About the Authors
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: LFC JMC MLW. Analyzed the data: LFC. Contributed reagents/materials/analysis tools: LFC JMC. Wrote the paper: LFC JMC MP MLW.