six genera exhibit a range of fruit types associated with several modes of seed dispersal among the ~475 species. As part of a broader effort to evaluate whether the diversification of Paullinieae might be considered an adaptive radiation, we examined the diversity of seed size and fruit morphology in the genus Serjania. Our goals is to explore relationships between fruit/seed phenotype and environment because seed size is an ecologically important character related to seedling establishment in various environments and is therefore subject to selection. Serjania fruits are schizocarps and seeds are dispersed in samaroid mericarps. We obtained images of Serjania fruits from the online Smithsonian Herbarium Collection. We measured seed width, seed length, total length of the fruit, wing width, wing length, and total fruit length using ImageJ, and we recorded associated locality metadata. So far, the dataset includes 104 seeds measured from 50 different species, with occurrences ranging from 25.83’N to 28.12’S and from 38.95’W to 108.22’W. We then used the locality data to extract climate data (temperature, rainfall, & seasonality) for each site using the worldclim dataset. Preliminary analysis of fruit size data and climate data revealed no significant relationship between climate variables and fruit morphology within Serjania using the raw data. Future work includes applying phylogenetic regression to account for the non-independence of species data points when examining correlations among traits or between traits and environment, and testing for a shift in diversification associated with the evolution of the liana habit in Sapindaceae.

1 - William Jewell College, Department of Biology, 500 College Hill, Liberty, MO, 64068, USA
2 - William Jewell College, Biology, 300 College Hill, Liberty, MO, 64068, United States

seed size
Neotropical biogeography.

Presentation Type: Poster
Number: PBG006
Abstract ID:1056
Candidate for Awards:None

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