1. Alycia L. Stigall, Department of Geological Sciences, Ohio University
Using Genetic Modeling of Sedimentary Parameters to Predict Species’ Geographic Range Shifts in Response to Environmental Change
Alycia L. Stigall, Department of Geological Sciences, Ohio University 1
This project aims to adapt methods of ecological niche modeling methods to predict the geographic ranges of fossil species based on sedimentary parameters. Developing a quantitative method specifically based on sedimentary variables (observable in the field or thin-section) to predict geographic occurrences of 2
species (and the potential for the converse), has the potential to improve biostratigraphic accuracy by providing a basis to distinguish actual evolutionary (e.g. temporal) versus environmental absence of taxa.
For this project, the Late Ordovician rocks in the Cincinnati, Ohio region are analyzed (Fig. 1). To date, three depositional sequences have been examined. Timelines within these units were established by identifying and correlating nine parasequences across the study area (Fig. 2). Sedimentology of each time slices has been constrained through field analysis and literature survey at multiple sites across the basin. These data form the basis for constructing environmental basemaps (Fig. 3B) for modeling analysis. Articulate brachiopods, which are abundant, are used for species occurrence data. To date, the ranges of 17 species have been modeled using sedimentary parameters. (ex. Fig. 3C) Initial results from a ground truthing component indicate high accuracy of model results for individual time slices. 3
The next step will be to examine the ability of niche models to provide accurate model predictions between time slices as environmental conditions shift. Additional refinement of niche modeling methods may provide a technique to locate desirable combinations of sedimentary conditions for resource extraction.