Postdoctoral Fellow

Multivariate evolutionary analysis: integrating structural equation modeling and phylogenetics

PI(s): Juan C Santos
Start Date: 1-Oct-2009
End Date: 30-Sep-2012
Keywords: comparative methods, software, computational modeling

One statistical approach with a long history in the social sciences is a multivariate method called Structural Equation Modeling (SEM). Most biological systems are multivariate, which are not easily dissected into their component parts. However, most biologists use only univariate statistical methods, which have definitive limitations in accounting for more than a few variables simultaneously. Therefore, the implementation of methodologies like SEM into biological research is necessary. However, SEM cannot be applied directly to most biological datasets or generalized across species because of the hierarchical pattern of evolutionary history (i.e., phylogenetic non-independence). The goals of my project are: (1) the development of a SEM based multivariate comparative analysis for biological datasets while incorporating the phylogeny on model construction and validation, (2) the development of software for this methodology, and (3) the implementation and generalization of the method using published empirical datasets. The proposed project will provide the foundations for the implementation of the already established SEM-based multivariate techniques into comparative biology.
The background of my NESCent project is associated with the development of statistical methodologies for my PhD thesis. During my graduate studies, I became interested in an integrative study of the biology of the poison frog family (Dendrobatidae). My field and lab experiments addressed different aspects of the natural history of this lineage. They include aspects of their evolutionary history (phylogeny and biogeography), physiology (metabolic rates), bioacoustics (advertisement calls), and aposematism (toxicity and conspicuousness). At the end of such experiences, I realized that the available comparative methodologies did not provide an adequate multivariate statistical framework and I decided to search for one. My future research plans will combine the development of other multivariate techniques, apply this techniques to other biological systems, and extending our knowledge of the poison frog system by developing more complex models of their biology. More information about my research at http://www.duke.edu/~js324.

Related products

Publications
  • A phylogeny for Aromobates (Anura: Dendrobatidae) with description of three new species from the Andes of Venezuela, taxonomic comments on Aromobates saltuensis, A. inflexus, and notes on the conservation status of the genus Barrio-Amoros, C. L., Santos, J. C. 2012. A phylogeny for Aromobates (Anura: Dendrobatidae) with description of three new species from the Andes of Venezuela, taxonomic comments on Aromobates saltuensis, A. inflexus, and notes on the conservation status of the genus. ZooTaxa 3422: 1-31.
  • A new striking dendrobatid frog (Dendrobatidae: Aromobatinae, Aromobates) from the Venezuelan Andes Barrio-Amoros, C. L., Rivero, R., Santos, J. C. 2011. A new striking dendrobatid frog (Dendrobatidae: Aromobatinae, Aromobates) from the Venezuelan Andes. ZooTaxa 3063: 39-52.
  • Redescription and generic assignation of Dendrobates rufulus Gorzula, 1990 (Anura: Dendrobatidae) from the Chimanti Massif, Venezuela Barrio-Amoros, C. L., Santos, J. C. 2011. Redescription and generic assignation of Dendrobates rufulus Gorzula, 1990 (Anura: Dendrobatidae) from the Chimanti Massif, Venezuela. Salamandra 47(3): 155-160.
  • Phenotypic integration emerges from aposematism and scale in poison frogs J. C. Santos and D. C. Cannatella (2011) Phenotypic integration emerges from aposematism and scale in poison frogs, Proceedings of the National Academy of Sciences, volume 108, issue 15, pp. 6175-6180
  • Redescription and generic assignation of Dendrobates rufulus Gorzula, 1990 (Anura: Dendrobatidae) from the Chimantá Massif, Venezuela. Salamandra 47(3): 155-160. Dendrobates rufulus Gorzula, 1990 is a poorly known dendrobatid, described from two specimens from the Chimantá Massif in the Venezuelan Guayana. We redescribe it based on six additional specimens and allocate this species to the genus Anomaloglossus. We also provide data on natural history, such as ecology, habitat, and vocalization.
  • Systematics of the Hyloxalus bocagei complex (Anura: Dendrobatidae), description of two new cryptic species, and recognition of H. maculosus Paez-Vacas, M. I., Coloma, L. A., Santos, J. C. 2010. Systematics of the Hyloxalus bocagei complex (Anura: Dendrobatidae), description of two new cryptic species, and recognition of H. maculosus. Zootaxa 2711: 1-75 (Monograph)
  • Amazonian Amphibian Diversity Is Primarily Derived From Late Miocene Andean Lineages Santos, J.C., L.A. Coloma, K. Summers, et al. (2009). Amazonian Amphibian Diversity Is Primarily Derived From Late Miocene Andean Lineages. Plos Biology 7(3): 448-461.
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