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SISTA Colloquium

DateMonday, January 30, 2012
Time12:00 pm
Concludes1:30 pm
LocationGould-Simpson 906
Grace Chiu (Senior Research Scientist @ CSIRO Mathematics, Informatics and Statistics; Visiting Scholar @ Statistics GIDP)
Anton Westveld (Statistician and Regular Faculty @ BIO5 Statistics Laboratory and Statistics GIDP)
SpeakerGrace Chiu, Ph.D. and Anton Westveld, Ph.D.
School/Dept.Chiu: Senior Research Scientist; Westveld: Faculty @ BIO5
AffiliationChiu: CSIRO; Westveld: BIO5

Food webs, phylogeny, social networks, and statistics: What is the common thread?

A food web is a network of nodes called trophic species. The role of each node as predator or prey determines the trophic or feeding relations that weave the web. Insight into the nature and degree of dependence among nodes has ecological implications, and can facilitate discoveries about trophic levels, stability of the ecosystem under species extinction, etc. In a recent paper, we adapted a novel statistical methodology called latent space modeling - originally developed to study social networks - to yield comprehensive understanding of food web structure and its contributing factors. This unified modeling framework expresses network links as the random response of within- and internode characteristics (predictors). Specifically, phylogeny is shown to have nontrivial influence on trophic relations in many webs, and for each web trophic clustering based on feeding activity and on feeding preference can differ substantially. In this talk, we will present a brief history of latent space modeling, and selected results from our recent paper and a related working paper.


Grace Chiu: Grace Chiu is Senior Research Scientist at the Division of Mathematics, Informatics and Statistics of CSIRO in Australia. She develops statistical methodologies for problems in the environmental sciences. Prior to joining CSIRO, she was a faculty member of the Department of Statistics and Actuarial Science at the University of Waterloo, with which she currently holds an adjunct appointment. She is also an affiliate faculty member of the Department of Statistics at the University of Washington, where she was postdoctoral fellow from 2003-05. Grace received her PhD in Statistics from Simon Fraser University. Currently, she is a Visiting Scholar at U of A with the Statistics GIDP.

Anton Westveld: Anton Westveld is a Statistician in the Statistics Laboratory @ the BIO5 Institute and a Regular Faculty Member in the Statistics GIDP. Anton received his PhD in Statistics from Statistics Department at the University of Washington in Seattle, where he was an active member in the Center for Statistics and the Social Sciences. He was postdoctoral fellow at the Center for Empirical Research in the Law and the Center for Applied Statistics at Washington University in St. Louis, after which he was Assistant Professor at the University of Nevada Las Vegas before moving to the University of Arizona. His research interests include Bayesian methodology and theory, statistical methods for interaction/relational data (network, game theoretic), and statistical applications in the social (economics, political science, public policy), environmental, and biological sciences.